北极高维度海域海冰嗜冷菌系统发育多样性及其低温水解酶分析  

Phylogenetic diversity and cold-adaptive hydrolytic enzymes of culturable psychrophilic bacteria associated with sea ice from high latitude ocean,Arctic

作　　者：俞勇[1] 李会荣[1] 陈波[1] 曾胤新[1] 何剑锋[1] 蔡明红[1] 

机构地区：[1]国家海洋局极地科学重点实验室中国极地研究中心,上海200136

出　　处：《微生物学报》2006年第2期184-190,共7页Acta Microbiologica Sinica

基　　金：国家"973项目"(2004CB719601);国家自然科学基金项目(30500001;40376001);国家海洋局青年海洋科学基金项目(2005112);科技部基础研究专项基金项目(2003DEB5J057)~~

摘　　要：应用样品直接稀释涂布平板、-1℃富集培养和-20℃冷冻24h后富集培养等3种方法,从北极加拿大海盆和格陵兰海的高纬度海域(77°30′N^81°12′N)海冰中分离到37株嗜冷菌。根据其16S rDNA全长序列所进行的系统发育分析表明,分离菌株分属于γ_变形细菌群(γ_Proteobacteria)的Colwellia、Marinobacter、Shewanella、Thalassomonas、Glaciecola、Marinomonas、Pseudoalteromonas和嗜纤维菌_曲挠杆菌_拟杆菌群(Cytophaga_Flexibacter_Bacteroide,CFB)的Flavobacterium、Psychroflexus等9个属。其中有9株菌的16S rDNA序列与已明确鉴定种的相似性在93.4%~96.9%,为潜在的新种。北极加拿大海盆海冰细菌BSi20002与南极威德尔海海冰细菌Marinobactersp.ANT8277的16S rDNA序列相似性为100%,表明在种水平上南、北两极也存在相同的细菌。分离的嗜冷菌在4℃条件下能产生多种大分子物质水解酶类,其中62.6%、51.4%和40.5%的菌株分别能水解Tween_80、明胶和淀粉。The phylogenetic diversity of culturable psychrophilic bacteria associated with sea ice from high latitude sea （77°30＇N - 81° 12＇N）, Canadian Basin and Greenland sea Arctic, was investigated. A total of 37 psychrophilic strains were isolated using three different methods of （ Ⅰ ） spread plate method： 100μL of each dilution ice-melt sample was spreaded onto the surface of Marine 2216 agar （DIFCO laboratories, Detroit, MI） and incubated for 2 to 6 weeks at 4℃ ; （ Ⅱ） bath culture and spread plate method： 1mL of sample was added to 9mL of NSW （unamended natural seawater, 0.2μm prefiltered and autoclaved） and incubated for 1 months at - 1 ℃, then spread plate method was used to isolate bacterial strains from the pre-cultured samples; （ Ⅲ ） cold shock, bath culture and spread plate method： samples were exposed to -20℃ for 24h, then bacterial strains isolated by bath culture and spread plate method under aerobic conditions. Nearly half of psychrophilic strains are isolated by using method Ⅲ . 16S rDNA nearly full-length sequence analysis reveal that psychrophilic strains fall in two phylogenetic divisions, γ-proteobacteria （in the genera Colwellia, Marinobacter, Shewanella, Thalassomonas, Glaciecola, Marinomonas and Pseudoalteromonas） and Cytophaga-Flexibacter-Bacteroides （in the genera Flavobacterium and Psychroflexus）. Nine of bacterial isolates （ BSi20007, BSi20497, BSi20517, BSi20537, BSi20170, BSi20001, BSi20002, BSi20675 and BSi20101） quite likely represent novel species （16S rDNA sequence similarity below 97%）. One of strains （BSi20002） from Canadian Basin shows 100% sequence similarity to the Antarctic Weddell sea ice isolate Marinobacter sp. ANT8277, suggesting bacteria may have a bipolar distribution at the species level. AF283859 sequences were submitted to the BLAST search program of the National Center for Biotechnology Information website （ NCBI, http,//www, ncbi. nlm.nih, gov）. Twenty sequences showing 100% similarity each other

关 键 词：北极 海冰 嗜冷菌 系统发育多样性 低温水解酶 

分 类 号：Q931[生物学—微生物学] Q936