Cloning Cellulase Genes from Victoria Falls Rainforest Decaying Logs Metagenome

Abstract

Abstract The Victoria Falls rainforest is a protected site whose forest floors harbor a host of cellulolytic microorganisms involved in biomass degradation. This study collected decaying logs and soil from the rainforest for bioprospecting cellulases from their metagenomes. Metagenomic DNA was isolated from the compound sample. Degenerate cellulase primers were used to amplify cellulase genes in the metagenome. The resulting amplicons cloned into Z-competent Escherichia coli DH5α were analyzed by functional screening for the production of cellulase extracellularly. Functional screening of the clones resulted in one clone (Clone-i) testing positive for extracellular cellulase production. Submerged fermentation of Clone-i was carried out for cellulase production. The cellulases were characterized to determine their activity’s optimum pH and temperature. The diversity of the cellulases produced by Clone-i was determined. Clone-i’s optimum enzyme activity was observed after 72 hours of incubation at 50°C and pH 5. Clone-i produced 80% more exoglucanases as compared to endoglucanases. The cellulolytic Clone-i’ isolate shows Victoria Falls rainforest’s potential as an enzyme bioprospecting site, reflecting that metagenomics is a valuable tool in microbial ecology.