Preliminary Study On Production Enzyme And Biological Activity Form Isolation And Identification Of Thermophilic Fungi In Tibetan Hot Spring

Xylanases are an important category under the glycoside hydrolase families and together with cellulases constitute nearly 25%market in enzyme sector.Some of the major applications of this enzyme are in bleaching of pulp and paper,food and feed sector.For several of these applications,enzymes from thermophilic sources are preferred.Thermophilic fungi are a kind of special fungi that can survive in high temperature environment.In recent years,it has been found that thermophilic fungi can produce a variety of thermostable enzymes and active metabolite,which has become a research focus.This study takes Tibetan hot spring as the research object and isolation of thermophilic fungal resources.The research results were as follows:1.Thermophilic fungi were isolated from Tibet hot springs using four different media,This study obtained 41 fungi isolates,which were further grouped into Malbranchea cinnamomea,Thermomyces lauginosus,Thermomyces dupontii,Melanocarpus albomyces,and Aspergillus fumigatus based on combined analysis of morphological characteristics and ITS phylogenetic relationships.2.This study explored Eukaryotic microorganism community diversity of Tibetan hot springs,based on the high-throughput sequencing technologies.The results showedthat microbial communities contained 6 Phylum,19 Class,52 Order,86 Family,and 110 Genus.The dominant genus of fungus was Aspergillus?Cladosporium?Microbotryozyma?Ophiocordyceps?Penicillium?Rhizophydium?Trichoderma?Pyrenochaetopsis etc.Our results exhibited a rich diversity of species in Tibetan hot springs.3.With a method of transparent circle,Enzyme activities were detected by five special selective media.Studies the enzyme activities of the isolated strains showed that 3 strains produced amylase,2 strains produced cellulose,5 strains produced xylanase,1strain produced protease,no strains produced glycosidase.Meanwhile,the xylanase produced by THN8Melanocarpus albomyces was rescreened,Xylanase activity reached 245.9U/mL.4.Screening of thermophilic fungi Melanocarpus albomyces for xylanase production research from Tibet hot springs,identify the optimal culture medium formula for xylanase production corncob powder 20 g/L,tryptone 15 g/L,MgSO₄ 0.3 g/L,KH₂PO₄ 0.35 g/L,the optimal liquid-fermented conditions for 45?,the fermentation time of 5 d,initial pH 5.5,inoculation amount of 8%?v/v?.The xylanase activity after optimization was 2.4 times higher than that before optimization.5.Filter method is used to separate the thermophilic fungi fermentation products and the bacteriostatic experiment of Enchytraeus bubosus,including Aspergillus fumigatus of fermented product of staphylococcus aureus inhibition effect is best,the diameter of bacteriostatic zone reached 22 mm,followed by Malbranchea cinnamomea,Thermomyces dupontii,the diameter of bacteriostatic zone reached 20 mm.The fermentation product of Thermomyces lauginosus is more effective to inhibit bacillus subtilis,the diameter of bacteriostatic zone reached 12 mm.