Isolation And Identification Of Mold From Mouldy Areca Catechu And Its Effect On Caenorhabditis Elegans

As one of the Four Great Southern Medicines,Areca possesses pharmacological effects of insecticide,extermination,depression,antioxidant,anti-fatigue etc.Now it has been widely used as a prevalent goods.In China,Hainan province provides the major source of Areca nut as well as processing and consumption.Situated at the verge tropical area,Hainan province has the sufficient sunshine,appropriate temperature and rainfall,which leads the mold to breed.In the same time,the mildew of areca nut and the events of exceeding the standard of mycotoxin in areca nut take place in Hunan province due to the Subtropical monsoon humid climate.The mildew and mycotoxin of areca before the expiration not only bring massive loss to the industry of medicinal and edible areca nut,but also threaten people's life and health.Hence,in this study,the moldy areca nut was taken as the research object.The diversity of microorganisms on the moldy areca nut was analyzed and the types of molds were identified.On this basis,the toxicity of dominant fungi on mildewed Areca catechu was evaluated by using C.elegans as model organism and fermentation broth as intervention medium.The specific research results are as follows.1.The microbial diversity of two batches of mildewed areca nut samples was analyzed by Macrogenomic Sequencing.Result shows that the top 3 at the phylum level,Actinobacteria,Ascomycota and Proteobacteria on Areca.B17,Ascomycota,Basidiomycota and Firmicutes on Areca.W17.The top 3 at the genus level,Streptomyces,Brevibacterium and Penicillium on Areca.B17,Aspergillus,Penicillium and Hyphopichia on Areca.W17.The top 3 at the species level,NRRL S-1868(Streptomyces sp.),NRRL F-5053(Streptomyces sp.)and Nocardiopsis potens on Areca.B17,Hyphopichia burtonii,Aspergillus ruber and Penicillium brasilianum on Areca.W17.2.The function of mycete on mildewed areca nut was annotated by Metagenomic Sequencing.Result shows that at the level 1,the number of genes annotated in the metabolism is the most,the number of genes annotated in the organismal systems by Areca.B17 is the least,and the number of genes annotated in the environmental information processing by Areca.W17 is the least.In Level 2,carbohydrate metabolism,amino acid metabolism and global and overview maps are the main pathways,and the relative abundance of signaling molecules and interaction and cardiovascular disease is relatively low.Among human diseases,the signal pathways annotated to cancer: overview,infectious diseases: viral and neurodegenerative diseases are the most.3.Nine dominant fungi were isolated from the mildewed Areca nut to identifying of 9dominant fungi with the basis of morphology,r DNA-ITS molecular biological technology,and the species evolution tree.X1,X2 and X4 are Cladosporium cladosporioides,X3 is Aspergillus tabacinus,X5 is Aspergillus niger,X6 and X7 are Aspergillus versicolor,X8 is Alternaria alternata,and x9 is Aspergillus sydowii.4.The resuls showed that Aspergillus niger can reduce the life of C.elegans by 62%,Alternaria alternata can reduce the life of C.elegans by 55.2%,and both of them can reduce the half lethal days of C.elegans by 72.2%.the inhibition of Aspergillus niger on the head swing frequency of C.elegans was significantly greater than Alternaria alternata.Aspergillus niger and Alternaria alternata had significant inhibition on the body length of C.elegans.Under heat stress,Aspergillus niger makes C.elegans more sensitive to heat,there was no significant difference in the later stage.