Screening for exopolysaccharide-producing bacteria from sub-tropical polluted groundwater

A selection of exopolysaccharide (EPS) -- producing bacterial strains was conducted in groundwater adjacent to an old controlled landfill in the City of Säo Carlos (Säo Paulo, Brazil). The strains were isolated in P and E media under aerobic and microaerophilic conditions at 25øC. A total of 26 strains were isolated and based on the mucoid mode of the colonies, 6 were selected and their morphological, physiological and biochemical aspects were characterized. All strains presented pigmentation, ranging from yellow to orange and from pink to salmon, with a shiny glistening aspect in all tested media. Strains Lb, Lc and Lg, which excelled the others with regard to the mucoid mode of the colonies, were selected to be cultured in E medium with alternate sucrose and glucose as carbon sources in anaerobiosis at 25øC to analyze the production of EPS. Strains Lc and Lg were classified as being of order Actinomycelates, suborder Corynebacterineae. Lg strain was identified as Gordonia polyisoprenivorans and Lc strain did not correspond to a known description and therefore a more detailed study is under preparation. Considering all ecological aspects and the metabolic potential associated with the microorganisms of the environment studied, as well as the capacity to produce pigment and EPS, and the presence of G. polyisoprenivorans, a rubber degrader bacterium, the potential of the groundwater analyzed is evident as a source of microorganisms to be utilized in studies related to environmental remediation

Screening for exopolysaccharide-producing bacteria from sub-tropical polluted groundwater

A selection of exopolysaccharide (EPS) -- producing bacterial strains was conducted in groundwater adjacent to an old controlled landfill in the City of São Carlos (São Paulo, Brazil). The strains were isolated in P and E media under aerobic and microaerophilic conditions at 25ºC. A total of 26 strains were isolated and based on the mucoid mode of the colonies, 6 were selected and their morphological, physiological and biochemical aspects were characterized. All strains presented pigmentation, ranging from yellow to orange and from pink to salmon, with a shiny glistening aspect in all tested media. Strains Lb, Lc and Lg, which excelled the others with regard to the mucoid mode of the colonies, were selected to be cultured in E medium with alternate sucrose and glucose as carbon sources in anaerobiosis at 25ºC to analyze the production of EPS. Strains Lc and Lg were classified as being of order Actinomycelates, suborder Corynebacterineae. Lg strain was identified as Gordonia polyisoprenivorans and Lc strain did not correspond to a known description and therefore a more detailed study is under preparation. Considering all ecological aspects and the metabolic potential associated with the microorganisms of the environment studied, as well as the capacity to produce pigment and EPS, and the presence of G. polyisoprenivorans, a rubber degrader bacterium, the potential of the groundwater analyzed is evident as a source of microorganisms to be utilized in studies related to environmental remediation.

Foi realizada a seleção de linhagens bacterianas produtoras de exopolissacarídeos (EPS) de águas subterrâneas adjacentes ao antigo aterro controlado da cidade de São Carlos (São Paulo, Brasil). O isolamento foi realizado nos meio P e E em condições de aerobiose e microaerofilia a 25°C. Foram isoladas 26 linhagens e, com base na mucosidade das colônias, 6 foram escolhidas e caracterizadas quanto a aspectos morfológicos, fisiológicos e bioquímicos. As colônias das linhagens apresentaram aspecto brilhante em todos os meios testados, com pigmentação variando de amarela a laranja e de rosa a salmão. As linhagens Lb, Lc e Lg, que se destacaram das demais pela mucosidade das colônias, foram selecionadas para cultivo em meio E suplementado alternadamente com glicose e sacarose como fonte de carbono, em anaerobiose a 25°C, para a verificação da produção de EPS. As linhagens Lc e Lg foram classificadas como sendo da ordem Actinomycetales, subordem Corynebacterineae. A linhagem Lg foi identificada como Gordonia polyisoprenivorans e a linhagen Lc não correspondeu a nenhum gênero descrito e, portanto, novas investigações estão em andamento. Considerando os aspectos ecológicos e o potencial metabólico associados aos microrganismos do ambiente estudado, como a capacidade de produzir pigmento e EPS, e a presença de Gordonia polyisoprenivorans, bactéria degradadora de borracha, fica evidente o potencial das águas subterrâneas em questão como fonte de microrganismos a serem utilizados em processos de remediação ambiental.