Abstract:The microbial growth and identification of main microorganisms in mung bean sprouts, soybean sprouts, pea seedlings sold in Guangzhou (supermarkets and farmers' markets), and the laboratory-grown mung bean sprouts were studied, and the overall microecological composition of bean sprouts was determined using 16S gene high-throughput sequencing method. The results showed that the total number of microorganisms in the finished mung bean sprouts was 106~107 CFU/g, which mainly came from the bean seeds (8.80×107 CFU/g in the cotyledon). The total number of the microorganisms was 8.10×106 CFU/g for the sterilized group after 36 h of germination and 7.90×106 CFU/g for the unsterilized group after 24 h of germination. The major microbial species were mainly Klebsiella, Enterobacteria, Pantobacteria, and Citrobacter. The core microbial groups in the overall microecology were Cyanobacteria, Proteobacteria, Firmicutes, and Bacteroidetes. Eleven drug susceptibility tests were conducted on 20 strains of Enterobacteriaceaes isolated from mung bean sprouts by the disk diffusion method. The results showed that the bacteria exhibited significant resistance to five antibiotics, namely erythromycin, rifampicin, cefoxitin, clindamycin, and penicillin. Results of this study showed that the commercially available bean sprouts carried a large number of microorganisms, among which the Enterobacteriaceae are opportunistic pathogens with broad-spectrum antibiotic resistance. Chemical disinfectants could extend the shelf life of mung bean sprouts by about 12 h. Consuming raw or inappropriately cooked bean sprouts would cause safety problems, which is worthy of reference for manufacturers, government regulatory authorities and consumers.
