Phylogenetic diversity and biogeography of protease-producing bacterioplankton in polar marine environments

浮游细菌是海洋生态系统的主要成员之一并且具有重要的生态学意义。胞外蛋白酶是这些细菌发挥特定生态功能、表征生理活性的一个重要标志。在极地低温海洋环境中同样分布着数量众多的浮游细菌，它们在极地海洋生态系统的物质循环与能量流动中扮演着极其重要的角色。而两极地区独特的地理位置及气候环境特征，是否会导致生存其中的浮游细菌群落组成存在差异，是一个广受关注的科学问题。此外，相距遥远的两极之间是否存在相同种属的海洋细菌，也是一个值得探讨的问题。 本研究采用16SrRNA基因文库与ARDRA分析相结合的分子生物学手段，对白令海北部海域的浮游细菌群落组成进行了研究。结果表明，检测到的细菌序列包括α-变形细菌纲（...Being major components of food webs, bacterioplankton play key roles in marine ecosystems. Extracellular proteases are one of important symbols showing the specific ecological function and physiological activity of planktonic bacteria. Playing important roles in biogeochemical cycles and energy flow in cold marine ecosystems, bacterioplankton have been observed in high abundance in polar marine en...学位：理学博士院系专业：生命科学学院生物化学与生物技术系_微生物学学号：2162007015383

极地环境污染物的微生物降解及其生物修复研究进展

随着人类社会的发展及其对未知世界探索能力的提高,环境污染目前已演变成为全球性问题,即使是远离人类居住地的南北极地区也不能幸免。任何污染在极地这样一个生态系统组成单调、环境承载能力脆弱的地方都可能带来严重后果,因此极地环境的污染治理尤为迫切。生物修复技术作为环境治理的重要方法与手段,受到了普遍关注。本文简要介绍了极地环境的污染现状以及近年来应用微生物开展极地环境污染物降解与生物修复的主要进展,并就研究中的一些潜在问题展开讨论。极地环境的污染治理与生物修复,将是21世纪环境微生物学研究人员的一项重要使命

白令海北部表层沉积物中细菌多样性的研究

提取白令海表层沉积物样品总DNA,构建沉积物中的细菌16SrDNA文库,通过RFLP酶切分型与序列测定,进行沉积物中的细菌多样性及系统发育分析。结果表明,该沉积物中细菌多样性丰富,获得的125条序列归属于10个细菌类群,包括占据优势地位的变形细菌(Pro-teobacteria,49.6%)、酸杆菌门(Acidobacteria,20.8%),以及拟杆菌门(Bacteroidetes,6.4%)、放线菌门(Actinobacteria,5.6%)、浮霉菌门(Planctomycetes,5.6%)、硝化螺旋菌门(Nitrospirae,4%)、疣微菌门(Verrucomicrobia,2.4%)、绿弯菌门(Chloroflexi,1.6%)、纤维杆菌门(Fibrobacteres,0.8%)、螺旋体(Spirochaetes,0.8%)。此外,还有一部分分类地位尚不明确的细菌(2.4%)。而在变形细菌中,δ、γ亚群为其中的优势类群

产菊糖酶的克鲁维酵母(Kluyeromyces sp.)Y-85的细胞固定化研究

学位：理学硕士院系专业：生命科学学院生物学系_微生物学学号：19942601

Polar microorganisms,a potential source for new natural medicines-A review

通讯作者。Tel: +86-592-2183217; Fax: +86-592-2184528; E-mail: [email protected] 作者简介: 曾胤新(1971− ), 男, 重庆人, 在职博士研究生, 副研究员, 研究方向为极地及海洋微生物学。E-mail: [email protected][中文文摘] 微生物是极地生态系统的重要组成部分。由于极地独特的地理、气候及环境特点,极地微生物所具有的新颖性与多样性,在科学研究、应用开发等方面都具有重要价值,并逐渐受到人们的广泛关注。有关极地微生物的资源勘探与代谢活性产物研究,已成为国际微生物学研究的热点之一。结合笔者的工作实践,对近年来极地微生物资源的勘探与收集情况进行了介绍,并着重对以医药与生物农药等为目标的极地微生物产活性化合物的研究现状进行了概述,同时还对目前一些影响研究工作开展的限制因素进行了讨论。可以预见,针对极地微生物资源的研究开发工作,将会给新型天然药物的筛选与发现带来新的机遇与突破。[英文文摘] Microorganisms are an important component of polar ecosystems.Based on the unique features of geographical location,climate and environment of polar regions,the novelty and biodiversity of polar microorganisms have attracted an increasing attention for their significant values in both scientific research and resources exploitation.Bioprospecting and natural products research of polar microorganisms have become a hot field of microbiology.In this review,following the introduction of bioprospecting and culture collection of polar microorganisms in recent years,the research and develop-ment of microbial bioactive compounds aimed for pharmaceuticals and biological agriculture chemicals are summarized.In addition,factors that currently limit the research progress are discussed.It is believed that the resources exploitation of polar microorganisms can provide an opportunity for discovery of new natural medicines.Compared to human pharma-ceuticals,the research and development of biological agriculture chemicals has more possibilities to achieve a break-through in a short period of time.国家自然科学基金(40676002);国家“973项目”(2004CB719601

Biomass and distribution characteristics of bacteria and protozoa in the Bering Sea in summer

1999年7月21日至8月1日在我国首次北极科学考察期间,考察了白令海中部的浮游细菌和原生动物,分析了其丰度、分布、生物量及其生态作用,结果显示,浮游细菌表层生物量为1.5～20.2μg/dm3,平均为浮游植物生物量的30%,100m以上水柱柱总生物量(720～3123mg/m2)平均为浮游植物柱总生物量的67%,因而是白令海夏季与浮游植物处同等量级的优势类群;原生动物表层生物量为1.2～27.4μg/dm3,100m以上水柱柱总生物量为189～1698mg/m2,平均为浮游植物柱总生物量的21%,其中粒径小于5,5～20μm和大于20μm的原生动物分别占其柱总生物量的13%,47%和40%;作为主要类群的异养腰鞭毛虫占原生动物柱总生物量的39%.浮游细菌和原生动物生物量的总体分布趋势从西部向东北和东部递减、从表层向深层衰减,20～25m水层温跃层和表层海流的存在对这一分布特性可能有较大的影响.原生动物受潜在的大、中型浮游动物捕食压力的制约,维持了一个相对较低的生物量水平,在一定程度上限制了微食物环(microbial foodloop)在该海域夏季生态系统营养中的作用.The abundance, biomass and distribution characteristics of bacteria and protozoa and their ecological role in the planktonic community of the Bering Sea were investigated between 21 July and 1 August 1999. Bacterial carbon biomass in the surface waters ranges from 1.5 to 20.2 μg/dm~3, which accounts for 30% of phytoplankton biomass on average. The biomass of bacteria integrated over the depth from 0 to 100 m of the water column varies from 720 to 3123 mg/m~2 and accounts for 67% of the total phytoplankton biomass. The biomass of protozoa ranges from 1.2 to 27.4 μg/dm~3 in the surface layers, and varies from 189 to 1698 mg/m~2 in the upper 100 m of the water column, which constitutes 21% of integrated biomass of phytoplankton. The integrated biomass of protozoa in being less than 5 μm, 5~20 μm and being greater than 20 μm size fractions accounts for 13%, 47% and 40% of the total biomass, respectively. As a main protozoan assemblage, the integrated biomass of dinoflagellates constituts 39% of the total biomass of protozoa. The biomass of bacteria and protozoa decreases from western to northeastern and eastern regions of the Bering Sea, and the biomass of these organisms also decreases with depth. Such distribution characteristics might be influenced by both the thermocline observed at a depth from 20 to 25 m and the water current existed in the surface layers in the investigation area. The great biomass of macrozooplankton in the investigation area suggests that it might be an important cause for the lower relative biomass of protozoa, which limits the role of the microbial loop in the Bering Sea in summer.国家自然科学基金资助项目(40006010,30270112);; 科技部基础数据(2003DEB5J057)资助项目