Cellulase production by B2S8 bacterial isolates using corn stover as a substrate

¹ Department of Agroindustrial Technology, Faculty of Agricultural Technology, Udayana University, Bukit Jimbaran, Badung, 80361 Bali Indonesia
² Department of Food Technology, Faculty of Agricultural Technology, Udayana University, Bukit Jimbaran, Badung, 80361 Bali Indonesia.
³ Department of Biology, Faculty of Science, Udayana University, Bukit Jimbaran, Badung, 80361 Bali Indonesia.

^* Corresponding author: ibwgunam@unud.ac.id

Abstract

The aim of this study was to determine the substrate concentration and fermentation time to produce high activity of cellulase enzyme. Crude cellulase production in different substrate concentrations and fermentation times used a factorial randomized block design (RBD) consisting of two factors. The first factor was the substrate concentration which consisted of 4 levels: 2%, 4%, 6%, and 8% (w/v). The second factor was the fermentation time which consisted of four levels: 24 h, 48 h, 72 h, and 96 h. This study used B2S8 cellulolytic bacterial isolates which had the highest value of cellulase activity and the highest rate of cellulose degradation in previous studies. To test the enzyme activity, this study used carboxymethyl cellulose (CMC), citrate buffer, and cellobiose. Protein levels were analyzed using the Lowry method. The results showed that the highest cellulase activity was under 8% (w/v) substrate concentration and fermentation time 96 h which resulted in endoglucanase activity was 0.1320 IU/mL, exoglucanase activity was 0.0320 IU/mL, β-glucosidase activity was 0.0172 IU/mL, dissolved protein level was 0.1719 mg/mL, specific endoglucanase activity was 0.9804 IU/mg, specific exoglucanase activity was 0.2730 IU/mg, and specific activity of β-glucosidase was 0.1260 IU/mg. The ability of B2S8 bacteria shows great potential for cellulase enzyme production and can be applied in lignocellulose hydrolysis.