Abstract:
Lignin recalcitrance is a key issue in producing value-added products from lignocellulose biomass. In situ biodegradable lignin-modifying
enzymes-producing bacteria are considered a suitable solution to lignin biodegradation problems, but exploitation of ligninolytic bacteria is
still limited to date. Hence, this study aimed to isolate and characterize potential lignin peroxidase ligninolytic bacteria from decomposing
soil, sawdust, and cow dung at Richard Bay, South Africa. The samples were collected and cultured in the lignin-enriched medium. Pure
isolated colonies were characterized through 16S rRNA gene sequencing. The ability of the isolates to grow and utilize aromatic monomers
(veratryl and guaiacol alcohol) and decolorize lignin-like dyes (Azure B, Congo Red, Remazol Brilliant Blue R) was evaluated. Of the twentysix
(26) bacteria isolates 10 isolates, including Pseudomonas spp. (88%), Enterobacter spp. (8%), and Escherichia coli (4%) were identified
as true lignin peroxidase producers. Pseudomonas aeruginosa (CP031449.2) and E. coli (LR025096.1) exhibited the highest ligninolytic
activities. These isolates could potentially be exploited in the industry and wastewater treatment as effective lignin degrading agents.