Biological Characterization and Whole-Genome Analysis of Isolated from Mink Fecal Samples

is an important part of the gut microbiota and a commonly used probiotic. In the present study, to assess the biological characteristics and probiotic properties of derived from mink, we isolated isolate from fecal samples, characterized its biological characteristics, optimized the hydrolysis of casein by its crude extract, and comprehensively analyzed its potential as a probiotic in combination with whole-genome sequencing. Biological characteristics indicate that, under low-pH conditions (pH 2), can still maintain a survival rate of 64.75%; under the conditions of intestinal fluid, gastric acid, and a temperature of 70 °C, the survival rate was increased by 3, 1.15 and 1.17 times compared with the control group, respectively. This shows that it can tolerate severe environments. The results of hydrolyzed casein in vitro showed that the crude bacterial extract of isolate exhibited casein hydrolyzing activity (21.56 U/mL); the enzyme activity increased to 32.04 U/mL under optimized reaction conditions. The complete genome sequencing of was performed using the PacBio third-generation sequencing platform. Gene annotation analysis results revealed that was enriched in several Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways, and most genes were related to Brite hierarchy pathways (1485-35.31%) and metabolism pathways (1395-33.17%). The egg-NOG annotation revealed that most genes were related to energy production and conversion (185-4.10%), amino acid transport and metabolism (288-6.38%), carbohydrate transport and metabolism (269-5.96%), transcription (294-6.52%), and cell wall/membrane/envelope biogenesis (231-5.12%). Gene Ontology (GO) annotation elucidated that most genes were related to biological processes (8230-45.62%), cellular processes (3582-19.86%), and molecular processes (6228-34.52%). Moreover, the genome of was predicted to possess 77 transporter-related genes. This study demonstrates that has potential for use as a probiotic, and further studies should be performed to develop it as a probiotic additive in animal feed to promote animal health.