Extracellular production of alkaline xylanase of alkalophilic Bacillus sp. by Escherichia coli carrying pCX311

Abstract

Escherichia coli HB101 carrying a plasmid pCX311 which contained an alkaline xylanase gene of the alkalophilic Bacillus sp. strain C-125 produced large amounts of xylanase. More than 70% of the pCX311-borne xylanase was found in the culture broth. LB-medium was most suitable for the production of extracellular xylanase. The production of the enzyme required the addition of Na + and was strongly inhibited by the addition of the glucose. Extracellular xylanase production by E. coli carrying pCX311 reached its maxium in 1 3 the cultivation period required by teh alkalophilic Bacillus sp. strain C-125. Furthermore, the activity of pCX311-encodence xylanase detected in the culture broth was higher than tha of xylanase produced by the alkalophilic Bacillus sp. strain C-125.