PHYTASE EXPRESSION VECTOR, PJPK AND BACILLUS SUBTILIS PJPK TRANSFORMED THEREWITH

摘要

PURPOSE: Phytase expression vector, pJPK has strong BJ27 promoter. Bacillus subtilis pJPK (KCTC 0526BP) transformed with pJPK expresses phytase highly, secrets expressed protein and is nontoxic to animal because of lacking endotoxin such as lipopolysaccharides. CONSTITUTION: Bacillus expression vector pJH27, having strong promoter BJ27, is ligated with 2.2 kb phytase gene originated from Bacillus amyloliquefaciens DS-11. The 2.2kb DNA includes SD sequence of phytase gene complementary to Bacillus subtilis 16S rRNA sequence (UCCUCC) for the overexpression of phytase. Resulting recombinant plasmid, pJPK, is introduced into E. coli JM83. Purified pJPK is transformed into Bacillus subtilis DB104 by protoplast transformation. Modified LB medium is consisted of 1% of potassium phosphate, 0.045% of magnesium sulfate, 4% of glucose, 1% of tryptone, 0.5% of yeast extract, 0.5% of NaCl and trace elements. 500-1000 unit of phytase is added to 1kg of animal feed. Animal experiment with porcine reveals that phytase produced from bacillus effectively degrades phytic acid in the animal feed.