Response surface optimization of CMCase from Staphylococcus saprophyticus and Klebsiella quasipneumoniae subsp. Similipneumoniae originated from termitarium of Odontotermes obesus

The continuous depletion of fossil fuel reserves and the rising demand for energy have led researchers to look into alternative renewable energy sources. Bioethanol derived from the lignocellulosic biomass (LCB) could be a cost-effective and viable alternative source. As cellulose is a major component of LCB, therefore, in this study, two potential CMCase producing bacterial strains were screened out from the termitarium of Odontotermes obesus. Based on morphological, biochemical, and molecular sequencing, isolates T12 and T13 were identified as Staphylococcus saprophyticus T12 and Klebsiella quasipneumoniae subsp. Similipneumoniae, respectively. Upon optimization through method like one factor at a time (OFAT) and response surface methodology (RSM), bacterial isolate T12 produced 17.47 U/mL of crude CMCase under optimal conditions of pH 7.0, 35 °C, and 48 h of incubation, representing a 1.25-fold increase from 13.87 U/mL in unoptimized conditions. Similarly, isolate T13 produced 18.18 U/mL of crude CMCase at pH 6.0, 41 °C, and 62 h of incubation, achieving a 1.50-fold increase from its unoptimized activity of 12.07 U/mL. Crude enzyme of both bacterial isolates exhibited high CMCase activity at mesophilic ranges, which makes these bacterial strains suitable for industrial processes such as bioethanol production, biopolishing and biostoning processes in textile industries.