Novel pH control strategy for efficient production of optically active l-lactic acid from kitchen refuse using a mixed culture system. (September 2016)

• Record Type: Journal Article
• Authors: Tashiro, Yukihiro; Inokuchi, Shota; Poudel, Pramod; Okugawa, Yuki; Miyamoto, Hirokuni; Miayamoto, Hisashi; Sakai, Kenji
• Is Part Of: Bioresource technology. Volume 216(2016)
• Page Start: 52
• Page End: 59
• Publication Date: 2016-09
• Subjects: LA lactic acid -- OP optical purity -- SLA selectivity of LA -- MKR model kitchen refuse; l-lactic acid production -- Novel pH control strategy -- Mixed culture -- Kitchen refuse; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.05.031
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Not-yet reported factors were investigated forl -LA production in meta-fermentation. l -LA production with 100% optically purity was achieved without sterilization. Constant pH control strategy did not improvel -LA production in meta-fermentation. Novel pH control by switching from swing to constant was the most efficient method. We indicated the importance of unusual manner of meta-fermentation system differently from pure culture system. Abstract: Uninvestigated control factors of meta-fermentation, the fermentative production of pure chemicals and fuels in a mixed culture system, were examined for production of optically purel -lactic acid (LA) from food waste. In meta-fermentations by pH swing control, l -LA production with 100% optical purity (OPl -LA ) was achieved even using unsterilized model kitchen refuse medium with preferential proliferation ofl -LA-producing Bacillus coagulans, a minor member in the seed, whereas agitation decreased OPl -LA drastically. pH constant control shortened the fermentation time but decreased OPl -LA and LA selectivity (SLA ) by stimulating growth of heterofermentative Bacillus thermoamylovorans . Deliberately switching from pH swing control to constant control exhibited the best performance forl -LA production: maximum accumulation, 39.2 g L −1 ; OPl -LA, 100%; SLA, 96.6%; productivity, 1.09 g L −1 h −1 . These results present a novel pH control strategy for efficientl -LA production in meta-fermentation based on a concept different from that of pure culture systems.