Iturin, an antifungal lipopeptide, fermentation by Bacillus subtilis was investigated focusing on the effects of nutrients, aeration and specific cell growth rate on iturin production. Cell growth and product formation were not affected by different kinds of carbon sources such as sucrose, glucose and fructose. However, high concentration (30g./.ㅣ) of carbon source was more effective on iturin production. Cell growth was increased with increase of soytone concentration as a nitrogen source, and production of iturin achieved an increase of 50% at 20g/ㅣ of soytone as compared with 10g/ㅣ. More increase of soytone concentration above 20g/ㅣ has not influenced iturin production. However, diauxic growth pattern appeared when only soytone was used as a sole nitrogen source probably due to the shortage of amino acids and/or peptides in soytone which could be assimilated by the cells. In fact, cells grow exponentially until stationary phase enriched with free amino acid mixtures or casamino acids were used as nitrogen source. The composition of three major components in iturin, n-$C_{14}$-fatty acid(FA)-B-amino acid(A), anteiso-$C_{14}$-FA-B-amino acid(B) and iso-$C_{14}$-FA-B-amino acid(C) was not changed significantly by the variation of dissolved oxygen concentration of culture broth, but changed substantially by the change of specific growth rates of the cell. This phenomenon was clealy demonstrated in chemostat culture. The component A was increased and B,C was decreased with decrease of the specific growth rate.
