Isolation and characterization of a biosurfactant producing strain, Brevibacilis brevis HOB1

Abstract

Biosurfactant-producing bacteria were isolated from the production water of an oil field. Isolates were screened for biosurfactant production using surface tension test. The highest reduction of surface tension was achieved with a bacterial strain which was identified by 16S rRNA gene sequencing as Brevibacilis brevis HOB1. It has been investigated using different carbon and nitrogen sources. It showed that the strain was able to grow and reduce the surface tension of the broth to 29 mN/m on commercial sugar and maltose, and to 32 mN/m on glucose after 72 h of growth. The maximum amount of biosurfactant was obtained when nitrate ions were supplied as nitrogen source. Biosurfactant produced by Brevibacilis brevis HOB1 was confirmed as a lipopeptide class of biosurfactant using TLC test and mass spectra. Lipopeptide isoforms were isolated from cell-free supernatants by acid-precipitation followed by one step of chromatographic separation on solid-phase ODS C18 column. The separation was confirmed by HPLC and ESI Q-TOF MS spectroscopy. Comparing the mass data obtained and the mass numbers reported for the lipopeptide complexes from other strains, it can be concluded that the major lipopeptide product of Brevibacilis brevis HOB1 is the surfactin isoform. This lipopeptide showed strong antibacterial and antifungal activity. It is a candidate for the biocontrol of pathogens in agriculture and other industries.

Production of biosurfactant from Bacillus licheniformis for microbial enhanced oil recovery and inhibition the growth of sulfate reducing bacteria

“…Cultivation studies have been done in 500 ml flasks containing 150 ml of the medium at 30°C for 48 hs. Experiments were conducted in independent triplicates [24].…”

Purification and structural characterization of fengycin homologues produced by Bacillus subtilis LSFM-05 grown on raw glycerol

“…Three families of lipopeptides are known to be produced by Bacillus, all of which contain a variable cyclic amino acid portion attached to a variable b-amino or b-hydroxy fatty acid. The most studied family is the surfactins, which may be the most powerful biosurfactants known and also exhibit antiviral and antifungal activity, and contain heptapeptides attached to a b-hydroxy fatty acid with carbon number in the range of 13-15 [13,19,37]. The mycosubtilin, iturin and bacillomycin family, contain heptapeptides attached to b-amino fatty acids and exhibit strong antifungal activity [7,33,44].…”

Evaluation of the effect of nutrient ratios on biosurfactant production by Serratia marcescens using a Box-Behnken design

“…Biosurfactants reduce surface tension (ST) and interfacial tension (IFT), facilitating the formation of emulsions [3][4][5]. Some of their potential applications include oil flow improvement, microbial enhanced oil recovery (MEOR) [6,7] and hydrocarbon biodegradation by increasing the bioavailability of hydrophobic compounds [8].…”