Respiration activity monitoring system (RAMOS), an efficient tool to study the influence of the oxygen transfer rate on the synthesis of lipopeptide by Bacillus subtilis ATCC6633

• Published in: Journal of biotechnology Vol. 134; no. 1; pp. 121 - 126
• Main Authors: Guez, J.S., Müller, C.H., Danze, P.M., Büchs, J., Jacques, P.
• Format: Journal Article Web Resource
• Language: English
• Published: Lausanne Elsevier B.V 20-03-2008; Amsterdam [New York, NY]: Elsevier; New York, NY Elsevier; Elsevier Science
• Subjects: Bacillus subtilis; Bacillus subtilis - metabolism; Bacteriology; Biological and medical sciences; Bioreactors - microbiology; Biosurfactant lipopeptide; Biotechnologie; Biotechnology; Chemical and Process Engineering; Engineering Sciences; Fundamental and applied biological sciences. Psychology; Life Sciences; Lipopeptides; Lipoproteins - biosynthesis; Lipoproteins - metabolism; Microbiology and Parasitology; Mycosubtilin; Oxygen - metabolism; Oxygen transfer rate; Peptides, Cyclic - metabolism; RAMOS; Sciences du vivant; Transcript analysis; Transcription, Genetic - genetics; RAMOS; Oxygen transfer rate; Biosurfactant lipopeptide; Bacillus subtilis; Mycosubtilin; Transcript analysis; Oxygen transfer; Bacillaceae; Biosurfactant; Messenger RNA; Bacillales; Bacteria; Respiration; Lipopeptide; Monitoring
• ISSN: 0168-1656; 1873-4863; 1873-4863
• DOI: 10.1016/j.jbiotec.2008.01.003

The effect of oxygen transfer rate (OTR) on the synthesis of mycosubtilin, a non ribosomal lipopeptide antifungal biosurfactant, was investigated in the respiration activity monitoring system (RAMOS) for two
Bacillus subtilis strains. These cultures were performed under definite oxygen-limited conditions without the adding of any anti-foam in the culture medium. By using four different filling volumes (FV) in the shaken bioreactors, different levels (20, 14, 9 and 7
mmol O
2
l
−1
h
−1) of oxygen-limited growth could be obtained. A 25-fold increase of the specific productivity of mycosubtilin was observed for
B. subtilis ATCC6633 in the case of the most severe oxygen limitation. But nearly no effect could be found with strain BBG100 carrying the constitutive P
repU
promoter instead of the natural P
myc
promoter. Transcript analysis of the
fenF gene belonging to the
myc operon indicated that the P
myc
promoter regulation could be slightly oxygen sensitive. Additionally, different patterns of the synthetised mycosubtilin homologues were obtained for different level of oxygen-limited growths. At the present state of investigation, oxygen regulation was thus shown to act at different levels suggesting the existence of a complex regulatory system of NRPS lipopeptide synthesis in the natural
B. subtilis ATCC6633 strain.