少动鞘氨醇单胞菌致感染性心内膜炎1例

少动鞘氨醇单胞菌(Sphingomonas paucimobilis) 是一种少见的条件致病菌,可引起手术后感染、创伤后腿部溃疡、菌血症、脑膜炎、慢性蜂窝织炎、手术后眼内炎等,未查见累及心瓣膜的报道.本文报道1例由少动鞘氨醇单胞菌所致感染性心内膜炎的病例.该患者为中年男性,因"反复发热2月余"入院.以发热伴左上腹痛为首...     

鞘氨醇单胞菌的研究进展

鞘氨醇单胞菌(Sphingomonas)不仅细胞膜含有比脂多糖更疏水的鞘糖脂,而且具有高效的代谢调控机制和基因调控能力,使其在威兰胶合成、环境修复和促进植物生长等方面具有巨大的应用潜力。目前国内在鞘氨醇单胞菌代谢机制方面的研究尚无新突破。本文主要综述了鞘氨醇单胞菌的系统分类、基因组学、基因调控机制及其应用等方面的研究,从基因层面分析鞘氨醇单胞菌产威兰胶的合成机制,为后续鞘氨醇单胞菌高密度发酵、工业化生产等研究提供理论基础,以便进一步发掘其在生物技术上的应用潜力。     

合成生物聚合物的重要微生物资源-鞘氨醇单胞菌

摘要：鞘氨醇单胞菌属的许多菌株能够合成结冷胶、沃仑胶、迪特胶等多种结构相似,物理性能多样的生物聚合物,统称为鞘氨醇胶。目前,结冷胶已经大规模的生产和应用,由于鞘氨醇单胞菌属的提出仅有十几年的历史,其他种类鞘氨醇胶的研究和开发才刚刚起步。本文综述了鞘氨醇单胞菌属分类研究的最新进展,以及鞘氨醇胶的结构、特性、生物合成途径、分子遗传学和基因工程的研究现状,并对今后的研究重点和方向进行了展望。     

少动鞘脂单胞菌S1胞外多糖发酵工艺条件研究

研究了摇瓶培养条件下少动鞘脂单胞菌引的胞外多糖的发酵工艺。Ｓ１菌的发酵产胶可采用二步发酵法：第一阶段,培养基成分为：蔗糖１０ｇ,ＮＨ_４ＮＯ_３　０．５ｇ,ＫＨ_２ＯＰ_４　０．５ｇ,ＭｎＳＯ_４　０．３ｇ,ＭｇＳＯ_４　０．１ｇ,吐温８０ ０．０２ｇ溶于蒸馏水并定容至１０００ｍＬ,ｐＨ７．２±０．１,温度３３℃～３５℃,高溶氧。第二阶段,发酵 １０～１２ｈ后,补加蔗糖４０ｇ／Ｌ,温度     

LB克隆系统的构建及在鞘氨醇单胞菌基因融合表达中的应用

为摆脱限制性酶切位点不足的限制,构建可灵活改变多基因融合方向的表达载体,基于ⅡS型和ⅡT型限制性内切酶LguⅠ和BbvC Ⅰ设计开发了 LB克隆系统.该克隆系统是以广宿主质粒pBBR1MCS-3为初始载体,利用 PCR的方法,在其多克隆位点区插入LB片段(GCTCTTCCTCAGC)构建得到的.LB片段含Lgu Ⅰ和B...     

鞘氨醇单胞菌TP-3合成新型生物聚合物Ss的发酵条件优化

鞘氨醇单胞菌(Sphingomonas sp.)TP-3能合成一种具有增稠性、假塑性、成凝胶特性和乳化性能的新型生物聚合物Ss。运用单因素实验和均匀设计法对菌株TP-3合成聚合物Ss的发酵条件进行优化, 实验结果表明, 培养基组成为葡萄糖41.2 g/L, 豆饼粉2.0 g/L, NaCl 0.85 g/L, K2HPO4 1.46 g/L, MgSO4 0.12 g/L, MnCl2 0.0075 g/L, FeSO4 0.002 g/L, 初始pH为7.0, 在27°C, 180 r/min的条件下摇床培养60 h, 聚合物Ss的产量达到21.5 g/L。该聚合物生产成本低, 在油田开发中极具应用前景。     

鞘氨醇激酶-磷酸鞘氨醇轴在血管生成相关性疾病中的作用

血管生成是指在原有血管的基础上形成新血管的过程.病理性血管生成是癌症、心血管类疾病和视网膜病变等一系列疾病的标志.1-磷酸鞘氨醇(sphingosine-1-phosphate,S1P)是一种信号脂质,由鞘氨醇激酶(sphingosine kinases,SPHK)合成,通过5种G蛋白偶联受体(sphingosine-...     

鞘氨醇激酶活性测定方法的建立及其初步应用

目的:建立生物样品中鞘氨醇激酶(SPK)活性和1-磷酸鞘氨醇(S1P)含量的测定方法.方法:用Flag标记的SPK基因表达载体转染ECV304细胞,用Western blot方法检测转染后SPK基因的表达,用酶促反应、同住素掺入和薄层层析的方法检测SPK的活性.提取细胞或组织的S1P,碱性磷酸酶消化去除磷酸根,然后利用SPK的催化活性和同位素标记的方法对S1P进行定量.结果:转染基因后细胞的SPK表达明显升高,活性显著增强,细胞内S1P的含量也明显增多.肝细胞生长因子(HGF)刺激能增强ECV304细胞SPK的活性和细胞内S1P水平.结论:建立了SPK活性和S1P含量的测定方法.     

鞘氨醇杆菌的研究进展

鞘氨醇杆菌是一类革兰氏阴性非发酵杆状细菌,很少引起人类感染,它的主要特点是含有大量的细胞膜鞘磷脂。由于其广泛的生态分布与石油降解能力,已引起了环境微生物学者的重视。本综述总结分析了鞘氨醇杆菌的分类学地位及其主要成员的进化亲缘关系,重点阐述了它们的生理生化特征方面的研究进展,最后总结了8个鞘氨醇杆菌的基因组特征,以期为深入研究鞘氨醇杆菌的功能及其泛基因组提供理论指导,并进一步对鞘氨醇杆菌的深入研究进行了展望。     

少动鞘脂单胞菌产结冷胶发酵培养基的响应面法优化

通过单因素试验分析不同碳源、氮源、无机盐对（Sphingomonas paucimobilisFJAT-5627）产胶量的影响,确定最适碳源、氮源、无机盐,并在单因素筛选试验的基础上,利用Box-Benhnken设计和响应面分析法对碳源、氮源和无机盐进行优化,得到少动鞘脂单胞菌产生结冷肢发酵培养基最佳优化组合.实验结果表明,少动鞘脂单胞菌产胶量发酵最适碳源、氮源和无机盐分别为淀粉、豆饼粉和KH₂PO₄.响应面法得到产胶量（Y）与碳源淀粉（x₁）、氮源豆饼粉（x₂）和无机盐KH₂PO₄（x₃）的回归方程为:Y=13.87+0.54x₁+0.22x₂-0.42x₃-3.26x₁²-1.85x₂²-1.51x₃²+0.053x₁x₂+0.067x₁x₃+0.4x₂x₃.优化培养基组合为:淀粉浓度为30g/L,豆饼粉浓度为5 g/L,KH₂PO₄的浓度为0.7g/L,且此组合下少动鞘脂假单胞发酵得到结冷胶可达23.87g/L.     

Enhanced Degradation of Hexachlorocyclohexane Isomers by Sphingomonas paucimobilis

Hexachlorocyclohexane (HCH) has been banned for use in technologically advanced countries; however, it is still in use in tropical countries like India. Earlier we reported the degradation of HCH isomers by Sphingomonas paucimobilis within 12 days of incubation. Here we report the role of different factors that could enhance the degradation rate of HCH isomers. We found that an increase in the cell number from 10² to 10⁸ cells/ml resulted in an increased degradation rate of HCH isomers viz. α, β, γ, and δ-HCH. While α-HCH and γ-HCH disappeared completely from the medium within 3 days of incubation, a maximum of only 90% and 85% degradation was observed for β and δ-HCH, respectively. We have also observed that adapted cultures degraded HCH isomers more efficiently than did the normal cultures. Received: 16 February 2000 / Accepted: 23 May 2000     

A colorimetric assay for gellan elaborated by Sphingomonas paucimobilis ATCC 31461

A colorimetric assay involving the dye toluidine blue O was developed to determine the concentration of the microbial heteropolysaccharide gellan elaborated by Sphingomonas paucimobilis ATCC 31461. Colour formation was linear up to a concentration of 0.7 mg/ml. The concentration of gellan produced in S. paucimobilis cultures was quantitated using this colorimetric dye-binding assay as well as the currently utilized gravimetric procedure, and comparable results were observed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Deproteinization of gellan gum produced by Sphingomonas paucimobilis ATCC 31461

Deproteinization is a technical bottleneck in the purification of viscous water-soluble polysaccharides. The aim of this work is to provide an appropriate approach to deproteinize crude gellan gum. Several methods of deproteinization were investigated, including Sevag method, alkaline protease, papain and neutral protease. The results revealed that Sevag method had high deproteinization efficiency (87.9%), but it showed dissatisfactory recovery efficiency of gellan gum (28.6%), which made it less advisable in industrial applications. The deproteinization by alkaline protease was demonstrated in this work for the first time, indicating alkaline protease was preferred in the deproteinization of crude gellan gum with high polysaccharide recovery (89.3%) and high deproteinization efficiency (86.4%).     

Effect of 2-deoxy-d-glucose on gellan gum biosynthesis by Sphingomonas paucimobilis

Bioprocess and Biosystems Engineering - 2-Deoxy-d-glucose (2-DG) is a non-metabolizable glucose analogue and competitive inhibitor of glycolysis. Effect of 2-DG on gellan gum biosynthesis by...