Enhancing biomolecule production from Bacillus velezensis PhCL using low-cost agricultural residues as feedstock and improving biomass hydrolysis through enzyme mutagenesis

Abstract

Bioproduction have been considered an alternative option for obtaining useful and eco-friendly chemicals for industrial applications. Bacillus velezensis, a trending bacterium first isolated in 2005, is well-known for its ability in producing various economic and environmentally-friendly biomolecules, such as industrial enzymes, biosurfactants, antioxidants, antibiotics, etc. However, most of the studies nowadays use edible sugar for biomolecule production which increased the production cost meanwhile raises concerns regarding hunger and food-energy competition. Meanwhile, several genomic sequencing studies suggested that various strains of B. velezensis have the ability in producing various lignocellulase, such as xylanase and CMCase. However, very few studies use agricultural wastes as feedstock for producing biomolecules. Therefore, for advancing the utilization of the lignocellulosic biomass, a newly isolated B. velezensis PhCL was characterized, and its potential for bioremediation was evaluated. Furthermore, various agricultural wastes were used as a fermentation feedstock for producing various biomolecules, and the amylase production was optimized via response surface methodology. The remaining biomass residue was also converted to biochar for further utilization. Moreover, for advancing the utilization of agricultural waste, a GH 11 xylanase was in silico analyzed and several mutants were constructed based on the analysis. The mutant showed better hydrolysis efficiency and released more reducing sugar from wheat straw. This study explored another approach for utilizing B. velezensis for value-added biomolecule production, which could be used for bioremediation and various industrial applications, from low-cost agricultural waste. Moreover, this study also contributed to the understanding of utilizing advanced computer programs for improving enzymatic performance meanwhile exploring the undermined structure-function relationship of xylanase. [...]