Production of lipopeptide antibiotic iturin A using soybean curd residue cultivated with Bacillus subtilis in solid-state fermentation.
Bacillus subtilis RB14-CS, which suppresses the growth of various plant pathogens in vitro by producing the lipopeptide antibiotic iturin A, was cultured using soybean curd residue, okara, a by-product of tofu manufacture in solid-state fermentation. After 4 days incubation, iturin A production reached 3,300 mg/kg wet solid material (14 g/kg dry solid material), which is approximately tenfold higher than that in submerged fermentation. When the okara product cultured with RB14-CS was introduced into soil infested with Rhizoctonia solani, which is a causal agent of damping-off of tomato, the disease occurrence was significantly suppressed. After 14 days, the number of RB14-CS cells remained in soil at the initial level, whereas almost no iturin A was detected in soil. As the okara cultured with RB14-CS exhibited functions of both plant disease suppression and nutritional effect on tomato seedlings, this product is expected to contribute to the recycling of the soybean curd residue.
Chemical Resources Laboratory, Tokyo Institute of Technology, R1-29-4259 Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
S
S
Mizumoto
M
M
Hirai
M
M
Shoda
D001412:Bacillus subtilis / Q000378:metabolism*; D019149:Bioreactors; D005285:Fermentation / Q000502:physiology*; D005308:Fertilizers; D018551:Solanum lycopersicum; D010456:Peptides, Cyclic / Q000096:biosynthesis*; D010940:Plant Proteins / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*; D045730:Soy Foods
D005308:Fertilizers; D010456:Peptides, Cyclic; D010940:Plant Proteins; D011134:Polysaccharides; C412882:okara, Glycine max; C013579:iturin A