紫色非硫细菌Rhodocista属一新分离株的鉴定及其系统学研究

从污水处理厂分离到一株紫色非硫细菌３－ｐ,该菌株具避光性,能形成孢囊,具片层状光合内膜,在波长７９８ｎｍ处的吸收峰很低,需硫胺素和维生素Ｂ１２作生长因子。该菌株可以琥珀酸为碳源,最佳生长温度为３４℃～４１℃,体内未发现Ｒ体结构,醌类的主要成分是Ｑ－９。对菌株３－ｐ的１６Ｓ ｒＲＮＡ基因的分子系统学分析结果表明,菌株３－ｐ与世纪红蒌菌（Ｒｈｏｄｏｃｉｓｔａ ｃｅｎｔｅｎａｒｉａ）关系最近,相似性为９     

一株紫色非硫光合细菌净化养殖水体初步研究

选取从杭州养鱼塘水样中分离得到的1株紫色非硫光合细菌菌株HZ-1,利用它的纯培养物处理养殖水体,测定COD去除率和亚硝态氮降解率。结果表明,菌株HZ-1可以有效地分解水体中的污染物,去除水体中的COD,对养鱼塘水去除率达到20.99%;对养虾池水去除率达到了36.09%;菌株HZ-1可以有效地降低水体的亚硝态氮,对养鱼塘水亚硝态氮的降解率为41.18%,具有较好净化效果。     

内蒙古碱湖中紫色非硫光合细菌的分离和鉴定

从内蒙古碱湖水样中分离得到一株紫色非硫光合细菌,命名为JH1-6.对该菌株进行了形态学观察、生理生化鉴定、活细胞吸收光谱以及16S rDNA序列分析.16S rDNA序列分析结果表明该菌株与沼泽红假单胞菌的16S rDNA序列同源性高达99%,结合形态特征和生理生化特性以及活细胞吸收光谱特征等,确定菌株JH1- 6在分类地位上属于沼泽红假单胞菌(Rhodopseudomonas palustris).     

紫色非硫细菌Rhodocista属一新分离株的鉴定及其系统学研究

从污水处理厂分离到一株紫色非硫细菌３ｐ ,该菌株具避光性,能形成孢囊,具片层状光合内膜,在波长７９８ ｎｍ 处的吸收峰很低,需硫胺素和维生素Ｂ１２ 作生长因子。该菌株可以琥珀酸为碳源,最佳生长温度为３４ ℃～４１ ℃,体内未发现Ｒ 体结构,醌类的主要成分是Ｑ９ 。对菌株３ｐ 的１６ＳｒＲＮＡ 基因的分子系统学分析结果表明,菌株３ｐ 与世纪红篓菌（ Ｒｈｏｄｏｃｉｓｔａ ｃｅｎｔｅｎａｒｉａ） 关系最近,相似性为９５ ％ ,二者可归为同一属;与Ｒｃ．Ｃｅｎｔｅｎａｒｉａ 的杂交结果表明,二者的ＤＮＡ 相关性为５６ ％ ,故可把３ｐ 定为一个新种：北京红篓菌（ Ｒｈｏｄｏｃｉｓｔａｐｅｋｉｎｅｎｓｅ ｓｐ ．Ｎｏｖ） ．     

紫色非硫细菌质粒的制备与性质

介绍一种适于紫色非硫细菌质粒的制备方法,该法简单,易操作,质粒ＤＮＡ纯度好,收率高,通过在加富培养基上连续传代数次,质粒ＤＮＡ可自行消除。     

紫色非硫细菌的砷代谢机制

[目的]系统阐述紫色非硫细菌(PNSB)砷代谢机制和砷代谢基因簇的进化关系.[方法]通过生物信息学方法分析了PNSB砷代谢基因簇的分布、组成、排布方式.采用UV-Vis和HPLC-ICP-MS方法,研究了3个PNSB种类对砷的抗性、砷形态及价态的转化、砷在细胞中的积累和分布以及磷酸盐对As细胞毒性的影响.[结果]砷基因簇分析表明:已公布全基因组序列的17个PNSB菌株基因组中均含有以ars operon为核心的砷代谢基因簇,由1-4个操纵子组成,主要含有与细胞质砷还原和砷甲基化代谢相关的基因,但基因的组成和排列方式因种和菌株而异,尤其是arsM和两类进化来源不同的arsC.实验结果表明:光照厌氧条件下,3个PNSB种类对As(V)和As(Ⅲ)均具有抗性,As(V)和As(Ⅲ)均能进入细胞 ;在胞内As(V)能够还原为As(Ⅲ)并被排出胞外,但不能将As(Ⅲ)氧化为As(V),也未检测到甲基砷化物 ;磷酸盐浓度升高,能够抑制As(V)进入细胞,降低As(V)对细胞的毒性,而不能抑制As(Ⅲ)进入细胞.[结论]PNSB砷代谢机制主体为细胞质As(V)还原,也还有砷甲基化途径.通过对砷代谢基因簇结构多样性特点和进化方式分析,提出了与Rosen不同的ars operon进化途径.这对深入开展PNSB砷代谢和基因之间的相互作用研究奠定基础.     

净化养殖水体紫色非硫光合细菌的筛选与鉴定

本研究从杭州养鱼塘水样及底泥样品中富集分离得到三株紫色非硫光合细菌,分别命名为HZ-3,HZ-4,HZ-5。 通过比较这三株菌对鱼、虾养殖水体的净化效果,筛选出菌株HZ-5 净化能力较强 ,经过5天的处理,该菌株使养鱼塘水样的COD 降低24.87%;使养虾池塘水样的COD 降低 36.99%;使养鱼塘水样的亚硝态氮的降解率达到97.79%。对菌株HZ-5进行了形态学观察、生理生化鉴定、活细胞吸收光谱以及16S rDNA序列分析。16S rDNA序列分析结果表明该菌株与沼泽红假单胞菌的16S rDNA序列有高达99％的同源性,结合形态特征和生理生化特性以及活细胞吸收光谱特征等,将其鉴定为沼泽红假单胞菌（Rhodopseudomonas palustris）。     

紫色非硫细菌固体石蜡双层平板培养法

紫色非硫细菌是一类不产氧光合细菌,具有重要的生态学意义和应用价值。建立固体石蜡双层平板法,与传统的培养法相比较,发现该方法可以更方便、更快捷地计数和分离紫色非硫细菌。结合分子生物学技术,将该方法应用于水稻土紫色非硫细菌的研究,发现以甲酸为碳源的固体石蜡双层平板法可以很好地对环境中可培养的紫色非硫细菌多样性进行研究。该方法的建立将更有助于紫色非硫细菌的研究。     

阳宗海中紫色非硫光合细菌的生态研究

为得到高原深水湖泊中的微生物生态分布信息,运用统计学软件,在2002年对阳宗海中的紫色非硫光合细菌的数量进行了数学分析。影响湖泊中PNSB数量分布的主要因素是水平位点、深度和采水期,溶氧、温度、透明度、COD和叶绿素a含量等环境因子对PNSB数量也有影响。各环境因子如叶绿素a含量和透明度之间也有相关性,对其进行了分析并计算出环境因子之间关系的一元回归方程。     

含奥氏酮嗜盐紫色硫细菌的分离鉴定及系统发育分析

[目的]为挖掘我国紫色硫细菌物种和光合蛋白基因资源.[方法]采用Pfennig紫色硫细菌无机选择性培养基和琼脂稀释法.[结果]从青岛东风盐场分离获得一株含奥氏酮、耐高浓度硫化物、嗜盐耐碱紫色硫细菌菌株283-1.该菌株能氧化硫化物产生硫粒储存在细胞内、嗜盐、细胞含有奥氏酮类胡萝卜素、细菌叶绿素a强吸收峰位于830 nm处、运动、不产生气囊,表明属于Marichromatium属.16S rDNA序列同源性比较和系统发育分析也表明这一点.但该菌株能在1%～15%NaCl、7.5 mmol/L 高浓度硫化物、45℃、5000lux、pH9.0条件下生长良好,能很好的光同化C3和C4有机酸和葡萄糖酸钠等特性,与Marichromatium属4个种有明显不同.[结论]菌株283-1是Marichromatium属一个新分离物,编号 Marichromatium sp.283-1.     

高脱氮活性海洋着色菌YL28生物膜特性

【背景】细菌生物膜在废水处理领域显示出良好的前景,但目前应用于海水养殖水体处理的菌株主要源自淡水菌株,存在难以适应海水高盐环境的问题。源自红树林的海洋着色菌(Marichromatiumgracile)YL28应用于海水养殖水体处理,不仅具有高效除氮能力,而且趋光贴壁能力很强。【目的】阐明海洋着色菌(Marichromatium gracile) YL28的生物膜形成特性和规律,以期为海水养殖水体生物膜反应系统的开发和应用提供参考。【方法】以生物膜和游离菌体生物量、脱氢酶活性、生物膜多糖含量和蛋白含量、无机三态氮去除活性为测定指标,在光照厌氧环境中研究海洋着色菌YL28菌株的生物膜形成规律、生物活性和脱氮效果。【结果】随着时间延长,4 000 lx光照时游离菌体生物量逐渐升高,但在稳定期前快速降低,而成膜生物量经过延滞期后逐渐升高并趋于稳定,表明培养过程中游离菌体能趋光贴壁生长并形成生物膜。在0-5 000 lx光照范围内培养4 d,低光照强度(500 lx)时成膜率(71.21%)最高,1 000-4 000 lx光照强度下成膜率虽然不是最高(54.64%-68.66%),但适宜菌体成膜,膜生物量干重达到0.60-0.80 mg/cm2。除了5 000 lx光照对成膜菌体脱氢酶活性有不利影响外,成膜菌体和游离菌体脱氢酶活性随光照强度升高而升高,而且没有明显差异。生物膜的形成会导致光反应器内部光照受限,但反应器内部游离菌体的脱氢酶活性并没有降低,由此表明,培养液中的菌体主要在生物膜及其界面生长并游离扩散至培养液中。随光照强度(1 000-5 000 lx)和培养时间(4-10 d)的变化,胞外复合物(Extracellularpolymericsubstances,EPS)中蛋白含量变异较大,多糖含量变化较小;随时间延长,蛋白含量升高,其中3 000 lx时蛋白含量最高;4 000 lx时生物膜菌体与游离菌体脱氮活性相比,单位质量菌体的氨氮和亚硝氮去除活性未受到明显影响,而硝氮去除活性有所降低。【结论】海洋着色菌YL28具有良好的生物膜形成能力,其成膜过程主要是菌体趋光贴壁生长成膜,成膜菌体具有良好的脱氮活性,这为利用生物膜系统消除海水养殖水体氮污染奠定了基础。     

以亚硝氮为唯一氮源生长的海洋紫色硫细菌去除无机三态氮

【目的】揭示以亚硝氮为唯一氮源生长的海洋紫色硫细菌去除水体中无机三态氮的特征和规律。【方法】在光照厌氧环境下,以乙酸盐为唯一有机物,在分别以氨氮、亚硝态氮、硝态氮为唯一氮源和三氮共存的模拟水体中,采用Nessler’s试剂分光光度法、N-(1-萘基)-乙二胺分光光度法和紫外分光光度法分别测定水体中氨氮、亚硝态氮和硝态氮的含量,比浊法测定菌体生物量。【结果】随着时间的延长,海洋紫色硫细菌Marichromatium gracile YL28分别在氨氮、亚硝态氮和硝态氮为唯一氮源的水体中对三氮的去除量增加,生物量增大,水体pH升高,并逐渐趋于平衡;YL28对氨氮的最大去除量和最大耐受浓度分别为9.64 mmol/L和36.64 mmol/L,当氨氮浓度低于3.21 mmol/L时,去除率可达97.61%以上;与氨氮相比,以亚硝态氮和硝态氮为唯一氮源,菌体的生长速率、生物量和水体最终pH较低,但对亚硝态氮和硝态氮的去除速率和去除量仍然很高,当亚硝态氮和硝态氮浓度分别达13.50 mmol/L和22.90 mmol/L时,YL28仍能够完全去除。在三氮共存的水体中,YL28也能良好的去除无机三态氮,对亚硝态氮和硝态氮去除能力更强。【结论】在模拟水体中,海洋紫色硫细菌YL28能够分别以氨氮、亚硝态氮和硝态氮为唯一氮源生长,具有良好的耐受和去除无机三态氮的能力,尤其对亚硝态氮具有良好的去除能力。本研究为进一步开发高效脱氮,尤其是去除亚硝态氮的不产氧光合细菌水质调节剂奠定了基础,也为微生物制剂的合理应用提供参考。     

Phylogenic status of a purple sulfur bacterium and its bloom in Lake Kaiike

Two bacterial species at the upper boundary of the H₂S-containing lower layer of Lake Kaiike, a purple sulfur bacterium and Macromonas sp., markedly changed their population densities in a single year (maximum cell numbers ranged between 10⁶ and <10³ cells ml^–1), although neither species ever entirely disappeared from the lake over at least the past 30 years. Genetic characteristics based on the sequence of the 16S rDNA of the purple sulfur bacterium showed it to be a new species of the Chromatiaceae family. This bloom of purple sulfur bacterium occurred when the H₂S layer was disturbed by an external intrusion of seawater.     

亚硝氮对海洋着色菌亚硝氮和氨氮去除以及光合色素合成的影响

【目的】在以亚硝氮为唯一氮源和亚硝氮-氨氮共存体系中,考察和分析海洋着色菌(Marichromatium gracile) YL28菌株对水体亚硝氮的环境适应能力。【方法】采用分光光度法分析亚硝氮、氨氮去除效率以及亚硝氮对菌体生物量和色素含量的影响,采用薄层层析法分析亚硝氮对菌体光合色素组成的影响。【结果】YL28菌株能以亚硝氮为唯一氮源生长,主要积累2种细菌叶绿素(BChl)组分(BChl aTHGG和BChl ap)、1种细菌脱镁叶绿素(Bphe)和玫红品(Rhodopin)、螺菌黄质(Spirilloxanthin)、脱水紫菌红醇(Anhydrorhodovibrin)、番茄红素(Lycopene) 4种类胡萝卜素(Car);YL28生物量和对亚硝氮的去除效率随亚硝氮浓度升高而降低,完全去除亚硝氮的浓度可达200 mg/L以上;当亚硝氮浓度高于25 mg/L,单位质量菌体BChl a和Car总量降低,BChl a和Car合成的末端产物(BChl ap和Spirilloxanthin)以及Bphe相对含量升高,其它4种色素组分相对含量则降低,但Car与BChl a相对含量的比值未见明显变化。当亚硝氮-氨氮共存时,YL28菌株对亚硝氮的耐受能力和去除能力明显提高,完全去除亚硝氮的浓度可达300 mg/L以上;氨氮减缓了亚硝氮对光合色素合成的抑制作用,提高了菌体色素合成总量,各色素组分相对含量的变化与亚硝氮为唯一氮源时的变化规律一致。【结论】YL28菌株能高效去除亚硝氮,亚硝氮对菌株生长和光合色素的合成有抑制作用,但氨氮能明显提高YL28菌株对亚硝氮的适应能力。这为进一步开发高效脱除亚硝氮的APB水质调节剂奠定了基础。     

Iron sulfur proteins of the purple sulfur bacterium Ectothiorhodospira shaposhnikovii

In addition to several cytochromes three iron sulfur proteins were detected in mixotrophically grown cells of Ectothiorhodospira shaposhnikovii, a member of the Chromatiaceae. They were identified as a bacterial ferredoxin and two high potential iron sulfur proteins (HIPIPs). The two HIPIPs were purified and characterized. They were named according to their differing retention times on a DEAE-cellulose column using a continuous NaCl gradient: early and late HIPIP. The HIPIPs contain 4 mol of non-heme iron and 4 mol of acid labile sulfur per mol protein. Under the conditions of purification the early HIPIP (E _{m, 7}+270 mV) was present in a semi-reduced state. Using ion-exchange chromatography the early HIPIP could be split into a reduced green-brown (pI=3.7) and an oxidized red-brown (pI=3.9) fraction. The late HIPIP (pI=3.8) showed a midpoint potential of only+155 mV, the lowest redox potential of a HIPIP described so far.Non-common abbreviations HIPIP high potential iron sulfur protein - MOPS 3(N-morpholino)propane sulfonate - SDS sodium dodecylsulfate     

Biogeochemical cycling of sulfur and iron in sediments of a south-east Asian mangrove,Phuket Island,Thailand

Benthic sulfate reduction and sediment pools of sulfur and iron were examined during January 1992 at 3 stations in the Ao Nam Bor mangrove, Phuket, Thailand. Patterns of sulfate reduction rates (0–53 cm) reflected differences in physical and biological conditions at the 3 stations, and highest rates were found at the vegetated site within the mangrove (Rhizophora apiculata) forest. Due to extended oxidation of mangrove sediments, a large portion of the added³⁵S-label was recovered in the chromium reducible pools (FeS₂ and S⁰) (41–91% of the reduced sulfur). Pyrite was the most important inorganic sulfur component, attaining pool sizes 50–100 times higher than acid volatile pools (FeS). HCl-extractable (0.5 M HCl) iron pools, including Fe(II)_HCl and Fe(III)_HCl, were generally low and Fe(III)_HCl was only present in the upper surface layers (0–5 cm). Maximum concentrations of dissolved Fe²⁺ (35–285 M) occurred just about the depth where dissolved H₂S accumulated. Furthermore Fe²⁺ and H₂S coexisted only where concentrations of both were low. There was an accumulation of organic sulfur in the deep sediment at 2 stations in the inner part of the mangrove. The reoxidation of reduced sulfides was rapid, and storage of sulfur was minor in the upper sediment layers, where factors like bioturbation, the presence of roots, or tidal mixing enhance oxidation processes.Author of correspondence.     

Purification and characterization of the photochemical reaction center of the thermophilic purple sulfur bacterium Chromatium tepidum

Pure reaction center preparations from the thermophilic species Chromatium tepidum have been obtained by lauryldimethylamine N-oxide treatment of chromatophores. The light-induced difference spectrum in presence of 10 mM sodium ascorbate revealed the presence of two high-potential cytochrome c hemes (-band, 555 nm; γ-band, 422 nm). The dithionite-minus-oxidized difference spectrum in the -band suggests the presence of additional hemes of low potential. These hemes are associated with a single polypeptide (M_r = 36 000). The reaction center pigments, probably four bacteriochorophyll a and two bacteriopheophytin a molecules, are associated with three polypeptides of apparent molecular weights equal to 33 000, 30 000 and 22 000. A carotenoid molecule is also bound to the reaction center. The three main absorption bands of this molecule are located at 480, 510 and 530 nm at liquid helium temperature. Photochemical activity is found to be stable, even after heating for 10 min at temperatures higher than 60 °C in intact chromatophore membranes. On the other hand, isolated reaction centers or chromatophores treated with 1% lauryldimethylamine N-oxide are fully inactivated after heating at temperatures higher than 50 °C. From these results, we propose that lipid-protein interactions are of prime importance in the thermal stabilization of Chromatium tepidum reaction centers.     

Occurrence of plant hormones in cells of the phototrophic purple bacterium Rhodospirillum rubrum 1R

Abstract Plant hormones from biomass of the purple non-sulfur bacterium Rhodospiririllum rubrum were isolated for the first time. These compounds show high physiological activities (300–330%) in the cytokinin bioassay. All three detected cytokinins are adenine derivatives, according to spectral analysis. One of them was identified as 6-(4-hydroxy-3-methyl-2-trans-2-bytenylamino)-9-ß-D-ribofuranosylpurine (zeatinriboside) as shown by thin-layer chromatography and reversed-phase high-performance liquid chromatography. The possible functions of bacterial cytokinins are also discussed.     

Induction of purple sulfur bacterial growth in dairy wastewater lagoons by circulation

Aims:  To determine whether circulation of dairy wastewater induces the growth of phototrophic purple sulfur bacteria (PSB).
Methods and Results:  Two dairy wastewater lagoons that were similar in size, geographic location, number and type of cattle loading the lagoons were chosen. The only obvious visual difference between them was that one was stagnant and the water was brown in colour (Farm 1), and the other was circulated and the water was red in colour because of the presence of PSB that contained carotenoid pigments (Farm 2). Both wastewaters were sampled monthly for 3 months and assayed for PSB and extractable carotenoid pigments (ECP). After this point, circulators were placed in the wastewater lagoon on Farm 1, and samples were taken monthly for 9 months and assayed for PSB and ECP. Before the installation of circulators, no PSB-like 16S rRNA sequences or ECP were observed in the wastewater from Farm 1; however, both were observed in the wastewater from Farm 2. After the installation of circulators, statistically greater levels of PSB and extractable carotenoid pigments were observed in the wastewater from Farm 1.
Conclusions:  Circulation enhances the growth of PSB in dairy wastewater.
Significance and Impact of this Study:  Because PSB utilize H₂S and volatile organic acids (VOA) as an electron source for photosynthesis, and VOA and alcohols as a carbon source for growth, the increase in these bacteria should reduce H₂S, volatile organic compounds and alcohol emissions from the lagoons, enhancing the air quality in dairy farming areas.