Isolation, Screening And Application Of Lactic Acid Bacteria For Inhibition Of Aspergillus Flavus In Silage

The whole plant corn silage is an indispensable foundation feed in the production of animal husbandry,especially in the ruminant feeding process.After the silage fermentation was completed,the herdsmen took the silage and exposed a large amount of air to the silage,so that the silage was fermented two times,leading to the mildew of the feed.Aflatoxin is one of the most common fungal spoilage of moldy feed,its metabolites have strong pathogenicity and carcinogenicity.Therefore,this experiment combined with molecular biology identification by traditional culture method,isolation and screening of high quality lactic acid bacteria silage and plant characteristics of Xinjiang traditional fermented food from natural fermentation of lactic acid bacteria were identified,further screened by double plate method,which has the obvious inhibition of lactic acid Bacteria aspergillus flavus growth into powder added to the whole corn silage in the determination of chemical composition,silage fermentation quality,mycotoxin content and silage bacterial diversity,discussed the effect of different combinations of lactic acid bacteria on the quality of corn silage,lactic acid bacteria to provide quality resources for extracting Gaoqing silage quality.The main results are as follows:1.Self-made Xinjiang characteristics of silage natural fermentation,in addition to reed silage sensory quality less,sensory quality of halostachyscaspica silage,tamarisk silage and corn silage were good.A total of 65 strains of lactic acid bacteria isolated from Xinjiang traditional fermented food and natural fermentation characteristics of Xinjiang silage,which were isolated from 41 strains of Lactococcus,Lactobacillus 24 strains.A total of 41 strains of lactic acid bacteria were isolated from silage,among which the content of Lactococcus in Reed silage was abundant,the content of Lactobacilli in corn silage was more,the number of Lactococcus and Lactobacilli in the Halostachys caspica silage and the Tamarix ramosissima silage were very different.Enterococcus faecium,Lactobacillus buchneri and Enterococcus lactis are the lactic acid bacteria isolated from the raw materials fermented food and the Xinjiang characteristic plant natural fermentation silage.2.The Bacteriostasis of lactic acid bacteria isolated from Xinjiang traditional fermented food and fermented silage produced by Xinjiang characteristic plant was studied by double plate method.It was finally determined that there were 7 species of lactic acid bacteria which had obvious inhibitory effect on Aspergillus flavus.In this experiment,1 strains of lactic acid bacteria belonging to the 5 species with the best bacteriostatic effect were selected for further combinatorial bacteriostatic test of Enterococcus faecium,Paenibacillus,Bacillus altitudinis,Weissella cibaria,and Lysinibacillus.The results showed that the combination of F1.3+F1.11+F1.25+YM1.7+SN1.2 strains had the best bacteriostatic effect.3.The combination of 5 groups of lactic acid bacteria,which had better bacteriostasis,was added to the whole plant corn silage.The results showed that the addition of lactic acid bacteria Lactobacillus treatment group and processing group was added to the corn silage in the fermentation process,the number of pH,EE,NH₃-N,LA and AA content increased with silage time prolonged,and sample two of LA and AA were significantly higher than that of the other groups?P<0.05?;DM,CP,WSC,NDF and ADF content decreased in silage,and sample four had the highest CP content and lowest NDF and ADF content;through the determination of aerobic exposure to AFT,ZEN and OTA was found in the silage fermentation process in each treatment group AFT and ZEN content with time silage decreased,in addition to deal with a group of OTA decreased.Outside,the rest of the sample one increased after 30 d in silage,during 7 d of aerobic exposure,except for 3 kinds of mycotoxin content in the control group,which were slowly increasing,the rest of the treatment groups did not increase.The AFT and ZEN contents in the sample four were significantly lower than those in the rest treatment groups?P<0.05?.Based on the synthesis of the toxin content and nutrient composition of the silage,the sample four has the best silage effect.4.The high throughput sequencing results of corn silage in control group and each treatment group showed that the addition of 4 kinds of lactic acid bacteria preparations to sample four increased the abundance of bacterial flora in corn silage,and Lactobacillu was the dominant bacteria in the fermentation process of corn silage.More species are not added in silage lactic acid bacteria preparation is better,adding lactic acid bacteria most samples fifth lactic acid bacteria abundance and processing group without adding lactic acid bacteria in the flora abundance of little difference in silage,add appropriate amount of Lactobacillus in improving the bacteria abundance will reduce the species of lactic acid bacteria in silage silage.Considering the fermentation quality,mycotoxin content and high-throughput sequencing results,the combination of four F1.11+F1.25+YM1.7+SN1.2 strains has great application prospects.