Screening And Identification Of Microbes With Certain Biological Function

Several microorganisms with a specific function, such as alkali-tolerant, salt-tolerant,acid-tolerant pullulanase-producing strains and nitrogen-fixing Paenibacillus, were isolated,purified and identified in this study.A total of120were selected from saline-alkali and near beer factory of Daqing andQiqihar, Heilongjiang Province.85salt-tolerant and alkali-tolerant strains,2acid-tolerancepullulanase-producing strains and12nitrogen-fixing Paenibacillus strains were screenedfrom aboved soils with selective isolation methods.The similarity levels of16S rRNA gene between strain CQ-X and Paenibacillus sabinaeT27~T、Paenibacillus forsythia T98T、Paenibacillus azotofixans ATCC15681T和Paenibacillussophorae S27~T98.74%、98.02%、97.45%and97.13%by PCR (polymerase chain reaction)and sequencing analysis. The phospholipids of strain CQ-X are diphosphatidylglycerol (DPG),phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylethanolamine (PE), anunidentified glycolipid (GL) and two unidentified amino lipids (AL). The major cellular fattyacids are anteiso-C15:0. DNA-DNA hybrid values between strain CQ-X and P.sabinae T27~T、P. forsythia T98T、P. azotofixans ATCC15681Tand P. sophorae S27~Twere61.5%、51.3%、28.5%and20.0%，respectively. One the basis of the phenotypic and chemotaxonomicanalyses,16S rRNA gene sequence comparisons and DNA-DNA hybridization data, thestrain CQ-X represents a novel species of the genus PaenibacIllus, for which the namePaenibacillus jamilae sp. nov. is proposed.The strains resources obtained in this study were provided to further research the growthmechanism of saline-alkali microorganism and nitrogen-fixing regulatory mechanism ofPaneibacillus; and laid a theoretical foundation for the practical application of acid-tolerantpullulanase and nitrogen-fixing fertilizer.