Identification and Characterization of Lactic Acid Bacteria (LAB) Isolated from Probiotic Drinks in Malaysia
- Author:
Wei Boon Yap
;
Rina Anak Sujang
;
Toong Seng Tan
- Publication Type:Journal Article
- Keywords:
Probiotics;
lactic acid bacteria;
antimicrobial;
acid tolerances
- MeSH:
Probiotics
- From:Malaysian Journal of Health Sciences
2015;13(1):23-31
- CountryMalaysia
- Language:English
-
Abstract:
Many studies have shown that probiotic strains added to a number of probiotic products are not compatible to that of
claimed. It is thus of note to validate probiotic strains added to probiotic products. In this study, three probiotic drinks,
A, B and C, were cultured on MRS agar and the number of bacterial colonies was enumerated. The bacterial counts
recovered from A (9.3 ± 6.9 log CFU/ml) and C (9.0 ± 6.9 log CFU/ml) were signifi cantly higher than B (5.2 ± 3.5 log
CFU/ml) and achieved the minimal amount recommended for probiotic bacteria. All of the isolates appeared as gram
positive rods microscopically and were proven to be catalase negative. However, there were only A1, A2, B4 and C1 that
were highly tolerant to the gastrointestinal pH 3 to 6. The four isolates produced and secreted antimicrobial substances
which inhibited the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). C1 showed the greatest
growth inhibition by forming 17.50-mm and 17.85-mm inhibition zones against E. coli and S. aureus, respectively. The
16s rDNA sequencing and phylogenetic analysis were performed to further identify the twelve isolates. The twelve isolates
were found to be Lactobacillus (L.), particularly L. casei and L. paracasei. However, the bacteria isolated from drink B
were incompatible to the labelled ones. In conclusion, probiotic drinks are possible to contain different bacterial counts
and probiotic strains from the labelled ones. These differences might affect health benefi ts rendered by probiotic strains
to consumers.
- Full text:W020150624346602271270.pdf
