title: Cell-recycle continuous fermentation of Enterococcus faecalis RKY1 for economical production of lactic acid by reduction of yeast extract supplementation.
abstract: Both lactic acid productivity and cell growth were linearly correlated with yeast extract supplementation in batch fermentation. During conventional continuous operation, although fresh feed was introduced into the bioreactor with a significantly low dilution rate (0.04 h(-1)), the amount of yeast extract employed was not enough to maintain the growth of microorganism. However, when the fresh feed contained 100 g/l glucose and 2 g/l yeast extract during cell-recycle continuous operation at a dilution rate of 0.04 h(-1), more than 90 g/l lactic acid was continuously produced, with the average productivity of 3.72 g/l·h. In this experiment, 82 g of yeast extract (77% of reduction yield) could be reduced for the production of 1 kg of lactic acid compared with batch fermentation of a similar volumetric productivity.
authors.affiliation: Department of Food Science and Technology, Yeungnam University, Gyeongsan 712-749, Republic of Korea, Hazardous Substances Analysis Division, Daegu Regional Food and Drug Administration, Daegu 704-940, Republic of Korea.
authors.forename: Ryun-Kyung
authors.initials: RK
authors.lastname: Lee
authors.forename: Hwa-Won
authors.initials: HW
authors.lastname: Ryu
authors.forename: Hurok
authors.initials: H
authors.lastname: Oh
authors.forename: Mina
authors.initials: M
authors.lastname: Kim
authors.forename: Young-Jung
authors.initials: YJ
authors.lastname: Wee
mesh_terms: D061249:Batch Cell Culture Techniques; D019149:Bioreactors; D002453:Cell Cycle; D003470:Culture Media / Q000737:chemistry; D013293:Enterococcus faecalis / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D019344:Lactic Acid / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D019344:Lactic Acid