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1.
Biopolymers ; 113(6): e23488, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35338709

ABSTRACT

Produced water (PW) and crude glycerin (CG) are compounds overproduced by the oil and biodiesel industry and significant scientific efforts are being applied for properly recycling them. The aim of this research is to combine such industrial byproducts for sustaining the production of xanthan by Xanthomonas campestris. Xanthan yields and viscosity on distinct PW ratios (0, 10, 15, 25, 50, 100) and on 100% dialyzed PW (DPW) in shaker batch testing identified DPW treatment as the best approach for further bioreactor experiments. Such experiments showed a xanthan yield of 17.3 g/L within 54 h and a viscosity of 512 mPa s. Physical-chemical characterization (energy dispersive X-ray spectroscopy, scanning electron microscopy and Raman spectroscopy) showed similarities between the produced gum and the experimental control. This research shows a clear alternative for upcycling high salinity PW and CG for the generation of a valued bioproduct for the oil industry.


Subject(s)
Polysaccharides, Bacterial , Xanthomonas campestris , Glycerol , Polysaccharides, Bacterial/chemistry , Viscosity , Water
2.
Environ Technol ; 43(7): 983-990, 2022 Mar.
Article in English | MEDLINE | ID: mdl-32811371

ABSTRACT

The present work aimed to give an economical destiny to the produced water, a residue generated by the oil and gas industry by means of producing bioactives such as xanthan gum and ramnolipid. These compounds are often used in combination during enhanced oil recovery strategies. On the other hand, reports on co-culture of bacterial strains that are responsible for their production are rare. This research shows a factorial design method associated with surface response analysis to optimize carbon sources, sucrose and crude glycerin, and fermentation agents for culturing Xanthomonas campestris and Pseudomonas aeruginosa using the described conditions. After the critical point validation resulting in xanthan and ramnolipid production of 8.69 and 4.80 g L-1, quality tests showed an apparent viscosity of 1006 cP with an emulsifying activity abouve 50% for 94 h.


Subject(s)
Industrial Oils , Xanthomonas campestris , Polysaccharides, Bacterial/chemistry , Water
3.
PeerJ ; 9: e12229, 2021.
Article in English | MEDLINE | ID: mdl-34631324

ABSTRACT

Mangroves are tropical ecosystems with strategic importance for climate change mitigation on local and global scales. They are also under considerable threat due to fragmentation degradation and urbanization. However, a complete understanding of how anthropogenic actions can affect microbial biodiversity and functional adaptations is still lacking. In this study, we carried out 16S rRNA gene sequencing analysis using sediment samples from two distinct mangrove areas located within the Serinhaém Estuary, Brazil. The first sampling area was located around the urban area of Ituberá, impacted by domestic sewage and urban runoff, while the second was an environmentally conserved site. Our results show significant changes in the structure of the communities between impacted and conserved sites. Biodiversity, along with functional potentials for the cycling of carbon, nitrogen, phosphorus and sulfur, were significantly increased in the urban area. We found that the environmental factors of organic matter, temperature and copper were significantly correlated with the observed shifts in the communities. Contributions of specific taxa to the functional potentials were negatively correlated with biodiversity, such that fewer numbers of taxa in the conserved area contributed to the majority of the metabolic potential. The results suggest that the contamination by urban runoff may have generated a different environment that led to the extinction of some taxa observed at the conserved site. In their place we found that the impacted site is enriched in prokaryotic families that are known human and animal pathogens, a clear negative effect of the urbanization process.

4.
J Mol Model ; 27(6): 189, 2021 May 27.
Article in English | MEDLINE | ID: mdl-34046767

ABSTRACT

Sulphate-reducing bacteria are commonly associated with biological causes of oil well souring. Biosulphetogenesis can directly affect oil quality and storage due to the accumulation of sulphides. In addition, these microorganisms can create bio-incrustation that can clog pipes. Sulphite reductase (SIR) is the enzyme responsible for converting ion sulphite into sulphide and several substances may interfere or control such activity. This interference can hinder growth of the sulphate-reducing bacteria and, consequently, it reduces sulphide accumulation in situ. This work focuses on molecular modelling techniques along with in vitro experiments in order to investigate the potential of two essential oils and one vegetable oil as main inhibitors of sulphite reductase activity. Docking simulation identified several substances present in Rosmarinus officinalis, Tea tree and Neem extractable oils as potential inhibitors of SIR. Substances present in Neem vegetable oil are the most potent inhibitors, followed by Rosmarinus officinalis and Tea tree essential oils. The Neem oil mixture showed a superior effectiveness in intracellular SIR inhibitory effects.


Subject(s)
Bacteria/drug effects , Bacteria/enzymology , Molecular Docking Simulation , Oils, Volatile/pharmacology , Oxidoreductases Acting on Sulfur Group Donors/antagonists & inhibitors , Sulfates/metabolism , Tea Tree Oil/pharmacology , Bacteria/metabolism , Rosmarinus/chemistry
5.
Rev. Ciênc. Méd. Biol. (Impr.) ; 20(1): 5-13, maio 5, 2021. tab, fig
Article in English | LILACS | ID: biblio-1354757

ABSTRACT

Introduction: sunscreen is a cosmetic used to protect human skin from the deleterious effects of UV radiation and thus minimize the risks of developing skin cancer. Extracts produced from fruits, such as Abiu, Guava, Rambutan and Grape, have significant concentrations of chromophores and phenolic substances that have the ability to absorb UV light and neutralize free radicals. The production of cosmetics from naturally occurring substances with such activities will be of great importance for Brazilian industry and could reduce the cost of production, given the large existing biodiversity in the country. Objectives: carry out a patent search for formulations and cosmetic products that contains phenolic rich fruit extracts as photoprotective and antioxidant bioactives. Methodology: a survey of patents was carried out in the database of the National Institute of Intellectual Property (INPI) and the European Patent Office (EPO), covering a time period between 2008 and 2018, using a combination of keywords related to herbal cosmetics and sunscreens. Results: this research identifies a significant number of patents related to plant extract in association with sunscreen product, however, no patent filings were identified for cosmetic products containing extracts of the evaluated fruits, either alone or in combination, for photoprotective and antioxidant purposes. Conclusion: the Brazilian and international market for sun care products moves millions to billions of dollars annually and have a significant annual growth prospect. Considering the great biodiversity existing in the country, the production of cosmetics from naturally occurring substances with such activities will be of great importance for the Brazilian industrial sector.


Introdução: os filtros solares são cosméticos usados para proteger a pele humana dos efeitos deletérios da radiação UV e assim, minimizar os riscos de desenvolvimento de câncer de pele. Extratos produzidos a partir de frutos, como Abiu, Goiaba, Rambutan e Uva, têm concentrações significativas de cromóforos e substâncias fenólicas que têm a capacidade de absorver a radiação UV e neutralizar os radicais livres. A produção de cosméticos a partir de substâncias naturais com essas atividades será de grande importância para a indústria brasileira e poderá reduzir o custo de produção, dada a grande biodiversidade existente no país. Objetivos: realizar uma busca de registros de patentes de formulações e produtos cosméticos que contêm extratos de frutos ricos em fenólicos como bioativos fotoprotetores e antioxidantes. Metodologia: foi realizado um levantamento de patentes no banco de dados do Instituto Nacional de Propriedade Intelectual (INPI) e do Escritório Europeu de Patentes (EPO), abrangendo um período de tempo entre 2008 e 2018, utilizando uma combinação de palavras-chave relacionadas a cosméticos à base de plantas e protetores solares. Resultados: esta pesquisa identificou um número significativo de patentes relacionadas ao extrato de plantas em associação ao produto protetor solar, no entanto, não foram identificados pedidos de patente para produtos cosméticos que contenham extratos das frutas avaliadas, isoladamente ou em combinação, para fins fotoprotetores e antioxidantes. Conclusão: o mercado brasileiro e internacional de produtos de proteção solar movimenta milhões a bilhões de dólares anualmente e tem a perspectiva de crescimento anual significativa. Considerando a grande biodiversidade existente no país, a produção de cosméticos a partir de substâncias naturais com essas atividades será de grande importância para o setor industrial brasileiro.


Subject(s)
Plants , Radiation Effects , Sunscreening Agents , Cosmetics , Phenolic Compounds , Sun Protection Factor , Database
6.
Biol Trace Elem Res ; 199(9): 3527-3539, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33094450

ABSTRACT

Melipona quadrifasciata anthidioides is a species of stingless bee popularly known in Brazil as "mandaçaia". Products derived from bees for food and therapeutic uses, have stimulated the evaluation of the chemical composition of geopropolis. Concentrations of 24 essential and potentially toxic elements were determined in geopropolis samples, using a sequential optical emission spectrometer with inductively coupled plasma (ICP OES) after microwave-assisted acid digestion. Principal component analysis (PCA) and Hierarchical cluster analysis (HCA) were used to carry out an exploratory analysis of the samples. The following elements were quantified (in mg Kg-1): Al (320,414.40-36,911.1), As (

Subject(s)
Trace Elements , Animals , Bees , Brazil , Environmental Monitoring , Ions , Microwaves , Trace Elements/analysis
7.
J Photochem Photobiol B ; 205: 111837, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32146271

ABSTRACT

The use of plant bioactives in cosmetic formulations are increasing due to the search for new sustainable sources of raw materials, greater concern for safety and possible social impacts caused by the incorrect use of natural resources. Plant extracts have been the subject of several studies in several industrial areas. However, the potential use of tropical fruits extracts in cosmetic formulations remains largely unexplored. Considering the impact on public health and the possibility of using wastes from fruit processing, the aim of this work is to identify, evaluate and develop a sunscreen based on rambutan peel extracts (Nephelium lappaceum L) as a natural additive for enhancing the final product sun protection factor (SPF). The phytochemical screening revealed the presence of tannins and flavonoids and the absence of coumarins. Even presenting a low sunscreen factor when used alone (SPF value 0.4), rambutan extract at 1.00% FTP concentration improved the photoprotective result (11.2) of the formulation containing 7.5% of ethylhexyl metoxycinnamate (EHMC) by 134%. The addition of rambutan extract in the formulation shows the potential to reduce the use of synthetic photoprotectors by about 64% of the total synthetic organic filters used to achieve the SPF value of 26.3. In addition, the sunscreen formulation supplemented with rambutan extract containing 1.00% RTP shows the potential to minimize the risk of synthetic agent toxicity and a 45% reduction in the cost of sunscreen production.


Subject(s)
Plant Extracts/chemistry , Sapindaceae , Sun Protection Factor , Sunscreening Agents/chemistry , Ethanol/chemistry , Flavonoids/analysis , Flavonoids/chemistry , Fruit/chemistry , Phytochemicals/analysis , Phytochemicals/chemistry , Solvents/chemistry , Tannins/analysis , Tannins/chemistry , Ultraviolet Rays
8.
J Photochem Photobiol B ; 201: 111639, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31698220

ABSTRACT

Increasing concerns about health safety, social impacts and fair trade have intensified the industrial interest for using natural products in commercial cosmetic formulations. Several studies are currently focusing on plant extracts, but tropical fruits, such as guava, remain yet unexplored and, consequently, underutilized. This research aims to evaluate the potential for using guava-fruit extract as a photoprotective additive agent for sun cream formulations. The phytochemical screening revealed the presence of flavonoids and tannins and the absence of coumarins. Although the Psidium guajava extract showed a low sun protection factor (SPF) value (1.0), it improved in about 134% the photoprotective result (8.1) of 7.5% 2-ethyl-hexyl methoxycinnamate formulation. Therefore, guava-fruit extract supplementation in the formulation shows the potential to reduce the use of synthetic photoprotectors in about 78.9% from the total synthetic organic filters used to achieve the SPF value of 18. Thus, sun cream supplemented with guava-fruit extract show the potential for minimizing the risk of synthetic agent toxicity, and a 65.8% reduction in the cost of the sunscreen production.


Subject(s)
Plant Extracts/chemistry , Psidium/chemistry , Sunscreening Agents/chemistry , Ultraviolet Rays , Drug Compounding , Fruit/chemistry , Fruit/metabolism , Psidium/metabolism , Spectrophotometry , Sun Protection Factor
9.
J Phycol ; 55(5): 1050-1058, 2019 10.
Article in English | MEDLINE | ID: mdl-31315155

ABSTRACT

The reuse of wastewater is important for reducing costs involved with algal lipid production. However, nutrient limitations, wastewater-borne microbes, and mixotrophic growth can significantly affect biomass yields and lipid/biomass ratios. This research compared the growth performances of both Chlorella vulgaris and Pseudokirchneriella subcapitata on domestic wastewater effluent. The experiments were conducted in the presence and absence of wastewater-borne bacteria, while additionally assessing the impact of distinct nitrate and glucose supplementations. When compared to the sterilized controls, the presence of wastewater-borne bacteria in the effluent reduced C. vulgaris and P. subcapitata total biomass production by 37% and 46%, respectively. In the corresponding treatments supplemented with glucose and nitrate, total biomass production increased by 12% and 61%, respectively. The highest biomass production of 1.11 and 0.72 g · L-1 was, however, observed in the sterilized treatments with both glucose and nitrate supplementations for C. vulgaris and P. subcapitata, respectively. Lipid to biomass ratios were, on average, threefold higher when only nitrate was introduced in the sterilized treatments for both species (0.4 and 0.5, respectively). Therefore, the combination of nitrate and glucose supplementation is shown to be an important strategy for enhancing algal lipid and biomass production when those algae are grown in the presence of wastewater-borne bacteria. On the other hand, in the absence of wastewater-borne bacteria, only nitrate supplementation can significantly improve lipid/biomass ratios.


Subject(s)
Chlorella vulgaris , Microalgae , Bacteria , Biomass , Glucose , Nitrogen , Wastewater
10.
Environ Technol ; 40(16): 2100-2106, 2019 Jul.
Article in English | MEDLINE | ID: mdl-29405085

ABSTRACT

Surfactants and co-surfactants play an important role in enhanced oil recovery for they improve petroleum solubility and reduce interfacial tensions between oil, water and the rock formation. Ethanol is receiving renewed attention as potential co-surfactant because of the negative results obtained with the use of salts and alkaline substances. Sulphate-reducing bacteria (SRB) can use surfactants and co-surfactants as carbon sources and, consequently, this can increase the biological accumulation of sulphide (souring). The aim of this research is to correlate SRB activity with different concentrations of co-surfactant (ethanol) as an attempt to quantifying in which concentration such compound can potentially increase or inhibit souring. The results show that the combination of surfactant (lauryl glucoside) and co-surfactant (ethanol) can increase SRB activity to about 2.3-fold. The highest sulphate consumption rate of 591 µg l-1 h-1 was observed in experiments with 0.03% and 1.5% (v/v) of surfactant and ethanol, respectively. The experiments indicated that SRB activity is only controlled by ethanol concentrations above 6.5% (v/v). Ethanol can potentially decrease costs with the use of biocides and significantly increase oil recovery ratios. Tests with the model Desulfovibrio vulgaris were not comparable with the results obtained with the SRB consortium.


Subject(s)
Desulfovibrio , Petroleum , Sulfates , Sulfides , Surface-Active Agents
11.
J Photochem Photobiol B ; 181: 115-121, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29549804

ABSTRACT

Cellulose has a highly diversified architecture and its enzymatic complexes are studied for achieving an efficient conversion and a high level of efficiency in the deconstruction of cellulolytic biomass into sugars. The aim of this investigation was to evaluate the effect of Laser or LED light in the cellulolytic activity (CMCase) and on the proliferation of the thermophilic microbial consortium used on the degradation process of a lignocellulosic biomass of green coconut shell. The irradiation protocol consisted of six Laser irradiations (λ660 ηm, 40 mW, 270 s, 13 J/cm2) or LED (λ632 ±â€¯2 ηm, 145 mW, 44 s, 13 J/cm2) with 12- h time intervals in nutrient deprivation conditions. After irradiation, the consortium was inoculated into a lignocellulosic biomass (coconut fibers). Non- irradiated consortium was also inoculated and acted as control. Cell proliferation and endoglucanase activity were quantified during the experimental time. Experiments were carried out in triplicate. The results showed an increase of 250 % of thermo-cellulolytic microorganisms for the LED group and 200% for the Laser group when compared to the control. The enzymatic index (red Congo method), showed a statistically significant difference in the process of degradation of the lignocellulosic biomass between the Laser and LED groups compared to the control group [p < 0.0029; p < 0.029, respectively] 48-hs after the inoculation of the microorganisms. At the end of 72-h, this significant difference was maintained for both irradiated groups (p < 0.0212). Based upon the protocol used on the present study, it is possible to concluded that LED light enhanced cell proliferation of the thermophilic microbial consortium while the Laser light increase the enzymatic index of the lignocellulosic biomass of green coconut shell.


Subject(s)
Lasers , Light , Microbial Consortia/physiology , Bacterial Proteins/metabolism , Biomass , Cellulase/metabolism , Cellulose/chemistry , Cellulose/metabolism , Cocos/metabolism , Gram-Positive Bacteria/enzymology , Gram-Positive Bacteria/growth & development , Hydrolysis/radiation effects , Microscopy, Fluorescence
12.
Arch Virol ; 162(3): 873-877, 2017 Mar.
Article in English | MEDLINE | ID: mdl-27896562

ABSTRACT

Equine infectious anemia is an important infectious disease that affects equids worldwide. Control of the disease is currently based on detection of anti-p26 EIAV by Agar Gel Immunodiffusion (AGID). In this work, 62 animals were examined by AGID and nested-PCR using primers for the gag gene. Fifty-three samples (85.5%) were positive by nested-PCR, whereas only 33 samples (53%) were positive for AGID. Fifteen amplicons obtained by nested-PCR were sequenced and the aligned results subjected to phylogenetic analysis. The analysis suggests that the Brazilian EIAV form a cluster with WSU5, EIAVUK and Wyoming strains from United States.


Subject(s)
Equine Infectious Anemia/virology , Infectious Anemia Virus, Equine/isolation & purification , Animals , Brazil , Horses , Infectious Anemia Virus, Equine/classification , Infectious Anemia Virus, Equine/genetics , Phylogeny , Polymerase Chain Reaction , Viral Core Proteins/genetics
13.
J Med Virol ; 88(1): 166-70, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26059266

ABSTRACT

Epidemiological surveillance for Human Bocavirus (HBoV) was conducted on 105 fecal specimens from children with acute gastroenteritis in Bahia, Brazil. Among of a total 105 stool samples, 44 samples were positive for HBoV as detected by nested-PCR. Of the 44 positive samples, co-infections with other enteric viruses (Norovirus, Adenovirus, and Rotavirus) were found in 12 pediatric patients. Mixed infections among HBoV with Norovirus were frequently observed in this population. The phylogenetic analysis identified the presence of HBoV-1, and HBoV 2A species. This study shows that HBoV is another viral pathogen in the etiology of acute gastroenteritis in children in Bahia, Brazil.


Subject(s)
Gastroenteritis/epidemiology , Gastroenteritis/virology , Human bocavirus/isolation & purification , Parvoviridae Infections/epidemiology , Parvoviridae Infections/virology , Adenoviridae/isolation & purification , Brazil/epidemiology , Child, Preschool , Coinfection/epidemiology , Coinfection/virology , Epidemiological Monitoring , Feces/virology , Female , Genotype , Human bocavirus/classification , Human bocavirus/genetics , Humans , Infant , Infant, Newborn , Male , Norovirus/isolation & purification , Phylogeny , Polymerase Chain Reaction , Prevalence , Rotavirus/isolation & purification
14.
Appl Biochem Biotechnol ; 171(8): 1933-43, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24013860

ABSTRACT

Microalgae farming has been identified as the most eco-sustainable solution for producing biodiesel. However, the operation of full-scale plants is still limited by costs and the utilization of industrial and/or domestic wastes can significantly improve economic profits. Several waste effluents are valuable sources of nutrients for the cultivation of microalgae. Ethanol production from sugarcane, for instance, generates significant amounts of organically rich effluent, the vinasse. After anaerobic digestion treatment, nutrient remaining in such an effluent can be used to grow microalgae. This research aimed to testing the potential of the anaerobic treated vinasse as an alternative source of nutrients for culturing microalgae with the goal of supplying the biodiesel industrial chain with algal biomass and oil. The anaerobic process treating vinasse reached a steady state at about 17 batch cycles of 24 h producing about 0.116 m(3)CH4 kgCODvinasse (-1). The highest productivity of Chlorella vulgaris biomass (70 mg l(-1) day(-1)) was observed when using medium prepared with the anaerobic digester effluent. Lipid productivity varied from 0.5 to 17 mg l(-1) day(-1). Thus, the results show that it is possible to integrate the culturing of microalgae with the sugarcane industry by means of anaerobic digestion of the vinasse. There is also the advantageous possibility of using by-products of the anaerobic digestion such as methane and CO2 for sustaining the system with energy and carbon source, respectively.


Subject(s)
Biofuels , Chlorella vulgaris/growth & development , Ethanol/metabolism , Saccharum/metabolism , Anaerobiosis , Biodegradation, Environmental , Chlorella vulgaris/metabolism , Humans , Lipids/biosynthesis , Solid Waste
15.
Bioresour Technol ; 131: 429-36, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23376206

ABSTRACT

The streams from municipal wastewater treatment plants (WWTP) have been considered a valuable medium for mass cultivation of algal biomass. The aim of this work is to test and compare the performance of Chlorella vulgaris on several streams from five stages, from two different WWTP. The results showed biomass yields ranging from 39 to 195mg dry-weightl(-1)days(-1). The best performance as biomass production was obtained with the centrate (effluent from drying the anaerobic sludge). After testing a wide range of N/P ratios with centrate, the highest productivity and growth rates were obtained with the original N/P ratio (2.0) of this stream. The highest removal rates were of 9.8 (N) and 3.0 (P) mgl(-1)days(-1), in the centrate. Finally, this research also suggests that microalgal production seems to be a promising process when coupled to wastewater treatment.


Subject(s)
Bioreactors/microbiology , Microalgae/physiology , Wastewater/microbiology , Water Pollutants, Chemical/metabolism , Water Purification/methods , Biodegradation, Environmental , Cell Proliferation , Water Pollutants, Chemical/isolation & purification
16.
Braz. arch. biol. technol ; 52(4): 1027-1036, July/Aug. 2009. ilus, tab
Article in English | LILACS | ID: lil-525625

ABSTRACT

The aim of this work was to investigate the anaerobic biomass formation capable of treating vinasse from the production of sugar cane alcohol, which was evolved within an anaerobic sequencing batch biofilm reactor (ASBBR) as immobilized biomass on cubes of polyurethane foam at the temperature of 55ºC. The reactor was inoculated with mesophilic granular sludge originally treating poultry slaughterhouse wastewater. The evolution of the biofilm in the polyurethane foam matrices was assessed during seven experimental phases which were thus characterized by the changes in the organic matter concentrations as COD (1.0 to 20.0 g/L). Biomass characterization proceeded with the examination of sludge samples under optical and scanning electron microscopy. The reactor showed high microbial morphological diversity along the trial. The predominance of Methanosaeta-like cells was observed up to the organic load of 2.5 gCOD/L.d. On the other hand, Methanosarcinalike microorganisms were the predominant archaeal population within the foam matrices at high organic loading ratios above 3.3 gCOD/L.d. This was suggested to be associated to a higher specific rate of acetate consumption by the later organisms.


Este trabalho investigou a formação de um biofilme anaeróbio capaz de tratar vinhaça da produção de álcool de cana-de-açúcar, que evoluiu dentro de um reator operado em bateladas seqüenciais com biofilme (ASBBR) tendo a biomassa imobilizada em cubos de espuma de poliuretano na temperatura de 55ºC. O reator foi inoculado com lodo granular mesofílico tratando água residuária de abatedouro de aves. A evolução do biofilme nas matrizes de espuma de poliuretano foi observada durante sete fases experimentais que foram caracterizadas por mudanças nas concentrações de matéria orgânica como DQO (1,0 a 20,0 g/L). A caracterização da biomassa foi feita por exames de amostras do lodo em microscopia ótica e eletrônica de varredura. O reator apresentou grande diversidade de morfologias ao longo do experimento. A predominância de células como Methanosaeta foram observadas até a carga orgânica de 2,5 gDQO/L.d. Por outro lado, microrganismos como Methanosarcina foram a população arquéia predominante nas matrizes de espuma em taxas de carregamento orgânico acima de 3,3 gDQO/L.d. Este fato pode estar relacionado com maior taxa de utilização específica de acetato por esses microrganismos.

17.
J Ind Microbiol Biotechnol ; 36(5): 769-73, 2009 May.
Article in English | MEDLINE | ID: mdl-19326159

ABSTRACT

This study investigated the bacterial community of a full-scale anaerobic digester, which suffers from intermittent seawater contaminations, using 16S rRNA gene clone analysis over different seasons. Bacteroidetes, Proteobacteria, and unclassifiable bacteria were the three major bacterial groups within the clone library (a total of 290 clones). A significant portion of the total clones (29.3%) was not affiliated to any previously reported phylum, and 55.3% of the unclassifiable clones (16.9% of the total clones) showed potential relations to the species of Thermotogae, rarely present under normal mesophilic anaerobic conditions. These results suggested that the novel populations may have the potential to play an important role in anaerobic processes, particularly under abnormal environmental conditions. Additionally, statistical analysis supported that seasonal variations in influent characteristics, and potential competitions among different populations, may be related to the unusual bacterial diversity and community dynamics observed over the study period.


Subject(s)
Bacteria/isolation & purification , Seawater/analysis , Sewage/microbiology , Bacteria/classification , Bacteria/genetics , Molecular Sequence Data , Phylogeny , Seasons
18.
Bioresour Technol ; 100(3): 1100-7, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18793833

ABSTRACT

A polyurethane packed-bed-biofilm sequential batch reactor was fed with synthetic substrate simulating the composition of UASB reactor effluents. Two distinct ammonia nitrogen concentrations (125 and 250 mg l(-1)) were supplied during two sequential long-term experiments of 160 days each (320 total). Cycles of 24h under intermittent aeration for periods of 1h were applied, and ethanol was added as a carbon source at the beginning of each anoxic period. Nitrite was the main oxidized nitrogen compound which accumulated only during the aerated phases of the batch cycle. A consistent decrease of nitrite concentration started always immediately after the interruption of oxygen supply and addition of the electron donor. Removal to below detection limits of all nitrogen soluble forms was always observed at the end of the 24h cycles for both initial concentrations. Polyurethane packed-bed matrices and ethanol amendments conferred high process stability. Microbial investigation by cloning suggested that nitrification was carried out by Nitrosomonas-like species whereas denitrification was mediated by unclassified species commonly observed in denitrifying environments. The packed-bed batch bioreactor favored the simultaneous colonization of distinct microbial groups within the immobilized microbial biomass. The biofilm was capable of actively oxidizing ammonium and denitrification at high ratios in intermittent intervals within 24h cycles.


Subject(s)
Bioreactors/microbiology , Nitrates/metabolism , Nitrites/metabolism , Quaternary Ammonium Compounds/metabolism , Sewage/microbiology , Water Pollutants, Chemical/metabolism , Water Purification/methods , Nitrates/isolation & purification , Nitrites/isolation & purification , Quaternary Ammonium Compounds/isolation & purification , Water Pollutants, Chemical/isolation & purification
19.
J Hazard Mater ; 139(2): 301-9, 2007 Jan 10.
Article in English | MEDLINE | ID: mdl-16872740

ABSTRACT

A horizontal-flow anaerobic immobilized biomass reactor (HAIB) containing denitrifying biomass was evaluated with respect to its ability to remove, separately and in a short operating period (30 days), organic matter, nitrate, and the hydrocarbons benzene (41.4 mg L-1), toluene (27.8 mg L-1), ethylbenzene (31.1 mg L-1), o-xylene (28.5 mg L-1), m-xylene (28.4 mg L-1) and p-xylene (32.1 mg L-1). The purified culture, which was grown in the presence of the specific hydrocarbon, was used as the source of cells to be immobilized in the polyurethane foam. After 30 days of operation, the foam was removed and a new immobilized biomass was grown in the presence of another hydrocarbon. The average hydrocarbon removal efficiency attained was 97%. The organic matter, especially ethanol, was removed with an average efficiency of 83% at a mean influent concentration of 1185.0 mg L-1. A concomitant removal of 97% of nitrate was observed for a mean influent concentration of 423.4 mg L-1. The independent removal of each hydrocarbon demonstrated that these contaminants can be biodegraded separately, without the need for a compound to be the primary substrate for the degradation of another. This study proposes the application of the system for treatment of areas contaminated with these compounds, with substitution and formation of a biofilm in a 30-day period.


Subject(s)
Bioreactors/microbiology , Ethanol/metabolism , Hydrocarbons, Aromatic/metabolism , Water Purification/instrumentation , Water Purification/methods , Anaerobiosis , Biodegradation, Environmental , Cells, Immobilized/metabolism , Paracoccus/growth & development , Paracoccus/isolation & purification , Paracoccus/ultrastructure , Pseudomonas/growth & development , Pseudomonas/isolation & purification , Pseudomonas/ultrastructure
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