from indigenous fermented foods and human gut ... - Thapar University

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Chapter IV: Results
Fig. 4.1 (C) Effect of simulated gastric and intestinal transit on viability of L. helvictus
and L. fermentum. Arrows indicate addition of simulated gastric juice at time 0 h and
simulated duodenum juice after 1 h, respectively. The values shown mean of three
experiments. Bar represent the standard error.
4.4 Phenotypic identification of strains
Gram-positive, catalase-negative and rod-shaped bacteria which were able to survive
the passage through simulated gastric and duodenum juice in the in vitro gastrointestinal
model were further identified, and their probiotic characteristics were studied.
The selected strains were identified to the species-level by both phenotypic and
genotypic investigations. Two strains (LAM-1 and LAM-2) were selected for further studies
which stemmed from mango pickle, and they showed phenotypic properties typical of
Lactobacillus casei strains. Accordingly, these bacteria were rod-shaped, produced DL-
lactate, possessed mDAP in the cell walls and did not produce gas from glucose fermentation
(Table 4.3). These strains were able to ferment ribose, a pentose sugar, which implies that the
strains were facultatively heterofermentative Lactobacilli. In addition, two strains from
(Kharoli) fermented mashed mustard (LKH-2 and LKH-3) also showed similar characteristics
to L. delbrueckii indicating that these could also be characterised as presumptive L.
delbrueckii strains. These two strains not only fermented ribose, but also an additional
pentose sugar, i.e., arabinose (Table 4.3). Two other strains (LKH-5 and Lamec-29) which