Surfactant supplementation to enhance the production of vitamin [K.sub.2]] metabolites in shake flask cultures using Escherichia sp. mutant FM3-1709

• Published in: Food technology and biotechnology Vol. 52; no. 3; p. 269
• Main Authors: Liu, Yan, Zheng, Zhi-Ming, Qiu, Hong-Wei, Zhao, Gen-Hai, Wang, Peng, Wang, Li, Li, Zhe-Min, Wu, He-Fang, Liu, Hong-Xia, Tan, Mu
• Format: Journal Article
• Language: English
• Published: Sveuciliste U Zagrebu 01.07.2014
• Subjects: Bacteriology; Cultures and culture media; Escherichia coli; Production processes; Surface active agents; Vitamin K
• ISSN: 1330-9862; 1334-2606

The effects of the addition of various surfactants on the cell growth and production of vitamin [K.sub.2]] metabolites, such as intracellular menaquinone-4 (MK-4), extracellular MK-4, intracellular MK-6 and extracellular MK-6, were studied in the submerged culture of Escherichia sp. All of the added surfactants caused the extension of the exponential phase. Betaine, polyoxyethylene oleyl ether and Tween-80 were favourable to the cell growth of Escherichia sp. mutant strain FM3-1709. The highest cell growth ([X.sub.max]), biomass production rate (Qx) and biomass yield ([Y.sub.x/s]) were (12.6 ± 0.2) g/L, (0.21 ± 0.01) g/(L-h) and (2.42 ± 0.02) g/g, respectively. The results show that the addition of all surfactants led to a lower production of intracellular MK-4, whereas the production of extracellular MK-4 increased remarkably. Among the five investigated surfactants, the addition of the nonionic surfactant polyoxyethylene oleyl ether (1.0 g/L) led to the highest production of extracellular MK-4 ((33.6 ± 0.4) mg/L), MK-6 ((2.56 ± 0.07) mg/L) and the highest yield of total MK-4 ((47.6 ± 0.4) mg/L) and Mk-6 ((6.0 ± 0.1) mg/L). The addition of polyoxyethylene oleyl ether proved to be more beneficial for the secretion of MK-4 than MK-6. Key words: surfactant, vitamin [K.sub.2]], shake flask cultures