Preliminary selection for potential probiotic Bifidobacterium isolated from subjects of different Chinese ethnic groups and evaluation of their fermentation and storage characteristics in bovine milk.
A total of 29 strains of Bifidobacterium were isolated from 18 samples of human feces in different ethnic minority regions of China. All isolates were identified as Bifidobacterium longum (9 strains) and Bifidobacterium pseudocatenulatum (20 strains) based on 16S rRNA gene sequencing and phylogenetic analysis. These strains were preliminarily tested for their suitability to become probiotics by assessing their ability to survive adequately at low pH conditions and their tolerance of different concentrations of bile salts and simulated gastrointestinal juices. In vitro tests were sequentially used to predict the survival of these strains in the simulated conditions in the human gastrointestinal tract. These strains were first exposed to pH 2.5 for 3h, and 7 out of the 29 strains were discriminated from the others by their high survival rates. Out of these 7 strains, 4 were found to grow and survive well at an even lower pH of 2.0 and in high bile salt concentration. Apart from the gastrointestinal survival capacity, both fermentation efficiency and storage characteristics are important criteria for selecting for suitable potential probiotic strains. Therefore, the fermentation efficiency in bovine milk and the bacterial viability during the storage in the resultant fermented milk were also evaluated for these 4 selected strains. In this study, we isolated and identified 29 novel Bifidobacterium strains. Based on our initial evaluation, at least 4 of them may serve as valuable resources for further dairy probiotic strain selection.
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
W J
WJ
Liu
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
Y F
YF
Chen
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
L Y
LY
Kwok
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
M H
MH
Li
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
T
T
Sun
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
C L
CL
Sun
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
X N
XN
Wang
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
T
T
Dan
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
Menghebilige
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China.
H P
HP
Zhang
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University; Dairy Processing Laboratory of National Dairy Production Technology and Research Center, Inner Mongolia, Hohhot, 010018, China. Electronic address: sts9940@sina.com.
T S
TS
Sun
D000818:Animals; D001644:Bifidobacterium / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D001647:Bile Acids and Salts / Q000494:pharmacology; D002681:China; D005006:Ethnicity; D005243:Feces / Q000382:microbiology; D005285:Fermentation; D005511:Food Handling; D041981:Gastrointestinal Tract / Q000382:microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D050296:Microbial Viability / Q000187:drug effects; D008892:Milk / Q000382:microbiology*; D010802:Phylogeny; D019936:Probiotics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013997:Time Factors
D001647:Bile Acids and Salts; D012336:RNA, Ribosomal, 16S
Bifidobacterium; fermentation and storage characteristics; human origin; potential probiotic