Probiotic potentiality of lactic acid bacteria isolated from Theki Dahi around various places of Pokhara valley
Date
2022
Authors
Journal Title
Journal ISSN
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Publisher
Department of Food Technology
Abstract
This research was undertaken to study the probiotic potentiality of lactic acid bacteria (LAB)
isolated from theki dahi around various places of Pokhara valley. A total of 48 samples were
collected from different locations, pooled together and finally examined accordingly. Based
on the morphological, biochemical and physiological characteristics, three types of
Lactobacilli (LAB A, B and C), two types of Leuconostoc (LEU A and B), two types of
Bifidobacterium (BIF A and B), one type of streptococci and three types of Lactococci (LCC
A, B and C) were identified. Also, probiotic strain of Lactobacillus casei sub sp. Shirota was
isolated from yakult sample. All the isolated microbes were then subjected to further
examination for probiotic potentiality test and compared to Lactobacillus casei sub sp.
Shirota.
All the bacteria were found to be Gram positive, catalase-oxidase negative, non-motile
bacteria, growing optimally at 30°C (expect Streptococcus thermophilus) and at 0% NaCl.
In terms of acid resistance, all of them were found to be resistant to low pH 2 and 4 for 2h
with a high resistance of LAB A and BIF B. Similarly, all of them were resistant to bile salt
(0.3% and 0.4%) and able to hydrolyze it. Among them, LAB A and BIF B showed high
resistance. With regard to antibiotic resistance, all of them were sensitive to penicillin G,
ampicillin and amoxicillin but only Lactobacilli and Bifidobacterium showed resistance to
ciprofloxacin. Finally, all the isolates were able to adhere to hexane. And, LAB A, BIF A
and BIF B showed high hydrophobicity. This study implies that theki dahi comprises variety
of LAB with probiotic properties. Statistically, in this study, LAB B and BIF A demonstrated
significantly similar probiotic properties (p<0.5) to the control organism. Thus, they can be
considered as potential candidate for probiotic organism in theki dahi. This research
ultimately helps to document as well as commercialize theki dahi as a potential probiotic
food of Nepal.
Description
Keywords
Probiotic potentiality, lactic acid, Theki Dahi