Characterization and evaluation of biosurfactant produced from a thermophilc Bacillus licheniformis

Abstract

The study emphasizes on the production of biosurfactant from thermophilic isolate BITSL006, found in Ramkund hotspring of Jharkhand. The isolate was cultivated in MSM using paneer whey with 16 g/L dextrose for biosurfactant production. The cell free supernatant was used to screen the ability of the isolate to produce biosurfactant. Based on screening methods, BITSL006 was selected as potent producer of biosurfactant and molecular sequencing confirm that the isolate was Bacillus licheniformis (ON795916). Optimization resulted in biosurfactant concentrations of 2.6 g/L in mineral salt medium (MSM) and 3.3 g/L in paneer water supplemented with mineral salt medium (PWSMSM). The biosurfactant was characterized as lipopeptide by FTIR and TLC analysis. FESEM-EDX analysis shows surface morphology and chemical composition of biosurfactant. Tensiometric analysis demonstrated its effectiveness in reducing surface tension from 71.78 mN/m (distilled water) to 44.54 mN/m (paneer water supplemented mineral salt medium) and 46.62 mN/m (mineral salt medium) indicating its surface activity. Moreover the biosurfactant displayed significant activity against various hydrocarbons and oils such as olive oil, mustard oil, diesel and crude oil, attributing to its increased cell surface hydrophobicity. Furthermore, it demonstrated potent antibacterial activity against E.coli, P. aeruginosa and S. aureus, along with effective antibiofilm activity against Bacillus sp. and S. aureus. Therefore, this marks the first report on biosurfactant production from thermophilic bacteria in Jharkhand using paneer whey. This highlights their thermostability, prolonged antibacterial and antibiofilm activity, as well as emulsification activity proposing it to be a potent candidate in pharmaceuticals, medical and environmental remediation.