15 research outputs found

    Microbiota de costões rochosos de Ubatuba (SP)

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    O biofilme do entremarés constitui-se de uma estrutura tridimensional, sendo composto, principalmente, por bactérias, cianobactérias, diatomáceas, protozoários e esporos de macroalgas, embebidos em uma matriz mucopolissacarídea. Neste sentido, o biofilme é importante fonte de alimento para algumas espécies, influenciando diretamente a estrutura da comunidade dos costões rochosos, embora tenha recebido pouca atenção pelas dificuldades associadas à sua amostragem e quantificação. O presente trabalho teve por objetivos avaliar a influência da contaminação orgânica sobre a composição e diversidade da microbiota (cianobactérias, bactérias heterotróficas) e do microfitoplâncton (diatomáceas e nanoheterótrofos) de costões rochosos com diferentes condições de impacto por efluentes orgânicos, bem como a sazonalidade das espécies microbianas predominantes em função da zonação (meso e infralitoral) e o grau de exposição às ondas (semi exposto e abrigado). Para tanto foram efetuadas coletas em 4 costões rochosos (2 semi expostos e 2 abrigados), no Município de Ubatuba (SP), com obtenção de três fragmentos rochosos de cada um, durante a maré baixa, em pontos georeferenciados nas duas faixas de zonação supracitadas, visando o isolamento e quantificação dos micro-organismos. As amostras destinadas à quantificação por epifluorescência foram acondicionadas em frascos com formaldeído a 5% de concentração final, para a fixação dos micro-organismos; enquanto aquelas destinadas ao isolamento foram colocadas em frascos com água do mar filtrada e esterilizada. Em cada ponto amostral foram registrados temperatura, oxigênio dissolvido (OD) e pigmento fotossintético (clorofila a). Os resultados obtidos sugerem que há diferenças tanto entre as praias analisadas quanto em relação aos parâmetros avaliados dentro de uma mesma praia, o que indica que, tanto a sazonalidade, quanto o efeito do impacto das ondas nos costões influenciam na estrutura da comunidade microbiana presente no seu biofilme havendo diferenças na predominância das espécies analisadas. A presença de micro-organismos indicadores de contaminação fecal, tanto na água quanto no biofilme das áreas amostradas sugere que há impacto por efluentes domésticos nas praias avaliadas e que o biofilme é um microambiente protetor para os micro-organismos nos sistemas entre-marés. Embora isto possa oferecer vantagens do ponto de vista produtivo do ecossistema, pode ser preocupante do ponto de vista da saúde pública e ambiental uma vez que acumulam também micro-organismos patogênicos e, à semelhança do que acontece em outros tipos de biofilmes, podem se transformar em potenciais fontes de contaminação do ambiente, da biota e de humanos. O presente estudo foi financiado pela FAPESP processo nº2011/27781-9Intertidal rocky shores biofilm is a tridimensional structure composed, mainly, by bacteria, cyanobacteria, diatoms, protozoans and macroalgae spores immersed in a mucopolysaccharides matrix. Thus, biofilm is an important food source for some species and has direct influence on the community structure of rocky shores although, due to difficulties in its sampling and quantification, has being given little attention. The present study aimed to evaluate the influence of organic contamination on biofilm composition and diversity of microbiota (cyanobacteria, heterotrophic bacteria) and microphytoplancton (diatoms and nanoheterotrophs) from rocky shores under different conditions as well as differences according to zonation (meso and infralittoral) and wave impacts (moderately exposed and sheltered). Therefore, 4 rocky shores from Ubatuba city (Sao Paulo, Brazil) were sampled during low tide, in georeferenced points from meso and infralittoral. Samples destined to quantification by epifluorescence were placed in vials with formaldehyde at 5% final concentration, for fixation of microorganisms while those intended for the isolation were placed in vials with sterile and filtered seawater. At each sampling point were recorded temperature, dissolved oxygen (DO) and photosynthetic pigment (chlorophyll a). The results suggest that there are differences between the analyzed beaches and in relation to the parameters assessed within a beach which indicates that both zonation and wave impact on rocky shores influence the structure of microbial community present in its biofilm. The presence of faecal indicators both in water and biofilm samples shows an impact by domestic effluents in the evaluated beaches and that biofilms can act as a protective microenvironment for microorganisms in intertidal systems. Although this may offer advantages for ecosystems productivity, it can be a problem for environment and public health since they can also accumulate pathogenic microorganisms and, similarly to what happens in other types of biofilms, can become potential sources of environment, biota and humans contamination. The present study was founded by FAPESP proc nº 2011/22781-9Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Utilização de parâmetros microbiológicos para avaliação do impacto da contaminação por petróleo e derivados em sedimentos marinhos. -

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    Os ecossistemas costeiros são considerados de grande importância sócio-econômica, política e cultural, pois possuem alta produtividade que suporta uma ampla gama de atividades econômicas e de lazer. Possuem elevado valor paisagístico, atraindo inúmeros habitantes e, assim, contribuem ao desenvolvimento das cidades litorâneas. Além disso, oferecem suporte às comunidades biológicas com manutenção de muitas espécies residentes ou que utilizam a zona costeira como berçário para reprodução, beneficiando a biodiversidade como um todo. Sendo uma região que sofre grande pressão antrópica, a Zona Costeira está sujeita a inúmeros impactos causados por atividades humanas, tais como as portuárias, industriais e de exploração de petróleo. Essas geram impactos por lançarem diversos poluentes, entre eles os hidrocarbonetos e metais que podem ter efeito deletério na biota local. No ambiente marinho, o compartimento mais afetado em relação a essa contaminação é o sedimento em função dos derivados de petróleo que atingem as águas costeiras possuírem maior densidade, nele se depositando. Atualmente existe uma grande preocupação com os impactos gerados por atividades antrópicas em ecossistemas litorâneos e muitos estudos têm sido feitos em busca de alternativas para avaliar e remediar tais impactos. Uma delas consiste no uso de micro-organismos tanto como indicadores da contaminação por poluentes quanto para a diminuição da contaminação, processo popularmente conhecido como biorremediação. Deste modo, o presente estudo teve como objetivos: 1) avaliar o efeito da presença de hidrocarbonetos na abundância de bactérias heterotróficas, cianobactérias e leveduras em sedimentos e águas estuarinas de duas regiões distintas, dos Estuários de Santos e do Rio Itanhaém, tanto no que diz respeito às características ambientais...Coastal ecosystems have great socio-economic, political and cultural importance, as well as high productivity which support a wide range of economic activities and leisure. They have high landscape value thus attracting numerous people contributing to the development of coastal cities. Moreover, its high productivity supports biological communities and maintenance of many species living or using the coastal zone as a nursery for breeding, benefiting whole biodiversity. Being a region that suffers high anthropogenic pressure, the Coastal Zone is subject to numerous impacts caused by human activities such as port activities, industrial and oil exploration. These generate impacts on the environment by launching several pollutants, including hydrocarbons and metals that can have deleterious effects on local biota. The most affected marine environment is the sediment due to oil products that reach coastal waters have a higher density and end up being deposited in sediments. Nowadays there is great concern about the impacts generated by human activities on coastal ecosystems and many studies have been done in search of alternatives to evaluate and remedy such impacts. One alternative is the use of micro-organisms both as indicators of contamination by pollutants and for reduction of contamination, a process popularly known as bioremediation. Thus, this study aimed to evaluate the effect of the presence of hydrocarbons in the abundance of heterotrophic bacteria, cyanobacteria and yeast on sediment and estuarine waters of two distinct regions: The Estuaries of Santos and Itanhaém River are located in the metropolitan area of Santos, Sao Paulo State; and to isolate microorganisms with emphasis on yeasts, for further evaluation of its potential both as bioindicators of hydrocarbon contamination and bioremediation of estuarine sediments in order to contribute... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Diversidade de microrganismos indicadores utilizados na avaliação da contaminação fecal de areias de praias recreacionais marinhas: Estado atual do conhecimento e perspectivas

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    Although the quality of sea recreational waters is already monitored by programs implanted in some Brazilian states, including the State São Paulo, little attention has been given to beach sands, which have been disregarded from the point of view of public health. However, this panorama is changing in recent years due to an increasing number of cases of mycoses and bacterial infections affecting people who frequent beaches and use sands as recreation places. This has caused greater concerns with the contamination of this environment, also measurable by the increase of the number of scientific works on sediments and recreational beach sands microbiota. Currently one knows that in general these sediments contain more microorganisms than the water and are therefore potential sources of contamination of human beings by pathogenic microorganisms. The results of works carried through in some countries are worrying, and have demonstrated the necessity of establishing standards and limits so that monitoring programs of the microbiological quality of beach sands are implanted. Such concern is especially high in Brazil, a country of a tropical climate where thousands of beaches, used for recreation, extend for almost eight thousand kilometers of the coast. In the context of Baixada Santista, studies carried through have shown that in certain situations beach sands can contain more microorganisms than waters and may be a risk to the health of users

    Densidade de Enterococcus sp em águas recreacionais e areias de praias do município de São Vicente-SP, Brasil e sua relação com parâmetros abióticos

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    Coastal cities attract a large number of tourists for their beautiful landscape and recreational activities, increasing the municipalities' income source. Thus, a need is clear for the establishment of beach quality monitoring programs to ensure bathers health. Although there is an effective monitoring program for recreational waters in Brazil there are no programs to certify the quality of beach sands. In this sense, the aim of this work was to analyze the density of bacteria from the genus Enterococcus in both sand and water from two beaches from São Vicente, São Paulo (Brazil) and correlate these densities to abiotic parameters such as: temperature, salinity, particle size, organic matter and tides). Water and sand samples were collected during February 2006 on the beaches of Gonzaguinha e Ilha Porchat and bacterial densities were determined by membrane filter technique. Temperature and salinity were measured in situ with a thermometer and a refractometer while particle size and organic matter were determined according to methods described by Suguio and Dean. There were significant differences between densities found in water and sand (p=0.004), being approximately 20 times higher in Gonzaguinha's beach sands. Similar results were found for Ilha Porchat beach samples, being the densities found in sand 3 times greater than those found in water. Both beaches showed a negative correlation between bacterial densities and salinity and temperature, suggesting a deleterious effect of these parameters on the bacterial community. On the other hand, no correlation was found between organic matter and particle size and bacterial densities. This work demonstrates that there is a great necessity for monitoring beach sand since the evaluation of beach quality is an important part of integrated coastal management programs

    Antimicrobial resistance of heterotrophic marine bacteria isolated from seawater and sands of recreational beaches with different organic pollution levels in southeastern Brazil: evidences of resistance dissemination

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    Antimicrobial resistance of marine heterotrophic bacteria to different antimicrobials agents were evaluated in seawater, dry and wet sands from three marine recreational beaches with different pollution levels. In all studied beaches, the greatest frequencies of resistance were found in relation to penicillin. on Gonzaguinha, the most polluted beach, 72.3% of all isolated strains showed simple resistance, whilst 8.33% had multiple resistance. The values found on Ilha Porchat beach, were 70.8% and 6.9% for simple and multiple resistances, respectively. on GuaraA(0), the less polluted beach, only 35.3% of isolated strains had simple resistance. Multiple resistance was not observed. While samples from Gonzaguinha and Ilha Porchat beach showed isolated strains resistant to seven and six different antimicrobial agents, respectively, samples from GuaraA(0) beach were resistant only to penicillin and erytromicin. The positive correlations obtained between the degree of seawater contamination and frequency and variability of bacterial resistance indicate that polluted marine recreational waters and sands are sources of resistant bacteria contributing thus, to the dissemination of bacterial resistance

    Heavy metals and TPH effects on microbial abundance and diversity in two estuarine areas of the southern-central coast of São Paulo State, Brazil

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    Coastal areas may be impacted by human and industrial activities, including contamination by wastewater, heavy metals and hydrocarbons. This study aimed to evaluate the impact of hydrocarbons (TPH) and metals on the microbiota composition and abundance in two estuarine systems in the coast of Sao Paulo: the Santos (SE) and Itanhaern (IE) estuaries. The SE was found to be chronically contaminated by heavy metals and highly contaminated by hydrocarbons. This finding was correlated with the increased density of cyanobacteria in sediments and suggests the possible use of cyanobacteria for bioremediation. These contaminants influence the density and composition of estuarine microbiota that respond to stress caused by human activity. The results are troubling because quantitative and qualitative changes in the microbiota of estuarine sediments may alter microbiological processes such as decomposition of organic matter. Moreover, this pollution can result in damage to the environment, biota and human health. (C) 2015 Elsevier Ltd. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

    Densities and antimicrobial resistance of Escherichia coli isolated from marine waters and beach sands

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    Bacterial resistance is a rising problem all over the world. Many studies have showed that beach sands can contain higher concentration of microorganisms and represent a risk to public health. This paper aims to evaluate the densities and resistance to antimicrobials of Escherichia coli strains, isolated from seawater and samples. The hypothesis is that microorganisms show higher densities in contaminated beach sands and more antimicrobial resistance than the water column. Density, distribution, and antimicrobial resistance of bacteria E. coli were evaluate in seawater and sands from two recreational beaches with different levels of pollution. At the beach with higher degree of pollution (Gonzaguinha), water samples presented the highest densities of E. coli; however, higher frequency of resistant strains was observe in wet sand (71.9 %). Resistance to a larger number of antimicrobial groups was observe in water (betalactamics, aminoglycosides, macrolides, rifampicins, and tetracyclines) and sand (betagalactamics and aminoglycosids). In water samples, highest frequencies of resistance were obtain against ampicilin (22.5 %), streptomycin (15.0 %), and rifampicin (15.0 %), while in sand, the highest frequencies were observe in relation to ampicilin (36.25 %) and streptomycin (23.52 %). At the less polluted beach, Ilha Porchat, highest densities of E. coli and higher frequency of resistance were obtain in wet and dry sand (53.7 and 53.8 %, respectively) compared to water (50 %). Antimicrobial resistance in strains isolated from water and sand only occurred against betalactamics (ampicilin and amoxicilin plus clavulanic acid). The frequency and variability of bacterial resistance to antimicrobials in marine recreational waters and sands were related to the degree of fecal contamination in this environment. These results show that water and sands from beaches with a high index of fecal contamination of human origin may be potential sources of contamination by pathogens and contribute to the dissemination of bacterial resistance
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