Volume 60, Issue 334, January - April 2024

Production and characterization of cellulolytic enzymes by chaetomium globosum for biomass saccharification and ethanol production

Kelvin Masinde Munyasi^1♦, George Isanda Omwenga¹, Fredrick Mjomba Mwamburi²

¹Biochemistry, Microbiology and Biotechnology Department Kenyatta University, P.O. Box 105285-00100, Nairobi, Kenya
²Pure and Applied Sciences Department Technical University of Mombasa, P.O Box 90420-80100, Mombasa, Kenya

^♦Corresponding author
Biochemistry, Microbiology and Biotechnology Department Kenyatta University, P.O. Box 105285-00100. Nairobi, Kenya

ABSTRACT

This study aimed to isolate, identify and characterize cellulase-producing fungi from a decaying tree trunk, and determine the effects of incubation time, moisture content and initial medium pH on cellulase production using untreated maize cobs and sugarcane bagasse under solid state fermentation after that, to saccharify for ethanol production. Samples were collected from Ngong Forest, Kenya, and screened for the isolation of cellulase producing fungi. The isolated fungi were grown to obtain pure cultures before DNA extraction, PCR amplification and sequencing. The fungus was cultured on substrates for cellulase production with enzymes obtained after fermentation subjected to cellulase assays; filter paper, exoglucanase and endoglucanase. Molecular data analysis was performed using the NCBI-BLAST algorithm and MEGA 11.0 software to identify the isolated fungus, while enzyme activity analysis was done using one-way ANOVA with R software at the P≤0.05 significance level, and the significant differences were determined via the Tukey post hoc test. The isolated fungus was identified as Chaetomium globosum. For the effect of incubation time on cellulase production, the fungus exhibited high enzyme production on different days within the incubation period, and the highest cellulase activity was recorded at a moisture content ratio of 1:2 and initial medium pH of 5. Saccharification optimization studies showed a 7% (v/v) enzyme concentration, 12% (v/w) substrate concentration and hydrolysis time of 72 hours were optimal for the maximum yield of reducing sugars. The total reducing sugar produced maximum bioethanol yield at 72 hours when Saccharomyces cerevisiae was used as a fermentation agent.

Keywords: Fungus, Cellulase, Enzymes, Production, Incubation, Moisture content, pH, Chaetomium globosum, Substrate, Reducing sugar, Fermentation, Ethanol

Discovery, 2024, 60, e14d1425

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DOI: https://doi.org/10.54905/disssi.v60i334.e14d1425

Published: 03 April 2024