Isolation And Screening Of Fungi From Two Special Habitats And Study On Me Tableolites Of Aspergillus Ustus 094102

The re-discovery of natural products and the decrease of the discovery rate of novel compounds draw the attention of researchers to some special habitats.In order to obtain fungi with good bioactivity and novel structure compounds from mangrove habitat and Arctic pole,we set up a series of novel bioactive meTableolites screening procedure by high performance liquid chromatography and mass spectrometrychemical screening,guided by the biological activity of fungi isolates.In this study,fungi strains were isolated from 10 Thailand mangrove soil samples and 4 Arctic pole soil samples.From the 10 mangrove samples,117 strains of fungi were obtained.After a series of biaoactivity screening of the 117 crude extracts,it is found that 43 strains showed activity against S.a,2 strains against E.coli,2 strains against C.a,23 strains with inhibition of A?1-42enzyme aggregation activity,30 strains with alpha glucosidase inhibitory activity,39 strains with HeLa cells inhibitory activity,and 65 strains with MCF-7 cells inhibitory activity.Then,using HPLC,LC-MS,and PCR technologies,DM29 was selected at last.There are 37 strains of fungi isolated from 4 soil samples in Arctic pole,but only 5 strains of fungi with activity against S.a,no strain were found with activity against C.a or E.coli.Aspergillus ustus 094102 was isolated from Wenchang mangrove.6-epi-ophiobolin G is the major secondary meTableolite produced by strain 094102,it can reverse the multidrug resistance of MCF-7/ADR.In this study,the strain 094102 was re-identified to be Aspergillus calidoustus,but there is still lack of sufficient evidence to determine.The optimal fermentation method for high yield mutant APOC6298 was solid fermentation,and the optimal fermentation time was 18 days.The extraction efficiency can be increased by 37.23%using prefreezing of the fermentation products.At present,a total of 14 batches of fermentation were carried.The total fermentation product was 82.34 kg,and the total amount of 6-epi-ophiobolin G was about 116.93 g.Under present conditions,the efficiency of purification from the extract to 6-epi-ophiobolin G is about 17.56%,and it is expected to obtain 20.54 g of 6-epi-ophiobolin G.