Yang X.,Shanghai JiaoTong University |
Hang X.,Shanghai Jiao Da Onlly Company Ltd |
Tan J.,Shanghai JiaoTong University |
Yang H.,Shanghai JiaoTong University
Anaerobe | Year: 2015
Bifidobacteria are common inhabitants of the human gastrointestinal tract, and their application has increased dramatically in recent years due to their health-promoting effects. The ability of bifidobacteria to tolerate acidic environments is particularly important for their function as probiotics because they encounter such environments in food products and during passage through the gastrointestinal tract. In this study, we generated a derivative, Bifidobacterium breve BB8dpH, which displayed a stable, acid-resistant phenotype. To investigate the possible reasons for the higher acid tolerance of B.breve BB8dpH, as compared with its parental strain B.breve BB8, a combined transcriptome and physiological approach was used to characterize differences between the two strains. An analysis of the transcriptome by RNA-sequencing indicated that the expression of 121 genes was increased by more than 2-fold, while the expression of 146 genes was reduced more than 2-fold, in B.breve BB8dpH. Validation of the RNA-sequencing data using real-time quantitative PCR analysis demonstrated that the RNA-sequencing results were highly reliable. The comparison analysis, based on differentially expressed genes, suggested that the acid tolerance of B.breve BB8dpH was enhanced by regulating the expression of genes involved in carbohydrate transport and metabolism, energy production, synthesis of cell envelope components (peptidoglycan and exopolysaccharide), synthesis and transport of glutamate and glutamine, and histidine synthesis. Furthermore, an analysis of physiological data showed that B.breve BB8dpH displayed higher production of exopolysaccharide and lower H+-ATPase activity than B.breve BB8. The results presented here will improve our understanding of acid tolerance in bifidobacteria, and they will lead to the development of new strategies to enhance the acid tolerance of bifidobacterial strains. © 2015 Elsevier Ltd.
food and beverages not for medical use and purposes, namely, American ginseng, proceed ginsing used as an herb, soy and yeast-based food and food beverages not used as a milk substitute.
Usne Llc and SHANGHAI JIAO DA ONLLY Co. | Date: 2007-07-17
Herbal supplements; Vitamin and mineral supplements; Vitamin supplements; Vitamin tablets; Vitamins.
Dietetic beverages adapted for medical purposes, dietetic foods adapted for medical purposes, dietetic capsules adapted for medical purposes, dietetic substances adapted for medical use, nutritional additives for medical purposes, dietetic food preparations adapted for medical purposes, nutritive substances for microorganisms, tonics (medicine), biological preparations for medical purposes, for medical use for human purposes.