一个甲烷氧化菌株的分离、鉴定及其特性研究

实验室自行设计方案分离多株以甲烷为唯一碳源的菌株, 对其中的1株QJ16进行了研究, 根据该菌株形态特征与16S rDNA序列的同源性分析, 证实该菌株是一个与其最近的甲基单胞菌属各成员都不相同的菌株。对该菌株的培养条件和利用甲烷的特性进行研究结果表明, 氮源以氯化铵和硝酸钾共同作用最好, 碳源以甲烷最佳, 最佳生长温度为30℃, 最佳生长pH为6~7; 在批式实验时菌株利用甲烷的最适pH为6.5左右, 微量元素Cu2+的浓度为15 mmol/ L。     

一个甲烷氧化菌株的分离、鉴定及其特性研究

实验室自行设计方案分离多株以甲烷为唯一碳源的菌株,对其中的1株QJ16进行了研究,根据该菌株形态特征与16S rDNA序列的同源性分析,证实该菌株是一个与其最近的甲基单胞菌属各成员都不相同的菌株.对该菌株的培养条件和利用甲烷的特性进行研究结果表明,氮源以氯化铵和硝酸钾共同作用最好,碳源以甲烷最佳,最佳生长温度为30℃,最佳生长pH为6～7;在批式实验时菌株利用甲烷的最适pH为6.5左右,微量元素Cu2 的浓度为15 μmol/L.     

Beyond the Chemiosmotic Theory: Analysis of Key Fundamental Aspects of Energy Coupling in Oxidative Phosphorylation in the Light of a Torsional Mechanism of Energy Transduction and ATP Synthesis—Invited Review Part 1

The core of this second article shows how logical errors and inconsistencies in previous theories of energy coupling in oxidative phosphorylation are overcome by use of a torsional mechanism and the unified theory of ATP synthesis/hydrolysis. The torsional mechanism is shown to satisfy the pioneering and verified features of previous mechanisms. A considerable amount of data is identified that is incompatible with older theories but is now explained in a logically consistent and unified way. Key deficiencies in older theories are pinpointed and their resolution elucidated. Finally, major differences between old and new approaches are tabulated. The new theory now provides the elusive details of energy coupling and transduction, and allows several novel and experimentally verifiable predictions to be made and a considerable number of applications in nanotechnology, energy conversion, systems biology, and in health and disease are foreseen.     

Beyond the Chemiosmotic Theory: Analysis of Key Fundamental Aspects of Energy Coupling in Oxidative Phosphorylation in the Light of a Torsional Mechanism of Energy Transduction and ATP Synthesis—Invited Review Part 2

The core of this second article shows how logical errors and inconsistencies in previous theories of energy coupling in oxidative phosphorylation are overcome by use of a torsional mechanism and the unified theory of ATP synthesis/hydrolysis. The torsional mechanism is shown to satisfy the pioneering and verified features of previous mechanisms. A considerable amount of data is identified that is incompatible with older theories but is now explained in a logically consistent and unified way. Key deficiencies in older theories are pinpointed and their resolution elucidated. Finally, major differences between old and new approaches are tabulated. The new theory now provides the elusive details of energy coupling and transduction, and allows several novel and experimentally verifiable predictions to be made and a considerable number of applications in nanotechnology, energy conversion, systems biology, and in health and disease are foreseen.     

1株产琼脂酶细菌的分离鉴定及其胞外酶活性测定

从四川省成都市青城山采集土壤,以琼脂作为唯一碳源,筛选到产琼脂酶细菌CMCK136;通过形态观察、生化鉴定、16S r DNA测序及序列分析鉴定其种属;随后测定了菌株CMCK136的胞外酶活性。菌株CMCK136被鉴定为芽胞杆菌属细菌,命名为Bacillus sp.CMCK136。菌株CMCK136的胞外琼脂酶的最适酸碱度为p H 7.0,最适温度为35℃。菌株CMCK136是产琼脂酶细菌家族的新成员,该菌株的发现进一步提示芽胞杆菌属很可能蕴含有尚待开发的琼脂酶资源。     

巢湖微囊藻产毒株的分离、保存及种属特异性鉴定

利用平板划线结合液体培养的方法从巢湖分离得到一个藻株,命名为Chaohu-1。甲醇粗提该藻株所产生的藻毒素(MCs),经固相萃取、HPLC检测,证实该藻株产生毒性最强的Microcystin-LR。藻细胞呈绿色球状,群体为无规则网状。全细胞PCR扩增藻蓝蛋白基因间隔序列(PC-IGS),结果与GenBank中已有的铜绿微囊藻属序列相似性达99%。综合形态学和分子生物学的分析结果,表明我们首次从巢湖分离得到1个产毒的铜绿微囊藻藻株。同时我们摸索出该藻株冻存及复苏方法,为藻株的长期保存及后续研究打下了基础。     

Isolation,Characterization of a Strain Capable of Degrading Imazethapyr and Its Use in Degradation of the Herbicide in Soil

One strain of bacterium IM-4, capable of degrading imazethapyr (IMZT), was isolated from the IMZT-contaminated soil. The isolate was identified as Pseudomonas sp. according to its physiological characteristics, biochemical tests, and 16S rRNA gene phylogenetic analysis. This strain could utilize IMZT as the sole carbon and energy source. About 73.4% of the 50 mg l⁻¹ initially added IMZT was degraded after 7 days of inoculation with strain IM-4. This strain also showed the capability to degrade other imidazolinone herbicides such as imazapyr, imazapic, and imazamox. The inoculation strain IM-4 to soil treated with IMZT resulted in a higher degradation rate than in noninoculated soil regardless if the soil was sterilized or nonsterilized. Inoculation of strain IM-4 could also mitigate the phytotoxic effects of IMZT on the growth of maize.     

1株产单宁酶细菌的分离鉴定及产酶条件研究

从富含单宁酸的土壤中分离筛选出1株产单宁酶的细菌,经过菌落形态观察和16S rDNA分子生物学鉴定,该细菌为肺炎克雷伯菌。对该菌所产胞外单宁酶的发酵条件进行了初步研究,得出最佳产酶条件：培养温度37℃,培养时间36 h,培养转速180 r/min,单宁酸含量2 g/L,最佳碳源为葡萄糖,最佳氮源为氯化铵,此时所产单宁酶活力为0.8 U/mL。     

一株耐盐葡萄球菌的分离鉴定及其特性分析

本文旨在分离筛选出在高盐环境中具有潜在应用可能性的菌株。在筛选耐盐酵母的过程中分离出一株耐盐菌株,采用形态特征观察、生理生化实验和16S rDNA基因测序进行菌株鉴定,鉴定结果显示该菌为沃氏葡萄球菌(Staphylooccus warneri),命名为SW-1。进一步对其药敏特性、耐盐性和表面疏水性进行检测,结果表明,该菌株对大部分抗生素极敏感,在含20%(质量分数)NaCl的LB培养基中仍能良好生长,对氯仿、乙酸乙酯和正丁醇的疏水率依次为43%、34%和39%。沃氏葡萄球菌SW-1在高盐条件下能快速适应环境积累生物量,具有优良的生物学特性,为开发和利用耐盐菌株提供参考。     

Isolation,Characterization and Kinetics of Perchlorate Reducing Magnetospirillum Species

Perchlorate reducing bacteria reduce perchlorate to chlorate (ClO₃?), which, in turn, is reduced to chlorite (ClO₂?) and ultimately to chloride (Cl^?). Magnetospirillum strains are reported to use chlorate/perchlorate as electron acceptors. This study describes the perchlorate reducing property of strain VITRJS5, a Magnetopsirillum isolated from freshwater sediment collected from Chelur freshwater lake, Kerala, India. The strain was microaerophile and was phylogenetically related to a Magnetospirillum sp., a member of the α-subclass of the class Proteobacteria. The placement of the isolate in the genus Magnetospirillum has further confirmed the presence of four key magnetosome membrane genes. PCR amplification and phylogenetic analysis of central metabolic genes such as nifH (nitrogenase) and cbbM (type II RubisCo) displayed the highest similarity (97% and 81%, respectively) with Magnetospirillum sp. BB-1 The growth kinetic parameters of the isolate were studied with acetate as the electron donor in batch experiments. Monod's substrate utilization model has been established with oxygen, nitrate and perchlorate as electron acceptors separately. The maximum specific growth rate (µ_max) and half-saturation constant (k_s^conc) for the bacterium varied while utilizing different electron acceptors. The maximum specific growth rate was 0.226, 0.190 and 0.096 per hour and half-velocity constant K_s was 25.09, 33.36 and 65.37 mg acetate/l for oxygen, nitrate and perchlorate, respectively. The reduction of perchlorate has been analyzed using kinetic studies of the substrate uptake by the bacteria and the half-velocity constant K_s was found to be 52.8 mg/l. The results indicate that the strain VITRJS5 effectively reduces perchlorate by using it as an electron acceptor.     

1株鞘细菌的分离筛选及对铅离子吸附条件的研究

通过单因素试验设计,探讨了不同鞘细菌添加量、初始浓度的铅离子溶液、吸附时溶液的温度和p H对鞘细菌吸附铅离子的影响。在此基础上,采用4因素3水平正交试验设计,进一步探讨鞘细菌对铅离子吸附影响的主要因素及最佳吸附组合。试验结果表明,最佳吸附组合为鞘细菌制备液添加量0.3 g/L、吸附溶液中铅离子初始浓度10 mg/L、摇床振荡吸附温度30℃以及吸附液p H 8。在此条件下,鞘细菌吸附铅离子的吸附量为3.09 mg/g,吸附率达92.74%。     

1株用于甜瓜采后病害生物防治的假单胞菌株的分离及鉴定

甜瓜以营养丰富口味独特而深受世人青睐。同时,其采后病害高效、"绿色"防治药剂的缺乏也成为多年来困扰甜瓜生产的难题。本文采用直接生物测定的方法,从健康的甜瓜表面分离到1株有生防潜能的菌株X4。该菌株对引起甜瓜主要采后病害的粉红单端胞菌(Trichothecium roseum)、镰刀菌(Fusarium spp.)和链格孢菌(Alternaria alternata)的防治效果分别达到了90.6%、84.4%和67.4%;定殖实验显示,接菌4 d后该菌在瓜内数量可上升并稳定至1.1×10~6CFU/ml;通过16S rDNA测定、形态特征观察及生理生化测定结果表明该菌为Pseudomonas fluorescens biovarⅢ。     

Isolation and Some Characterization of an Acidic Polysaccharide with Anti-calcification Activity from Coccoliths of a Marine Alga,Pleurochrysis carterae

Coccolith is a calcified scale with species-specific fine structure produced by marine unicellular coccolithophorid algae, and consists of calcium carbonate crystals and organic matrices. EDTA-soluble organic materials extracted from coccoliths of Pleurochrysis carterae showed anti-calcification activity. They were separated by anion-exchange HPLC, and two fractions, fractions A and B, were obtained. Fraction B, which was more active than fraction A, was further separated into six consecutive fractions, B1-B6, by second anion-exchange HPLC. ¹H NMR spectral analyses of these fractions suggested that a novel acidic polysaccharide, designated CMAP, existed throughout B1-B6 and that the latter four fractions mainly contained another acidic polysaccharide, PS-2, characterized previously. Since PS-2 did not show anti-calcification activity, CMAP was found to be the active principle.     

一株DMP降解菌的分离鉴定及其降解特性

从山东省潍坊市污染河流底泥中筛选到1株能够以酞酸酯(Phthalic acid esters, PAEs)为唯一碳源和能源生长的微生物, 命名为JDC-3, 根据形态学观察、生理生化指标测定和分子生物学鉴定结果, 将该菌株初步鉴定为戴尔福特菌属(Delftia sp.), 以一对简并引物, 首次在该属中扩增出编码邻苯二甲酸双加氧酶的基因片段。同时以邻苯二甲酸二甲酯(Dimethyl phthalate, DMP)为目标测试物, 利用高效液相色谱(HPLC)测定了JDC-3的降解性能, 得出该菌对DMP降解的最佳条件为: pH 7.0~8.0、温度30°C~35°C; 在不同DMP初始浓度下研究了该菌的降解动力学, 结果表明当浓度低于300 mg/L时的降解动力学方程为ln C = - 0.06837 t + A, 半衰期为12.48 h, 当初始浓度不断增加, DMP对JDC-3的抑制能力增强, JDC-3对DMP的降解速率不断下降, 半衰期增大。     

Mineralogical,Chemical and Biological Characterization of an Anaerobic Biofilm Collected from a Borehole in a Deep Gold Mine in South Africa

A biofilm sample was collected from an anaerobic water and gas-flowing borehole, 1.474 km below land surface in the Evander Au mine, Republic of South Africa. The biofilm was 27 wt% ZnS, which was ～ 2 × 10⁷times more concentrated than the dissolved Zn measured in the borehole water. X-Ray diffraction indicated that the Zn was present in the form of fine grained, 4.7 ± 0.9 nm particles with smaller amounts of pyrite (FeS ₂ ). Scanning electron microscopy, coupled with energy-dispersive X-ray spectroscopy confirmed the identity of these minerals in the biofilm. Using transmission electron microscopy, the fine-grained ZnS minerals were found to coat the 1 μ m-diameter rod-shaped bacteria that made up the primary substructure of the biofilm. The FeS ₂ was present as framboids (spherical aggregates of 0.5–1 μ m FeS ₂ crystals) up to 10 μ m in diameter and as large, 2–3 μ m euhedral crystals that were not nucleated on the bacterial surfaces, but were found within the biofilm. Analyses of 16S rDNA utilizing clone libraries and a phylochip indicates that the ZnS rich biofilm is dominated by methanogens with a significant sulfate-reducing bacterial population and minor sulfide and CH ₄ -oxidizing chemolithotrophs. This biofilm community is sustained by sulfate, bicarbonate and H ₂ -bearing paleometeoric water.     

Geobacillus uralicus,a New Species of Thermophilic Bacteria

The K^T ₂ strain of thermophilic spore-forming bacteria was isolated from a biofilm on the surface of a corroded pipeline in an extremely deep well (4680 m, 40–72°C) in the Urals. The cells are rod-shaped, motile, gram-variable. They grow on a complex medium with tryptone and yeast extract and on a synthetic medium with glucose and mineral salts without additional growth factors. The cells use a wide range of organic substances as carbon and energy sources. They exhibit a respiratory metabolism but are also capable of anaerobic growth on a nitrate-containing medium. Growth occurs within the 40–75°C temperature range (with an optimum of 65°C) and at pH 5–9. The minimum generation time (15 min) was observed at pH 7.5. Ammonium salts, nitrates, and arginine are used as nitrogen sources. The G+C content of the DNA is 54.5 mol %. From the morphological, physiological, and biochemical properties and the nucleotide sequence of the 16S rRNA gene, it was concluded that the isolate K^T ₂ represents a new species of the genus Geobacillus, Geobacillus uralicus.     

一株番茄表面着生醋酸菌的分离鉴定及产酸条件优化

醋酸菌是食醋酿造过程中的关键菌种,性能优良的菌种对于产品品质的提升意义重大。以分离自番茄表面的产醋酸菌为研究对象,通过生理生化指标鉴定、16S rRNA编码基因比对及系统发育树构建等方法对其种类进行鉴定,并通过单因素实验、正交实验对鉴定为醋酸菌的菌株进行培养条件优化。结果表明,所分离的3株醋酸生产菌中,BQ-1被鉴定为醋酸杆菌属(Acetobacteraceae),在以酵母粉为主要氮源,蔗糖为主要碳源的培养基中,其最高产酸量为1823 g·L-1。由于该菌株在番茄表面具有很强的生长能力,因此有望应用于番茄果醋的酿造。     

一株拮抗香蕉枯萎病的内生细菌的分离及其几丁质酶基因信号肽的分泌活性分析

目的：旨在分离并选择一株香蕉内生细菌作为内生基因工程生防菌,并克隆其几丁质酶基因的信号肽序列。方法：从香蕉植株杆下部分离并选择了一株拮抗香蕉枯萎病且具有分泌几丁质酶能力的内生细菌,对该菌株进行了形态观察、生理生化测定和16S rDNA序列分析,克隆了其几丁质酶基因的编码序列并预测了其信号肽,构建了含有信号肽和不含信号肽的几丁质酶的表达菌株BL-chi1和BL-chi2。结果：结合形态观察、生理生化特征和16S rDNA序列比对分析确定该菌株为Klebsiella属,将该菌株命名为KKWB 5;BL-chi1和BL-chi2经IPTG诱导后,均表达了与预期蛋白大小一致的蛋白,同时BL-chi1诱导后的培养基上清中出现一条约45kDa的条带,而BL-chi2和空载体的BL-pET22b诱导后的培养基上清中均无此条带;几丁质水解试验发现,BL-chi1诱导后的培养基上清中的蛋白经浓缩和纯化后都能在几丁质平板上形成透明水解圈。结论：该几丁质酶的信号肽能被BL21（DE3）所识别,将几丁质酶分泌到培养基中,并且分泌的几丁质酶具有水解几丁质的生物学活性。内生菌KKWB-5的分离及其几丁质酶分泌信号肽序列的克隆为进一步构建内生工程菌来防治香蕉枯萎病打下了基础。     

一株具有广谱抗菌活性小单孢菌的分离和鉴定

从南昌瑶湖的农田土壤样品中分离到一株具有广谱抗菌活性的稀有放线菌.通过形态特征、培养特征、生理生化特性、细胞化学成分及16S rRNA基因序列等多相分类特征研究,将该稀有放线菌鉴定为炭样小单孢菌.     

一株具有广谱抗菌活性小单孢菌的分离和鉴定

从南昌瑶湖的农田土壤样品中分离到一株具有广谱抗菌活性的稀有放线菌。通过形态特征、培养特征、生理生化特性、细胞化学成分及16S rRNA基因序列等多相分类特征研究, 将该稀有放线菌鉴定为炭样小单孢菌。