Prevalence,Phenotype And Aflatoxin Production Of Aspergillus Flavus In Market Peanuts And Corns In Guangxi

Aspergillus flavus is a saprophytic fungi that exists in the natural environment,it sporulate abundantly which can disperse into the environment easily by air.A.flavus pollute peanuts,corns and other common economic crops,which may cause significant economic losses,and threat the health of humans and animals.The objective of the study was to investigate the prevalence of Aspergillus flavus of peanuts and corns in Guangxi,analyze the phenotype and aflatoxin B1 production of Aspergillus flavus isolated from peanuts,corns and poultry farms in Guangxi.The first part of the study was to investigate the prevalence of Aspergillus flavus in peanuts and corns sold in market,a total number of 768 samples were collected,of which,278 peanuts were obtained from 12 cities and 290 corns obtained from 9 cities.A.flavus were isolated from 252 samples by morphology.Aspergillus flavus were detected in all cities,and the positive rate was between 20.00%and 55.00%,Fangchenggang and Chongzhuo were more serviously.There were no significant differences between sampling dates and seasons,while the contamination was more serviously in raining time.The phenotype of 339 strains of Aspergillus flavus from different areas and sources(peanuts,corn,air,egg surface,pharynxs and lungs of chickens)were analysed by sclerotium.The results show 19.17%(65/339)were S strains,27.43%(93/339)were L strins and 53.39%(181/339)were N strains.Then a total number of 162(162/339)strains were randomly selected to detect the production of aflatoxin B1 by enzyme-linked immunosorbent assay(ELISA),aflatoxin B1 were detected in 63 out of 162 strains.S-type strains produce the highest level of aflatoxin B1,the range of aflatoxin B1 was 0～712.34ng/ml,the average level of aflatoxin B1 was 357.33 ng/ml;followed by L-type strains,the average level of aflatoxin B1 was 180.53 ng/ml;the lowest level of toxicity is N-type,and the average aflatoxin B1 was 133.43 ng/ml.