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1.
Chinese Journal of Biotechnology ; (12): 1017-1031, 2021.
Article in Chinese | WPRIM | ID: wpr-878611

ABSTRACT

Cyanobacteria is one of the promising microbial chassis in synthetic biology, which serves as a typical host for light-driven production. With the gradual depletion of fossil resources and intensification of global warming, the research on cyanobacterial cell factory using CO2 as carbon resource is ushering in a new wave. For a long time, research focus on cyanobacterial cell factory has mainly been the production of energy products, such as liquid fuels and hydrogen. One of the critical bottlenecks occurring in cyanobacterial cell factory is the poor economic performance, which is mainly caused by the inherent inefficiency of cyanobacteria. The problem is particularly prominent for these extremely cost-sensitive energy products. As an indispensable basis for modern industry, polymer monomers belong to the bulk chemicals with high added value. Therefore, increasing attention has been focused on polymer monomers which are superior in overcoming the economic barrier in commercialization of cyanobacterial cell factories. Here, we systematically review the progress on the production of polymer monomers using cyanobacteria, including the strategies for improving production, and the related technologies for the application of this important microbial cell factory. Finally, we summarize several issues in cyanobacterial synthetic biology and proposed future developing trends in this field.


Subject(s)
Cyanobacteria , Macromolecular Substances , Polymers , Synthetic Biology
2.
Chinese Journal of Biotechnology ; (12): 604-614, 2021.
Article in Chinese | WPRIM | ID: wpr-878585

ABSTRACT

Proton-pumping rhodopsin (PPR) is a simple photosystem widely distributed in nature. By binding to retinal, PPR can transfer protons from the cytoplasmic to the extracellular side of the membrane under illumination, creating a proton motive force (PMF) to synthesize ATP. The conversion of light into chemical energy by introducing rhodopsin into nonphotosynthetic engineered strains could contribute to promoting growth, increasing production and improving cell tolerance of microbial hosts. Gloeorhodopsin (GR) is a PPR from Gloeobacter violaceus PCC 7421. We expressed GR heterologously in Escherichia coli and verified its functional activity. GR could properly function as a light-driven proton pump and its absorption maximum was at 539 nm. We observed that GR was mainly located on the cell membrane and no inclusion body could be found. After increasing expression level by ribosome binding site optimization, intracellular ATP increased, suggesting that GR could supply additional energy to heterologous hosts under given conditions.


Subject(s)
Cyanobacteria/metabolism , Escherichia coli/metabolism , Proton Pumps , Rhodopsin/metabolism , Rhodopsins, Microbial/metabolism
3.
Chinese Journal of Biotechnology ; (12): 1229-1236, 2021.
Article in Chinese | WPRIM | ID: wpr-878626

ABSTRACT

Lactate is an important industrial chemical and widely used in various industries. In recent years, with the increasing demand for polylactic acid (PLA), the demand for lactate raw materials is also increasing. The contradiction between the high cost and the market demand caused by the heterotrophic production of lactate attracts researchers to seek other favorable solutions. The production of lactate from photosynthetic carbon fixation by cyanobacteria is a potential new raw material supply strategy. Based on the photosynthetic autotrophic cell factory, it can directly produce high optical purity lactate from carbon dioxide on a single platform driven by solar energy. The raw materials are cheap and easy to obtain, the process is simple and controllable, the products are clear and easy to separate, and the double effects of energy saving and emission reduction and production of high value-added products are achieved at the same time, which has important research and application value. This paper reviews the development history of cyanobacteria carbon sequestration to produce lactate, summarizes its research progress and encounters technical difficulties from the aspects of metabolic basis, metabolic engineering strategy, metabolic kinetics analysis and technical application, and prospects the future of this technology.


Subject(s)
Carbon Cycle , Carbon Dioxide , Cyanobacteria/genetics , Lactic Acid , Metabolic Engineering , Photosynthesis
4.
Braz. arch. biol. technol ; 64: e21200401, 2021.
Article in English | LILACS | ID: biblio-1249212

ABSTRACT

Abstract The cyanobacterial exopolysaccharides (EPSs) are considered as one of the important group of biopolymers having significant ecological, industrial, and biotechnological importance. Cyanobacteria are regarded as a very abundant source of structurally diverse, high molecular weight polysaccharides having variable composition and roles according to the organisms and the environmental conditions in which they are produced. Due to their structural complexity, versatility and valuable biological properties, they are now emerging as high-value compounds. They are possessing exceptional properties and thus are being widely explored for various applications like in food and pharmaceutical industries, in bioremediation for removal of heavy metals, for soil conditioning, as biopolymers, bioadhesives, and bioflocculants. However, poor understanding of their complex structural properties, lack of concrete information regarding the genes encoding the proteins involved in the EPS biosynthetic pathways, their process of production and about the associated factors controlling their structural stability, strongly limits their commercialization and applications in the various fields of biotechnology. Owing to the above context, the present review is aimed to organize the available information on applications of cyanobacterial EPSs in the field of biotechnology and to identify the research gaps for improved industrial utilization and commercialization of these biomaterials.


Subject(s)
Biodegradation, Environmental , Biotechnology/methods , Cyanobacteria , Polysaccharides
5.
Porto Alegre; s.n; 2020. 92 p. mapas, ilus, tab.
Thesis in Portuguese | ColecionaSUS, LILACS, ColecionaSUS, CONASS, SES-RS | ID: biblio-1147142

ABSTRACT

O presente trabalho tem como objetivo estimar o volume de esgoto gerado no RS em Demanda Bioquímica de Oxigênio (DBO kg/dia), e o volume de esgoto (DBO kg/dia) que chega até as estações de tratamento de esgoto ETEs; diagnosticar a eficiência das estações de tratamento de esgotoem relação ao percentual de remoção de (DBO kg/dia); correlacionando com a presença de cianobactérias próximas aos pontos de captação de água superficial para consumo humano; analisar se há inativação ou remoção de protozoários no lançamento do efluente ao retornar ao manancial. Como resultado obteve-se o volume total de matéria orgânica lançada nos corpos hídricos por dia estimado no Rio Grande do Sul é 511.769,00 DBO kg/dia no RS. As Estações de Tratamento de Esgoto captam 390.285,45 DBO kg/dia apresentaram resultados de remoção de 145.500,50 DBO kg/dia e de 22.963,21 DBO kg/dia residual; O volume ocioso das ETEs fica em torno de 5.049,89 L/s. O processo de eliminar ou inativar grande quantidade de protozoários presentes no afluente se dá através de etapas terciárias avançadas nas ETEs. Não encontramos no RS no ano 2019 ETEs com esses tipos avançados de tratamento. Sugere-se então que haja um melhor aproveitamento destas estações de tratamento no que se refere à quantidade e qualidade de volume de esgoto tratado e que sejam ampliados estudos para viabilidade de projetos de execução de novas ETEs para os demais municípios que despejam seus esgotos in natura nos mananciais impactando-os.


This work aims to estimate the volume of sewage generated in RS in Biochemical Oxygen Demand (BOD kg/day), and the volume of sewage (BOD kg/day) that reaches the sewage treatment stations (STS)s; diagnose the efficiency of sewage treatment station in relation to the percentage of removal (BOD kg/day); correlating with the presence of cyanobacteria close to the surface water intake points for human consumption; analyze if there is inactivation or removal of protozoa in the discharge of the effluent when returning to the source. As a result, the total volume of organic matter released into water bodies per day estimated in Rio Grande do Sul is 511,769.00 BOD kg/day in RS. The Sewage Treatment Plants capture 390,285.45 BOD kg/day showed removal results of 145,500.50 BOD kg/day and 22,963.21 BOD kg/day residual; The idle volume of ETEs is around 5,049.89 L/s. The process of eliminating or inactivating a large amount of protozoa present in the tributary takes place through advanced tertiary stages in the STSs. We did not find in RS in the year 2019 STSs with these advanced types of treatment. It is therefore suggested that there is a better use of these treatment plants with regard to the quantity and quality of the volume of treated sewage and that studies for the feasibility of projects for the execution of new STSs be expanded to the other municipalities that dump their raw sewage in water sources impacting them.


Subject(s)
Water Pollutants/analysis , Water Purification/prevention & control , Cyanobacteria/pathogenicity , Environmental Hazards , Health Risk , Correlation of Data , Wastewater Treatment Plants , Investigative Techniques , Basic Sanitation , Environment , Environmental Exposure/prevention & control , Organic Matter/analysis , Health Promotion/methods , Microbiology
6.
Article in English | SES-SP, LILACS, BBO, SES-SP | ID: biblio-1139476

ABSTRACT

ABSTRACT Almost half of the Brazilian population has no access to sewage collection and treatment. Untreated effluents discharged in waters of reservoirs for human supply favor the flowering of cyanobacteria - and these microorganisms produce toxins, such as saxitoxin, which is a very potent neurotoxin present in reservoirs in the Northeast region. A recent study confirmed that chronic ingestion of neurotoxin-infected water associated with Zika virus infection could lead to a microcephaly-like outcome in pregnant mice. Cyanobacteria benefit from hot weather and organic matter in water, a condition that has been intensified by climate change, according to our previous studies. Considering the new findings, we emphasize that zika arbovirus is widespread and worsened when associated with climate change, especially in middle- or low-income countries with low levels of sanitation coverage.


RESUMO No Brasil, quase metade da população não tem acesso a coleta e tratamento de esgotos. Os efluentes não tratados, devido a contaminação das águas de reservatórios para abastecimento humano, geram florações de cianobactérias - e esses microrganismos produzem toxinas, como a saxitoxina, uma neurotoxina bastante potente e presente nos reservatórios da região Nordeste. Estudo recente confirmou que a ingestão crônica de água contaminada com neurotoxinas associada a infeção pelo zika vírus em camundongos prenhes poderia levar a desfecho semelhante a microcefalia. Cianobactérias são beneficiadas por tempo quente e matéria orgânica na água, e essas condições estão sendo intensificadas pelas mudanças climáticas, segundo nossos estudos anteriores. Aqui, ressaltamos que, à luz dos novos achados, a arbovirose do zika, associada às mudanças do clima, se amplifica e se agrava, sobretudo em países de média ou baixa renda, com baixos níveis de cobertura de saneamento.


Subject(s)
Humans , Climate Change , Zika Virus Infection/epidemiology , Brazil/epidemiology , Risk , Cyanobacteria/physiology , Cell Proliferation , Environmental Policy
7.
São Paulo; s.n; s.n; 2020. 236 p. tab, graf.
Thesis in Portuguese | LILACS | ID: biblio-1290815

ABSTRACT

Os aminoácidos tipo micosporinas (MAAs) são compostos, produzidos por algumas espécies de cianobactérias e outros microorganismos, principalmente quando são expostos a radiação ultravioleta (UVR). Estes compostos, que vêm demonstrando funções fotoprotetoras e antioxidantes, têm sido pesquisados para aplicação em protetores solares e em produtos antienvelhecimento. O presente estudo focou na caracterização de cianobactérias e outros organismos quanto à produção de MAAs com potencial aplicação em cosméticos. Neste estudo foram desenvolvidos diversos métodos para identificação (via HPLC-DAD-MS/HRMS), purificação (via HPLC-DAD) e quantificação de MAAs (via LC-MS/MS). Pelo método de identificação de MAAs verificou-se que, das 75 cianobactérias estudadas, 27 cepas (38%) sintetizam MAAs. A cepa Oscilatoria sp. CMMA 1600 produziu a maior diversidade de MAAs. 10 MAAs diferentes foram identificados incluindo um MAA de massa molecular 316 Da. Através de dados espectroscópicos obtidos via HPLC-DAD-HRMS e RMN 1D e 2D confirmou-se que se tratava da micosporina-glicina-alanina. A biossíntese natural deste composto por cianobactérias foi relatada pela primeira vez neste estudo. Quanto à quantificação de MAAs, o protocolo de extração otimizado possibilitou uma excelente recuperação dos compostos de interesse, além de ser bastante simples e não utilizar solventes poluentes. As análises via LC-MS/MS foram realizadas através de experimentos de MRM em modo positivo usando uma coluna de fase reversa. O método validado permitiu determinar e quantificar com precisão os MAAs porphyra-334, shinorina e micosporina-glicina-alanina em corridas de apenas 6 minutos, com limites de deteção inferiores a 0,005 µg.mg -1. Aplicando o método de LC-MS/MS realizaram experimentos de indução de MAAs através de exposição à UVR tendo-se observado um aumento da concentração de MAAs nas cepas que já sintetizam estes compostos e, outras cepas começaram a produzir pelo menos um MAA. As cepas de S. torques-reginae (ITEP-024 e ITEP-026) produziram a maior concentração de MAAs. A cepa ITEP-024 foi ainda exposta a diferentes radiações tendo-se observado que a UVB é que mais influencia a produção de MAAs. Neste estudo foi demonstrado o potencial das cianobactérias como produtores de MAAs que podem ser utilizados como fotoprotores em protetores solares


Mycosporines and mycosporine-like amino acids (MAAs) are UV-absorbing compounds produced by cyanobacteria and other organisms, especially upon exposer to solar ultraviolet radiation (UVR). These compounds are photoprotective and some have additional antioxidant functíons useful to the natural cosmetics market. This study aims to identify MAAs-producing cyanobacteria with potential applicatíons in cosmetics. A HPLC-DAD-MS/HRMS method for the identification of MAAs was developed. Out of the 75 cyanobacteria studied, 27 strains (38%) synthesized MAAs. Oscilatoria sp. CMMA 1600, from homocyte type, produced the greatest diversity of MAAs. 10 different MAAs were identified including a MAA with molecular weight of 316 Da. The chemical structure of mycosporine-glycine-alanine was confirmed by 1D/2D NMR and HRMS analyses. This compound has never been reported from a natural source. In this study, a validated LC-MS/MS quantification method for MAAs is also presented. An easy-to-handle and rapid extraction procedure was developed which uses only water and volatile additives as the extractor solvents. The LC-MS/MS method was performed using multiple reaction monitoring in positive mode with a reverse-phase column. The method enabled the accurate determination and quantification of the MAAs porphyra-334, shinorine and mycosporine-glycine-alanine in a 6 minutes running time, with limits of detection < 0.005 µg.mg-1. MAAs induction experiments were performed through UVR exposure. MAAs are constitutively produced by some cyanobacteria and production was further enhanced following UVirradiance. Other strains start to produce at least one MAA after UV-irradiance. Sphaerospermopsis torques-reginae strain (ITEP-024 and ITEP-026) produced the highest concentration of these photoprotective compounds. S. torques-reginae ITEP 024 strain was further exposed to different radiation compositíons. MAAs were significantly influenced by UVB. In this study, the potential of cyanobacteria as MAA producers, that can be used as photoprotectors in sunscreens, has been demonstrated


Subject(s)
Health Strategies , Cyanobacteria/classification , Cosmetics/classification , Amino Acids/analysis , Ultraviolet Rays , Pharmaceutical Preparations , Monitoring , Validation Study
8.
Rev. méd. Urug ; 36(3): 301-310, 2020. tab, graf
Article in Spanish | LILACS, BNUY | ID: biblio-1127110

ABSTRACT

Resumen: Las cianobacterias son bacterias fotosintéticas del plancton de aguas dulces y saladas. Su acumulación excesiva en las aguas recreacionales y potables se conoce como floración algal, con potenciales efectos en la salud de seres humanos. Son predominantemente estivales, en cursos de aguas dulces y pueden alcanzar las costas oceánicas. Esta es una revisión bibliográfica basada en las publicaciones registradas en PubMed-Medline, BVS (Biblioteca Virtual en Salud que incluye SciELO, LILACS, IBECS), Springer, Science Direct, Portal Timbó, y obtenidas con los términos "cianobacterias", "cianotoxinas", "microcistina", "floraciones algales", "pediatría", "niños", "recreacional" "intoxicación" "exposición", sin límites de año de publicación. Su objetivo es actualizar el conocimiento sobre cianotoxinas y efectos en la salud humana, analizar escenarios de riesgo de exposición a cianobacterias, particularmente en niños, y reforzar medidas preventivas de la exposición y promover acciones desde el sector sanitario. Las manifestaciones clínicas de la intoxicación por exposición reciente son malestar general, irritación de piel y mucosas, síntomas respiratorios e incluso afectación hepática en casos graves. Es preciso incluir estas floraciones en la etiopatogenia de estos cuadros y relacionarlos con la exposición utilizando la monitorización de floraciones del país. La exposición a cianobacterias es un riesgo emergente para la salud. La evidencia científica de los últimos años consolida el conocimiento de efectos en la salud humana por exposición a cianobacterias. Recientemente se identifica el baño, juegos infantiles e ingesta de arena en costas con altos niveles de contaminación como un escenario de riesgo en niños. La evidencia de hepatoxicidad por cianotoxinas es aún más escasa, aunque existen casos documentados. El sistema de monitoreo de playas permite a los equipos de salud incorporar la sospecha de exposición a cianobacterias y el posible contacto con sus toxinas, para poder realizar un diagnóstico temprano y participar en la prevención de la exposición.


Summary: Cyanobacteria are photosynthetic bacteria from fresh and saltwater plankton. Its excessive accumulation in recreational and drinking waters is known as algal bloom that could potentially affect human health. They are mainly seen in summer, in freshwater waterways and can reach the ocean coasts. This is a bibliographic review based on the publications registered in PubMed-Medline, BVS (Virtual Health Library that includes SciELO, LILACS, IBECS), Springer, Science Direct, Portal Timbó, and obtained with the terms "cyanobacteria", "cyanotoxins", "Microcystine", "algal blooms", "pediatrics", "children", "recreational" "intoxication" "exposure" without year of publication limits. The review aims to update knowledge about cyanotoxins and their effect on human health; analyze risk scenarios of exposure to cyanobacteria, particularly in children, and reinforce preventive measures for exposure, as well as to promote actions from the health sector. The clinical manifestations of recent exposure poisoning are general malaise, skin and mucous irritation, respiratory symptoms and even liver insufficiency in severe cases. It is necessary to include these blooms in the pathogenesis of these clinic cases and relate them to the exposure using the monitoring of blooms in the country. Exposure to cyanobacteria is an emerging health risk. The scientific evidence of the last years consolidates knowledge on the effect of exposure to cyanobacteria on human health. Recently, bathing, children's games, and sand intake on coasts with high levels of contamination have been identified as a risk scenario for children. Evidence of cyanotoxin hepatoxicity is even scarcer, although there are documented cases. The beach monitoring system allows health teams to incorporate the suspicion of exposure to cyanobacteria and possible contact with their toxins, to make an early diagnosis and participate in the prevention of exposure.


Resumo: As cianobactérias são bactérias fotossintéticas do plâncton de águas doces e salgadas. Sua acumulação excessiva em águas recreacionais e potáveis é conhecida como floração algal com potenciais efeitos sobre a saúde de seres humanos. São predominantemente estivais, ocorrem em cursos de águas doces e podem alcançar as costas oceânicas. Esta é uma revisão bibliográfica baseada nas publicações indexadas em PubMed-Medline, BVS (Biblioteca Virtual em Saúde que inclui SciELO, LILACS, IBECS), Springer, Science Direct, Portal Timbó, e obtidas com os termos "cianobactérias", "cianotoxinas", "microcistina", "florações algais", "pediatria", "crianças", "recreacional" "intoxicação" "exposição", sem limites de ano de publicação. Seu objetivo é atualizar o conhecimento sobre cianotoxinas e efeitos sobre a saúde humana; analisar cenários de risco de exposição a cianobactérias, particularmente em crianças e reforçar medidas preventivas de exposição e promover ações do setor sanitário. As manifestações clínicas da intoxicação por exposição recente são mal-estar geral, irritação de pele e mucosas, sintomas respiratórios e incluso afetação hepática nos casos graves. É preciso incluir estas florações, na etiopatogenia destes quadros e relacioná-las com a exposição utilizando o monitoramento das florações do país. A exposição a cianobactérias é um risco emergente para a saúde. A evidência científica dos últimos anos consolida o conhecimento sobre os efeitos sobre a saúde humana por exposição a cianobactérias; recentemente foram identificados como um cenário de risco para crianças: o banho, jogos infantis e ingestão de areia nas costas com altos níveis de contaminação. A evidência de hepatoxicidade por cianotoxinas é ainda escassa embora existam casos documentados. O sistema de monitoramento de praias permite as equipes de saúde incorporar a suspeita de exposição a cianobactérias e o possível contacto com suas toxinas, para poder realizar um diagnóstico precoce e participar na prevenção da exposição.


Subject(s)
Humans , Infant , Child, Preschool , Child , Adolescent , Coastal Pollution , Cyanobacteria , Harmful Algal Bloom , Environmental Exposure
9.
Cienc. tecnol. salud ; 7(1): 129-136, 2020. ^c27 cmilus
Article in Spanish | LILACS | ID: biblio-1121037

ABSTRACT

El impacto antrópico cercano al lago de Amatitlán ha generado niveles altos de eutrofización que conllevan cambios en la dinámica del ecosistema. Uno de ellos es la proliferación de cianobacterias del género Microcystis que pueden llegar a ser perjudiciales para la fauna y flora de lugar e incluso para los seres humanos. Se presenta el caso de cultivo de un consorcio de fitoplancton, tomado directamente del lago y llevado al laboratorio en condiciones controladas, para medir su consumo y aporte de nitrógeno y fósforo, además de los cambios en los factores fisicoquímicos y la biomasa. Se observó la presencia de diatomeas del genero Nitszchia y cianobacterias como Dolichospermum, con una marcada dominancia de Microcystis sp. Se analizó el porcentaje de cambio en la concentración de nutrientes. Los resultados indican que hubo un aumento en las concentraciones de amonio, nitrato y nitrógeno inorgánico disuelto, mientras que disminuyó el nitrógeno total, el fósforo total y los ortofosfatos. Esto indica que hay aporte de nitrógeno inorgánico, consumo de fósforo y nitrógeno orgánico. El fósforo parece ser el nutriente limitante, ya que, al consumirse en un 90 % la biomasa empieza a decrecer.


The anthropic impact near lake Amatitlán has generated high levels of eutrophication that lead to changes in ecosystem dynamics. One of them is the proliferation of cyanobacteria of the genus Microcystis that can be harmful to the fauna and flora of the place and even to humans. The case of cultivation of a phytoplankton consortium, taken directly from the lake and taken to the laboratory under controlled conditions, to measure its consumption and contribution of nitrogen and phosphorus, in addition to changes in physicochemical factors and biomass is presented. The presence of diatoms of the genus Nitszchia and cyanobacteria such as Dolichospermum was detected, with a marked dominance of Microcystis sp. The percentage change in nutrient concentration was analyzed. The results indicated that there was an increase in the amounts of dissolved inorganic ammonium, nitrate and nitrogen, while total nitrogen, total phosphorus and orthophosphates decreased. This indicates that there is contribution of inorganic nitrogen, consumption of phosphorus and organic nitrogen. Phosphorus seems to be the limiting nutrient, since, when consumed by 90 %, biomass begins to decrease.


Subject(s)
Humans , Lakes/analysis , Cyanobacteria , Microcystis , Phosphorus/analysis , Phytoplankton , Eutrophication , Nitrogen/analysis
10.
Rev. argent. microbiol ; 51(1): 72-76, mar. 2019. graf
Article in Spanish | LILACS | ID: biblio-1041817

ABSTRACT

Este trabajo tuvo como objetivo evaluar el efecto de rotaciones arroceras sobre la población de cianobacterias durante el ciclo de cultivo. El estudio se condujo en Entre Ríos (Argentina). Se evaluaron cuatro rotaciones: arroz-soja (AS); arroz-soja-maíz-soja (ASMS): arroz-arroz (AA) y arroz-pradera (AP). Muestras de suelo y agua se tomaron en cuatro estados del cultivo: implantación, macollaje, panoja embuchada y madurez fisiológica. El número potencial de cianobacterias fue menor en relación a otras áreas arroceras. Los menores recuentos se registraron en el período de implantación y los mayores en el de panoja embuchada. El análisis estadístico no mostró efecto de las rotaciones sobre el número de cianobacterias, aunque AA presentó la mayor abundancia. Se reconocieron un total de 13 géneros de cianobacterias Lyngbya, Oscillatoria,Plectonema, Spirulina, Anabaena, Nostoc, Aulosira, Calothrix, Gloeotri-chia, Aphanocapsa,Croococcus, Mycrocystis y Gloeocapsa. La rotación AP registró la riqueza de géneros.Las rotaciones AS y AA presentaron mayor proporción de cianobacterias filamentosas. Los valores de biodiversidad de Simpson fueron bajos. Se concluyó que las rotaciones arroceras evaluadas tuvieron efecto sobre la proporción de cianobacterias unicelulares a filamentosas, los géneros presentes y la riqueza.


The aim of this study was to evaluate the effect of different rice rotations on cyanobacteria populations during the growing season. The study was conducted in Entre Ríos (Argentina). Four crop rotations were evaluated: rice-soybean (AS); rice-soybean-corn-soybean (ASMS); rice-rice (AA) and rice-pasture (AP). Soil and water samples were collected in 4 stages: implantation, tillering, booting and physiological maturity. The potential number of cyanobacteria population was lowerin relation to other rice sites previously reported. The lowest counts were recorded during implantation whereas the highest counts were obtained during booting. The statistical analysis showed no effect of rotation on the variable number of cyanobacteria, although AA was the most abundant. A total of 13 taxa were identified: Lyngbya, Oscillatoria, Plectonema, Spirulina, Anabaena, Nostoc, Aulosira, Calothrix, Gloeotrichia, Aphanocapsa, Croococcus, Mycrocystis and Gloeocapsa. AP rotation recorded the lowest number of genera. AS and AA had a higher proportion of filamentous cyanobacteria. Simpson's index was low. It was concluded that crop rotations had a differential effect on some aspects of cyanobacteria population such as the proportion of unicellular to filamentous cyanobacteria, genera presence and richness.


Subject(s)
Cyanobacteria/classification , Cyanobacteria/growth & development , Crop Rotation , Oryza/microbiology , Water Samples , Statistical Analysis
11.
Chinese Journal of Biotechnology ; (12): 1411-1423, 2019.
Article in Chinese | WPRIM | ID: wpr-771788

ABSTRACT

Biorefinery technologies provide promising solutions to achieve sustainable development facing energy and environment crisis, while abundant sugar feedstock is an essential basis for biorefinery industries. Photosynthetic production of sucrose with cyanobacteria is an alternative sugar feedstock supply route with great potentials. Driven by solar energy, cyanobacteria photosynthetic cell factory could directly convert carbon dioxide and water into sucrose, and such a process could simultaneously reduce carbon emissions and supply sugar feedstocks. Here we introduced the history and updated the state-of-the-art on development of cyanobacteria cell factories for photosynthetic production of sucrose, summarized the progress and problems on mechanisms of sucrose synthesis, metabolic engineering strategies and technology expansions, and finally forecasted the future development direction in this area.


Subject(s)
Carbon Dioxide , Cyanobacteria , Metabolic Engineering , Photosynthesis , Sucrose
12.
Chinese Journal of Biotechnology ; (12): 795-804, 2019.
Article in Chinese | WPRIM | ID: wpr-771330

ABSTRACT

The cyanobacterial circadian clock has three relatively independent parts: the input path, the core oscillator, and the output path. The core oscillator is composed of three clock proteins: KaiA, KaiB, and KaiC. The interactions among these three proteins generate a rhythmic signal and convey the input signals to the output signals to maintain the accuracy and stability of the oscillation of downstream signals. Based on the cyanobacterial circadian clock and the structure, function, and interaction of the clock proteins of the core oscillator, combining the recent results from our laboratory, this review summarized the recent progresses of the molecular mechanism of KaiA in regulating KaiC's enzymatic activity, mediating phase reset of the oscillator, and competing with CikA for the binding site of KaiB.


Subject(s)
Bacterial Proteins , Genetics , Metabolism , Circadian Clocks , Genetics , Circadian Rhythm Signaling Peptides and Proteins , Metabolism , Cyanobacteria , Genetics , Enzyme Activation , Genetics
13.
Braz. j. biol ; 78(1): 108-116, Feb. 2018. tab, graf
Article in English | LILACS | ID: biblio-888831

ABSTRACT

Abstract Although Planktothrix agardhii often produces toxic blooms in eutrophic water bodies around the world, little is known about the fate of the organic matter released by these abundant Cyanobacteria. Thus, this study focused in estimating the bacterial consumption of the DOC and DON (dissolved organic carbon and dissolved organic nitrogen, respectively) produced by axenic P. agardhii cultures and identifying some of the bacterial OTUs (operational taxonomic units) involved in the process. Both P. agardhii and bacterial inocula were sampled from the eutrophic Barra Bonita Reservoir (SP, Brazil). Two distinct carbon degradation phases were observed: during the first three days, higher degradation coefficients were calculated, which were followed by a slower degradation phase. The maximum value observed for particulate bacterial carbon (POC) was 11.9 mg L-1, which consisted of 62.5% of the total available DOC, and its mineralization coefficient was 0.477 day-1 (t½ = 1.45 days). A similar pattern of degradation was observed for DON, although the coefficients were slightly different. Changes in the OTUs patterns were observed during the different steps of the degradation. The main OTUs were related to the classes Alphaproteobacteria (8 OTUs), Betaproteobacteria (2 OTUs) and Gammaproteobacteria (3 OTUs). The genus Acinetobacter was the only identified organism that occurred during the whole process. Bacterial richness was higher at the slower degradation phase, which could be related to the small amounts of DOM (dissolved organic matter) available, particularly carbon. The kinetics of the bacterial degradation of P. agardhii-originated DOM suggests minimal loss of DOM from the Barra Bonita reservoir.


Resumo Embora Planktothrix agardhii frequentemente forme florações tóxicas em corpos d'água pelo mundo, pouco ainda se sabe sobre o destino da matéria orgânica liberada por essa abundante Cyanobacteria. Assim, este estudo foi focado na estimativa do consumo bacteriano do carbono orgânico dissolvido (DOC) e nitrogênio orgânico dissolvido (DON) produzido por culturas axênicas de P. agardhii e identificação de algumas das unidades taxonômicas operacionais (OTUs) bacterianas envolvidas no processo. Ambos a linhagem de P. agardhii e o inóculo bacteriano foram amostrados do reservatório eutrófico de Barra Bonita (SP, Brasil). Foram observadas duas fases distintas da degradação do DOC: durante os três primeiros dias, coeficientes mais altos de degradação foram calculados, que foram então seguidos por uma fase mais lenta da degradação do carbono. O valor máximo calculado para o carbono bacteriano particulado (POC) foi de 11,9 mgL-1, o que equivale a aproximadamente 62,5% do DOC disponível para consumo, e o seu coeficiente de mineralização foi de 0,477 dia-1 (t1/2 = 1,45 dias). Um padrão similar de degradação foi observado para DON, embora os coeficientes sejam ligeiramente diferentes. Foram observadas mudanças nos padrões de OTUs durante os diferentes passos da degradação. As principais OTUs foram relacionadas às classes Alphaproteobacteria (8 OTUs), Betaproteobacteria (2 OTUs) e Gammaproteobacteria (3 OTUs). O gênero Acinetobacter foi o único organismo identificado que ocorreu durante todo o processo. A maior riqueza bacteriana foi observada durante a fase lenta de degradação, o que pode estar relacionado às pequenas quantidades de matéria orgânica dissovida (DOM) disponíveis, particularmente o carbono. A cinética da degradação bacteriana da MOD de P. agardhii, quando comparada ao tempo de retenção do reservatório, sugere que existe uma perda mínima após sua liberação em Barra Bonita.


Subject(s)
Carbon/metabolism , Cyanobacteria/metabolism , Cyanobacteria/chemistry , Proteobacteria/metabolism , Humic Substances/analysis , Nitrogen/metabolism , Biodegradation, Environmental , Carbon/analysis , Eutrophication , Nitrogen/analysis
14.
São Paulo; s.n; 2018. 109 p.
Thesis in Portuguese | LILACS | ID: biblio-946506

ABSTRACT

INTRODUÇÃO: A urbanização em bacias hidrográficas contribui para a eutrofização antrópica dos seus corpos d´água, propiciando proliferações de algas tóxicas como as cianobactérias. Existe um padrão característico de sazonalidade nas florações de algas e comunidades de cianobactérias, embora estas algas possam estar presentes ou mesmo dominantes, na maior parte do ano, trazendo problemas práticos associados à elevada biomassa de cianobactérias e potenciais ameaças à saúde pelo aumento de toxinas. A hipótese desta tese é de que as variações do tempo e do clima podem influenciar a qualidade da água de abastecimento ao propiciar florações das algas tóxicas, cianobactérias, que geram toxinas dificilmente filtradas pelos mecanismos comuns, gerando um problema de saúde pública que pode ser agravado com as mudanças climáticas conjuntamente o fenômeno de urbanização crescente nos países de economia emergente. OBJETIVO: O objetivo deste estudo foi investigar qual a influência do tempo e do clima na qualidade da água de abastecimento público de bacias urbanizadas através do indicador de algas tóxicas chamadas cianobactérias. MATERIAL E MÉTODOS: Para tanto investigou-se em primeiro lugar qual o contexto das proliferações de cianobactérias em reservatório de abastecimento público e suas consequências bem como qual o estado da arte sobre a qualidade da água de reservatórios eutrofizados em bacias urbanizadas, foi elaborado um mapeamento bibliográfico para saber qual a extensão do problema e do que se sabe a respeito. E, por fim, correlacionou-se a influência do tempo e do clima na qualidade da água para abastecimento no caso da bacia urbanizada da Represa Guarapiranga, localizada ao sul da Cidade de São Paulo, com vistas à previsibilidade e prevenção do fenômeno das florações das cianobactérias. RESULTADOS E DISCUSSÃO: Chegando-se a conclusão de que a pressão antrópica e o uso do solo são um fator determinante para a eutrofização de reservatórios de abastecimento e que, por tanto, bacias hidrológicas ocupadas pelo espraiamento urbano são particularmente propensas a apresentar reservatórios de água contaminados com algas toxicas, ao mesmo tempo que são as mais visadas para abastecer a população em seu entorno. O mapeamento bibliográfico mostrou que a proliferação de cianotoxinas em reservatórios eutrofizados é prevalente em diferentes latitudes e climas. A modelagem de correlação teve sucesso em explicar de 16% à 30% das florações na Guarapiranga de acordo com episódios de Irradiação e de precipitação pluviométrica, sendo resultados coerentes com a literatura, embora sejam baixo para gerar um modelo preditivo. CONSIDERAÇÕES FINAIS: A pressão antrópica da urbanização de bacias hidrográficas sem planejamento ou infra-estrura sanitária se mostrou uma questão de Saúde Pública e Saúde Urbana. As florações de cianobactérias se apresentaram como fenômenos presentes em diferentes latitudes, climas e graus de organização do espaço, mostrando assim serem uma questão global de saúde pública. A modelagem para o caso de São Paulo resultou em valores de explicação insuficientes para gerar um modelo preditivo do fenômeno das florações, evidenciando o sistema complexo de interação ambiente-ocupação humana-uso do solo- clima, exigindo assim que sejam acrescentadas demais variáveis ao modelo


INTRODUCTION: Urbanization in hydrographic basins contributes to the anthropic eutrophication of their water bodies, propitiating toxic algae proliferation such as cyanobacterias. There is a characteristic pattern of seasonality in algae blooms and cyanobacteria communities, although theses algae may be present or even dominant during most part of the year. They cause practical problems associated with high biomass volumes, and potential health threats by the rise of toxins. This thesis\' hypothesis is that weather and climate variations can influence the quality of drinking water supply, because toxins are hardly filtered by ordinary mechanisms. The problem can be aggravated by climate change conjointly with the rapid widespread of urbanization in low and middle income countries. OBJECTIVE: This study\'s aim was to investigate the influence of weather and climate variables on the quality of water from the public drinking water supply system of an urbanized watershed through the indicator of toxic algae - denominated cyanobacterias. MATERIALS AND METHODS: First, the cyanobacterias\' blooms in eutrophic reservoir and its\' consequences, was studied by literature review and by an exploratory analysis of monthy weather varables and cyanobacterias data. Secondly, a bibliographical mapping review was drafted in order to know the extension of the problem and what is known regarding it. Finally, data of weather and climate were correlated with the quality of supple water of the, Guarapiranga reservoir, located on the south of São Paulo metropolitan area, acknowledging predictability and prevention of the phenomenon of cyanobacteria bloom. FINDINGS AND DISCUSSION: The conclusion was that the anthropic pressure and land use are determinant factors to the eutrophication of supply reservoir and, therefore, hydrological basins occupied by urban sprawling are particularly at risk of presenting water reservoirs contaminated with toxic algae. They are the most targeted to supply water to their neighbor population. The bibliographic mapping showed that the proliferation of cyanotoxins in eutrophized reservoirs is prevalent in different latitudes and climates. The correlation modeling was successful in explaining 16% to 30% of blooms in Guarapiranga according to episodes of irradiation and low precipitation, matching results found in literature, although they are low for the creation of a predicative model. FINAL CONSIDERATIONS: The anthropic pressure of urbanization on hydrographic basins without planning or sanitary infrastructure guidelines was shown to be a matter of public and urban health. Cyanobacterias\' blooms was shown to be a phenomena present in different latitudes, climates and degrees of space organization, proving to be a matter of global public health. The modeling for the case of São Paulo has resulted in insufficient explanation values to generate a predictive model of the phenomena of flowering, indicating the complex interaction system involving environment, human occupation, land use and climate, and demanding that more variables be acknowledged in the model


Subject(s)
Cyanobacteria , Environmental Biomarkers , Fresh Water/analysis , Seasons , Urban Health , Water Supply , Meteorology , Eutrophication , Hydrographic Basins , Public Health
15.
São Paulo; s.n; 2018. 97 p.
Thesis in Portuguese | LILACS | ID: biblio-913028

ABSTRACT

O aporte artificial de nutrientes nos ambientes aquáticos tem favorecido a incidência de florações de cianobactérias, causando impactos na qualidade da água e colocando em risco a saúde humana. O gênero de cianobactéria Cylindrospermopsis, amplamente distribuído em água doce pelo mundo, é capaz de produzir diversas cianotoxinas, dentre elas saxitoxina e análogos. O objetivo deste trabalho foi elaborar um modelo de exposição referente à ingestão de água contaminada por saxitoxina e análogos através da recreação de contato primário e do consumo de água. Os dados de densidade de células de Cylindrospermopsis e de concentrações de saxitoxina e análogos na água bruta foram obtidos da Rede de Monitoramento de Qualidade de Águas Superficiais da CETESB (2015 e 2016) do reservatório Itupararanga. O modelo conceitual de exposição e o cálculo da ingestão diária crônica de saxitoxina e análogos consideraram: concentrações máxima e mínima de saxitoxina e análogos encontradas na água bruta do reservatório, vias de exposição, população exposta, taxa de ingestão de água, frequência e duração da exposição, peso corporal para adultos (maiores de 21 anos) e crianças (menores de 5 anos), para cenários de exposição relativos à recreação de contato primário e consumo de água potável. Os valores de células de cianobactérias estiveram entre 2.216 e 203.082 céls.mL-1 e as concentrações de saxitoxina e análogos estiveram entre 0,04 e 0,37 µg equivalente STX..L-1. Os resultados obtidos na análise da água bruta do reservatório, estiveram abaixo do valor estabelecido na legislação brasileira para água potável (3 µg equivalente STX.L-1), mas não atenderiam as especificações adotadas por Oregon e Ohio (0,3 µg equivalentes STX.L-1) e à proposta em discussão no Comitê Permanente para Gestão Integrada da Qualidade da Água destinada ao Consumo Humano no Estado de São Paulo (0,13 µg equivalente STX.L-1), indicando a possibilidade da ocorrência de efeito adverso à saúde em grupos sensíveis que utilizem água do reservatório, dependendo da eficiência de remoção dessas cianotoxinas no processo de tratamento. Os valores de ingestão diária crônica estimados, para recreação, variaram de 2,55 x 10-6 a 1,08 x 10-4 µg equivalente STX. kg-1.dia-1 (adultos) e 2,78 x 10-9 a 4,35 x 10-4 µg equivalente STX. kg-1.dia-1 (crianças). Para ingestão de água potável, esses valores variaram de 2,5 x 10-4 a 1,47 x 10-2 µg equivalente STX. kg-1.dia-1 (adultos) e 5,36 x 10-5 a 2,55 x 10-2 µg equivalente STX. kg-1.dia-1 (crianças). Esses valores indicaram que as crianças estão mais expostas que os adultos, fato preocupante, pois elas são mais sensíveis aos efeitos de substâncias tóxicas, e apesar de estudos indicarem efeitos da saxitoxina em cultura de células neurais, sua capacidade de atravessar a barreira hematoencefálica e de causar danos cognitivos em ratos, os efeitos da exposição crônica em humanos ainda são desconhecidos. Não foi possível estimar os riscos à saúde da população exposta à saxitoxina e análogos, pela falta de dados na literatura, porém o modelo de exposição proposto é um avanço para a identificação de lacunas para a condução da avaliação de risco à saúde humana considerando a exposição crônica


The artificial enrichment of nutrients in aquatic environments has favored the incidence of cyanobacteria blooms, causing impacts on water quality and putting human health at risk. The genus of cyanobacteria Cylindrospermopsis, widely distributed throughout the world in freshwater environments, is able to produce cianotoxin, among them saxitoxin and its analogues. The objective of this work was to elaborate a model of exposure referring to the ingestion of water contaminated by saxitoxin and analogues through recreation of primary contact and water consumption. Cylindrospermopsis cell density and saxitoxin and analogues concentrations in surface water were obtained from the CETESB Surface Water Quality Monitoring Network for the Itupararanga reservoir in 2015 and 2016. The development of the conceptual model of exposure and the calculation of the chronic daily intake of saxitoxin and analogues, considered: maximum and minimum concentrations of saxitoxin and analogues found in the raw water of the reservoir, route of exposure, exposed population, rate of water intake, frequency and duration of exposure, body weight for adults (over 21 years) and children (under 5 years), for exposures scenarios concerning recreation of primary contact and consumption of drinking water. The values of cyanobacteria cells were between 2,216 and 203,082 cells.L-1 and the concentrations of saxitoxin and analogues were between 0.04 and 0.37 µg STX equivalent. L-1. The comparison of these variables indicated a significant positive correlation between them. The results obtained in the raw water analysis of the reservoir were below the value established in Brazilian legislation for drinking water (3 µg equivalent STX.L-1), but would not meet the specifications adopted by US states Oregon and Ohio (0.3 µg equivalents.L-1) and the proposed value for the Standing Committee for Integrated Water Quality Management for Human Consumption in the State of São Paulo (0,13 µg equivalent STX.L-1), indicating the possibility of adverse health effects in sensitive groups using water from the reservoir. Estimated chronic daily intake values, for recreation, ranged from 2.55 x 10-6 to 1.08 x 10-4 µg STX equivalent. kg-1.day-1 (adults) and 2.78 x 10-9 to 4.35 x 10-4 µg STX equivalent. kg-1.day-1 (children). For water intake, these values ranged from 2.5 x 10-4 to 1.47 x 10-2 µg STX equivalent. kg-1 day-1 (adults) and 5.36 x 10-5 to 2.55 x 10-2 µg STX equivalent. kg-1. day-1 (children). These values indicated that children are more exposed than adults, a worrying fact because they are generally more sensitive to the effects of toxic substances than adults, and although studies indicate that saxitoxin was able to cross the blood brain barrier and to cause cognitive damage in rats, as well as changes in neural cell cultures, the effects of chronic exposure in humans are still unknown. It was not possible to estimate the health risks of the population exposed to saxitoxin and the like, due to the lack of data in the literature, but the proposed exposure model is an advance for the identification of gaps for conducting the human health risk assessment considering the exposure chronic


Subject(s)
Cylindrospermopsis , Environmental Exposure , Fresh Water , Recreational Water , Saxitoxin , Water Pollution , Cyanobacteria , Drinking , Water Supply
16.
Braz. j. biol ; 77(3): 495-505, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-888794

ABSTRACT

Abstract The hydrological periods drive the structure and organization of aquatic communities in semiarid regions. We hypothesize that a decrease of the precipitation during the dry period will favor the development of the periphytic algal community, leading to higher richness and density in this period. To test this hypothesis, we investigated the changes in the periphytic algal community structure in three shallow and eutrophic ecosystems of the Brazilian semiarid. The sampling was performed between 2007 and 2010 at two-mensal intervals. The sampling of periphytic algal was performed in aquatic macrophytes and rocks. The abiotic variables were analyzed simultaneously. Dominance in diatoms, cyanobacteria and chlorophytes, respectively, was observed in two periods. In the dry period, waters were alkaline and had high concentrations of nitrate and total phosphorus associated with the highest densities of Bacillariophyceae. In the rainy period the water was warmer, oxygenated and high concentrations of ammonia and soluble reactive phosphorus with diatoms remained dominant but with reduced density, while cyanobacteria and chlorophytes increased. Overall, periphytic algal community composition no responded to changes in the hydrological periods. However, the hydrological periods altered the dynamics of periphytic algal community, supported by the alternation of the most representative classes (diatoms and cyanobacteria) between the hydrologic periods. Our data suggest that the morphometric and chemical and physical characteristics of lentic aquatic ecosystems studied were more important in the dynamics of periphytic algal community than the hydrological periods and types of substrates.


Resumo Os períodos hidrológicos impulsionam a estrutura e organização das comunidades aquáticas em regiões semiáridas. Nós hipotetizamos que uma diminuição da precipitação durante o período seco irá favorecer o desenvolvimento da comunidade de algas perifíticas, levando a uma maior riqueza e densidade nesse período. Para testar esta hipótese, nós investigamos as mudanças na estrutura da comunidade de algas perifíticas em três ecossistemas rasos e eutróficos do semiárido brasileiro. As amostragens foram realizadas entre 2007 e 2010 em intervalos de bimensais. A amostragem das algas perifíticas foi realizada em macrófitas aquáticas e rochas. As variáveis abióticas foram analisadas simultaneamente. A dominância de diatomáceas, cianobactérias e clorófitas, respectivamente, foi observada em todos os períodos. No período seco, as águas foram alcalinas com altas concentrações de nitrato e fósforo total associado às maiores densidades de Bacillariophyceae. Durante o período chuvoso as águas apresentaram-se mais quentes, oxigenadas e com altas concentrações de amônia e fósforo reativo solúvel. As diatomáceas permaneceram dominantes, mas com densidade reduzida, enquanto as cianobactérias e clorofíceas aumentaram. No geral, a composição da comunidade de algas perifíticas não respondeu as mudanças nos períodos hidrológicos. No entanto, os períodos hidrológicos alteraram a dinâmica da comunidade de algas perifíticas, apoiados pela alternância das classes mais representativas (diatomáceas e cianobactérias) entre os períodos hidrológicos. Nossos dados sugerem que as características morfométricas, químicas e físicas dos ecossistemas aquáticos lênticos estudados foram mais importantes na dinâmica da comunidade de algas perifíticas do que os períodos hidrológicos e tipos de substratos.


Subject(s)
Cyanobacteria/physiology , Diatoms/physiology , Ecosystem , Brazil
17.
Braz. j. microbiol ; 48(1): 25-31, Jan.-Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-839353

ABSTRACT

Abstract Dyes are recalcitrant compounds that resist conventional biological treatments. The degradation of three textile dyes (Indigo, RBBR and Sulphur Black), and the dye-containing liquid effluent and solid waste from the Municipal Treatment Station, Americana, São Paulo, Brazil, by the cyanobacteria Anabaena flos-aquae UTCC64, Phormidium autumnale UTEX1580 and Synechococcus sp. PCC7942 was evaluated. The dye degradation efficiency of the cyanobacteria was compared with anaerobic and anaerobic-aerobic systems in terms of discolouration and toxicity evaluations. The discoloration was evaluated by absorption spectroscopy. Toxicity was measured using the organisms Hydra attenuata, the alga Selenastrum capricornutum and lettuce seeds. The three cyanobacteria showed the potential to remediate textile effluent by removing the colour and reducing the toxicity. However, the growth of cyanobacteria on sludge was slow and discoloration was not efficient. The cyanobacteria P. autumnale UTEX1580 was the only strain that completely degraded the indigo dye. An evaluation of the mutagenicity potential was performed by use of the micronucleus assay using Allium sp. No mutagenicity was observed after the treatment. Two metabolites were produced during the degradation, anthranilic acid and isatin, but toxicity did not increase after the treatment. The cyanobacteria showed the ability to degrade the dyes present in a textile effluent; therefore, they can be used in a tertiary treatment of effluents with recalcitrant compounds.


Subject(s)
Animals , Cyanobacteria/metabolism , Coloring Agents/metabolism , Seeds/drug effects , Textiles , Allium/drug effects , Brazil , Biotransformation , Lettuce/drug effects , Aerobiosis , Coloring Agents/toxicity , Chlorophyta/drug effects , X-Ray Absorption Spectroscopy , Hydra/drug effects , Anaerobiosis , Industrial Waste , Mutagens/metabolism
18.
Rev. chil. nutr ; 44(4): 360-370, 2017. tab, graf
Article in English | LILACS | ID: biblio-899842

ABSTRACT

RESUMEN Llayta es el nombre asignado a la biomasa seca de macrocolonias de una cianobacteria filamentosa, clasificada como Nostoc sp. Llayta crece en humedales andinos de Sudamérica y ha sido considerada como un ingrediente alimenticio desde tiempos precolombinos. Este estudio pretende contribuir a la definición de la calidad nutritiva de la Llayta, proporcionando información sobre su composición bioquímica e identificar aspectos críticos de interés toxicológico. Los resultados mostraron que el 60% del total de sus aminoácidos son indispensables, contenía un 2% de lípidos totales, 32% del total de ácidos grasos eran poliinsaturados, la vitamina E fue la más abundante (4,3 mg%), el contenido de polifenoles totales es 64 mg equivalentes de ácido gálico, su actividad antioxidante es 17,4 μmoles equivalentes de Trolox, la fibra total fue el 56% del peso seco y presentó un contenido promedio de arsénico total de 9,2 ± 5,4 ppm. Esta cianobacteria no es productora de microcistina, por lo que las colonias de la Llayta podrían considerarse inocua para el consumo humano.


ABSTRACT Llayta is the name assigned to the dry biomass of macrocolonies of a filamentous cyanobacterium classified as Nostoc sp. Llayta grows in the Andean wetlands of South America and has been considered a food ingredient since pre-Columbian times. This work is an effort to contribute to define the nutritional quality of Llayta providing information on its biochemical composition and to identify key toxicological aspects. The results indicated that 60% of its aminoacids were indispensable, total lipids were 2% of dry weight, polyunsaturated fatty acids were 32% of total fatty acids, vitamin E was the most abundant (4.3 mg%), total polyphenols were 64 mg (equivalent to galic acid), antioxidant activity was 17.4 μmoles (equivalent to Trolox), total fiber was 56% of dry weight and accumulated 9.2 ± 5.4 ppm of total arsenic. Since Nostoc sp. Llayta is a cyanobacterium strain that does not synthesize the cyanotoxin microcystin, the Llayta colonies can be considered innocuous for human consumption.


Subject(s)
Humans , Arsenic , Microcystis , Nostoc , Microalgae , Nutritive Value , Cyanobacteria
19.
São Paulo; s.n; s.n; 2017. 143p ilus, graf, tab.
Thesis in Portuguese | LILACS | ID: biblio-876551

ABSTRACT

Apesar dos diversos estudos sobre a presença de cianobactérias e a correlação entre fatores ambientais que influenciam ou desencadeiam florações, é ainda incipiente a informação sobre o controle fisiológico e bioquímico da produção de metabólitos secundários, cianotoxinas e compostos orgânicos voláteis (COVs) nestes organismos. Os COVs mais comumente encontrados em cianobactérias são a geosmina e o 2- metil-isoborneol, compostos que resistem ao tratamento convencional da água, causam mau cheiro e alteram seu gosto, além de bioacumular em peixes e moluscos. Estudos sobre possíveis sistemas de competição (alelopatia) entre linhagens de cianobactérias, ou entre elas e outros organismos, podem contribuir para elucidação do papel da produção de COVs por cianobactérias. Dessa forma, os objetivos deste projeto foram (i) prospectar a produção de COVs e seus efeitos na auto-regulação fisiológica em cianobactérias mantidas em laboratório; e (ii) desenvolver um método analítico, por microextração em fase sólida (SPME) e cromatografia em fase gasosa com detecção por espectrometria de massas (GC-MS), para a determinação destes compostos. Foram realizados ensaios para avaliar os perfis de produção dos COVs em duas linhagens de M. aeruginosa em diferentes fases de crescimento, sob diferentes intensidades luminosas (50, 150 e 250 ?µmol.fótons.m-2.s-1) e também ao longo do ritmo circadiano, avaliando a influência dos períodos claro e escuro. Para avaliar efeitos alelopáticos, exsudatos de uma linhagem de M. aeruginosa produtora de microcistinas foram testados em culturas de outra linhagem de M. aeruginosa não produtora de toxinas por meio de técnicas tradicionais de cultivo com monitoramento do crescimento. Na análise da produção de COVs, por GC-MS, observou-se que se destacam, majoritariamente, os compostos α-ciclocitral, ß-ciclocitral e ß-ionona, sendo o ß-ciclocitral o mais abundante, em todas as condições testadas, para as ambas as linhagens estudadas. A linhagem não toxigênica, no entanto, apresentou produção mais elevada de todos os compostos identificados. Dentre as intensidades luminosas testadas, a intensidade de 250 µmol.fótons.m-2s-1 foi a que apresentou a maior taxa de crescimento para a linhagem LTPNA 08 e relação negativa entre o aumento da irradiância e a produção de ß-ciclocitral. Foram identificadas, também, variações na produção dos compostos α-ciclocitral, ß-ciclocitral e ß-ionona nas linhagens ao longo do ritmo circadiano, sendo as maiores concentrações encontradas no período escuro. Observou-se morte celular e redução na produção de COVs 24 horas após adição de exsudatos pertencentes à linhagem de M. aeruginosa toxigênica em cultivos da linhagem não-toxigênica. Sendo assim, pode-se inferir que a produção dos COVs pode sofrer alterações qualitativas e quantitativas dependendo do estímulo ambiental presente, tanto por interações bióticas (com outros organismos e ritmo circadiano), quanto por fatores abióticos (intensidade luminosa)


There are several studies on the presence of cyanobacteria and the correlation between environmental factors that may influence or trigger blooms. However, information concerning the physiological and biochemical control of the production of secondary metabolites, toxins and volatile organic compounds (VOC) by cyanobacteria is poorly understood. Geosmin and 2-methyl-isoborneolare are commonly found VOC in cyanobacteria, they resist to conventional water treatment and can cause bad smell and taste in the final water. In addition, VOC can bioaccumulate in fish and shellfish. Studies on possible competition systems (allelopathy) either among strains of cyanobacteria or among them and other organisms such as green microalgae, may help to elucidate the role of VOC production by cyanobacteria. Thus, the main objectives of this study are: (i) prospect the production of VOCs and their effects on physiological self-regulation in cyanocrobacteria kept in the laboratory; and (ii) to develop an analytical method, by solid phase microextraction (SPME) and gas chromatography with mass spectrometry detection (GC-MS), for the determination of these compounds. The assays were carried out to evaluate the production profiles of VOCs in two strains of M. aeruginosa at different growth stages under different light intensities (50, 150 and 250 µmol.fótons.m-2.s-1) and also along of the circadian rhythm, evaluating the influence of light and dark periods. To assess allelopathic effects, exudates from a microcystin-producing strain of M. aeruginosa were tested on cultures of another non-toxin producing M. aeruginosa strain by traditional growth monitoring culture techniques. In the analysis of VOC production by GC-MS, it was observed that α-cyclocyclal, ß-cyclocyclal and ß-ionone compounds were the most prominent, with ß-cyclocitral being the most abundant in all conditions tested, for both strains studied. The non-toxigenic lineage, however, showed higher production of all the identified compounds. Among the light intensities tested, the intensity of 250 µmol.fótons.m-2s-1 was the one with the highest growth rate and positive relation between the irradiance increase and the ß-cyclocitral production. Variations in the production of the α-cyclocyclal, ß-cyclocyclal and ß-ionone compounds were also identified in the lines along the circadian rhythm, being the highest concentrations found in the dark period. Cell death and reduction in VOC production were observed 24 hours after addition of exudates belonging to the toxigenic M. aeruginosa lineage in cultures of the non-toxigenic lineage. Thus, it can be inferred that the production of VOCs can undergo qualitative and quantitative changes depending on the environmental stimulus present, both by biotic interactions (with other organisms and circadian rhythm) and by abiotic factors (luminous intensity)


Subject(s)
Cyanobacteria , Volatile Organic Compounds/analysis , Allelopathy , Gas Chromatography-Mass Spectrometry/methods , Microcystis/growth & development , Solid Phase Microextraction/methods
20.
Biol. Res ; 50: 16, 2017. graf
Article in English | LILACS | ID: biblio-838970

ABSTRACT

Acaryochloris marina is an oxygenic cyanobacterium that utilizes far-red light for photosynthesis. It has an expanded genome, which helps in its adaptability to the environment, where it can survive on low energy photons. Its major light absorbing pigment is chlorophyll d and it has α-carotene as a major carotenoid. Light harvesting antenna includes the external phycobilin binding proteins, which are hexameric rods made of phycocyanin and allophycocyanins, while the small integral membrane bound chlorophyll binding proteins are also present. There is specific chlorophyll a molecule in both the reaction center of Photosystem I (PSI) and PSII, but majority of the reaction center consists of chlorophyll d. The composition of the PSII reaction center is debatable especially the role and position of chlorophyll a in it. Here we discuss the photosystems of this bacterium and its related biology.


Subject(s)
Photosynthesis/physiology , Chlorophyll/biosynthesis , Cyanobacteria/metabolism , Adaptation, Physiological , Genome, Bacterial , Cyanobacteria/genetics
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