光照对深海热液喷口周围可培养微生物的生长影响

研究采用析因实验设计,探讨了光照和培养温度对深海热液喷口周围可培养微生物生长繁殖的影响。样品培养10天后。对培养液中蛔菌量进行显微计数,实验数据用SFSS11．0统计软件中的方差分析程序进行处理。统计结果显示：在标准大气压下,在33℃、50℃和65℃三个实验温度中,当温度为33℃时,光照培养液中细茼浓度约为暗培养液中的3．5倍;而在50℃和65℃的培养液中其细菌浓度均比暗培养液中的要低。研究结果为进一步荻取、认识与开发利用深海喷口周围细菌贵源打下了基础。     

劳盆地深海热液喷口沉积物中细菌多样性研究

采用PCR-RFLP技术调查了劳盆地深海热液喷口两位点沉积物中的细菌多样性。结果表明, 在劳盆地深海热液喷口沉积物环境中细菌多样性十分丰富, 样品DY1中发现6个细菌类群, DY2中则存在4个细菌类群, 其中Gammaproteobacteria细菌亚群和Epsilonproteobacteria细菌亚群在两文库中均占据最大比例, 为沉积物样品中的优势菌群。另外, 在克隆文库中还发现了一些与数据库中的已知序列同源性较低的类群, 从而说明劳盆地深海热液喷口沉积物中存在特有的微生物种属。     

南大西洋深海热液区可培养硫氧化微生物多样性及其硫氧化特性

【目的】探索南大西洋热液环境中的硫氧化细菌多样性并研究其硫氧化特性。【方法】通过富集培养和分离纯化获得硫氧化细菌,利用变性梯度凝胶电泳(DGGE)分析富集菌群组成结构,采用离子色谱法对获得的硫氧化细菌硫氧化特性进行检测。【结果】从南大西洋深海环境样品中共分离到48株菌,分属于alpha-Proteobacteria(28株,58.3%)、Actinobacteria(11株,22.9%)和gama-Proteobacteria(9株,18.8%)共3个门,其中Thalassospira、Martelella和Microbacterium为优势属。DGGE结果表明深海热液环境样品中微生物多样性丰富且不同站位存在差异。硫氧化特性研究结果表明,约60%的分离菌株具有硫氧化能力,可以氧化S_2O_3~(2–)生成SO_4~(2–)。获得一株硫氧化能力较强的潜在新种L6M1-5,在实验条件下可高效氧化S_2O_3~(2–),最大氧化速率可达0.56 mmol/(L·h)。【结论】南大西洋深海热液环境中可培养硫氧化细菌多样性丰富,为研究热液环境中的硫循环过程提供了实验材料和理论参考;同时高效硫氧化菌的获得,为工业化含硫废水的处理提供了良好的菌种资源。     

基于宏基因组学重建来自深海热液喷口的Epsilonproteobacteria基因组及其代谢分析

【背景】非致病性Epsilonproteobacteria广泛存在于全球各种不同的自然环境中,特别是一些极端生境如深海热液喷口,并且经常在微生物群落中作为优势物种被发现。然而,由于现阶段培养技术的限制,仅有为数不多的深海热液Epsilonproteobacteria被分离培养,极大限制了对其生理特征、代谢方式以及生态功能的深入认识。【目的】研究深海热液未培养Epsilonproteobacteria的进化地位、代谢潜能及其在原位生态系统中可能发挥的作用。【方法】基于宏基因组学Binning的方法,从采集自东太平洋海隆深海热液烟囱体样本中构建4个高质量的Epsilonproteobacteria基因组Bin225、Bin51、Bin54和Bin189,并进行了系统发育和代谢途径的分析。【结果】Bin189在系统发育树上相对独立于其他所有已知的Epsilonproteobacteria类群,而其余3个重构基因组都与Nitratiruptor sp. SB155-2具有较近的亲缘关系。在代谢潜能方面,所有的基因组除了都含有sqr硫氧化和rTCA碳固定途径的基因以外,也同时具有脂多糖输出转运子和多种分泌系统。Bin189显示出与其它基因组显著不同的代谢特征,其中还检测到与有机物和氨基酸转运相关的功能基因。而其他的3个基因组均具有完整的反硝化途径的功能基因,其中2个还具有Sox系统、氢化酶和鞭毛移动系统。【结论】Bin189可能是一种新发现的深海热液兼性化能营养型Epsilonproteobacteria,推测其余的3个类群能够利用硫化物和氢气作为能源进行化能自养生长。考虑到它们多样的代谢潜能,这些Epsilonproteobacteria类群很可能在深海热液微生物群落的形成发展和地球化学元素循环中发挥重要作用。     

深海热液区微生物矿化过程的功能群和分子机制

深海热液区富含铁、锌、铜等含金属矿物(硫化物、氧化物、碳酸盐等)和无机小分子气体(H_2S、H_2、CO_2、CH_4等),具有独特的生态系统。微生物是深海热液生态系统的主要生产者和重要组成,并以控制矿化和诱导矿化两种途径参与了深海热液区的生物地球化学循环。在深海热液区存在着不同类型的微生物参与了生物矿化过程,如硫氧化菌、金属氧化菌、硫还原菌和金属还原菌等。本文详述了这些微生物参与的生物矿化现象、菌群多样性和矿化过程的分子机制,并对研究微生物矿化的研究工作进行了展望。     

深海热液生物共附生可培养硫氧化细菌的多样性及硫氧化特性

[背景]深海热液环境中存在大量H2S及含硫化合物,许多微生物与大型生物形成了紧密的共生体系,例如硫氧化细菌,它们利用其独特的代谢体系协助宿主更好地适应极端环境,但目前尚未对热液底栖生物共附生的硫氧化细菌进行培养鉴定和功能分析.[目的]了解深海热液生物共附生硫氧化细菌的种群特征和功能特征,筛选出深海热液生物共附生微生物中...     

基于流式细胞仪高通量分选的深海微生物单细胞培养

[目的]建立适用于海洋微生物的流式细胞分选与高通量单细胞培养的方法,通过该方法从印度洋深海样品中分离微生物纯培养菌株.[方法]利用流式细胞仪单细胞分选功能,以前向角(FSC)和侧向角(SSC)散射光信号代替荧光信号作为分选逻辑,对深海水体和沉积物样品中微生物进行单细胞高通量分选和培养.[结果]确定了流式细胞分选的区域和...     

深海热液区化能自养菌Caminibacter profundus氢酶及其对H2的响应特点

化能自养菌中的氢酶在深海热液区生态系统的物质和能量转化中具有重要作用。以Caminibacter profundus为研究对象,通过设计PCR引物,克隆编码膜结合的类型I NiFe-氢酶大亚基基因序列hynL并进行生物信息学分析;研究hynL相对表达、甲基紫晶(MV)还原氢酶活性以及菌株生长对H2浓度变化的响应特点。结果表明,从C.profundus克隆获得864 bp的hynL基因片段,其编码的氨基端序列与Lebetimonas acidiphila的相似性为99%,与热液区化能自养的Epsilonproteobacteria D类群的类型I NiFe氢酶大亚基属同一分支。hynL相对表达量和MV还原的氢酶活性分别于12 h和24 h达到最高,此时菌体处于指数生长期;hynL相对表达量和MV还原的氢酶活性和菌株生长的最适H2浓度均为60%。提示C.profundus通过调控hynL的表达,响应环境中H2浓度的变化,以影响菌株能量代谢的催化过程和生长繁殖。     

不同降压过程对深海海水中可培养细菌群落组成的影响

【目的】控制不同的压力变化过程,比较对深海水样中可培养细菌组成的影响,探讨马里亚纳海沟深海水样中可培养细菌在不同降压处理过程下的丰度变化和群落组成。【方法】利用保压技术采集无污染、深度6001 m的深海水样后,模拟缓慢降压和快速降压过程,通过2216E培养基及2216E加氧化三甲胺(TMAO)富集培养基,对分离得到的可培养菌株进行16S rRNA基因测序分析和丰度检测。【结果】通过缓慢降压和快速降压处理后,深海海水样品中可培养细菌的丰度和群落组成差异较大。其中,在缓慢降压处理的样品中,平均丰度约为190 CFU/mL,且种群组成单一,以Bacillus属为主(占总菌落数的96%);而快速降压处理的样品中,平均丰度约为437 CFU/mL,主要分布在4个属中:Bacillus (占总菌落数的27.8%)、Achromobacter (24.4%)、Microbacterium (34.4%)和Pseudomonas (13.7%)。值得一提的是,添加TMAO后,2种降压过程处理的样品中,可培养细菌的平均丰度均没有明显提升,但样品中的可培养细菌种类明显提升,部分种属的丰度也发生了明显的变化。此外,一些种属仅在特定的压力和底物存在的条件下出现。【结论】不同的降压方式能够影响深海海水中可培养细菌的丰度和群落组成,添加TMAO的富集实验表明可以增加分离到的细菌的种类,为下一步的深入研究提供良好的研究基础。     

深海热液区超嗜热古菌Thermococcus sp. TVG2的培养分离与鉴定

【目的】培养分离大西洋脊热液区的超嗜热古菌,为进一步认识该生态系统中的物种及其特点奠定基础。【方法】将大西洋脊热液区海水样品用YTSV培养基富集培养,选取其中富集效果最佳的TVG2培养物用减绝稀释法分离纯化。对所分离菌株进行形态、生理生化特征等分析,并通过分子生物学手段对其进行初步鉴定。【结果】菌株TVG2属于超嗜热厌氧球菌,直径约1.0 μm;生长温度范围50?88 °C,最适生长温度82 °C;生长pH范围为5.0?9.0,最适生长pH 6.5;生长NaCl浓度为1.0%?4.0% (质量体积比),最适生长浓度为2.5%;元素硫可显著提高菌株TVG2的生物量,但非生长必需;丙酮酸钠能显著促进该菌株生长,但葡萄糖对其生长则有抑制作用。根据其形态特征、生理生化特性及16S rRNA基因序列分析,确定菌株TVG2属于热球菌属。【结论】用YTSV培养基从大西洋脊热液区样品中分离获得超嗜热厌氧菌株TVG2,并确定其为Thermococcus属成员,命名为Thermococcus sp. TVG2。     

Characteristics of pullulanases from extremely thermophilic archaea isolated from deep-sea hydrothermal vents

Two out of three extremely thermophilic anaerobic archaea, isolated from deep-sea hydrothermal vents, produced pullulanase activity in the presence of maltose in the growth medium. Enzyme activities were mainly extracellular and characterized by optimum temperatures of 95°C and 80–95°C, optimum pH of 5.0–7.0 and a high degree of thermostability. One strain when grown in a fermenter with maltose as inducer produced pullulanase at 35 U/l. © Rapid Science Ltd. 1998     

一株深海热液口嗜热芽孢杆菌SY27F代谢产物活性的研究

【目的】对一株来源于深海热液口嗜热芽孢杆菌的次生代谢产物进行抑菌活性和抗肿瘤活性的初步研究。【方法】采用纸片法和微量肉汤稀释法检测嗜热芽孢杆菌SY27F次生代谢产物的抑菌活性,采用CCK-8法测定其次生代谢产物的抗肿瘤活性。【结果】抑菌实验表明,嗜热芽孢杆菌代谢产物对大肠杆菌、金黄色葡萄球菌均有抑菌作用,其最低抑菌浓度分别为1.56 mg/mL和3.13 mg/mL;细胞实验表明,其代谢产物对肿瘤细胞A549、HepG2、HeLa、MCF-7均有一定的抑制作用,其半致死浓度分别为0.390、0.451、0.704、1.105 mg/mL;与人肝肿瘤细胞(HepG2)相比,其对人正常肝细胞(L02)表现出良好的生物相容性。【结论】嗜热芽孢杆菌SY27F次生代谢产物具有一定的抑菌和抗肿瘤活性,可为寻找新型抑菌抗肿瘤活性物质提供优质资源。     

Isolation and characterization of Thermus thermophilus Gy1211 from a deep-sea hydrothermal vent

We examined a single, non-spore-forming, aerobic, thermophilic strain that was isolated from a deep-sea hydrothermal vent in the Guaymas Basin at a depth of 2000 m and initially placed in a phenetic group with Thermus scotoductus (X-1). We identified this deep-sea isolate as a new strain belonging to Thermus thermophilus using several parameters. DNA–DNA hybridization under stringent conditions showed 74% similarity between the deep-sea isolate and T. thermophilus HB-8^T (T = type strain). Phenotypic characteristics, such as the utilization of carbon sources, hydrolysis of different compounds, and antibiotic sensitivity were identical in the two strains. The polar lipids composition showed that strain Gy1211 belonged to the genus Thermus. The fatty acids composition indicated that this strain was related to the marine T. thermophilus strain isolated from the Azores. The new isolate T. thermophilus strain Gy1211 grew optimally at 75°C, pH 8.0, and 2% NaCl. A hydrostatic pressure of 20 MPa, similar to the in situ hydrostatic pressure of the deep-sea vent from which the strain was isolated, had no effect on growth. Strain HB-8^T, however, showed slower growth under these conditions. Received: November 26, 1997 / Accepted: May 20, 1999     

Recent developments in the thermophilic microbiology of deep-sea hydrothermal vents

The diversity of thermophilic prokaryotes inhabiting deep-sea hot vents was actively studied over the last two decades. The ever growing interest is reflected in the exponentially increasing number of novel thermophilic genera described. The goal of this paper is to survey the progress in this field made in the years 2000–2005. In this period, representatives of several new taxa of hyperthermophilic archaea were obtained from deep-sea environments. Two of these isolates had phenotypic features new for this group of organisms: the presence of an outer cell membrane (the genus Ignicoccus) and the ability to grow anaerobically with acetate and ferric iron (the genus Geoglobus). Also, our knowledge on the diversity of thermophilic bacteria from deep-sea thermal environments extended significantly. The new bacterial isolates represented diverse bacterial divisions: the phylum Aquificae, the subclass Epsilonproteobacteria, the order Thermotogales, the families Thermodesulfobacteriaceae, Deferribacteraceae, and Thermaceae, and a novel bacterial phylum represented by the genus Caldithrix. Most of these isolates are obligate or facultative lithotrophs, oxidizing molecular hydrogen in the course of different types of anaerobic respiration or microaerobic growth. The existence and significant ecological role of some of new bacterial thermophilic isolates was initially established by molecular methods.     

Copepoda from deep-sea hydrothermal vents and cold seeps

Recent explorations of hydrothermal vents in the eastern Pacific (Juan de Fuca spreading zone, Guaymas Basin in the Gulf of California, East Pacific Rise at 21° N and 13° N, and Galapagos Rift) and on the Mid-Atlantic Ridge have revealed many copepods, mostly siphonostomatoids with few poecilostomatoids. In these habitats in depths from 1 808 to 3 650 m water temperatures may reach nearly 15 ° C. Among more than 22 000 copepods from vents examined two new families, 11 new genera, and 32 new species were represented.In addition, two new copepods were found in 3 260 m at cold seeps at the base of the West Florida Escarpment in the Gulf of Mexico, an environment not thermally active, with water temperatures about 4.39 °C.Some of these copepods were associated with host invertebrates such as a Nuculana-like protobranch bivalve, a polychaete, and two species of shrimps. Others were obtained from washings of bivalves or vestimentiferans or by means of corers or slurp guns.     

A deep-sea hydrothermal vent isolate, Pseudomonas aeruginosa CW961, requires thiosulfate for Cd2+ tolerance and precipitation

Pseudomonas aeruginosa CW961, an isolate from the vicinity of a deep-sea hydrothermal vent, grew in the presence of 5 mM Cd²⁺ and removed Cd²⁺ from solution. Sulfate was sufficient for growth when Cd²⁺ was not present in the culture medium; however, thiosulfate was necessary for Cd²⁺ precipitation and cell survival in the presence of Cd²⁺.