title: Screening of Cholesterol-lowering Bifidobacterium from Guizhou Xiang Pigs, and Evaluation of Its Tolerance to Oxygen, Acid, and Bile.
abstract: Cardiovascular and cerebrovascular diseases seriously harm human health, and Bifidobacterium is the most beneficial probiotic in the gastrointestinal tract of humans. This work aimed to screen cholesterol-lowering Bifidobacterium from Guizhou Xiang Pig and evaluate its tolerance to oxygen, acid, and bile. Twenty-seven aerotolerant strains with similar colony to Bifidobacterium were isolated through incubation at 37℃ in 20% (v/v) CO2-80% (v/v) atmospheric air by using Mupirocin lithium modified MRS agar medium, modified PTYG with added CaCO3, and modified PTYG supplemented with X-gal. Ten strains with cholesterol-lowering rates above 20% (w/w) were used for further screening. The selected strains' tolerance to acid and bile was then determined. A combination of colony and cell morphology, physiological, and biochemical experiments, as well as 16S rRNA gene-sequence analysis, was performed. Results suggested that BZ25 with excellent characteristics of high cholesterol-removal rate of 36.32% (w/w), as well as tolerance to acid and bile, was identified as Bifidobacterium animalis subsp. lactis. To further evaluate Bifidobacterium BZ25's growth characteristic and tolerance to oxygen, culture experiments were performed in liquid medium and an agar plate. Findings suggested that BZ25 grew well both in environmental 20% (v/v) CO2-80% (v/v) atmospheric air and in 100% atmospheric air because BZ25 reached an absorbance of 1.185 at 600 nm in 100% atmospheric air. Moreover, BZ25 was aerotolerant and can grow in an agar medium under the environmental condition of 100% atmospheric air. This study can lay a preliminary foundation for the potential industrial applications of BZ25.
authors: College of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China; Key Laboratory of Agricultural and Animal Products Store & Processing of Guizhou Province, Guiyang 550025, China.
authors: Rujiao
authors: R
authors: Zhang
authors: College of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China; Key Laboratory of Agricultural and Animal Products Store & Processing of Guizhou Province, Guiyang 550025, China; Guizhou Province Key Laboratory of Fermentation Engineering and Biopharmacy, Guiyang 550025, China.
authors: Laping
authors: L
authors: He
authors: College of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China; Key Laboratory of Agricultural and Animal Products Store & Processing of Guizhou Province, Guiyang 550025, China.
authors: Ling
authors: L
authors: Zhang
authors: School of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, China.
authors: Cuiqin
authors: C
authors: Li
authors: College of Liquor and Food Engineering, Guizhou University, Guiyang 550025, China; Key Laboratory of Agricultural and Animal Products Store & Processing of Guizhou Province, Guiyang 550025, China.
authors: Qiujin
authors: Q
authors: Zhu
keywords: Bifidobacterium; Screening; and oxygen; bile; cholesterol; identification; tolerance to acid