Identification and enumeration of Clostridium spp. In sufu

In this study, Clostridium spp. was counted in 49 Chinese commercial sufu samples, and 25 samples were detected Clostridium in all samples: the detection rate was 51.02%. About 93.87% of the samples contained Clostridium at low levels (log CFU/g＜3.0) and one sample had over 4.12lg CFU/g indicating potential hazard to consumers. The 16S rDNA identification was carried out on the genus Clostridium, and the isolates were confirmed as Clostridium botulinum, Clostridium sporogenes, Clostridium beijerinckii and Clostridium bifermentans, while Clostridium butyricum, Clostridium botulinum, Clostridium perfringens and Clostridium bifermentans were the species detected in the sufu samples by high-throughput sequencing. Based on these results, the research on the number and distribution of clostridium and the possible risks of biotoxins in fermented food needs to be strengthened. To our knowledge, this is the first study to isolate and identify Clostridium spp. in sufu.