The Primary Study On Thermotolerant Fungi Diversity And Enzyme Activities In Turpan Region Of Xinjiang

The aim of this research was to analyze the biodiversity of the thermotolerant fungi isolated from soil samples of Turpan, Xinjiang provinces and the enzymes they produced. Total 12 soil samples were collected from Turpan area, of Xinjiang.Thermotolerant fungi were isolated using dilution-plate method. The diversity was analysized based on morphology and 18 S rDNA sequences. Enzyme activities were detected by using six special selective media. A strain of high-yield cellulose, named Aspergillus sp.M9-2-1, and the conditions of the cellulose production were optimized by single factor experiment and orthogonal experiment. The research methods and results are as follows:1. Using two kinds of isolation medium, PDA and Rose Bengal Medium, 129 strains of thermotolerant fungi were isolated from 12 soil samples from Turpan area.From these samples, based on morphology characteristics and 18 S rDNA sequence analysis, 20 species in genera were identified. These genera included Aspergillus,Emericella, Penicillium, Gymnascella, Thermomyces, Scopulariopsis,Pseudallescheria, Trichoderma, Chaetomium and Alternaria. Aspergillus sp. and Emericella sp. were the dominant populations, respectively shared 55.04% and30.23% of the whole species numbers.2. With a method of transparent circle, Enzyme activities were detected by six special selective media. Studies the enzyme activities of the isolated strains showed that 13 strains produced glycosidase, 13 strains produced amylase, 11 strains produced cellulose, 16 strains produced xylanase, 8 strains produced protease, 10 strains produced lipase.Among which M9-2-5 and P7-2-1 produced five enzymes.3. Shake flask culture was used and the yield of cellulose was taken as main index to ensure the optimum culture conditions of submerged fermentation for Aspergillus sp.M9-2-1. To extract the four kinds of fermentation cultivation factors(initial pH, culture temperature, inoculum amount and culture time) conducted apreliminary exploration. Orthogonal experiment was designed on the based of single factor experiment. Results showed that the optimal conditions for producing cellulose were initial pH 5.0, inoculum amount 3%, culture temperature 35°C and culture time96 h. The primary and secondary factors affecting the fermentation to produce cellulase in turn is initial pH, cultivation time, culture temperature, inoculation amount.Studies showed that the thermotolerant fungi were abundant in soils from Turpan area of Xinjiang. The enzymes which the thermotolerant fungi produced were various.This not only laid the foundation for the functional enzymes exploitation and utilization and the follow-up study of applying high temperature enzyme, but also provided the material to identify the groups of fungi resources in China.