Detection Of Biogenic Amine-producing Strains AHLs In Xinjiang Smoked Horse Sausage And Its Effect On Biogenic Amines

This study was to examine the effect of N-acyl-homoserine lactone(AHL)-based quorum sensing(QS)on biogenic amine(BA)formation by BA-producing strains which stem from Xin jiang smoked horse-meat sausages.Bacteria are now known to communicate intercellularly by detecting diffusible signaling molecules,which facilitate coordinated activities within a bacterial community in response to their environment.These molecules have been found either to be present or to increase in concentration in different food systems.Agrobacterium tumefaciens A136 and KYC55-based bioassays confirmed AHL production by biogenic amines strains.The production ability of AHLs was quantified on the basis of ?-galactosidase activity.The influence of different temperature and p H on ?-galactosidase activity and BAs production was determined.Several qualitative and quantitative methods to determine BAs produced by microorganisms have been described,but have little information focused on AHLs affect the production of BAs in ferment foods.This study has great significance to biogenic amines intestine smoked horse in both theoretical and practical aspects.The study could be provides technical support for the safety of smoked horse intestines and other fermented meat production.The main conclusions in our study are as follows: 1.Detection of quorum sensing by biogenic amines strains which stem from smoked horse-meat sausagesThis study was to examine the effect of N-acyl-homoserine lactone(AHL)-based quorum sensing(QS)on biogenic amine(BA)formation by biogenic amines strains.Cross-feeding plate assay and 96 well way by A136 and KYC55-based bioassays.The production ability of AHLs was quantified on the basis of ?-galactosidase activity and BAs were analyzed by HPLC.AHLs could be regulated the formation of biofilm by biognic amines strains.In this chapter,The main ideals are as follows:(1)Agrobacterium tumefaciens A136 and KYC55-based bio-assays confirmed AHL production by 12 biogenic amines strains.(2)The production ability of AHLs was quantified and different in different in different culation time on the basis of ?-galactosidase activity by Klebsiella sp.?Enterobacter cloacae? Pantoea agglomerans.(3)The retention time of C4-HSL,C6-HSL,C8-HSL are separately 4.04,4.44,4.77 minute by HPLC.According to QA/QC of HPLC confirmed that Klebsiella sp.?Enterobacter cloacae have C4-HSL?C6-HSL?C8-HSL.(4)The biofilm formation was mostly influenced by temperature,so we analysis the formation of biofilm by the there biogenic amines strains which were cultured in TSB.From the results we can known that biogenic amines strains could grew in different temperature and the time and nutriention affected the formation of biofilm.The more time cultured the strains,the more nutriention was used up.At 28 and 37? temperature,the capability of biofilm by Klebsiella sp.have no significant,Enterobateriaceae and Pantoea agglomerans have a significant.2.Effect of N-acyl-homoserine lactones on biogenic amine formation by biogenic amines strains were cultured at different temperature and p HIn this paper,in order to known the effect of N-acyl-homoserine lactone(AHL)-based quorum sensing(QS)on biogenic amines(BAs)formation by Klebsiella sp.,Enterobateriaceae and Pantoea agglomerans,in different temperature and p H.The main contents are as follows:(1)Samples of the three strains were cultured NB(the value of p H adjusted to 5.0?5.5?6.0?6.5).p H had a significant influence on the stability of ?-galactosidase by Klebsiella sp.,Pantoea agglomerans and Enterobacter cloacae(P < 0.05).(2)p H had a significant influence on the content of PUT,PHE and HIS by Klebsiella sp.?Enterobacter cloacae and Pantoea agglomerans,at different p H conditions.(3)AHLs production by Klebsiella sp.,Pantoea agglomerans and Enterobacter cloacae were different at 10?20 and 37?.(4)The production of PUT,PHE and HIS by Klebsiella sp.,Pantoea agglomerans and Enterobacter cloacae were different at 10?20 and 37?.(5)The trends of p H are different by the three biogenic amines strains were cultured at different p H and temperature conditions.(6)The effect of N-acyl-homoserine lactone(AHL)-based quorum sensing on biogenic amine formation by Klebsiella sp.,Pantoea agglomerans and Enterobacter cloacae at different p H and temperature conditions.3.The study of influences in biogenic amines content and the production ability of AHLs in smoked horse-meat sausages systemSimulating the process of fermented sausages,use screened stain as fermentation agent in the second chapter,and observe the fermentation and maturation process,grasping the different of biogenic amines with the influence of p H and total number of colonies,and use DGGE for microbial monitoring of significant changes,the conclusions of this chapter as following :(1)The change trends of biogenic amines is basically different in smoked horse-meat sausages system and pure bacterial system.(2)Strains steam from smoked horse-meat sausages system confirmed quorum sensing.(3)Correlation analysis showed that the content of PHE and HIS and TRY with p H value?total bacterial count by the test CK?A and B group showed a positive correlation(P<0.05);PHE and HIS and TRY and total bacterial count also have a positive correlation of group A and group B(P<0.01).PHE of test C groups with p H have negative correlation,HIS and TRY of test C and p H have no correlation;meanwhile,PHE and HIS and TRY with total bacterial counts also have no correlation.(4)Analyzing the colony dynamic of smoked horse-meat sausages in maturation process.According to the DGGE figure,Lactobacillus plantarum origin from horse-meat,and with fermentation time extending,there have different strains.