title: Alkyl hydroperoxide reductase enhances the growth of Leuconostoc mesenteroides lactic acid bacteria at low temperatures.
abstract: Lactic acid bacteria (LAB) can cause deterioration of food quality even at low temperatures. In this study, we investigated the cold-adaptation mechanism of a novel food spoilage LAB, Leuconostoc mesenteroides NH04 (NH04). L. mesenteroides was isolated from several spoiled cooked meat products at a high frequency in our factories. NH04 grew rapidly at low temperatures within the shelf-life period and resulted in heavy financial losses. NH04 grew more rapidly than related strains such as Leuconostoc mesenteroides NBRC3832 (NBRC3832) at 10°C. Proteome analysis of NH04 demonstrated that this strain produces a homolog of alkyl hydroperoxide reductase--AhpC--the expression of which can be induced at low temperatures. The expression level of AhpC in NH04 was approximately 6-fold higher than that in NBRC3832, which was grown under the same conditions. Although AhpC is known to have an anti-oxidative role in various bacteria by catalyzing the reduction of alkyl hydroperoxide and hydrogen peroxide, the involvement of AhpC in cold adaptation of food spoilage bacteria was unclear. We introduced an expression plasmid containing ahpC into NBRC3832, which grows slower than NH04 at 10°C, and found that expression of AhpC enhanced growth. These results demonstrated that AhpC, which likely increases anti-oxidative capacity of LAB, plays an important role in their rapid growth at low temperatures.
authors: Product Development Laboratory, NH Foods Ltd., Chikusei, Ibaraki 308-0042 Japan.
authors: Seitaro
authors: S
authors: Goto
authors: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 Japan.
authors: Jun
authors: J
authors: Kawamoto
authors: Research Center for Low Temperature and Materials Sciences, Kyoto University, Kyoto, 606-8501 Japan.
authors: Satoshi B
authors: SB
authors: Sato
authors: Product Development Laboratory, NH Foods Ltd., Chikusei, Ibaraki 308-0042 Japan.
authors: Takashi
authors: T
authors: Iki
authors: Product Development Laboratory, NH Foods Ltd., Chikusei, Ibaraki 308-0042 Japan.
authors: Itaru
authors: I
authors: Watanabe
authors: Product Development Laboratory, NH Foods Ltd., Chikusei, Ibaraki 308-0042 Japan.
authors: Kazuyuki
authors: K
authors: Kudo
authors: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 Japan.
authors: Nobuyoshi
authors: N
authors: Esaki
authors: Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 Japan.
authors: Tatsuo
authors: T
authors: Kurihara
keywords: AhpC; Cold adaptation; Food spoilage; Lactic acid bacteria