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1.
Biol. Res ; 52: 5, 2019. tab, graf
Article in English | LILACS | ID: biblio-1011408

ABSTRACT

BACKGROUND: A moderately thermophilic, slightly halophilic, aerobic, Gram-stain negative, bacterial strain, SLM16, was isolated from a mixed of seawater-sand-sediment sample collected from a coastal fumarole located in Whalers Bay, Deception Island, Antarctica. The aim was to screen for thermophilic microorganisms able to degrade primary amines and search for amine transaminase activity for potential industrial application. RESULTS: Identification and partial characterization of the microorganism SLM16 were carried out by means of morphological, physiological and biochemical tests along with molecular methods. Cells of strain SLM16 were non-motile irregular rods of 1.5-2.5 µm long and 0.3-0.45 µm wide. Growth occurred in the presence of 0.5-5.5% NaCl within temperature range of 35-55 °C and pH range of 5.5-9.5, respectively. The DNA G+C composition, estimated from ftsY gene, was 66% mol. Phylogenetic analysis using de 16S rRNA gene sequence showed that strain SLM16 belongs to the marine bacterial genus Albidovulum. CONCLUSION: Strain SLM16 is a moderate thermophilic Gram negative microorganisms which belongs to the marine bacterial genus Albidovulum and is closely related to Albidovulum inexpectatum species based on phylogenetic analysis. Additionally, amine-transaminase activity towards the arylaliphatic amine α-methylbenzylamine was detected.


Subject(s)
Seawater/microbiology , DNA, Bacterial/genetics , Rhodobacteraceae/isolation & purification , Rhodobacteraceae/enzymology , Transaminases/metabolism , Phylogeny , RNA, Ribosomal, 16S/genetics , Bacterial Typing Techniques , Sequence Analysis, DNA , Rhodobacteraceae/classification , Antarctic Regions
2.
Braz. j. microbiol ; 49(4): 749-756, Oct.-Dec. 2018. tab, graf
Article in English | LILACS | ID: biblio-974295

ABSTRACT

ABSTRACT Pyrene and benzo[a]pyrene (BaP) are high molecular weight polycyclic aromatic hydrocarbons (PAHs) recalcitrant to microbial attack. Although studies related to the microbial degradation of PAHs have been carried out in the last decades, little is known about degradation of these environmental pollutants by fungi from marine origin. Therefore, this study aimed to select one PAHs degrader among three marine-derived basidiomycete fungi and to study its pyrene detoxification/degradation. Marasmiellus sp. CBMAI 1062 showed higher levels of pyrene and BaP degradation and was subjected to studies related to pyrene degradation optimization using experimental design, acute toxicity, organic carbon removal (TOC), and metabolite evaluation. The experimental design resulted in an efficient pyrene degradation, reducing the experiment time while the PAH concentration applied in the assays was increased. The selected fungus was able to degrade almost 100% of pyrene (0.08 mg mL-1) after 48 h of incubation under saline condition, without generating toxic compounds and with a TOC reduction of 17%. Intermediate metabolites of pyrene degradation were identified, suggesting that the fungus degraded the compound via the cytochrome P450 system and epoxide hydrolases. These results highlight the relevance of marine-derived fungi in the field of PAH bioremediation, adding value to the blue biotechnology.


Subject(s)
Polycyclic Aromatic Hydrocarbons/metabolism , Seawater/microbiology , Basidiomycota/metabolism , Phylogeny , Polycyclic Aromatic Hydrocarbons/chemistry , Pyrenes/metabolism , Pyrenes/chemistry , Basidiomycota/isolation & purification , Basidiomycota/classification , Basidiomycota/genetics , Benzo(a)pyrene/metabolism , Benzo(a)pyrene/chemistry , Biodegradation, Environmental , Fungal Proteins/genetics , Fungal Proteins/metabolism , Cytochrome P-450 Enzyme System/genetics , Cytochrome P-450 Enzyme System/metabolism
3.
Electron. j. biotechnol ; 33: 17-28, May. 2018. ilus, tab
Article in English | LILACS | ID: biblio-1025039

ABSTRACT

Genetic manipulation of bacteria is a procedure necessary to obtain new strains that express peculiar and defined genetic determinants or to introduce genetic variants responsible for phenotypic modifications. This procedure can be applied to explore the biotechnological potential associated with environmental bacteria and to utilize the functional properties of specific genes when inserted into an appropriate host. In the past years, marine bacteria have received increasing attention because they represent a fascinating reservoir of genetic and functional diversity that can be utilized to fuel the bioeconomy sector. However, there is an urgent need for an in-depth investigation and improvement of the genetic manipulation tools applicable to marine strains because of the paucity of knowledge regarding this. This review aims to describe the genetic manipulation methods hitherto used in marine bacteria, thus highlighting the limiting factors of the different techniques available today to increase manipulation efficiency. In particular, we focus on methods of natural and artificial transformations (especially electroporation) and conjugation because they have been successfully applied to several marine strains. Finally, we emphasize that, to avoid failure, future work should be carried out to establish tailored methodologies for marine bacteria.


Subject(s)
Seawater/microbiology , Bacteria/genetics , Genetic Engineering , Transformation, Bacterial , Genome , Electroporation , Conjugation, Genetic , Metagenomics , Single-Cell Analysis , Genetic Vectors
4.
Braz. j. microbiol ; 49(1): 10-12, Jan.-Mar. 2018. tab
Article in English | LILACS | ID: biblio-889198

ABSTRACT

ABSTRACT Vitellibacter aquimaris D-24T (=KCTC 42708T = DSM 101732T), a halophilic marine bacterium, was isolated from seawater collected from Desaru beach, Malaysia. Here, we present the draft genome sequence of D-24T with a genome size of approximately 3.1 Mbp and G + C content of 39.93%. The genome of D-24T contains genes involved in reducing a potent greenhouse gas (N2O) in the environment and the degradation of proteinaceous compounds. Genome availability will provide insights into potential biotechnological and environmental applications of this bacterium.


Subject(s)
Seawater/microbiology , Genome, Bacterial , Flavobacteriaceae/genetics , Phylogeny , Base Composition , DNA, Bacterial/genetics , Molecular Sequence Data , Base Sequence , Flavobacteriaceae/isolation & purification , Flavobacteriaceae/classification , Malaysia
5.
Braz. j. microbiol ; 48(4): 671-679, Oct.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-889179

ABSTRACT

ABSTRACT Thraustochytrids are unicellular protists belonging to the Labyrinthulomycetes class, which are characterized by the presence of a high lipid content that could replace conventional fatty acids. They show a wide geographic distribution, however their diversity in the Antarctic Region is rather scarce. The analysis based on the complete sequence of 18S rRNA gene showed that strain 34-2 belongs to the species Thraustochytrium kinnei, with 99% identity. The total lipid profile shows a wide range of saturated fatty acids with abundance of palmitic acid (16:0), showing a range of 16.1-19.7%. On the other hand, long-chain polyunsaturated fatty acids, mainly docosahexaenoic acid and eicosapentaenoic acid are present in a range of 24-48% and 6.1-9.3%, respectively. All factors analyzed in cells (biomass, carbon consumption and lipid content) changed with variations of culture temperature (10 °C and 25 °C). The growth in glucose at a temperature of 10 °C presented the most favorable conditions to produce omega-3fatty acid. This research provides the identification and characterization of a Thraustochytrids strain, with a total lipid content that presents potential applications in the production of nutritional supplements and as well biofuels.


Subject(s)
Seawater/microbiology , Fatty Acids/metabolism , Stramenopiles/metabolism , Phylogeny , Biotechnology , Fatty Acids/chemistry , Stramenopiles/isolation & purification , Stramenopiles/classification , Stramenopiles/genetics , Antarctic Regions
6.
Electron. j. biotechnol ; 29: 13-21, sept. 2017. ilus, tab, graf
Article in English | LILACS | ID: biblio-1017057

ABSTRACT

Background: The past years have witnessed a growing number of researches in biofilm forming communities due to their environmental and maritime industrial implications. To gain a better understanding of the early bacterial biofilm community, microfiber nets were used as artificial substrates and incubated for a period of 24 h in Mauritian coastal waters. Next-generation sequencing technologies were employed as a tool for identification of early bacterial communities. Different genes associated with quorum sensing and cell motility were further investigated. Results: Proteobacteria were identified as the predominant bacterial microorganisms in the biofilm within the 24 h incubation, of which members affiliated to Gammaproteobacteria, Alphaproteobacteria and Betaproteobacteria were among the most abundant classes. The biofilm community patterns were also driven by phyla such as Firmicutes, Bacteroidetes, Chloroflexi, Actinobacteria and Verrucomicrobia. The functional analysis based on KEGG classification indicated high activities in carbohydrate, lipid and amino acids metabolism. Different genes encoding for luxI, lasI, agrC, flhA, cheA and cheB showed the involvement of microbial members in quorum sensing and cell motility. Conclusion: This study provides both an insight on the early bacterial biofilm forming community and the genes involved in quorum sensing and bacterial cell motility.


Subject(s)
Seawater/microbiology , Bacteria/growth & development , Bacteria/genetics , Bacterial Physiological Phenomena , Bacteria/isolation & purification , Bacteria/classification , Bacterial Adhesion , Cell Movement , Biofilms , Biodiversity , Quorum Sensing , Biofouling , Metagenomics , High-Throughput Nucleotide Sequencing , Mauritius
7.
Braz. j. microbiol ; 48(3): 393-394, July-Sept. 2017.
Article in English | LILACS | ID: biblio-889136

ABSTRACT

Abstract Dietzia sp. 111N12-1, isolated from the seawater of South China Sea, shows strong petroleum hydrocarbons degradation activity. Here, we report the draft sequence of approximately 3.7-Mbp genome of this strain. To the best of our knowledge, this is the first genome sequence of Dietzia strain isolated from the sea. The genome sequence may provide fundamental molecular information on elucidating the metabolic pathway of hydrocarbons degradation in this strain.


Subject(s)
Seawater/microbiology , Actinomycetales/isolation & purification , Actinomycetales/genetics , Genome, Bacterial , Hydrocarbons/metabolism , Phylogeny , Biodegradation, Environmental , Actinomycetales/classification , Actinomycetales/metabolism , Petroleum/metabolism , Base Sequence , China
8.
9.
Braz. j. microbiol ; 48(1): 37-42, Jan.-Mar. 2017. tab, graf
Article in English | LILACS | ID: biblio-839338

ABSTRACT

Abstract Quantification of bacteria being grazed by microzooplankton is gaining importance since they serve as energy subsidies for higher trophic levels which consequently influence fish production. Hence, grazing pressure on viable and non-viable fraction of free and particle-associated bacteria in a tropical estuary controlled mainly by protist grazers was estimated using the seawater dilution technique. In vitro incubations over a period of 42 h showed that at the end of 24 h, growth coefficient (k) of particle-associated bacteria was 9 times higher at 0.546 than that of free forms. Further, ‘k’ value of viable cells on particles was double that of free forms at 0.016 and 0.007, respectively. While bacteria associated with particles were grazed (coefficient of removal (g) = 0.564), the free forms were relatively less grazed indicating that particle-associated bacteria were exposed to grazers in these waters. Among the viable and non-viable forms, ‘g’ of non-viable fraction (particle-associated bacteria = 0.615, Free = 0.0086) was much greater than the viable fraction (particle-associated bacteria = 0.056, Free = 0.068). Thus, grazing on viable cells was relatively low in both the free and attached states. These observations suggest that non-viable forms of particle-associated bacteria were more prone to grazing and were weeded out leaving the viable cells to replenish the bacterial standing stock. Particle colonization could thus be a temporary refuge for the “persistent variants” where the viable fraction multiply and release their progeny.


Subject(s)
Bacteria , Ecosystem , Environmental Microbiology , Eukaryota , Seawater/microbiology , Water Microbiology , Biodiversity
10.
São Paulo; s.n; 2016. 147 p.
Thesis in Portuguese | LILACS | ID: biblio-868416

ABSTRACT

O uso das águas costeiras para fins recreacionais está associado com benefícios à saúde e bem-estar, todavia eventuais impactos negativos podem diminuir estes benefícios. Esses usos variam de acordo com o tipo de atividade desenvolvida, sendo que a recreação de contato primário requer contato direto e prolongado com a água, durante a qual pode ocorrer ingestão acidental. A Resolução CONAMA nº 274/2000 dispõe sobre os critérios de balneabilidade e reza que as condições da qualidade das águas recreacionais devem ser avaliadas através de indicadores microbiológicos de contaminação fecal, e ainda recomenda que seja realizada pesquisa de organismos patogênicos em praias sistematicamente impróprias. Dada a escassez de dados da ocorrência de patógenos em águas costeiras, no período de 2010 a 2012, a CETESB realizou o Estudo de microrganismos patogênicos nas praias do Litoral Paulista pesquisando enterovírus, adenovírus, vírus da hepatite A, Cryptosporidium sp e Giardia sp, no intuito de preencher esta lacuna e gerar dados primários. Assim, o objetivo deste trabalho foi estimar a probabilidade de infecção por Cryptosporidium sp e Giardia sp após exposição a águas recreacionais costeiras usando como ferramenta a Avaliação Quantitativa de Risco Microbiológico (AQRM), como também o risco de doença. As concentrações de (oo)cistos nas águas das praias são oriundas dos relatórios de Qualidade das Praias Litorâneas no Estado de São Paulo da CETESB dos anos de 2011 e 2012. Nesse período foram analisadas 203 amostras coletadas de 12 praias na 1ª fase e de cinco praias na 2ª fase para a pesquisa de ocorrência de (oo)cistos. As amostras de água foram coletadas na isóbata de um metro, com frequência mensal. Giardia sp foi o microrganismo mais frequente, presente em 43 por cento das amostras e Cryptosporidium sp em 13 por cento . O cenário de exposição considerou tipos de atividade, tipos de usuários (crianças, adultos e esportistas), concentração de (oo)cistos, volume de ingestão, duração e frequência da exposição. A probabilidade de infecção foi maior em praias com mais amostras positivas para oocistos e cistos, no grupo dos esportistas e para Giardia sp. Em alguns casos os valores de risco de doença ultrapassaram o risco tolerável pela U.S. EPA (2012) de 3,6 por cento casos de gastroenterite, assim como ultrapassaram os resultados de incidência acumulada encontradas por LAMPARELLI et al. (2015). Os resultados apontaram a necessidade de melhoria nos sistemas de tratamento de efluentes no Litoral Paulista. A AQRM é uma ferramenta capaz de estimar a probabilidade de infecção no cenário das águas recreacionais e pode auxiliar no gerenciamento dos riscos


The use of coastal water for recreational purposes has been associated with benefits to health and well-being; however some negative impacts can diminish such benefits. The usages can vary according to the type of activity but the primary contact demands physical contact resulting in a high probability in accidental ingestion of water. Brazilian legislation for coastal recreational waters CONAMA 274/2000 establishes criteria for fecal indicator bacteria and furthermore recommends investigation of pathogenic organisms for beaches which classification is systematically as improper. Given the scarcity of data referring to pathogenic presence in beaches´ waters, CETESB carried out a study, in 2010 and 2012, for quantifying enterovirus, adenovirus, hepatitis A virus, Cryptosporidium sp and Giardia sp in coastal waters of São Paulo state in order to obtain data about their occurrence of these pathogens in coastal waters. The objective of this study was to estimate the annual risk of infection and disease for Giardia sp and Cryptosporidium sp by ingestion of water during primary contact recreation using QMRA approach. Concentrations of both parasites were taken from the annual report entitled Quality of coastal beaches in São Paulo state by CETESB (2011 and 2012). In these years were analyzed 203 samples of water for quantifying (oo)cysts of Giardia and Cryptosporidium from 12 beaches in the first year and five beaches in the second year of research. The samples were collected at one meter isobaths, with monthly frequency. Giardia was the most frequent parasite present in 43 per cent of samples and Cryptosporidium sp in 13 per cent . Exposure scenario was built considering types of activity, beach goers (children, adults and athletes), concentration of parasites, ingestion rate, duration and frequency of exposure. The probability of annual infection was higher in beaches in which there were more positive results for parasites for athletes and for Giardia infection. The tolerable risk for gastroenteritis by USEPA, which is 3.6 per cent , was overpassed in some cases. Though the results found in this study overpassed the cumulative incidence reported by LAMPARELLI et al. (2015). The results indicate the need for improvements in wastewater treatment systems in the coastal area of São Paulo. As QMRA is a tool capable in estimating the probability of infection it can help to highlight crucial issues in risk management


Subject(s)
Cryptosporidium/pathogenicity , Drinking , Giardia/pathogenicity , Recreational Water , Risk Assessment , Seawater/microbiology , Communicable Diseases/transmission , Microbiology
11.
Clin. biomed. res ; 36(3): 165-167, 2016. ilus
Article in English | LILACS | ID: biblio-831723

ABSTRACT

Vibrio vulnificus is a bacterium present in natural marine environments that causes infections in immunocompromised people. Sepsis in humans caused by this microorganism is usually accompanied by bullous skin lesions. In the present study we report a case of infection caused by this bacterium affecting a diabetic man, 74 years old, who fell overboard and hurt his leg. The identification of the V. vulnificus was made in the blood culture sample. This is the first report of isolation of V. vulnificus in Santa Catarina, Brazil, showing the dissemination of this bacterium in warm seawater over the world (AU)


Vibrio vulnificus é uma bactéria que se desenvolve em ambientes marinhos naturais e causa infecção em pessoas imunocomprometidas. Sepse em humanos causada por esse microrganismo é geralmente acompanhada por lesões bolhosas da pele. Relatamos um caso de infecção causada por esta bactéria que afetou um homem diabético, de 74 anos, que caiu ao mar e machucou a perna. A identificação do V. vulnificus foi feita na amostra de hemocultura. Este é o primeiro relato de isolamento de V. vulnificus em Santa Catarina, Brasil, elucidando a disseminação das bactérias de ambiente marítimo de água quente pelo mundo (AU)


Subject(s)
Humans , Aged , Vibrio Infections/microbiology , Vibrio vulnificus/isolation & purification , Brazil/epidemiology , Seawater/microbiology , Wound Infection/microbiology
12.
Braz. j. microbiol ; 46(4): 1019-1026, Oct.-Dec. 2015. graf
Article in English | LILACS | ID: lil-769652

ABSTRACT

Recreational water quality is commonly assessed by microbial indicators such as fecal coliforms. Maceió is the capital of Alagoas state, located in tropical northeastern Brazil. Its beaches are considered as the most beautiful urban beaches in the country. Jatiúca Beach in Maceió was found to be unsuitable for bathing continuously during the year of 2011. The same level of contamination was not observed in surrounding beaches. The aim of this study was to initiate the search for the sources of these high coliform levels, so that contamination can be eventually mitigated. We performed a retrospective analysis of historical results of fecal coliform concentrations from 2006 to 2012 at five monitoring stations located in the study region. Results showed that Jatiúca Beach consistently presented the worst quality among the studied beaches. A field survey was conducted to identify existing point and non-point sources of pollution in the area. Monitoring in the vicinity of Jatiúca was spatially intensified. Fecal coliform concentrations were categorized according to tide range and tide stage. A storm drain located in northern Jatiúca was identified as the main point source of the contamination. However, fecal coliform concentrations at Jatiúca were high during high tides and spring tides even when this point source was inactive (no rainfall). We hypothesize that high fecal coliform levels in Jatiúca Beach may also be caused by aquifer contamination or, more likely, from tide washing of contaminated sand. Both of these hypotheses will be further investigated.


Subject(s)
Bacteria/chemistry , Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/microbiology , Brazil/chemistry , Brazil/classification , Brazil/genetics , Brazil/isolation & purification , Brazil/microbiology , Environmental Monitoring/chemistry , Environmental Monitoring/classification , Environmental Monitoring/genetics , Environmental Monitoring/isolation & purification , Environmental Monitoring/microbiology , Feces/chemistry , Feces/classification , Feces/genetics , Feces/isolation & purification , Feces/microbiology , Recreation/chemistry , Recreation/classification , Recreation/genetics , Recreation/isolation & purification , Recreation/microbiology , Retrospective Studies/chemistry , Retrospective Studies/classification , Retrospective Studies/genetics , Retrospective Studies/isolation & purification , Retrospective Studies/microbiology , Seasons/chemistry , Seasons/classification , Seasons/genetics , Seasons/isolation & purification , Seasons/microbiology , Seawater/chemistry , Seawater/classification , Seawater/genetics , Seawater/isolation & purification , Seawater/microbiology , Water Pollution/chemistry , Water Pollution/classification , Water Pollution/genetics , Water Pollution/isolation & purification , Water Pollution/microbiology
13.
Braz. j. microbiol ; 46(2): 377-387, Apr-Jun/2015. tab, graf
Article in English | LILACS | ID: lil-749728

ABSTRACT

Three bacterial isolates identified as Alcanivorax borkumensis SK2, Rhodococcus erythropolis HS4 and Pseudomonas stutzeri SDM, based on 16S rRNA gene sequences, were isolated from crude oil enrichments of natural seawater. Single strains and four bacterial consortia designed by mixing the single bacterial cultures respectively in the following ratios: (Alcanivorax: Pseudomonas, 1:1), (Alcanivorax: Rhodococcus, 1:1), (Pseudomonas: Rhodococcus, 1:1), and (Alcanivorax: Pseudomonas: Rhodococcus, 1:1:1), were analyzed in order to evaluate their oil degrading capability. All experiments were carried out in microcosms systems containing seawater (with and without addition of inorganic nutrients) and crude oil (unique carbon source). Measures of total and live bacterial abundance, Card-FISH and quali-, quantitative analysis of hydrocarbons (GC-FID) were carried out in order to elucidate the co-operative action of mixed microbial populations in the process of biodegradation of crude oil. All data obtained confirmed the fundamental role of bacteria belonging to Alcanivorax genus in the degradation of linear hydrocarbons in oil polluted environments.


Subject(s)
Alcanivoraceae/metabolism , Petroleum/metabolism , Pseudomonas stutzeri/metabolism , Rhodococcus/metabolism , Alcanivoraceae/classification , Alcanivoraceae/genetics , Alcanivoraceae/isolation & purification , Biotransformation , Cluster Analysis , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Microbial Consortia , Molecular Sequence Data , Phylogeny , Pseudomonas stutzeri/classification , Pseudomonas stutzeri/genetics , Pseudomonas stutzeri/isolation & purification , /genetics , Rhodococcus/classification , Rhodococcus/genetics , Rhodococcus/isolation & purification , Sequence Analysis, DNA , Seawater/microbiology
14.
Rev. argent. microbiol ; 46(3): 218-230, oct. 2014. ilus, tab
Article in English | LILACS | ID: lil-734583

ABSTRACT

.


Bacterial richness in maritime Antarctica has been poorly described to date. Phylogenetic affiliation of seawater free-living microbial assemblages was studied from three locations near the Argentinean Jubany Station during two Antarctic summers. Sixty 16S RNA cloned sequences were phylogenetically affiliated to Alphaproteobacteria (30/60 clones), Gammaproteobacteria(19/60 clones), Betaproteobacteria and Cytophaga-Flavobacteriia- Bacteroides (CFB), which were (2/60) and (3/60) respectively. Furthermore, six out of 60 clones could not be classified. Both, Alphaproteobacteria and Gammaproteobacteria, showed several endemic and previously undescribed sequences. Moreover, the absence of Cyanobacteria sequences in our samples is remarkable. In conclusion, we are reporting a rich sequence assemblage composed of widely divergent isolates among themselves and distant from the most closely related sequences currently deposited in data banks.


Subject(s)
Bacteria/isolation & purification , Seawater/microbiology , Antarctic Regions , Base Sequence , Bacteria/classification , Bacteria/genetics , DNA, Bacterial/genetics , DNA, Ribosomal/genetics , Evolution, Molecular , Microbiota , Molecular Sequence Data , Phylogeny , Ribotyping , RNA, Bacterial/genetics , /genetics
15.
Article in English | IMSEAR | ID: sea-163213

ABSTRACT

Aim: We report antimicrobial activities of bacteria associated with 10 native and one invasive species of seaweeds on par with bacteria found in the seawater and sediment. Bacteria exhibiting antimicrobial activity were phylogenetically analysed using 16S rRNA gene. Place and Duration of Study: Samples of seaweeds, seawater and sediments collected at 6 localities of south east coast of India between December 2009 and January 2010 during monsoon season. Methodology: Culturable bacteria in seaweeds (epibiotics and endobiotics), seawater and sediments were isolated through serial dilutions using 1.5% ZoBell marine agar (HiMedia, India). Bacterial isolates producing antibiotics were identified by screening against commercial antibiotics and they were subjected to morphological, Gram’s staining and biochemical studies. Chemical property and stability of antimicrobial substances obtained from the promising bacteria active against plant pathogens were studied. Phylogenetic analysis of antibiotics-producing marine bacteria was made using 16S rRNA gene sequencing technique. Results: A number of673 isolates obtained through the isolation process were found to be the member of 27 bacterial genera, with species of Bacillus recording a maximum of 40.2%. Generally species of bacterial isolates in the association (seaweeds: epibiotics, 39.54% and endobiotics, 40.74%, seawater 8.61% and sediments 11.11%) produced antibiotics and active against plant pathogens (Xanthomonas axonopodis pv. citri, X. oryzaepv. oryzae and Ustilaginoidea virens) were associated with seaweeds (epibiotics 33.46% and endobiotics 43.11%) and sediments (23.43%). Extracellular components of active bacteria are proteins and retaining bioactivity at pH 7.0, up to 40°C and antifungal property up to 60°C. Extracts obtained from the active bacteria are nonpolar lipophilic substances exhibited only antifungal activity. Conclusion: Bacterial population were considerably higher in seaweeds as compared to seawater and sediments, and at the same time higher bacterial population was recorded in Gulf samples than the open coast samples. Most of the bacterial isolates associated with seaweeds were found to produce antibiotics.


Subject(s)
Bacteria/isolation & purification , Bacteria/microbiology , Geologic Sediments/microbiology , Microbial Sensitivity Tests , Phylogeny , Plants/microbiology , Seaweed/microbiology , Seawater/microbiology , Xenobiotics
16.
Rev. Soc. Bras. Med. Trop ; 47(3): 327-333, May-Jun/2014. tab, graf
Article in English | LILACS | ID: lil-716393

ABSTRACT

Introduction This research aimed to identify and quantify potentially pathogenic Vibrio from different cultivations of bivalve shellfish in the State of Santa Catarina, Brazil, and water regions in the South Bay, as well as correlate the incidence of these microorganisms with the physicochemical parameters of marine waters. Methods Between October 2008 and March 2009, 60 oyster and seawater samples were collected from six regions of bivalve mollusk cultivation, and these samples were submitted for Vibrio counts. Results Twenty-nine (48.3%) oyster samples were revealed to be contaminated with one or more Vibrio species. The Vibrio parahaemolyticus and Vibrio vulnificus counts in the samples ranged from < 0.5 log10 Most Probable Number (MPN) g–1 to 2.3 log10 MPN g–1 oyster and from < 0.5 log10 MPN g–1 to 2.1 log10 MPN g–1 oyster, respectively. Of the 60 seawater samples analyzed, 44 (73.3%) showed signs of contamination with one or more vibrio species. The counts of V. parahaemolyticus and V. vulnificus in the samples ranged from < 0.3 log10 MPN·100mL–1 to 1.7 log10MPN·100mL–1 seawater and from < 0.3 log10 MPN·100mL–1 to 2.0 log10 MPN·100mL–1 seawater, respectively. A positive correlation between V. vulnificus counts and the seawater temperature as well as a negative correlation between the V. parahaemolyticus counts and salinity were observed. Conclusions The results suggest the need to implement strategies to prevent vibrio diseases from being transmitted by the consumption of contaminated bivalve shellfish. .


Subject(s)
Animals , Crassostrea/microbiology , Food Microbiology , Seawater/microbiology , Shellfish/microbiology , Vibrio/isolation & purification , Aquaculture , Brazil , Temperature , Vibrio/classification , Vibrio/pathogenicity
17.
Braz. j. microbiol ; 44(4): 1349-1357, Oct.-Dec. 2013. graf, mapas, tab
Article in English | LILACS | ID: lil-705279

ABSTRACT

Arraial do Cabo is where upwelling occurs more intensively on the Brazilian coast. Although it is a protection area it suffers anthropogenic pressure such as harbor activities and sporadic sewage emissions. Short-time studies showed a high variability of bacterial production (BP) in this region but none of them evaluated BP during long periods in a large spatial scale including stations under different natural (upwelling and cold fronts) and anthropogenic pressures. During 2006, we sampled surface waters 10 times (5 in upwelling and 5 in subsidence periods) in 8 stations and we measured BP, temperature as well as the concentrations of inorganic nutrients, pigments and particulate organic matter (POM). BP was up to 400 times higher when sewage emissions were observed visually and it had a positive correlation with ammonia concentrations. Therefore, in 2007, we did two samples (each during upwelling and subsidence periods) during sewage emissions in five stations under different anthropogenic pressure and we also measured particles abundance by flow cytometry. The 12 samples in the most impacted area confirmed that BP was highest when ammonia was higher than 2 μM, also reporting the highest concentrations of chlorophyll a and suspended particles. However, considering all measured variables, upwelling was the main disturbing factor but the pressure of fronts should not be neglected since it had consequences in the auto-heterotrophic coupling, increasing the concentrations of non fluorescent particles and POM. Stations clustered in function of natural and anthropogenic pressures degrees and both determined the temporal-spatial variability.


Subject(s)
Bacteria/growth & development , Heterotrophic Processes , Seawater/microbiology , Brazil , Spatio-Temporal Analysis
18.
Electron. j. biotechnol ; 15(5): 18-18, Sept. 2012. ilus, tab
Article in English | LILACS | ID: lil-657677

ABSTRACT

Background: Cellulases and lipases have broad industrial application, which calls for an urgent exploration of microorganisms from extreme environments as valuable source of commercial enzyme. In this context, the present work describes the bioprospection and identification of deep-sea bacteria that produce cellulases and lipases, as well their optimal temperature of activity. Results: The first step of this study was the screening of cellulolytic and lipolytic deep-sea bacteria from sediment and water column, which was conducted with substrates linked with 4-Methylumbelliferyl. Among the 161 strains evaluated, 40 were cellulolytic, 23 were lipolytic and 5 exhibited both activities. Cellulolytic and lipolytic bacteria are more common in sediment than at the water column. Based on the ability to produce cellulases and lipases three isolates were selected and identified (16S rRNA sequencing) as Bacillus stratosphericus, B. aerophilus and B. pumilus. Lipases of strain B. aerophilus LAMA 582 exhibited activity at a wide temperature range (4º to 37ºC) and include psychrophilic behaviour. Strain Bacillus stratosphericus LAMA 585 can growth in a rich (Luria Bertani) and minimal (Marine Minimal) medium, and does not need an inducer to produce its mesophilic cellulases and lipases. Conclusions: Deep-sea sediments have great potential for bioprospection of cellulase and lipase-producing bacteria. The strains LAMA 582 and LAMA 585 with their special features, exhibit a great potential to application at many biotechnology process.


Subject(s)
Seawater/microbiology , Bacteria/enzymology , Cellulase , Lipase , Bioprospecting
19.
Rev. argent. microbiol ; 43(2): 107-110, jun. 2011. ilus, graf
Article in English | LILACS | ID: lil-634680

ABSTRACT

In this study, two halophilic bacterial strains isolated from saline habitats in Argentina grew in the presence of gas oil. They were identified as Halomonas spp. and Nesterenkonia sp. by 16S ribosomal RNA sequencing. Chemotaxis towards gas oil was observed in Halomonas spp. by using swimming assays.


En el presente trabajo se aislaron dos cepas bacterianas halofílicas a partir de muestras obtenidas en ambientes salinos de Argentina, que crecieron en presencia de gasoil como única fuente de carbono. Las cepas aisladas se identificaron como Halomonas spp. y Nesterenkonia sp. mediante secuenciación del gen del ARN ribosomal 16S. En ensayos de swimming, las cepas del genero Halomonas spp. mostraron una respuesta quimiotáctica hacia el gas oil.


Subject(s)
Chemotaxis/drug effects , Halomonas/drug effects , Micrococcaceae/drug effects , Petroleum , Argentina , Biodegradation, Environmental , Hydrocarbons , Halomonas/growth & development , Halomonas/isolation & purification , Micrococcaceae/growth & development , Micrococcaceae/isolation & purification , Ribotyping , Salt Tolerance , Species Specificity , Seawater/microbiology , Water Microbiology , Water Pollutants, Chemical
20.
Rev. peru. med. exp. salud publica ; 28(2): 237-246, jun. 2011. ilus, graf, mapas, tab
Article in Spanish | LILACS, LIPECS | ID: lil-596561

ABSTRACT

Objetivos. Determinar el potencial antimicrobiano de actinomicetos marinos frente a cepas S. aureus meticilino-resistentes (MRSA) y E. faecalis vancomicina-resistentes (VRE). Materiales y métodos. En dos medios de cultivo se sembraron 29 cepas de actinomicetos aislados de sedimento marino. Se evaluó la capacidad inhibitoria mediante pruebas de antagonismo in vitro para MRSA y VRE. Se procesó los extractos orgánicos de tres actinomicetos seleccionados para determinar la Concentración Mínima Inhibitoria (CMI) del compuesto activo. Resultados. La mayoría de los actinomicetos aislados correspondieron a un grupo homogéneo de blanco-grisáceos (62 por ciento) con buen nivel de crecimiento en agar marino. Los porcentajes inhibitorios fueron superiores a 85 por ciento para ambos patógenos con halos de inhibición mayores a 69 y 78 mm de diámetro para MRSA y VRE respectivamente. Los extractos diclorometánicos de tres de los actinomicetos aislados (I-400A, B1-T61, M10-77) mostraron gran potencial inhibitorio de ambos patógenos, siendo M10-77 la cepa de actinomiceto de mayor actividad antibiótica frente a S. aureus ATCC 43300 resistente a meticilina y E. faecalis ATCC 51299 resistente a vancomicina con una Concentración Mínima Inhibitoria (CMI) de 7,9 y 31,7 μg/ mL respectivamente. El análisis filogenético de la cepa M10- 77 presenta un 99 por ciento de similaridad con la especie marina Streptomyces erythrogriseus. Conclusiones. El sedimento marino de la costa central del Perú es fuente promisorio de cepas de actinomicetos con gran capacidad de producir compuestos bioactivos capaces de inhibir patógenos tipificados como multidrogo-resistentes tales como S. aureus meticilino resistentes y E. faecalis vancomicina resistentes.


Objectives. To determine the antimicrobial potential of marine actinomycetes against drug-resistant pathogens represented by strains of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). Materials and methods. Strains of actinomycetes (29) isolated from marine sediment were evaluated by their characteristics in two culture media and by testing their inhibitory capacity by in vitro antagonism against multi-drug resistant (MDR) pathogenic bacteria for MRSA and VRE. Organic extracts of 3 selected actinomicetes were processed to determine the minimum inhibitory concentration (MIC) of the active compound. Results. Most isolated actinomycetes belong to a homogeneous group of write-gray actinomycetes with a good growth in Marine Agar. The inhibitory rates of the isolates were above 85 percent for both pathogens with inhibition zones greater than 69 and 78 mm in diameter for MRSA and VRE respectively. Dichloromethane extracts of 3 isolates (I-400A, B1-T61, M10-77) showed strong inhibitory activity of both pathogens, M10-77 being the highest actinomycete strain with antibiotic activity against methicillin-resistant S. aureus ATCC 43300 and vancomycin-resistant E. faecalis ATCC 51299 with a minimum inhibitory concentrations (MIC) of 7.9 and 31.7 μg/ml respectively. Phylogenetic analysis of M10-77 strain showed 99 percent similarity with the marine species Streptomyces erythrogriseus. Conclusions. Marine sediments of the central coast of Peru, are a source of actinomycetes strains showing high capacity to produce bioactive compounds able to inhibit pathogens classified as multi-drugresistant such as methicillin-resistant S. aureus and vancomycin-resistant E. faecalis.


Subject(s)
Actinobacteria/physiology , Antibiosis , Enterococcus faecalis , Methicillin-Resistant Staphylococcus aureus , Actinobacteria/isolation & purification , Enterococcus faecalis/drug effects , Geologic Sediments/microbiology , Peru , Seawater/microbiology , Vancomycin/pharmacology , Water Microbiology
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