The Research On The Relevance Among Microbial Proteome Changes,Metabolic And Bacterial Changes In Chilled Fresh Tan Sheep Meat During Storage

In this study,the microbial differential proteins and differential metabolites on the surface of chilled Tan sheep meat were systematically detected by using the proteomics and metabolomics technology.The correlation among the changes in protein composition,the succession of microbial communities and the composition of microbial metabolism during the storage of chilled Tan sheep meat were re-searched,the specific study are as follows:1.The chilled Tan sheep meat sealed and packaged in trays were used as the research object to identi-fy the differences among the samples of Tan sheep meat at different storage time by analyzing the sur-face microbial protein based on the combined protein chip and surface-enhanced laser desorption ioni-zation time-of-flight mass spectrometry(SELDI-TOF-MS)platform.The VIP value(threshold>1)of the first principal component of the Orthogonal correction partial least squares discriminant analysis(OPLS-DA)model were combined with the p-value of the t-test(p<0.05)to finding the differentially expressed proteins.The results showed that,132 differential protein peaks were identified by using the Bio-marker Wizard software,the mass-to-charge ratios of 75 differential protein peaks were retrieved from the Swiss-Prot database,the remaining 57 proteins are unknown proteins.From the differential proteins above-mentioned,19 bacterial proteins associated with the microorganisms of Tan sheep meat were found.2.The microbial differential metabolites in chilled Tan sheep meat were detected by using the Gas chromatography-time-of-flight mass spectrometry(GC-TOF-MS).These 8 differential metabolites are mainly D-Glyceric acid,Asparagine,Glucose-1-phosphate,5'-Inosine-5'-monophosphate,Ribose,Acet-anilide,Aspartic Acid and Phenylalanine.The correlation analysis between these 8 differentials with 19 possible bacterial differential proteins were conducted by using the principal component analysis and heat map analysis.The results showed that,the NADH-ubiquinone oxidoreductase chain 4L.Suppres-sin-28 and ATP-synthesizing proteins are significantly correlated with acetanilide,at the same time,a negative correlation between differentially expressed somatostatin-28 and differential metabolites was appeared,while,the ATP-synthesizing proteins have a positive correlation with differential metabolites.The differential proteins associated with asparagine are keratin-associated protein 3-1,thioredoxin,and macrophage migration inhibitory factor,and all are positively correlated;glucose-1-phosphate and 5'-inosinic acid are all negatively correlated with NADH-ubiquinone oxidoreductase chain 4L,somatosta-tin-28 and necrosis induced Phytophthora protein,but all are positively associated with keratin protein 8-1 and ATP synthesis protein.3.The initial composition on the surface of chilled Tan sheep meat from Yanchi County,Ningxia was identified as Pseudomonas,Enterobacter,Brochothrix thermosphacta and Lactobacillus Beijerinck by using the selective medium culture method;The most important spoilage bacteria are Pseudomonas and Enterobacteriaceae.The correlation between the changes in protein composition and succession of mi-crobial communities were studied by using the principal component analysis and heat map analysis.The results showed that:Pseudomonas and C.thermophila are significantly correlated with differential pro-tein necrosis induced Phytophthora protein,NADH-ubiquinone Oxidase reductase chain 4L,somatosta-tin-28,60S ribosomal protein L40,ATP synthase F(0)complex subunit and proteins;enterobacteri-aceae and Lactobacillus Beijerinck have a great degree of connection with ?2-microsphere protein,macrophage migration inhibitory factor,40S ribosomal protein S26,apolipoprotein E and phospholipid binding protein.