# Analysis of Bacterial Diversity in Jersey Cow Colostrum and Mature Milk and the Study of the Probiotic Functions of Ligilactobacillus salivarius CR29

## TL;DR

This study analyzed bacteria in Jersey cow milk and found a promising probiotic strain, Ligilactobacillus salivarius CR29, with strong antibacterial properties and good survival in harsh conditions.

## Contribution

The study identifies Ligilactobacillus salivarius CR29 as a novel probiotic strain with strong antibacterial activity and high survival in simulated gastrointestinal conditions.

## Key findings

- Nine lactic acid bacterial strains showed probiotic potential, with CR29 exhibiting the strongest antibacterial activity.
- CR29 had high survival rates under 0.3% bile salt (56.28%) and pH 2 (77.59%) conditions.
- CR29 survived 47.86% after simulated gastrointestinal passage and showed no hemolytic activity.

## Abstract

This study used 16S rDNA high‐throughput sequencing to analyze the bacterial diversity of Jersey cow colostrum and mature milk, and evaluated the probiotic properties of Ligilactobacillus salivarius CR29 isolated from the samples. The bacterial community structure of the Jersey cow milk samples was analyzed, and lactic acid bacteria were isolated using MRS medium. The potential probiotic strains were evaluated for growth, acid production, hemolytic activity, antibacterial activity, antibiotic sensitivity, acid and bile tolerance, hydrophobicity, autoaggregation and coaggregation abilities, as well as their survival in a simulated gastrointestinal environment. The results showed that nine lactic acid bacterial strains isolated from the milk samples exhibited probiotic potential, among which Ligilactobacillus salivarius CR29 showed no hemolysis and had strong antibacterial activity, significantly inhibiting several pathogens compared to other strains. CR29 was sensitive to multiple antibiotics (such as tetracycline and rifampicin), and its survival rates under 0.3% bile salt and pH 2 conditions were 56.28% and 77.59%, respectively. Its survival rate after simulated gastrointestinal passage was 47.86%. In summary, Ligilactobacillus salivarius CR29 demonstrated excellent probiotic potential and may be applied in functional foods and health‐related fields in the future.