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Studies On Biological Characteirstics Of Saline-alkali Tolerance Microorganisms

Posted on:2011-01-05Degree:MasterType:Thesis
Country:ChinaCandidate:Y WangFull Text:PDF
GTID:2250330425982773Subject:Microbiology
Abstract/Summary:PDF Full Text Request
Saline-alkali tolerance microorganisms are one of the hot spot of extrememicroorganisms researches, they also have become the important materials in accessing newstrains, new genes and explaining the mechanism of saline-alkali tolerance, nay, they mayprovide theoretical basis for our country’s bioremediation of saline-alkali soil. This study wasscreening saline-alkali tolerance microorganisms in the extreme environments, research theirgrowth characteristics and physiological and biochemical characteristics, and then part of thestrains were identified. Panjin Red Beach is not only a located in Liao river estuary but also avery rare shallow shoal. At present, there was no research reports about extreme environmentsmicroorganisms in this area.45samples from Panjin Red Beach were isolated by CZ, starch casein, LB and GAUmedium, then increasing salinity-alkalinity was used for the secondary screening. Thecapacitys of aline-alkali tolerance microorganisms obtained were tested by using several stepsof changed salinity and pH. Morphological tests were carried to identify the bacteriare-screened. The analyze of CNY0802, CNY0813, CNY0816and CNY0820on16S rDNAidentification was carried which Genomic DNA was extracted with chloroform and their PCRprimers were universal. Then,they were sequenced after getting the recycle collection, fourphylogenetic trees were constructed on the basis of the tests. Moreover, they were tested indifferent salinity, temperature, pH, Mg2+concentration, anions and cations conditions. Theresults were summarized as follows.Primary screening of samples have got more than100aline-alkali tolerance stains.Re-screening of the100strains have got27bacteria,4actinomycetes,5mold. Saltnitytolerance of bacteria significantly was better than actinomyces and mold, however,theadaptive capacityof the changs in pH of actinomyces and mold were stronger. Four sectionssequence were obtained by PCR, their size were1528bp,1502bp,1493bp and1526bprespectively. Results of phylogenetic trees revealed they belonged to Halobacillus,Haererehalobacter, Halomonas, Halobacillus respectively, and their the homology of thenearest species were no less than99%. Characteristics text outcomes showed that the four bacteria had stronger capacitys to adept to environmental change(such as salinity, temperatureand pH), and the concentration of Mg2+affect part of their saltnity tolerance, meanwhile, thedifferent kinds of anions and cations have significantly impacted on the growth of them.Different types of anions had a greater impact on the growth of the bacteria CNY0802andCNY0820that were Gram-negative bacteria, and they had no influences on the bacteriaCNY0802and CNY0820which were Gram-Positive Bacteria. The optimal growth positiveion factor of four bacteria was Na+.The results of this study certainly maked sense to the development of the northeastextreme environments microbial resources, enrich our strains and genetic resource, and itcould provide useful materials.
Keywords/Search Tags:aline-alkali tolerance microorganisms, Red Beach, 16S rDNA, phylogenesis analysis, growing characteristics
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