Identificação de actinomicetos isolados de solo impactado com resíduos petroquímicos e seleção de potenciais degradadores de misturas de diesel e biodiesel

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

Actinomycetes are Gram positive bacteria, predominantly filamentous, mainly found in soil. Few studies assess their ability for fuel degradation, although some authors state that they are good candidates for hydrocarbon bioremediation application. The main objectives of this study were to identify actinomycetes obtained from petroleum hydrocarbon contaminated soil, and to select actinomycetes that degrade diesel and soybean biodiesel blends (B0, B10 and B100) and produce lipases and esterases, among soil isolates with and without contamination history. Identification through morphological and molecular analysis showed that 94,5% of the landfarming isolates belong to the genus Streptomyces. Three Streptomyces sp. isolates showed the alkB gene, although only one of them was capable of degrading diesel (B0). The comparison between isolates from contaminated and not contaminated soil showed they have similar degradation profiles, since all isolates with ability for degrading fuel mainly used biodiesel as carbon source. The selection of microorganisms with potential for degradation was conducted using DCPIP redox indicator, growth in solid medium with oil as the sole carbon source, and production of lipases and esterases. Both selected isolates were used in the biodiesel biodegradation assay (B100) in liquid medium. The analysis of biodiesel samples through infrared spectroscopy in the end time (28 days) of the growth curve showed that the formation of a degradation product is not necessarily related to the degradation of biodiesel ester, but it may indicate the degradation of subproducts generated in the transesterification of soybean oil.

ASSUNTO(S)

actinomicetos biodegradação ambiental Óleo diesel biodiesel

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