title: Enhancement of Exopolysaccharide Production of Lactobacillus fermentum TDS030603 by Modifying Culture Conditions.
abstract: To optimize culture conditions that enhance production of a highly viscous exopolysaccharide of Lactobacillus fermentum TDS030603, a chemically defined medium was examined. The best yield was found to be 199 ± 23 mg/l when 48-hr cultivation was microaerobically performed at 30°C in the chemically defined medium supplemented with 5% glucose and 1% ammonium citrate without pH control. In response to the optimized exopolysaccharide production, the mRNA expression levels of epsB, epsE, and epsG elevated significantly. Our results indicated that the optimal C/N ratio and/or microaerobic condition can alter the expression levels of several exopolysaccharide biosynthesis-related genes promoting the exopolysaccharide production yield.
authors.affiliation: Department of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Tala
authors.initials: T
authors.lastname: Shi
authors.affiliation: Department of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Ni Putu Desy
authors.initials: NP
authors.lastname: Aryantini
authors.affiliation: Research Center, Yotsuba Milk Products Co., Ltd., 465-1 Wako, Kitahiroshima, Hokkaido 061-1264, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Uchida
authors.affiliation: Department of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Tadasu
authors.initials: T
authors.lastname: Urashima
authors.affiliation: Department of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukuda
keywords: chemically defined medium; gene expression; highly viscous exopolysaccharide; probiotics