AUTHOR=Zhang Yan , Liang Shuang , Zhao Meng Di , Yang Xue , Choi Seong Ho , Li Guang Yu 

TITLE=Screening and Identification of Latilactobacillus curvatus Z12 From Rumen Fluid of an Adult Female Sika Deer as a Potential Probiotic for Feed Additives

JOURNAL=Frontiers in Veterinary Science

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2021.753527

DOI=10.3389/fvets.2021.753527

ISSN=2297-1769

ABSTRACT=<p>Lactic acid bacteria (LAB) are the main microorganisms used as probiotics against gastrointestinal inflammation. The objective of this study was to evaluate the potential probiotic characteristics (antimicrobial activity, artificial gastrointestinal model resistance, cell surface hydrophobicity, and autoaggregation ability) and safety characteristics (hemolytic activity, antimicrobial resistance, and <italic>in vivo</italic> safety) of LAB isolated from the rumen fluid of an adult female sika deer. Two isolated strains identified as <italic>Latilactobacillus curvatus Z12</italic> and <italic>Z19</italic> showed good antimicrobial activity against enteropathogenic <italic>Escherichia coli</italic> (ATCC25922), <italic>Salmonella typhi</italic> (ATCC14028), and <italic>Staphylococcus aureus</italic> (ATCC25923). In addition, <italic>L. curvatus Z12</italic> exhibited higher artificial gastrointestinal model resistance, cell surface hydrophobicity and autoaggregation ability than <italic>L. curvatus Z19</italic>. Therefore, regarding safety characteristics, only <italic>L. curvatus Z12</italic> was evaluated. Upon assessment of safety, <italic>L. curvatus Z12</italic> was negative for hemolytic activity and susceptible to penicillin G and cefamandole. Furthermore, an <italic>in vivo</italic> safety assessment showed that high-dose <italic>L. curvatus Z12</italic> (10<sup>9</sup> CFU/mL) supplementation not only had no adverse effects on body weight gain, feed intake, and organ coefficients of treated mice but also played a key role in promoting the immune system maturation of treated mice. This research revealed that <italic>L. curvatus Z12</italic> possesses desirable probiotic characteristics and could be used as a potential probiotic feed additive to improve sika deer health.</p>