Incidence of laccase
and biosurfactant producing bacteria from mesophilic to extreme environments to
harness potential contribution in dye degradation and antimicrobial activity
Peter Jyotsna K., Kumar Arun, Yadav Ashok K. and Mehta Praveen K.
Res. J. Biotech.; Vol. 20(11); 98-108;
doi: https://doi.org/10.25303/2011rjbt0980108; (2025)
Abstract
Three separate bacterial populations were isolated and screened from diverse locations,
classified as mesophiles, halophiles and thermophiles. Halophiles and thermophiles
exhibited greater laccase activity than mesophiles and enhanced biosurfactant property
noted in thermophiles. Based on phenotypic and biochemical characteristics, T17
was identified as Pseudomonas sp. and H27 as Bacillus sp. Bacillus sp. (laccase
positive, best grown at 5% NaCl) was assessed for its ability to degrade Gentian
violet, Safranine and Bromothymol blue at 24, 48 and 72 h of incubation across various
dye concentrations (1 to 10%). The most effective dye degradation occurred with
safranine (24.12%), followed by bromothymol blue (22.85%) and gentian violet, which
exhibited over 20.16% degradation at 72 h. Thermophilic Pseudomonas sp. was utilized
to assess the antimicrobial activity of its partially purified biosurfactant.
It was particularly effective against Fusarium sp., Rhizoctonia sp. and Helminthosporium
sp. at concentrations of 250 and 300 μg/ml, but it did not inhibit Alternaria sp.
Similarly, the antibacterial activity of partially purified biosurfactant from Pseudomonas
sp. was effective against all bacterial pathogens across a broad spectrum of concentrations
ranging from 100 to 300 μg/ml. The findings underscore the extensive potential applications
of laccase and biosurfactants sourced from halophiles and thermophiles.
