Autochthonous Lactobacillus spp. isolated from Murrah buffalo calves show potential application as probiotic


Lactic acid bacteria (LAB) are applied as probiotics that stimulate digestion, immunity and represents suitable alternatives to conventional antimicrobials in animal production systems. The present study aimed to isolate, characterize, and examine the prospective LAB from Murrah buffalo calves’ faecal samples as potential species-specific probiotics. Accordingly, 96 lactobacilli strains were isolated; out of which 55 isolates were Gram-positive, catalase-negative and vancomycin-resistant. These isolates had been presumptively identified as Lactobacillus species and further confirmed by genus-specific PCR. Seventeen isolates were shortlisted based on cell surface hydrophobicity (CSH) and auto-aggregation properties and identified by 16S rDNA sequencing. Cluster analysis from the phylogenetic tree revealed four different groups comprising of L. reuteri (11), L. salivarius (4), L. mucosae (1) and L. agilis (1). Out of these, seven isolates were non-hemolytic and showed better resistance to adverse gastrointestinal tract (GIT) conditions viz. tolerance to pH, bile salts and phenol. The selected isolates also exhibited significant (P < 0.05) co-aggregation abilities with antimicrobial activity against the pathogenic strain of E. coli. All the selected LAB were susceptible to all antibiotics tested except three isolates. BF-17 was resistant to cefadroxil whereas BF-26 against amikacin and cefadroxil, and BF-J17 to ciprofloxacin and norfloxacin. In addition to that, these isolates showed optimal enzyme secreting activities (amylase and protease) except BF-14 strain. Principal component analysis (PCA) based on probiotic phenotypic data, selected L. reuteri BF-H9 and L. salivarius BF-17 as most promising novel probiotic candidates and requires further in vivo evaluation. These Lactobacillus isolates could be used as probiotics by adding them into premix, mineral blends, and concentrates in lyophilized form, or they could be used to produce fermented milk for young calves.

Read full text: Anukarna Singh, Sachin Kumar, V.V. Vinay, Bhawna Tyagi, Prasanta Kumar Choudhury, H.M. Rashmi, P.S. Banakar, Nitin Tyagi, Amrish Kumar Tyagi, Autochthonous Lactobacillus spp. isolated from Murrah buffalo calves show potential application as probiotic, Current Research in Biotechnology, Volume 3, 2021, Pages 109-119,