Brucella pituitosa strain BU72, a new hydrocarbonoclastic bacterium through exopolysaccharide-based surfactants production

Abstract

Abstract Hydrocarbons and heavy metals pollution is considered among the most prevalent and serious problems in environment due to their toxicity and persistence. Bioremediation, using microorganisms, is considered as one of the most effective ways to reduce this type of pollution. In the present study, we unveil the bioremediation potential of Brucella pituitosa strain BU72. Besides its ability to grow on multiple hydrocarbons as sole carbon source and highly tolerant to several heavy metals, BU72 was able to produce different exopolysaccharide-based surfactants (EBS) when grown with glucose or with crude oil as sole carbon source. These EBS demonstrated particular and specific functional groups as determined by Fourier transform infrared (FTIR) spectral analysis that showed a strong absorption peak at 3250 cm− 1 generated by -OH group for both EBS. The major differences in the FTIR spectra, of EBS produced are the increase of functional groups and the protein content. To better understand the EBS production coupled to the degradation of hydrocarbons and heavy metal resistance, the genome of strain BU72 was sequenced. Annotation of the genome revealed the presence of multiple genes putatively involved in EBS production pathways coupled with resistance to heavy metals genes such as arsenic tolerance and cobalt-zinc-cadmium resistance were identified. The genome sequence analysis showed the potential of BU72 to synthesize secondary metabolites and confirmed the presence of genes involved in plant-growth promoting. Here we provide a physiological and metabolic characterization associated with genomic analyses of BU72 considered as a promising candidate for application in the bioremediation.