Production of xylanase was studied using recombinant Bacillus subtilis harboring pJHKJ4 vector. As a gene source of xylanase, Bacillus sp. originated gene was used as strong xylobiose producer because it mainly produced a xylobiose from xylan as a hydrolysis product. In semi-defined medium containing 20 g/L of glucose and 3 g/L ammonium sulfate, 260 IU/mL of xylanase activity was obtained in 48 hours of cultivation.
It was found that the supplementation of sodium glutamate, which can be utilized both carbon and nitrogen source, enhanced markedly the production of xylanase. When 0.3%(w/v) of glutamate was supplemented to the control medium, the production of xylanase was markedly increased to 530 IU/mL which corresponded almost double compared with that in the control experiment (260 IU/mL). By supplementation of sodium glutamate, total cellular RNA level was increased almost twice, especially ribosomal RNA. Other extracellular protein expression was increased as same manner as xylanase expression. This enhancement seems to be result from increase of ribosomal RNA by adding mono-sodium glutamate.
