Host-associated probiotics(HAPs)are bacteria originally isolated from rearing water or the host's gastrointestinal tract in order to enhance the host's growth and health.This study investigated the HAP potenti...Host-associated probiotics(HAPs)are bacteria originally isolated from rearing water or the host's gastrointestinal tract in order to enhance the host's growth and health.This study investigated the HAP potential of Bacillus sp.PM8313,isolated from wild red sea bream(Pagrus major),through characterization and feeding trials.Results based on in vitro tests showed that PM8313 is safe,confirming its hemolytic,cytotoxic,and antibiotic resistance.In addition,PM8313 showed advantages as a probiotic with high viability in the gastrointestinal model and a high cell adhesion rate.Whole-genome sequencing demonstrated that PM8313 has a 4,615,871 bp single circular chromosome and a guaninecytosine content of 45.25%.It also showed the absence of genes encoding virulence factors,such as cytotoxin,enterotoxin,hemolysin,sphingomyelinase,and phospholipase.In the feeding trial,a supplemental diet of 1×10^(8)CFU/g PM8313 positively altered the weight gain,digestive enzyme activity,and intestinal microbiota composition of red sea bream.Analysis of nonspecific immune parameters and immune-related gene expression,and a challenge test showed that PM8313 supplementation increases immunity and pathogenic bacteria resistance.Our findings suggest that PM8313 should be considered for application as a novel HAP to red sea bream aquaculture.展开更多
基金financially supported by the grant (R2022016) from the National Institute of Fisheries Science,Republic of Koreathe National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2022R1A2C1012655).
文摘Host-associated probiotics(HAPs)are bacteria originally isolated from rearing water or the host's gastrointestinal tract in order to enhance the host's growth and health.This study investigated the HAP potential of Bacillus sp.PM8313,isolated from wild red sea bream(Pagrus major),through characterization and feeding trials.Results based on in vitro tests showed that PM8313 is safe,confirming its hemolytic,cytotoxic,and antibiotic resistance.In addition,PM8313 showed advantages as a probiotic with high viability in the gastrointestinal model and a high cell adhesion rate.Whole-genome sequencing demonstrated that PM8313 has a 4,615,871 bp single circular chromosome and a guaninecytosine content of 45.25%.It also showed the absence of genes encoding virulence factors,such as cytotoxin,enterotoxin,hemolysin,sphingomyelinase,and phospholipase.In the feeding trial,a supplemental diet of 1×10^(8)CFU/g PM8313 positively altered the weight gain,digestive enzyme activity,and intestinal microbiota composition of red sea bream.Analysis of nonspecific immune parameters and immune-related gene expression,and a challenge test showed that PM8313 supplementation increases immunity and pathogenic bacteria resistance.Our findings suggest that PM8313 should be considered for application as a novel HAP to red sea bream aquaculture.
