Affiliation:
1. Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University , No. 600, Changjiang Road, Harbin 150030 , China
2. Yangzhou Yangda Kangyuan Dairy Co., Ltd , No. 88, Dingxing Road, Guangling District, Yangzhou 225004 , China
3. Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences , Wanning 571533 , China
Abstract
Abstract
Aims
During fermentation, the accumulation of acidic products can induce media acidification, which restrains the growth of Bifidobacterium animalis subsp. lactis Bb12 (Bb12). This study investigated the nutrient consumption patterns of Bb12 under acid stress and effects of specific nutrients on the acid resistance of Bb12.
Methods and results
Bb12 was cultured in chemically defined medium (CDM) at different initial pH values. Nutrient consumption patterns were analyzed in CDM at pH 5.3, 5.7, and 6.7. The patterns varied with pH: Asp + Asn had the highest consumption rate at pH 5.3 and 5.7, while Ala was predominant at pH 6.7. Regardless of the pH levels (5.3, 5.7, or 6.7), ascorbic acid, adenine, and Fe2+ were vitamins, nucleobases, and metal ions with the highest consumption rates, respectively. Nutrients whose consumption rates exceeded 50% were added individually in CDM at pH 5.3, 5.7, and 6.7. It was demonstrated that only some of them could promote the growth of Bb12. Mixed nutrients that could promote the growth of Bb12 were added to three different CDM. In CDM at pH 5.3, 5.7, and 6.7, it was found that the viable cell count of Bb12 was the highest after adding mixed nutrients, which were 8.87, 9.02, and 9.10 log CFU ml−1, respectively.
Conclusions
The findings suggest that the initial pH of the culture medium affects the nutrient consumption patterns of Bb12. Specific nutrients can enhance the growth of Bb12 under acidic conditions and increase its acid resistance.
Funder
Enterprise innovation projects
Publisher
Oxford University Press (OUP)
Cited by
1 articles.
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