OPTIMIZATION OF CELLULASE PRODUCTION BY ASPERGILLUS NIGER ISOLATED FROM SOIL SAMPLES IN IBADAN, NIGERIA

Abstract

Cellulolytic microorganisms have found relevance in various industrial applications. The genus Aspergillus is among the cellulase-producing organisms that have been studied over time. Hence, this study aimed to establish the optimal conditions for cellulase production by Aspergillus niger isolated from soil. Soil samples were aseptically collected in Ziploc bags from four locations in Ibadan: Bashorun, Akobo, University of Ibadan, and Bodija. Isolation, cellulose degradation, and screening for cellulase production by the isolated A. niger were done on Potato Dextrose Agar (PDA), Carboxyl Methylcellulose (CMC) agar, and Congo red agar, respectively. Furthermore, cellulase production by A. niger was optimized using standard procedures. The results showed that ten of the fifteen isolated A. niger were cellulase producers, and two isolates (A. niger ISOd and A. niger ISOg) exhibited the largest zones of clearance (24 mm and 21 mm, respectively). Optimizing temperature, pH, carbon and nitrogen sources, % CMC concentration, and incubation time of A. niger ISOd demonstrated the highest cellulase yield of 0.32 U/mL at 37 ⁰C, 1.28 U/mL at 4.5, 0.93 U/mL using glucose, 0.26 U/mL using peptone, 0.39 U/mL using 5% CMC, and 1.20 U/mL at 72 h, respectively, compared to other isolates. In conclusion, A. niger ISOd is a good microbial cellulase producer that may be harnessed for useful food and industrial applications. In addition, this study supports Sustainable Development Goal 3, which targets good health and well-being.