Isolation, Screening and Characterization of a Novel Extracellular Laccase Producing Bacillussp

Abstract

Laccase is a unique, green biological catalyst with several applications due to its high prolific activity. They have sparked widespread attention as potential industrial enzymes in a range of industries, including bioremediation in pulp and paper, textiles, and food. Laccase has also shown enormous potential for anti-cancer treatment due to its proliferation inhibitory actions, which are still being explored. Isolation and identification of laccase producing bacteria, becomes an essential one. The laccase producing bacterial colonies were isolated from the collected samples by serial dilution technique. Seven samples comprising of decaying wood soil, ant- induced soil and soil contaminated with dyes and effluents of dyeing industry were collected from Kurukshetra and Panipat districts of Haryana. Preliminary screening of bacterial strains was carried out by spreading of these samples on nutrient agar medium supplemented with 0.1% guaiacol followed by incubation at 37℃ for 72 h resulted in 56 laccase positive colonies. The formation of a reddish brown color demonstrates that the bacterial strains are capable of producing laccase. These isolated bacterial colonies were subjected to quantitative screening for extracellular laccase production in submerged fermentation using modified Horikoshi’s medium supplemented with Guaiacol. The bacterial isolates exhibited differences in laccase production and the isolate UV25 showed the highest level of laccase activity 250.04 IU/L among all the isolates. This bacterial isolate was examined for morphological and biochemical characteristics according to Bergey’s Manual of Systematic Bacteriology and it was identified as Bacillus species.