NADH Oxidase of Streptococcus thermophilus 1131 is Requiredfor the Effective Yogurt Fermentation with Lactobacillus delbrueckiisubsp. bulgaricus 2038

Bioscience of Microbiota, Food and Health

Hiroshi HORIUCHI²  Yuji YAMAMOTO³  Yasuko SASAKI¹  Takao MUKAI³  Hiroko KAWASHIMA² 

[1] School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan;Food Science Institute, Meiji Co., Ltd., 540 Naruda, Odawara, Kanagawa 250-0862, Japan;School of Veterinary Medicine, Kitasato University, 35-1 Higashi 23, Towada, Aomori, 034-8628, Japan

关键词: yogurt fermentation;    NADH oxidase;    Lactobacillus delbrueckii subsp. bulgaricus;    Streptococcus thermophilus;   

DOI  :  10.12938/bmfh.33.31

学科分类：生物科学（综合）

来源: Nihon Bifizusukin Senta / Japan Bifidus Foundation

【 摘 要 】

References(47)Cited-By(3)We previously reported that dissolved oxygen (DO) suppresses yogurt fermentation with anindustrial starter culture composed of Lactobacillus delbrueckii subsp.bulgaricus (L. bulgaricus) 2038 andStreptococcus thermophilus 1131, and also found that reducing the DO inthe medium prior to fermentation (deoxygenated fermentation) shortens the fermentationtime. In this study, we found that deoxygenated fermentation primarily increased the cellnumber of S. thermophilus 1131 rather than that of L.bulgaricus 2038, resulting in earlier l-lactate and formateaccumulation. Measurement of the DO concentration and hydrogen peroxide generation in themilk medium suggested that DO is mainly removed by S. thermophilus 1131.The results using an H2O-forming NADH oxidase (Nox)-defective mutant ofS. thermophilus 1131 revealed that Nox is the major oxygen-consumingenzyme of the bacterium. Yogurt fermentation with the S. thermophilusΔnox mutant and L. bulgaricus 2038 was significantly slowerthan with S. thermophilus 1131 and L. bulgaricus 2038,and the DO concentrations of the mixed culture did not decrease to less than 2 mg/kgwithin 3 hr. These observations suggest that Nox of S. thermophilus 1131contributes greatly to yogurt fermentation, presumably by removing the DO in milk.

【 授权许可】

Unknown