Two-Component Signal Transduction Systems in the Cyanobacterium Synechocystis sp. PCC 6803

Introduction Rapid adaptation to environmental challenges is vitally important for bacterial survival and growth. One way in which bacteria control their response to changing environmental conditions is through the mechanism of two-component signal transd…     

Sodium Acetate Stimulates PHB Biosynthesis in Synechocystis sp. PCC 6803

IntroductionA large variety of bacteria are able to synthesizepolyhydroxyalkanoic acids (PHAs) and to depositlarge amounts of these polyesters as insolubleinclusions in cytoplasm[1 ] . PHAs have attractedthe interest of the chemical industry because oftheir biodegradable properties for applications invarious technical,medical,and pharmaceuticalapplications[2 ] .Poly-β-hydroxybutyrate(PHB) isatypical PHA that is produced by heterotrophicbacteria,such as Alcaligenes eutrophus andEscherichi…     

自养小球藻转化为异养代谢生长后细胞的超微结构与相关生化组成

利用细胞培养技术转化绿色自养的小球藻(Cholrella protothecoides)进行异养生长代谢.酶法分析反映,异养转化过程中细胞培养液中葡萄糖的利用率很高。转化后的细胞光合片层消失,叶绿体同时消失,细胞被一些大的酯肪泡填充,异养藻细胞的细胞壁也比原自养藻细胞加厚,而且细胞表而发生皱缩现象。再次将异养藻细胞置于自养生长条件下,细胞的光合片层和叶绿体结构又得以重建。生化分析显示,经异养转化后藻细胞蛋白质含量下降,为原绿色自养细胞的1/5;相反脂肪含量大幅度增加,是原初的4.4倍,达到细胞干重的72.％。异养藻细胞样品各氨某酸含量都低于自养藻细胞样品,前者以谷氨酸含量较高,后者含甘氨酸最多。在自养藻细胞样品中亚油酸的相对含量最高,为56.50％;转化为异养生长后变成油酸的相对含量占优势,达69.36％,说明异养转作用可明显降低细胞中脂防酸的不饱和程度。     

发现于浮游硅藻中的长链正烷烃

广泛分布于古代沉积岩、现代沉积物及各种生物体中的烷烃类是构成石油的重要组分。生油岩与原油中烷烃化合物的特征与原油母质来源之间的关系是研究石油成因最基本和普遍注意的问题。通常认为,以浮游藻类等低等水生植物为主来源的有机质烷烃类化合物以C_(15)—C_(17)等低分子量烷烃类占优势,而以陆源高等植物为主的母质输入的有机质烷烃类化合物以高     

蓝细菌光系统Ⅱ的组成相关基因和遗传修饰

蓝细菌是研究光合作用的理想实验系统，在光系统Ⅱ组成，相关基因及遗传修饰等分子水平上的探索已取得重大进展，主要介绍了光系统Ⅱ反应中心蛋白复合物，天线色素蛋白复合物，细胞色素蛋白复合物，锰稳定蛋白复合物等主在蛋白成份，相关基因，以及利用分子生物学操作对蛋白组分功能的研究工作。     

聚胞藻热模拟产烃研究

采用ＧＣ和ＧＣＭＳ对蓝藻聚胞藻原生烃类及热解烃类进行了分析．聚胞藻在２５０ ℃～３００ ℃热解产气属于低熟气,以非烃气为主,产气组分参数反映了原核生物母质来源的特征．热解作用使其氯仿沥青“Ａ”含量和烷烃含量大幅度提高．原生烷烃以正烷烃为主,主峰为ｎＣ１７ ．热解烷烃仍以低碳数正烷烃为主,主峰为ｎＣ１７ ,反映了典型的藻类母质来源的烷烃特征．热解烷烃中还检出了丰富的二环倍半萜和五环三萜．五环三萜以Ｃ３０ 莫烷为主峰,并含有丰度较高的Ｃ３０藿烯,表明生成的烃类属于低熟油     

盐藻热模拟产物中长链类异戊二烯烃的检出

通过对自然条件下培养获得的盐藻样品的热模拟烃研究，首次从藻类生物的热模拟产物中发现了含量丰富的长链规则类异戊二烯烃，特别是检出高含量２，６，１０，１４，１８－五甲基二十烷，表明高盐环境中的规则ｉＣ２５有可能来源于特殊的嗜盐藻类，从而为沉积物中发现的长链规则类异戊二烯烃的母质来源及古环境判识提供新的参考证据。     

颗石藻热模拟产物中芳烃生物标志物分布

颗石藻原样和不同温度热模拟实验分析结果表明，颗石藻对低熟原油中长链烷基芳烃的贡献不容忽视；藻类通过生物化学作用将无机硫转化为有机还原硫，是岩石和原油中有机硫化合物中硫的来源之一；应用甲基菲指数判识有机质成熟度时应结合其他成熟度参数；在低熟条件下，用三芴相对含量判识氧化还原环境更为可靠。     

Contributions of DPOR at Low Light Intensi.ty to Chlorophyll Biosynthesis and Growth in the Synechocystis sp. PCC 6803

Introduction Chlorophylls (Chls) and bacteriochlorophylls (Bchls) are two of the most abundant classes of natural pigments, and their biosynthesis is a major metabolic activity in the ecosystem[1]. Protochlorophyllide (Pchlide) is an intermediate in the Chl and Bchl biosynthetic pathway of photosynthetic organisms and its reduction to chlorophyllide (Chlide) is a key regulatory step in the Chl biosynthesis pathway. In this reaction, the porphyrin D-ring of Pchlide is converted to chlorin b…     

Alternative Respiration Induced by Glucose Stimulation and Variation of Adenylate Energy Charge in Glucose-Starved Cells of Green Alga Chlorella Protothecoides

IntroductionCyanide- resistant or alternative respiration hasbeen reported to be widespread in higher plants,phytoplanktons and microorganisms[13 ] . Thestudies of the inhibitor- resistant respiration havecontributed much to the understanding of theorganization and control of complex intracellularrespiratory systems and biochemical processes.Grant and Hommersand[4 ,5] examined theinhibitor- resistantrespiratory characteristics of thegreen alga Chlorella protothecoides grown in highconcentrati…