Specific Release of Bacteriochlorophylls B800 of LH2 from Rhodobacter azotoformans Induced by Sodium Dodecyl Sulfate

采用吸收光谱法研究了十二烷基硫酸钠(SdS)诱导rHOdObACTEr AzOTOfOrMAnS外周捕光复合体lH2细菌叶绿素(bACTErIOCHlOrOPHyllS,bCHlS)的解离行为和规律.结果表明:室温下,在10MMOl？l-1TrIS-HCl(PH8.0)缓冲液中,低浓度SdS只诱导lH2中b800细菌叶绿素解离生成游离bCHlS,而b850不受影响;当浓度达到0.08%(W/V)时,能特异性地诱导b800缺失,其缺失过程和游离bCHlS的生成过程均符合单指数模型,且二者的速率常数近似相等.高浓度SdS能同时诱导b800和b850解离生成游离bCHlS,其中b800可发生缺失,而b850则不完全解离,解离过程均符合单指数模型;b800对SdS更敏感,其解离速率常数约是b850的4倍,游离bCHlS生成速率常数明显低于b800解离速率常数,而与b850解离速率常数相接近.The release behaviors of bacteriochlorophylls of peripheral light-harvesting complex LH2 from Rhodobacter azotoformans induced by sodium dodecyl sulfate (SDS) were investigated using absorption spectroscopy.The results indicated that bacteriochlorophylls of B800 band are released from their binding sites and transformed into free bacteriochlorophylls by incubating LH2 sample in 10 mmol?L-1 Tris-HCl (pH 8.0) buffer containing SDS of low concentration at room temperature.However, the bacteriochlorophylls of B850 band are not released.The dynamics of B800 release and free BChl formation induced by 0.08% (w/V) SDS can be well fitted by the monoexponential model.The rate constant of B800 release is nearly equal to that of free BChls formation.The release of both B800 and B850 of LH2 can be induced by high concentration SDS, simultaneously.The bacteriochlorophylls of B800 band can be completely transformed into free BChls, but not for B850.Although both of their release processes show monoexponential models in 1% SDS solution, the release rate constant of B850 is remarkably lower than that of B800 and close to that of free BChls formation.国家自然科学基金(No.30970068);国家科技基础条件平台建设(No.2005DKA21209);厦门大学近海海洋环境科学国家重点实验室高级访问学者基金(No.MELRS0907);山西省回国留学人员科研(No.200713)资助项

乳清酸磷酸核糖转移酶启动子及应用和构建体与载体

通过扩增圆红冬孢酵母乳清酸磷酸核糖转移酶基因组DNA上下游序列，进行生物学信息分析和功能验证，获得可有效表达目的基因于圆红冬孢酵母，并因此能够用于圆红冬孢酵母遗传工程操作和菌株改良的启动子和终止子。本发明还涉及包含这些元件的DNA构建体和载体。待填

Isolation and characterization of pigment-protein complexes from Rhodobacter azotoformans

【目的】为揭示不产氧光合细菌产氢菌株色素蛋白复合体(PPC)色素组成和含量与光合放氢的关系奠定基础。【方法】以PPC特征光谱为检测指标,采用硫酸铵分级分离、dEAE-纤维素层析、吸收光谱和SdS-PAgE等方法进行了固氮红细菌(rHOdObACTEr AzOTOfOrMAnS,r.AzOTOfOrMAnS)r7产氢菌株PPC的分离纯化、纯度分析和鉴定;采用表面增强激光解吸电离离子飞行时间质谱、HPlC-MS和荧光光谱法对其中一种PPC进行了组成分析和能量传递活性测定。【结果】从r7菌株获得了3种纯化的PPC,1种为反应中心与中心捕光色素蛋白复合体(rC-lH1),2种为外周捕光色素蛋白复合体(lH2),其中一种lH2的吸收光谱具有异常的423nM强吸收峰,其蛋白的两种亚基的分子量分别为5356.8dA和5697.8dA,类胡萝卜素属球形烯系,分子量为562dA,激发光能够从类胡萝卜素向细菌叶绿素以及细菌叶绿素向细菌叶绿素传递。【结论】固氮红细菌产氢菌株含有2种不同光谱特性的lH2,其中一种具有新光谱特性。ObjectiveIn order to reveal the relationships of compositions and content of pigment in pigment-protein complexes(PPC ) and hydrogen photoevolution from anoxygenic phototrophic bacteria.Methods We isolated and identified pigment-protein complexes using a separation strategy of subsequent fractionated ammonium-sulfate precipitation,ion exchange column chromatography,absorption spectra and sodium dodecylsulfate polyacrylamide gel electrophoresis(SDS-PAGE ) from hydrogen-producing Rhodobacter azotoformans R7.We investigated the characterizations of the peripheral light-harvesting complex(LH2 ) with an unusual absorption spectrum by surface enhanced laser desorption / ionization time of flight mass spectrometry(SELDI-Tof-MS ),high performance liquid chromatography-mass spectrometry(HPLC-MS) and fluorescence spectra.ResultsWe acquired three types of PPC, the reaction center and core light-harvesting complex(RC-LH1 ) and two kinds of LH2,from strain R7 incubated anaerobically in the light.The two LH2 showed the different absorption spectra,one of them displayed unusual absorption spectrum with the maximum absorption band at 423 nm.The unusual LH2 consisted of two kinds of protein subunits with the molecular weight of 5556.8 Da and 5697.8 Da and carotenoid of spheroidene series with the molecular weight of 562 Da.It was also capable of transferring energy from carotenoid to bacterialcholorophyll and from B800 bacterialcholorophyll to B850 bacterialcholorophyll.Conclusions Rhodobacter azotoformans R7 with hydrogen-producing capacity could photosynthesize two types of LH2 under anaerobically in the light,one of them presented novel spectral property.国家自然科学基金(30970068);国家科技基础条件平台建设项目(2005DKA21209);近海海洋环境科学国家重点实验室(厦门大学)高级访问学者基金(MELRS0907)---

Identification and characterization of a purple sulfur bacterium from mangrove with rhodopin as predominant carotenoid

【目的】挖掘我国海洋紫色硫细菌物种资源、深入理解紫色硫细菌在红树林生态系统中的作用。【方法】采用琼脂振荡稀释法、显微技术、紫外可见吸收光谱法、TlC、HPlC和MS法。【结果】从福建泉州洛阳桥红树林潮间带泥水样分离获得一株细胞内含多个硫粒的细菌菌株,光合内膜呈囊状、含细菌叶绿素A和螺菌黄质系类胡萝卜素,结合16S rrnA基因序列分析和系统发育分析,表明该菌株属于海洋着色菌属(MArICHrOMATIuM)。该菌株细胞球杆状;最适PH范围5.7-6.7;最适盐度范围2%-3.5%;温度范围20℃-35℃;能耐受3.6 MMOl/l硫化物;主要积累玫红品类胡萝卜素,而不是螺菌黄质;3种细菌叶绿素组分中,一种为bCHl AP,另2种未见报道;不需要生长因子;可光同化固定CO2、能很好利用多种有机酸盐、多价态氮化物和硫化物,尤其能利用柠檬酸、葡萄糖、蔗糖、果糖和丙醇;对氯霉素、头孢唑林、苯、对羟基联苯、恩诺沙星、啶虫脒、HgCl2和CdCl2的IC50值分别为70、100、20、20、3、170、5 Mg/l和25 Mg/l。【结论】该菌株是一株轻度耐酸、高含玫红品类胡萝卜素的紫色硫细菌,被鉴定为MArICHrOMATIuM grACIlE新菌株,编号yl28。该菌株具有广泛利用多种碳源、氮源和硫源物质的能力,对抗生素氯霉素和头孢唑啉、农药啶虫脒、重金属汞和镉具有较强耐受性,对抗生素恩诺沙星较敏感。[Objective]To exploit resources of purple sulfur bacteria in China and further investigate its response mechanism to ecological environment of mangrove.[Methods] Repeated agar shake dilution method,microscope techniques,UV-Vis absorption spectra,thin layer chromatography,HPLC and MS were used.[Results] We isolated a purple sulfur bacterium,designated as strain YL28,from a intertidal sediment sample collected from inshore mangrove near Luoyang Bridge of Quanzhou city,Fujian Province of China.Cells were ovoid to rod shaped,0.5 μm-1 μm × 2 μm-3 μm.Color of cell suspensions was reddish-brown.It possessed vesicular intracytoplasmic membrane structures,contained rhodopin and phytylated bacteriochlorophyll a as well as the other two novel bacteriochlorophyll a intermediates.The optimum growth was at 2%-3.5% NaCl,pH 5.7-6.7 and 20℃-35℃.Photoautotrophically growth anaerobically in the light with sulphide,sulphur,thiosulfate,sulfite as electron donor.Globules of S0 distributed inside the cells.Photoheterotrophic growth with various organic substrates,especially citrate,glucose,sucrose,fructose and propanol in the presence of sulfide.Nitrogen sources: ammonium salts,N2,urea,glutamate,nitrate and nitrite.Vitamins were not required.Qualitative assessment of IC50 values of chloromycetin,cefazolin,benzene,hydroxy biphenyl,enrofloxacin,acetamiprid,mercuric chloride and cadmium chloride were 70,100,20,20,3,170,5 mg/L and 25 mg/L,respectively.[Conclusion]Based on phenotype characteristics and 16S rRNA gene sequence similarity of 99% to M.gracile,strain YL28 was identified as novel isolate of M.gracile despite its different physiological characteristics with respect to the species of M.gracile.The organism is possessed of slightly acid tolerance,higher amount of carotenoid of rhodopin and tolerance towards certain antibiotics,pesticide as well as heavy metals.国家自然科学基金(31070054);福建省自然科学基金(2010J01209);中国科学院城市环境与健康重点实验室基金(KLUEH201005)---

一种酵母菌落PCR菌体前处理的方法

本发明公开了一种酵母菌落PCR菌体前处理的方法。该方法为：菌体经过灭活，两步酶解，最后煮沸的处理后，上清可直接用于PCR反应。本方法制备的样品可有效地扩增基因组上单拷贝、长片段基因。此方法为大规模的酵母筛选和鉴定提供了新的途径

基于支持向量机遥感图像融合分类方法研究进展

总结了近年来国际上图像融合以及支持向量机的应用的研究进展,分析了支持向量机用于遥感图像融合分类的趋势、优势以及目前存在的问题,指出了该研究领域的研究方向

基于支持向量机遥感图像融合分类方法研究进展

总结了近年来国际上图像融合以及支持向量机的应用的研究进展,分析了支持向量机用于遥感图像融合分类的趋势、优势以及目前存在的问题,指出了该研究领域的研究方向。

一种用于在光纤侧面均匀蒸镀增透膜的夹具

 本发明公开了一种用于在光纤侧面均匀蒸镀增透膜的夹具,该夹具包括上半部分和下半部分,被该夹具夹持的光纤在镀膜过程中采用公转与自转相结合的形式转动,其中该上半部分与镀膜机的旋转部件相连接,由镀膜机的旋转部件带动该上半部分转动,使该上半部分侧面夹持的光纤围绕该夹具中心转动,形成公转；该下半部分与镀膜机的机体相连接,在该上半部分转动时保持不动,由该下半部分表面的齿轮轨道迫使该上半部分中夹持光纤的部件在随该上半部分转动的同时自身同步转动,形成自转。利用本发明,减少了光纤对此波段激光的反射,提高了光纤对激光器的准直效率,提高了激光器的可靠性。同时该夹具还可用于其他柱状体物体的侧壁镀膜,具有广泛的应用价值

Deletion of the DGAAT gene with a bleomycin resistance cassette in the oleaginous yeast Rhodosporidium toruloides

The red yeast Rhodosporidium toruloides is oleaginous with a great propensity to accumulate intracellular lipids over 70% of its dry cell weight when carbohydrates were fed as carbon sources. Therefore, this yeast has been intensively studied recently in order to produce microbial lipid for a sustainable biodiesel industry. On the other hand, the biochemical machinery of lipid metabolism may be explored for production of value-added metabolites. For example, diacylglycerols, the precursor to triacylglycerols, are attractive because of their special biological activities. In this study, we isolated the genomic DNA sequence of the acyl-coenzyme A:diacylglycerol acyltransferase gene (DGAAT). We generated a knockout construction with bleomycin resistance cassette replacing the 1858 bp open reading frame of the DGAAT gene. The haploid strain R. toruloides NP11 was electroporated with the cassette, and transformant was observed on YEPD medium containing 50 μg/ml Zeocine. It should be noted that the wild-type strain were killed by 5 μg/ml Zeocine. Further PCR analysis and genome walking showed that the bleomycin cassette was integrated into the chromosome of the yeast. These results demonstrated that cassette was functional in R. toruloides under the control of the DGAAT promoter and the terminator. We will discuss more details and progress of this project during the conference.The red yeast Rhodosporidium toruloides is oleaginous with a great propensity to accumulate intracellular lipids over 70% of its dry cell weight when carbohydrates were fed as carbon sources. Therefore, this yeast has been intensively studied recently in order to produce microbial lipid for a sustainable biodiesel industry. On the other hand, the biochemical machinery of lipid metabolism may be explored for production of value-added metabolites. For example, diacylglycerols, the precursor to triacylglycerols, are attractive because of their special biological activities. In this study, we isolated the genomic DNA sequence of the acyl-coenzyme A:diacylglycerol acyltransferase gene (DGAAT). We generated a knockout construction with bleomycin resistance cassette replacing the 1858 bp open reading frame of the DGAAT gene. The haploid strain R. toruloides NP11 was electroporated with the cassette, and transformant was observed on YEPD medium containing 50 μg/ml Zeocine. It should be noted that the wild-type strain were killed by 5 μg/ml Zeocine. Further PCR analysis and genome walking showed that the bleomycin cassette was integrated into the chromosome of the yeast. These results demonstrated that cassette was functional in R. toruloides under the control of the DGAAT promoter and the terminator. We will discuss more details and progress of this project during the conference