title: Effect of temperature on continuous fermentative lactic acid (LA) production and bacterial community, and development of LA-producing UASB reactor.
abstract: A frequently used fermentation manner in lactic acid (LA) production, batch fermentation by pure cultures, has a limited practicability: low volumetric productivity and high energy consumption. In this study, continuous LA fermentation was performed in a completely stirred tank reactor at 12h HRT, inoculated with anaerobic digester sludge. Glucose (25 g COD/L) was used as a feedstock and temperature was increased from 35 to 60°C. LA production significantly increased from 50°C, which was negligible up to 45°C, with obvious bacterial community change. At 50 and 55°C, LA production was maximized, reaching 23 g COD/L, corresponding to 92% LA conversion efficiency. Pyrosequencing analysis showed that microbial diversity was simplified at 50-60°C, and the sequences closely related with Bacillus coagulans became predominant, followed by Lactobacillus fermentum. An LA-producing upflow ananerobic sludge blanket reactor was successfully developed, which enhanced the productivity up to 4.8 gLA/L/h by shortening HRT to 4h.
authors: Clean Fuel Department, Korea Institute of Energy Research, 102 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea.
authors: Dong-Hoon
authors: DH
authors: Kim
authors: Wan-Taek
authors: WT
authors: Lim
authors: Mo-Kwon
authors: MK
authors: Lee
authors: Mi-Sun
authors: MS
authors: Kim
mesh_terms: D001421:Bacteria, Anaerobic / Q000502:physiology*; D019149:Bioreactors / Q000382:microbiology*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D019344:Lactic Acid / Q000096:biosynthesis* / Q000302:isolation & purification; D059013:Microbial Consortia / Q000502:physiology*; D012722:Sewage / Q000382:microbiology*; D013696:Temperature
chemical_list: D012722:Sewage; D019344:Lactic Acid