Crust Microbial Strains Screening And Study On Its Metabolite

In this thesis, soil biological crust from Maowusu desert in Wushenqi banner wasselected as the research object in ordos city of Inner Mongolia. Each sample microbialbiomass in the crust was separated by the training method. Bacterial strain was separatedaccording to the colonial morphology differences. After determination of the isolatedbacteria16s rDNA sequence, analysis of species diversity and population diversitydistribution was conducted. Take the separated650bacteria strains as the research object,through the confrontation test, the bacteria EN-S-80-9and BH-C-20which have strongerantagonistic action to four kinds of pathogenic bacteria in screening test get gladiolusanthrax, fusarium oxysporum. Experiments were also conducted on the physiological andbiochemical identification and species identification. The strains produce IAA ability togive53secretions the IAA capacity of strains. The main results are as follows:1) Take the72soil biological crust sample in maowusu desert as the research object;those crusts were developed respectively for the separation and purification of culturalmicroorganisms. The results show that, the bacteria have more diversity and the diversityof actinomycetes is relatively low. Results show that biomass contents in cortex weremore than that corresponding under the cortex.2) Crust of different developed microbe quantity changes from high to lowdecrement；Crust soil microorganisms with plant distance increases, the number and sizeof the bacteria present diminishing.3) Sequence alignment: BLAST sequences comparison analysis is conducted usingthe550effective16S rDNA, in addition to26strains have been reported and thesimilarity of less than97%, the others all is equal or greater than97%.550strains ofbacteria isolated groups are mainly distributed in the Firmicutes, actinomyces door, anddeformation bacteria door etc. The Firmicutes of the genus Bacillus, section bacterium,actinomyces doorshort bacteriumas the dominant fungi genera and sequence alignmentresults show that the microorganism crust of strain diversity exists.4) The bacterial EN-S-80-9and BH-C-20which has strong antagonistic action to,Fusarium oxysporum, beancurd sheet Fusarium, orchid black rot was screened fromseparated650bacteria. Through the physiological and biochemical test and16S rDNAsequence analysis, they are identified as Paenibacillus terraes and Brevibacteriumhalotolerans.5)53secretion the IAA capacity of strains, accounting for8.2%of the total numberof screening strains...