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

Abstract

A gene encoding the Carboxymethyl cellulase (CMCase) of a psychrophilic marine bacterium, Psychrobacter aquimaris LBH-10 was cloned in Escherichia coli JMB109. The optimal conditions of rice bran, ammonium chloride, and initial pH of the medium for cell growth of E. coli JM109/LBH-10 were 73.4 g/L, 5.8 g/L, and 6.5, respectively, whereas those for production of CMCase were 57.1 g/L, 6.4 g/L, and 6.7. The optimal temperatures for cell growth and the production of CMCase by E. coli JM109/LBH-10 were found to be and 40 and 35°C, respectively. The optimal agitation speeds and aeration rates of a 7 L bioreactor for cell growth and production of CMCase were 480 rpm and 1.0 vvm. In this study, the optimal conditions for cell growth and the production of CMCase by E. coli JM109/ LBH-10 were found to be different from those for its wild type, P. aquimaris LBH-10. The maximal production of CMCase by E. coli JM109/LBH-10 was 576.8 U/mL, which was 1.80 times higher than that by P. aquimaris LBH-10.

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

“…The treated reaction mixtures were boiled for 10 min and cooled in tap water for color stabilization. Their optical densities were measured at 550 nm [19]. A calibration curve was prepared with an authentic glucose (Sigma-Aldrich, Dorset, UK) [1].…”

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

“…coli JM109/LBH-10 contains a gene encoding the cellulase of Psychrobacter aquimaris LBH-10 ( Lee et al 2014). The medium used for the production of cellulase contained the following components: 57.1 g/L rice bran, 6.40 g/L ammonium chloride, 5.0 g/L K2HPO4, 1.0 g/L NaCl, 0.6 g/L MgSO4·7H2O, and 0.6 g/L (NH4)2SO4.…”

“…Psychrobacter aquimaris utilizes carboxymethyl cellulose (CMC); it was isolated from seawater and identified by its 16S rDNA sequence . The gene encoding the cellulase of P. aquimaris LBH-10 was cloned into E. coli JM109 to construct the recombinant E. coli JM109/LBH-10 ( Lee et al 2014). The optimal conditions for the production of CMCase by E. coli JM109/LBH-10 have been established.…”