Transcriptome analysis revealed growth phase-associated changes of a centenarian-originated probiotic Bifidobacterium animalis subsp. lactis A6

BMC Microbiology

Hongxing Zhang¹  Chengfei Fan²  Jieran An²  Hui Wang²  Yanling Hao³  Zhengyuan Zhai³ 

[1] Department of Food Science, Beijing University of Agriculture, 7 Bei Nong Road, Changping District, 102206, Beijing, China;Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qing Hua East Road, Hai Dian District, 100083, Beijing, China;Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science and Nutritional Engineering, China Agricultural University, 17 Qing Hua East Road, Hai Dian District, 100083, Beijing, China;Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China;

关键词: Bifidobacterium animalis;    RNA-seq;    Growth phase;    Tad pili;    Adhesion;   

DOI  :  10.1186/s12866-022-02474-5

来源: Springer

【 摘 要 】

BackgroundThe physiology and application characteristics of probiotics are closely associated with the growth phase. Bifidobacterium animalis subsp. lactis A6 is a promising probiotic strain isolated from the feces of a healthy centenarian in China. In this study, RNA-seq was carried out to investigate the metabolic mechanism between the exponential and the stationary phase in B. lactis A6.ResultsDifferential expression analysis showed that a total of 815 genes were significantly changed in the stationary phase compared to the exponential phase, which consisted of 399 up-regulated and 416 down-regulated genes. The results showed that the transport and metabolism of cellobiose, xylooligosaccharides and raffinose were enhanced at the stationary phase, which expanded carbon source utilizing profile to confront with glucose consumption. Meanwhile, genes involved in cysteine-cystathionine-cycle (CCC) pathway, glutamate dehydrogenase, branched-chain amino acids (BCAAs) biosynthesis, and Clp protease were all up-regulated in the stationary phase, which may enhance the acid tolerance of B. lactis A6 during stationary phase. Acid tolerance assay indicated that the survival rate of stationary phase cells was 51.07% after treatment by pH 3.0 for 2h, which was 730-fold higher than that of 0.07% with log phase cells. In addition, peptidoglycan biosynthesis was significantly repressed, which is comparable with the decreased growth rate during the stationary phase. Remarkably, a putative gene cluster encoding Tad pili was up-regulated by 6.5 to 12.1-fold, which is consistent with the significantly increased adhesion rate to mucin from 2.38% to 4.90% during the transition from the exponential phase to the stationary phase.ConclusionsThis study reported growth phase-associated changes of B. lactis A6 during fermentation, including expanded carbon source utilizing profile, enhanced acid tolerance, and up-regulated Tad pili gene cluster responsible for bacterial adhesion in the stationary phase. These findings provide a novel insight into the growth phase associated characteristics in B. lactis A6 and provide valuable information for further application in the food industry.

【 授权许可】

CC BY