Study On The Bacterial Diversity Of Traditional Fermented Sausages In Different Regions Of China And The Fermentation Characteristics Of The Target Strains For Fermentation

Chinese traditional fermented sausages are widely distributed in regions and have a wide variety of products,which is one of the typical representatives of traditional Chinese fermented meat products.With the development of industrialization,traditional fermented sausages have the advantage of rich flavor compared with Western industrialized products,but they have encountered more and more challenges in terms of product quality stability,production cycle and food safety.The promotion of traditional fermented sausages had a negative impact.In order to solve the existing problems of traditional fermented sausages,the microbial fermentation environment of hand-made sausages is imitated to the greatest extent to retain the rich flavor of traditional fermented sausages.The composition of the bacterial community during natural fermentation is particularly important.In this study,in order to evaluate the bacterial diversity and colony structure distribution of traditional fermented sausages in different regions of China,and to screen starters to improve the quality of sausages,high-throughput sequencing technology was adopted to pass alpha diversity,beta diversity,and species composition.To analyze and compare the bacterial diversity of sausages and the bacterial community structure of fermented sausages in different regions,the isolated strains were identified by 16s rDNA strain identification technology,and the fermentation characteristics of the fermentation target strains were studied.The main research contents and results are as follows:1)????(Firmicutes)is the dominant phylum of Sichuan sausage bacteria and Lactobacillus is the dominant bacterial genus of Sichuan sausage bacteria.Besides the relatively prominent A5 samples,the remaining four samples are consistent in similarity in bacterial distribution.In Guangdong,????(Proteobacteria)is the dominant phylum of B1 and B3,Cyanobacteria is the dominant phylum of B2 and B5,and ????(Firmicutes)is the dominant phylum of B4.Acinetobcter is the dominant bacterium of B1,Streptococcus is the dominant bacterium of B2,Serratia is the dominant bacterium of B3,Lactococcus is the dominant bacterium of B4,and Macrococcus is the dominant bacterium of B5.Each sample of GD sausage has its own characteristics,but also has certain regional characteristics.In Hunan,????(Firmicutes)is the dominant phylum of C1,C2,C3,and C5.C4 is different from the other four samples,and Cyanobacteria is its dominant phylum.Weissella,Macrococcus,Tetragenoccus,Acinetobcter and Lactococcus are the dominant genus of C1?C5,respectively.The distribution of sausages in Hunan and Guangdong has the same characteristics and samples have both their own characteristics and regional characteristics.Cyanobacteria is the dominant phylum in D1?D5 samples.Paenibacillus,Serratia,Leuconostoc,Serratia and lactococcus are the dominant genus of D1-D5.2)Sichuan belongs to a subtropical monsoon humid climate,Guangdong and Hunan belong to a subtropical monsoon climate,and Harbin is located in northeast China and belongs to a temperate monsoon climate.There are large differences in the location and climate of the four different regions,and this difference also affects the bacterial diversity and colony structure of fermented sausages.The microorganisms of the fermented sausages in the four regions are distributed on the basis of consistency(phylum are basically the same)and have their own unique characteristics(the relative abundance is different).The colony structure of SC and HB has its own unique characteristics and the distribution of the community structure of sausage bacteria in HN and GD regions was consistent.3)Traditional fermented sausages from 4 regions are rich natural microbial resource banks and due to their very rich microbial diversity,they provide a variety of choices for selecting excellent starters.Eight strains were initially isolated that met the expected target.After 16s rDNA strain identification,the results showed that three strains were the target strains.The fermentation capacity of 3 strains was measured.The results showed that the strains S1,S2,and S3 all entered the logarithmic growth phase at about 12 hours.The optimal growth temperature was 30?.With the increase of salt and nitrite concentrations,the growth of the 3 strains were inhibited,but at high salt and nitrite concentrations,the inhibition of strains S2 and S3 was not obvious,and the acid-producing ability of strains S2 and S3 were stronger than that of strain S1.Strains S2 and S3 are more suitable for use as sausage starters.The study found that there is a certain correlation between the difference in climate and geographical location and the bacterial diversity and community structure of fermented sausages,and this association has caused the regional characteristics of sausages to a certain extent.The distribution characteristics of sausage bacteria are reserved for us.On the basis of the rich flavor of sausage,it provides a theoretical basis for improving the quality of sausage products and promoting the promotion of traditional fermented sausage products.