Caracterização genômica de Acinetobacter junii SB132 degradadora de diesel e sua interação com substratos hidrofóbicos

Abstract

Accidental spills of crude oil can have catastrophic consequences in natural environments. However, some native bacterial populations can thrive under these conditions by utilizing crude oil components in their metabolism. This natural ability of bacteria can be used to gather genetic and metabolic information to contribute to the development of new bioremediation technologies, such as cleaning industrial waste. Thus, this research investigated the biodegradation potential of Acinetobacter junii SB132, by experimental procedures and genomic analyzes, to understand its mechanisms of interaction, absorption and metabolization of hydrophobic compounds of diesel oil. This bacterial strain, previously isolated by selection on petroleum-containing substrate and identified by morphological and molecular analysis, had the ability to grow in diesel oil as sole carbon and energy source. In addition, in laboratory tests, emulsion layers were observed between cell free culture supernatant and hydrophobic compounds. Additionally, fresh oil-free cells were able to adhere to hydrophobic substrates as well as form a biofilm on the polystyrene plate surface. Its genome draft had a size of 3.5 Mb, which is equivalent to the genomes of the Acinetobacter strains deposited in GenBank, in which the annotation revealed subsystems related to the metabolism of aliphatic and aromatic hydrocarbons. Thus, it is possible that A. junii SB132 uses cell adhesion mechanisms, through biofilm formation, to contact the hydrophobic substrates present in diesel oil and so be able to metabolize them through the degradation pathways of these compounds.