Isolation and Characterization of Microorganisms from Natural Sources Capable of Producing Ligninase and Sarbose Oxidase Enzymes

Abstract

This study focuses on the isolation and characterization of microorganisms from natural sources capable of producing ligninase and sarbose oxidase enzymes, which have significant potential for industrial applications. A diverse array of microorganisms, including bacteria and fungi, was isolated from forest soil, compost, decaying wood, and agricultural soil. Preliminary screening on selective media indicated substantial enzyme activity, with 40% of bacterial strains and 60% of fungal strains showing ligninase activity, and 35% of bacterial and 45% of fungal strains demonstrating sarbose oxidase activity. Enzyme activity assays further confirmed these findings. For ligninase, the guaiacol and Azure B assays revealed high enzymatic activity in 45 bacterial and 32 fungal strains. Similarly, spectrophotometric and chromogenic assays for sarbose oxidase identified significant activity in 28 bacterial and 20 fungal strains. Molecular identification using 16S rRNA and ITS sequencing categorized these strains into known lignin-degrading and sarbose-oxidizing genera, such as Pseudomonas, Streptomyces, Trametes, and Phanerochaete. Optimization of enzyme production was achieved by varying media compositions, temperature, and pH levels. Ligninase production was maximized with 0.5% peptone and 0.2% yeast extract at 30°C and pH 6.0. For sarbose oxidase, optimal production occurred with 1% sarbose and ammonium sulfate at 28°C and pH 7.0. Characterization of these enzymes revealed molecular weights between 35-50 kDa for ligninase, with maximum activity at pH 6.0 and 30°C, and kinetic parameters indicating high affinity and catalytic efficiency for sarbose oxidase. These findings suggest significant applications for these enzymes in bioremediation, biofuel production, and the pharmaceutical industry. Ligninase-producing strains can degrade lignin-rich industrial wastes, facilitating biomass recycling and biofuel conversion. Sarbose oxidase-producing strains can aid in the bioconversion of rare sugars for pharmaceutical synthesis. Despite challenges in enzyme stability, genetic manipulation, and industrial scale-up, the study provides a foundation for future research to enhance enzyme yields and broaden their application scope, emphasizing the potential of natural microbial resources in sustainable biotechnological processes.