PRODUCTION OF A LIPOPEPTIDE ANTIBIOTIC, SURFACTIN, BY RECOMBINANT BACILLUS-SUBTILIS IN SOLID-STATE FERMENTATION

Production of a lipopeptide antibiotic, surfactin, in solid state ferm entation (SSF) on soybean curd residue, Okara, as a solid substrate wa s carried out using Bacillus subtilis MI113 with a recombinant plasmid pC112, which contains Ipa-14, a gene related to surfactin production cloned at our laboratory from a wild-type surfactin producer, B. subti lis RB14. The optimal moisture content and temperature for the product ion of surfactin were 82% and 37 degrees C, respectively. The amount o f surfactin produced by MI113 (pC112) was as high as 2.0 g/kg wet weig ht, which was eight times as high as that of the original B. subtilis RB14 at the optimal temperature for surfactin production, 37 degrees C . Although the stability of the plasmid showed a similar pattern in bo th SSF and submerged fermentation (SMF), production of surfactin in SS F was 4-5 times more efficient than in SMF. (C) 1995 John Wiley and So ns, Inc.