Microoranism Screening To Degradate Deoxynivalenol And Its Effects On Piglets Fed Diet Contaminated With Deoxynivalenol

Deoxynivalenol（DON）is a widely distrubted mycotoxin.It is also called vomiting toxin because it can cause vomiting in pigs.DON is a toxic secondary metabolite produced by fungi such as Fusarium spp.It is mainly found in grains and processed products.It has serious health problems to humans and livestock.DON can induce cell apoptosis,cause oxidative stress,anddestroy the immune system.Biodegradation of DON into less-or non-toxic substances using microorganisms is considered the best approach for DON detoxification.Althogh various microoganisms capable of detoxifying DON have been reported,the microorgnisms suitable for applying in the food or feed directly are scarce.In this study,we aimed to isolate and screen DON-degrading bacteria from natural samples and tested its degradation ablity in vitro and in vivo,and then provide foundation for this bacteria as new feed additive to address DON contamination.The results of the study are as follows:1.Screening and identification of DON degrading bacteriaThe bacterial strain（ASAG 216）showed to possess the capability of detoxifying 100μg/m L DON by 81.1%within 8 h was isolated from the intestine of a donkey.After morphological observation and 16S r DNA sequence analysis,the strain was identified as Bacillus subtilis.2.Study on the characteristics of B.subtilis ASAG 216 on degrading DONThe B.subtilis ASAG 216 has a broad temperature（35～50℃）and p H（6.5～9.0）tolerance on DON degradation,apart from its ability to withstand conditions which generally prevail during the intestinal transit.In addition,B.subtilis ASAG 216 showed antibacterial activity on Escherichia coli,Salmonella typhimurium,and Staphylococcus aureus.Moreover,the DON-degradation ability of B.subtilis ASAG 216 could be contributed to dehydrogenases in the supernatant.3.Ameliorative effects of B.subtilis ASAG 216 on DON-induced mycotoxicosis in pigletsIn order to further explore whether Bacillus subtilis ASAG 216 can play a role in animals,a test was carried out with piglets as the test subject,and it was found that the average daily gain（ADG）and average daily feed intake（ADFI）of piglets fed DON-contaminated feed significantly decreased（P<0.05）,serum aspartate aminotransferase（AST）,immunoglobulin A（Ig A）,diamine oxidase（DAO）,Peptide YY（PYY）and methane dicarboxylate The content of acid aldehyde（MDA）increased significantly（P<0.05）,the concentration of hydrogen peroxide（H₂O₂）in the liver increased significantly（P<0.05）,and the content of total glutathione peroxidase（GPx）decreased significantly（P<0.05）,adding Bacillus subtilis ASAG 216 to the DON-contaminated diet to restore the above indicators to normal.In summary,the Bacillus subtilis ASAG 216 screened in this study not only has the ability to efficiently degrade DON in vitro,but also can relieve the DON-induced piglets mycotoxicosis in vivo.This study laid a theoretical foundation for the application of Bacillus subtilis ASAG 216.