Optimizing Iron Supplement Strategies for Enhanced Surfactin Production with Bacillus subtilis

• Published in: Biotechnology progress Vol. 20; no. 3; pp. 979 - 983
• Main Authors: Wei, Yu-Hong, Wang, Li-Fen, Chang, Jo-Shu
• Format: Journal Article
• Language: English
• Published: USA American Chemical Society 01.05.2004; American Institute of Chemical Engineers
• Subjects: Bacillus subtilis; Bacillus subtilis - drug effects; Bacillus subtilis - metabolism; Biological and medical sciences; Biotechnology; Cell Culture Techniques - methods; Culture Media - metabolism; Dose-Response Relationship, Drug; Emulsification; Fermentation; Fundamental and applied biological sciences. Psychology; Iron; Iron - pharmacokinetics; Iron - pharmacology; Lipopeptides; Peptides, Cyclic - biosynthesis; Q1; Q2; Reproducibility of Results; Sensitivity and Specificity; Supplements; surfactin; Bacteria; Iron; Bacillales; Bacillaceae; Bacillus subtilis; Production
• DOI: 10.1021/bp030051a
• ISSN: 8756-7938

Supplement of Fe2+ into fermentation medium was utilized as a tool to optimize the iron‐mediated enhancement of surfactin production from Bacillus subtilis ATCC 21332. Up to 3000 mg L−1 of surfactin was produced using an iron‐enriched minimal salt (MS) medium amended with an optimal Fe2+ dosage of 4.0 mM, leading to 8‐fold and 10‐fold increase in cell concentration and surfactin yield, respectively, as compared to those without Fe2+ supplement. In addition to resulting in an optimal production yield of surfactin, a supplement of 4.0 mM of Fe2+ also propelled maximum overall surfactin production rate to a highest value of 24 mg L−1 h−1. Our results also show that production of surfactin followed a growth‐associated kinetic model. The best yield coefficient estimated from the model was ca. 162 mg surfactin (g dry cell)−1. The supernatant of the iron‐enriched culture of B. subtilis ATCC 21332 exhibited the ability to emulsify kerosene and achieved a maximum emulsion index ( E24) of 80% for culture supplemented with 4.0 mM of Fe2+. Comparison of emulsion index and the corresponding surfactin production indicates that the emulsification activity was essentially contributed by surfactin.