Abstract:To evaluate the consumption risk of kumquat, MALDI-TOF-MS was adopted to investigate the distribution of Enterobacteriaceae on kumquat surface by screening the pathogenic microorganisms, which were identified by biochemical identification and 16S rDNA sequencing identification to confirm the results. Six species of Enterobacteriaceae were isolated and identified as Enterobacter gergoviae, Klebsiella pneumonia, Enterobacter sakazakii, Pantoea dispers, Enterobacter cloaca and Enterobacter cancerogenus, among which Klebsiella pneumonia, Enterobacter cancerogenus and Enterobacter sakazakii had high detection rates. The results of MALDI-TOF-MS were consistent with those of the two other methods on genus but partly different on species. The cluster analysis of isolated microorganisms by MALDI-TOF-MS showed that the microorganisms of the same genus were comparatively close relatives; however, microorganisms of the same species had some differences in mass spectrums. The results indicated that there were Enteropathogens on the surface of kumquats, which resulted in a consumption risk. Enhancing the routine detection and risk assessment of pathogens in agricultural products was suggested. , MALDI-TOF-MS could be used for rapid detection of agricultural microorganisms with the advantages of high resolution and classification analysis on the basis of protein level.
