Wereport the evaluation of probiotic properties of potent lactic acid bacteria (LAB) from the gut of freshwater fishes, Labeo rohita and Catla catla, for eventually developing probiotic strains for the prevention of bacterial infections...
moreWereport the evaluation of probiotic properties of
potent lactic acid bacteria (LAB) from the gut of freshwater
fishes, Labeo rohita and Catla catla, for eventually developing
probiotic strains for the prevention of bacterial infections
in aquaculture and food preservation. Five different LAB
strains were isolated and characterized for their probiotic
properties. Based on physiological, morphological and biochemical
characteristics, three isolates from Labeo rohita and
two fromCatla catla were identified as putative probiotics and
were denoted as LR11, LR14 and LR16 and CC3 and CC4,
respectively. Isolates CC3 and CC4 were acid (pH 2.5) and
bile salt (0.3 % oxygall) tolerant and exhibited strong antibacterial
activities against all pathogens including Aeromonas
hydrophila. In addition, all LAB isolates were susceptible to
tested antibiotics, except CC3 and CC4 which were vancomycin
resistant. Furthermore, the isolates CC3 and CC4
showed significantly higher in vitro cell surface properties,
i.e., hydrophobicity, auto- and co-aggregation. Biochemical
tests, PCR detection and 16S rRNA sequence analysis established
that LR11, LR14, LR16, CC3 and CC4 are Enterococcus
avium TSU11, Enterococcus pseudoavium TSU14,
Enterococcus raffinosus TSU16, Lactobacillus gasseri TSU3
and Lactobacillus animalis TSU4, respectively. Studies
revealed that, Lactobacillus gasseri TSU3 and Lactobacillus
animalis TSU4 are ideal probiotic candidates for its use in
aquaculture and require further exploratory in vivo evaluation
and safety studies.
