Optimum Culture Conditions of Microbial Isolates Obtained from Pap Processing Waste for Cellulase Production

Abstract

The cost of cellulase is high due to cost of its substrate and producer microorganisms. The aim of this study was therefore, to investigate the cellulolytic potential of two indigenous isolates from pap processing wastes. The two indigenous isolates of bacteria and fungi strains were screened for cellulase production by growing on carboxymethyl cellulose (CMC) agar plate. Parameters such as substrate concentration, pH, temperature, incubation period were determined for cellulase production. The two organisms were isolated and identified as Aspergillus niger and Bacillus sp. The pap processing waste medium inoculated with Aspergillus niger had the highest cellulase activity of 7.2U/ml after 96 hours of incubation than the medium inoculated with Bacillus sp. that had highest cellulase activity of 4.31U/ml after 48 hours of incubation. As the concentration of pap processing waste increased up to 20%, cellulase activity increased with the maximum of 14.0 U/ml and 18.0 U/ml by Bacillus sp. and Aspergillus niger respectively. As the initial pH increased from 4 to 6 the cellulase activity increased with pH 6 as the optimum for maximum cellulase activity of 20.0 U/ml and 16.0 U/ml respectively for Aspergillus niger and Bacillus sp. The incubation temperature of 35° C was the optimum for the maximum cellulase activity of 22.0 U/ml and 18.0 U/ml respectively for Aspergillus niger and Bacillus sp. In conclusion, this research work has established the potential of pap processing waste that, if well harnessed can be used for the production of cellulase.