ABSTRACT
The importance and protection of mangrove ecosystems has been recognized in Brazilian Federal law since 1965. Being protected in law, however, has not always guaranteed their protection in practice. Mangroves are found in coastal and estuarine locations, which are prime real estate for the growth of cities, ports and other economic activities important for Brazilian development. In this mini-review we introduce what mangroves are and why they are so important. We give a brief overview of the microbial diversity found in mangrove sediments and then focus on diversity studies from Brazilian mangroves. We highlight the breadth and depth of knowledge about mangrove microbial communities gained from studying Brazilian mangroves. We report on the exciting findings of molecular microbial ecology methods that have been very successfully applied to study bacterial communities. We note that there have been fewer studies that focus on fungal communities and that fungal diversity studies deserve more attention. The review ends with a look at how a combination of new molecular biology methods and isolation studies are being developed to monitor and conserve mangrove ecosystems and their associated microbial communities. These recent studies are having a global impact and we hope they will help to protect and re-establish mangrove ecosystems.
Subject(s)
Humans , Biodiversity , Coasts/legislation & jurisprudence , Ecosystem , Legislation, Environmental , Wetlands/legislation & jurisprudence , Ecology , Methodology as a Subject , NatureABSTRACT
Thirty water samples were collected, at two week intervals, from the estuary of the River Cocó. The aim was to characterize the presence, distribution and types of Aeromonas spp, in the estuary of the River Cocó, Ceara, Brazil (03º46'28.83''S e 38º26'36.52''S). Aeromonas were identified in 19 (63 percent) samples analyzed by plating and CFU counts. Presence/absence tests were positive for 11 (37 percent) of the samples resulting in the detection of Aeromonas in a total of 23 (77 percent) of samples. CFU counts varied from < 10 to 1.4 x 10(4) CFU mL-1 . From the isolated strains seven species of Aeromonas were identified: A. caviae (29/69), A. veronii bv. sobria (13/69), A. veronii bv. veronii (8/69), A. trota (6/69), A. media (5/69), A. sobria (4/69) and A. hydrophila and Aeromonas sp. (2/69). Of the 38 strains tested, 23 (60 percent) showed resistance to at least one of the eight antimicrobials. Multiple resistance to antibiotics was observed in A. caviae, A. media, A. sóbria and A. veronii bv. sobria. Aeromonas caviae showed the highest multiple resistance, being resistant to four antibiotics. The presence of those microorganisms may contribute to the occurrence of gastroenteritis, mainly in children, since they are considered opportunists.
Subject(s)
Humans , Child , Anti-Bacterial Agents , Aeromonas/isolation & purification , Drug Resistance, Microbial , Estuaries , Gram-Negative Bacterial Infections , Water Microbiology , Bacteriological Techniques , Methods , Water SamplesABSTRACT
The aims of this study were to count and identify sucrose positive and negative vibrios isolated from cultivated Crassostrea rhizophorae oysters during their growing cycle. Every month for 12 months, 10 to 18 oysters were collected for study. Collections occurred at the Center for Studies of Coastal Aquaculture (CSCA), which is associated with the Institute of Marine Science, Labomar, located in Euzebio, Ceará, Brazil. Approximately 150 oysters and their intervalvular liquor were studied. Vibrio Standard Plates Counts (SPC) from oyster meat and their intervalvular liquor varied from 25 to 59,000,000 CFU/g. For most of the 12 months of the oysters' life, it was possible to identify Vibrio parahaemolyticus. Vibrio carchariae was identified in four collections. Among other isolated species, the most important, considering public health risks, was V. vulnificus, although only one strain was confirmed. We concluded that retail purchased oysters should never be eaten raw or undercooked because many species of the genus Vibrio are known to be pathogenic to humans and live naturally on and in shellfish throughout their life cycle.
Subject(s)
Animals , Crassostrea/microbiology , Shellfish/microbiology , Vibrio/isolation & purification , Vibrio/classificationABSTRACT
Fruit and soil yeasts isolated from the Amazon, Atlantic Rainforests and an organic farm were screened for killer activity against yeasts. Killer yeasts were then tested against the phytopathogen Moniliophthora perniciosa (syn. Crinipellis perniciosa) and a Dipodascus capitatus strain and a Candida sp strain inhibited its growth.
Leveduras de frutas e de solo isoladas da Floresta Amazônica, Mata Atlântica e de uma fazenda orgânica foram selecionadas em uma triagem para atividade micocinogênica. As estirpes micocinogênicas foram posteriormente testadas frente a Moniliophthora perniciosa (syn. Crinipellis perniciosa). Uma estirpe de Dipodascus capitatus e outra de Candida sp.inibiram o crescimento deste fitopatógeno.
Subject(s)
Fruit/growth & development , Fruit/microbiology , Fungi/genetics , Fungi/isolation & purification , In Vitro Techniques , Yeasts/genetics , Yeasts/isolation & purification , Soil Microbiology , Methods , Methods , VirulenceABSTRACT
Guava leaf tea of Psidium guajava Linnaeus is commonly used as a medicine against gastroenteritis and child diarrhea by those who cannot afford or do not have access to antibiotics. This study screened the antimicrobial effect of essential oils and methanol, hexane, ethyl acetate extracts from guava leaves. The extracts were tested against diarrhea-causing bacteria: Staphylococcus aureus, Salmonella spp. and Escherichia coli. Strains that were screened included isolates from seabob shrimp, Xiphopenaeus kroyeri (Heller) and laboratory-type strains. Of the bacteria tested, Staphylococcus aureus strains were most inhibited by the extracts. The methanol extract showed greatest bacterial inhibition. No statistically significant differences were observed between the tested extract concentrations and their effect. The essential oil extract showed inhibitory activity against S. aureus and Salmonella spp. The strains isolated from the shrimp showed some resistance to commercially available antibiotics. These data support the use of guava leaf-made medicines in diarrhea cases where access to commercial antibiotics is restricted. In conclusion, guava leaf extracts and essential oil are very active against S. aureus, thus making up important potential sources of new antimicrobial compounds.
O chá de folhas de goiaba Psidium guajava Linnaeus é comumente usado como remédio nas gastrenterites e diarréias infantis por aqueles que não têm acesso a antibióticos. Esta pesquisa estudou o efeito antibacteriano sobre bactérias causadoras de diarréias, do óleo essencial e do extrato de folhas de goiabeira usando como diluente: metanol, hexano e acetato de etila. Os extratos foram testados sobre Staphylococcus aureus, Salmonella spp. e Escherichia coli. As bactérias testadas foram isoladas de camarão sete-barbas Xiphopenaeus kroyeri (Heller) usando-se como controle cepas padrão, de cada espécie. Das bactérias testadas, o melhor efeito inibitório foi observado sobre Staphylococcus aureus. O extrato de metanol apresentou maior inibição bacteriana. O óleo essencial mostrou ação inibitória contra S. aureus e Salmonella spp. Foi demonstrada alguma resistência das cepas isoladas de camarão aos antibióticos comerciais testados. Estes dados confirmam que remédios à base de folhas de goiabeira podem ser utilizados em casos de diarréia provocada por essas bactérias, quando o uso de antibiótico for restrito. Conclui-se que extratos de folhas de goiaba e o seu óleo essencial são muito ativos contra S. aureus, tornando-os importantes fontes em potencial de novos compostos antimicrobianos.
Subject(s)
Animals , Humans , Anti-Bacterial Agents/pharmacology , Escherichia coli/drug effects , Penaeidae/microbiology , Psidium/chemistry , Salmonella/drug effects , Staphylococcus aureus/drug effects , Anti-Bacterial Agents/isolation & purification , Microbial Sensitivity Tests , Plant Extracts/pharmacology , Plant Leaves/chemistry , Plant Oils/pharmacologyABSTRACT
Seventeen months after a 1,3 million L oil spill into Guanabara Bay, analyses of mangrove sediments showed that the three sites closest to the spill remain highly polluted (>10 µg-g-1 polyaromatic hydrocarbons). A fourth site was less polluted, from which most hydrocarbon degrading bacteria were isolated.
Dezessete meses após um derramamento de 1,3 milhões de litros de óleo na Baía de Guanabara, análises de sedimento do manguezal mostraram que os três pontos de amostragem mais próximos do local do acidente permanecem altamente poluídos (>10 µg-g-1 hidrocarbonetos poliaromáticos). Do quarto ponto de amostragem, o menos poluído, foi isolada a maioria das bactérias degradadoras de hidrocarbonetos.
Subject(s)
Bacteria/isolation & purification , Coastal Lagoon , Hazardous Materials Spill , In Vitro Techniques , Wetlands , Oils , Biodegradation, Environmental , Methods , Water SamplesABSTRACT
New and exciting molecular methods, many using the 16S small sub-unit ribosomal nucleic acid molecule, are opening the microbial "black box" in soil. These studies have added much to our knowlodge of microbial diversity in soils, and are beginning to advance our understanding of the relationship between this diversity and its function in soil processes. Over the next few years, the knowlodge gained from molecular studies will, we hope, lead to improvements in sustainable land management and sustainable exploitation of soil genetic resources. As we enter the third millenium, it is appropriate to review the application of 16S rDNA methods to soil microbiology. This review examines 16S ribosomal DNA (rDNA) methods and their application to soil. It mentions their limits and suggests how they may be applied in the future.