Rapid Statistical Optimization of Cultural Conditions for Mass Production of Carboxymethylcellulase by a Newly Isolated Marine Bacterium, Bacillus velezensis A-68 from Rice Hulls

Abstract

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater, identified as Bacillus velezensis by analyses of 16S rDNA and partial sequences of the gyrA, and designated as B. velezensis A-68. The optimal conditions for production of CMCase by B. velezensis A-68 were established using response surface methodology (RSM). The optimal concentrations of rice hulls and yeast extract, and initial pH of the medium for cell growth were 60.2 g/l, 7.38 g/l, and 7.18, respectively, whereas those for production of CMCase were 50.0 g/l, 5.00 g/l, and 7.30. The analysis of variance (ANOVA) implied that the most significant factor for cell growth as well as production of CMCase was yeast extract. The optimal concentrations of K2HPO4, NaCl, MgSO4•7H2O, and (NH4)2SO4 in the medium for cell growth were 7.50, 1.00, 0.10, and 0.80 g/l, respectively, which were the same as those for production of CMCase. The optimal temperatures for cell growth and production of CMCase were 30 and 35℃, respectively. The maximal production of CMCase under optimized conditions was 83.8 U/ml, which was 3.3 times higher than that before optimization. In this study, rice hulls, agro-byproduct, were developed as a substrate for production of CMCase and time for production of CMCase was reduced to 3 days using a newly isolated marine bacterium.

Construction of Recombinant Escherichia coli JM109/LBH-10 and Comparison of Its Optimal Condition for Production of Carboxymethyl cellulase with Its Wild Type, Psychrobacter aquimaris LBH--10

“…The value of the adjusted determination coefficient (Adj. R 2 = 0.9229) was very high to advocate for a high significance of this model [26,27]. The predicted determination of coefficient of 0.8001 was in reasonable agreement with the Adj.…”

Enhanced Production of Carboxymethylcellulase by Recombinant Escherichia coli Strain from Rice Bran with Shifts in Optimal Conditions of Aeration Rate and Agitation Speed on a Pilot-Scale

“…Its value of the adjusted coefficient of determination (Adj. R 2 = 0.9442) was relatively high to advocate for this model's significance [26]. This model with the multiple correlation and adjusted coefficients indicated that the above equation was adequate for predicting the production of CMCase by E. coli KACC 91335P without shifts in optimal conditions of the agitation speed and/or aeration rate.…”

Enhanced Production of Cellulase from the Agricultural By-product Rice bran by Escherichia coli JM109/LBH-10 with a Shift in Vessel Pressure of a Pilot-scale Bioreactor

“…Dry cell weight was measured as described previously Kim et al 2013). The activity of cellulase was measured by the 3,5-dinitrosalicylic acid (DNS) method (Kim et al 2012b).…”