Comparative analysis of the bacterial diversity of Chinese fermented sausages using high-throughput sequencing

Abstract

Chinese dry fermented sausage is a spontaneously fermented food with complex microbial diversity. In this study, the bacterial diversity of long- and round-type Chinese dry fermented sausages from the same region was evaluated using high-throughput sequencing (HTS) technology. Results showed that Proteobacteria, Firmicutes, Bacteroidota, and Actinobacteria were the dominant phyla, accounting for more than 90% of the total. For all samples, Acinetobacter and Psychrobacter comprised the largest proportion of bacteria, followed by Pseudomonas and Macrococcus. The relative abundances of bacterial community proportions at the phylum level were similar but varied greatly at the genus level. The operational taxonomic units (OTUs) of dry fermented sausages ranged from 546 to 1385, and 121 shared OTUs were observed among all samples. Except for shared OTUs, the unique OTUs of round sausages were about three times as high as those of long sausages from the same factory. The bacterial diversity composition showed a stronger correlation with the factory than the product type. Moreover, potentially pathogenic and spoilage bacteria, such as Aeromonas, Pseudomonas, Brochothrix, Serratia, Streptococcus, and Photobacterium, can be detected. Hence, HTS technology is a useful tool to identify the manufacturer, quality and safety of fermented sausages.