Camel Digestive Tract Microbial Degradation Study Of Foodborne Heterocyclic Amine IQ

2-Amino-3-methylimidazo[4,5-f]quinoloneexists(IQ)exists in processed meat products.It is a kind of organic substance with mutagenic and carcinogenic effect.In order to study the degradation characteristics of IQ by digestive tract microbes in camel,this study takes the digestive tract microorganism of camel as the research object,collects the camel digestive tract(rumen,intestinal)content,uses inorganic salt medium with IQ as the sole carbon and nitrogen source,enrichment culture of three generations under aerobic conditions,using high throughput sequencing technology to understand the diversity of microbial community and the stress response of community structure to IQ,using HPLC(high performance liquid chromatography)to detect the ability of three generations of cultures to degrade IQ.Using traditional microbiological methods and molecular biological methods to isolate,purify and identify the cultivate bacteria,and screen the efficient degradation strains.High throughput sequencing showed that the degradation of IQ was rich in microbial population,divided into 316 genera and 61 classes,belonging to 24 categories.Among them,the highest abundance of the five categories:Proteobacteria,Actinobacteria,Bacteroidetes,Planctomycetes,Firmicutes.After three generations of stress culture,the dominant bacteria in the rumen and intestine were still the Proteobacteria,but the relative content was reduced,and the secondary dominant bacteria group changed into Actinobacteria.From the analysis of class level,the main group of degradation IQ was Sphingobacteriia.Further analysis of genera level,in the process of three generations of IQ stress culture,the contents of Sphingobacterium,Brevundimonas,Pseudomonas,Stenotrophomonas,Ochrobactrum were higher.There were some differences in the composition of three generations of IQ stress culture.the contents of Bacteroidetes in the first generation of rumen and intestine were increased significantly by 27.26%and 11.76%,the contents of Sphingobacteriia in the first generation of rumen and intestine were increased by 31.85%,15%,the contents of Sphingobacterium and Pseudomonas were increased in the first generation samples of rumen and intestine,and increased by 28.19%and 16.44%in the rumen,and the intestine increased by 13.37%and 5.84%..The degradation of IQ in the rumen and intestinal tract decreased with the increase of the algebra.The degradation rate of IQ was 37.8%,17.8%,and 14.95%,respectively,and the degradation rate was about 34.25%,21.66%,respectively.The pure culture was isolated and purified from the third generation culture solution,and identified by physiological,biochemical and molecular identification.Of these,23 strains(KX832680-KX83270702)were derived from the camel intestine,and the other 27 strains(KX832703-KX832729)were derived from the rumen,50 strains belong to:Ochrobactrum,Staphylococcus,Bacillus,Lysinibacillus,Jeotgalibacillus,Brevibacillus,Pseudomonas,Acinetobacter,Microbacterium.Periodic testing bacteria absorbance value(600 nm)by UV spectrophotometer,dynamic detecting the residues of heterocyclic amines IQ by HPLC,determine the degradation ability to IQ of cultivable microorganism in the digestive tract of camel.By verifying the ability of the strain to degrade IQ,2 good degradation effect strains L6(Ochrobactrum sp.)and L15(KX832714)were screened from camel rumen,2 good degradation effect strains C1(Ochrobactrum sp.)and C16(KX832696)were screened from the intestinal tract of camel,the results of the growth characteristics and degradation rate of 4 strains under the cultivation of IQ stress showed that the degradation rate of 4 strains in medium with IQ(30 mg/L)as sole carbon source and nitrogen source was 28.55%and 25.19%.In this study,the microbial degradation of IQ in the digestive tract of camel was studied to understand the community structure of the degrading microorganisms,to isolate and screen the degrading strains,and to investigate the degradation characteristics of the degrading microorganisms.It is hoped that this study can provide theoretical basis and experimental methods for the degradation of toxic and harmful substances in the digestive tract of animals,and find out the microbial resources which can ensure food safety and have application prospect.