铜绿假单胞菌对长链烷烃的摄取模式*

研究了一株铜绿假单胞菌(CGMCC 1.1785)摄取长链烷烃的模式。铜绿假单胞菌1.1785能够以固态的长链烷烃为唯一碳源生长,在培养过程中产生表面活性代谢物。烃与水相的界面面积是细菌生长重要的影响因素,说明传质限制的存在。由于该菌不能够利用鼠李糖脂增溶的烃作为碳源,因此添加鼠李糖脂能够强化烃摄取的主要原因是烃界面的扩大。细胞表面疏水性从开始的急剧升高到后来的不断下降,说明在不同生长阶段细胞对烃的摄取模式是不同的。由此认为,铜绿假单胞菌1.1785既没有通过表面活性剂介导模式获取烃,也并非完全通过直接接     

一株铜绿假单胞菌及其产生的鼠李糖脂特性研究

研究高效代谢表面活性剂的菌种,并对菌种和表面活性剂的理化性质进行分析。采用菌种16S rDNA序列分析对菌种进行鉴定,采用紫外光谱扫描、色谱柱层析、薄层层析、单糖分析对生物表面活性剂的种类进行鉴定,并对表面活性剂的理化性质进行研究。从油田采出水中筛选出一株高效代谢生物表面活性剂的菌株T-1,经16S rDNA鉴定为铜绿假单胞菌属(Pseudomonas aeruginosa)。该菌种以甘油和大豆油为碳源的培养基培养4 d后,其发酵液表面张力30.216 mN/m,EI24为100%。根据表面活性剂的红外光谱分析并结合薄层分析,可确定T-1样品中含有糖脂类物质,进一步的表面活性剂的单糖分析显示水解终产物为单一的鼠李糖,最终确定其产物为鼠李糖脂,苯酚-硫酸法测定其鼠李糖脂产率为5.2 g/L,从发酵液提取的棕黄色生物表面活性剂粗品,其表观临界胶束浓度为45 mg/L,该鼠李糖脂对环境(耐温、耐酸碱、耐盐)具有较强的适应性。该表面活性剂对恶劣环境具有较强的耐受性,可应用于微生物采油等用途。     

9株海洋来源铜绿假单胞菌合成鼠李糖脂的比较分析

目的:从海洋来源的铜绿假单胞菌中筛选多株具有鼠李糖脂合成能力的菌株。方法:以9株分离自不同海洋环境的铜绿假单胞菌为研究对象,考察并比较其发酵合成鼠李糖脂生物表面活性剂的表面活性、产量和产物成分的差异,扩增并比对合成途径中的关键基因。结果:9株菌的发酵产物均具有表面活性,其中菌株1A01151发酵液的表面活性最强,表面张力值可降低至28 m N/m;9株菌的基因组中均含有鼠李糖脂合成途径中关键基因rhl AB和rhl C,都具有合成单、双鼠李糖脂的能力;菌株1A01151和1A00364的发酵产量最高(2.69 g/L),产物经LC-MS/MS检测,所合成的鼠李糖脂同系物组分不同,双糖双脂的含量最高(1A01151:75.96%;1A00364:61.01%)。结论:海洋来源的铜绿假单胞菌是具有鼠李糖脂高产潜力的菌株,可用于合成性能不同、组成多样的鼠李糖脂生物表面活性剂。     

含血红蛋白基因(VHb)的铜绿假单胞菌重组菌的构建及鼠李糖脂表达条件的研究

将RDR（ribonucleotide diphosphate reductase）启动子驱动下的透明颤菌（Vitreoscillasp．）血红蛋白（Vitreoscilla hernoglobin,VHb）基因的表达载体pSETRDR-VHb转入铜绿假单胞（Pseudamanas aeruginosa）s301菌株中。并对其中阳性转化子AY26菌株进行了鼠李糖脂表达条件的研究。正交实验k（4。）优化培养基,最佳组分为：硫酸镁0．075％、硝酸钠0．5％、清油3mUL、酒石酸钠0．4％。在限碳培养条件下,转化子SY26鼠李糖脂产量达到12．9dL,比对照菌株S301（8．4g／L）提高150％,5L发酵罐放大实验验证,重组菌AY26的表面活性剂产量达到33．12g／L。     

铜绿假单胞菌锌离子摄取系统的研究进展

锌作为一种结构、催化和信号的成分,在许多生理过程中起着关键的作用.它也是病原微生物生长所必需的,不但参与病原微生物代谢和各种毒力因子的调控,而且是病原微生物在宿主中感染和定殖所必需的.铜绿假单胞菌侵染宿主发挥毒力时,宿主会采取营养免疫的策略来限制体内环境中游离的锌离子浓度而抑制该病原菌的感染和定殖.反过来,铜绿假单胞菌...     

铜绿假单胞菌生物膜研究进展

生物膜（biofilm,BF）是细菌为了适应生存环境的需要而形成的与浮游细胞相对应的生存形式,是细菌生来具有的本领。不同的细菌形成生物膜的能力是不同的,铜绿假单胞菌极易形成生物膜,临床许多生物医学材料相关感染和某些慢性顽固性感染性疾病都与之密切相关,在生物膜中的细菌不仅耐抗生素还可耐抗体的杀菌作用,危害性严重。     

铜绿假单胞菌中鼠李糖脂生物合成的研究进展*

鼠李糖脂因其具有环境友好和卓越的物理化学特性,而有望成为化学合成表面活性剂的替代物。近年来鼠李糖脂得到了广泛的研究,其目的是利用低价的可再生资源进行大规模生产,但目前的研究成果仍不足以选育出更具商业竞争力的鼠李糖脂过量合成菌株。为此,进一步理解鼠李糖脂生物合成的复杂基因调控网络,探索降低生产成本的发酵工艺势在必行。综述了铜绿假单胞菌中鼠李糖脂的生物合成途径、群体感应对主要基因的调控、鼠李糖脂在生物膜形成中所发挥的作用,以及发酵优化对鼠李糖脂产量的影响。有助于加深对鼠李糖脂生物合成的认识,为提高鼠李糖脂产量提供重要参考信息。     

铜绿假单胞菌超微结构观察

铜绿假单胞菌超微结构观察佳木斯医学院附一院感染科１５４００２高庆伟郭丽曼齐淑芳邱守义佳木斯医学院微生态学教研室杨景云华西医科大学传染科黄安华曹钟梁雷秉钧ＰＡ做为呼吸道感染的重要条件致病菌,广泛分布于自然界,亦常存在于上呼吸道、肠道、皮肤等处。可以通过...     

铜绿假单胞菌中鼠李糖脂生物合成的研究进展*

鼠李糖脂因其具有环境友好和卓越的物理化学特性,而有望成为化学合成表面活性剂的替代物。近年来鼠李糖脂得到了广泛的研究,其目的是利用低价的可再生资源进行大规模生产,但目前的研究成果仍不足以选育出更具商业竞争力的鼠李糖脂过量合成菌株。为此,进一步理解鼠李糖脂生物合成的复杂基因调控网络,探索降低生产成本的发酵工艺势在必行。综述了铜绿假单胞菌中鼠李糖脂的生物合成途径、群体感应对主要基因的调控、鼠李糖脂在生物膜形成中所发挥的作用,以及发酵优化对鼠李糖脂产量的影响。有助于加深对鼠李糖脂生物合成的认识,为提高鼠李糖脂产量提供重要参考信息。     

铜绿假单胞菌czcCBA基因与生物修复

铜绿假单胞菌(Pseudomonas aerugionsa)的外排泵系统RND是它产生耐重金属离子胁迫的一个重要原因。阐述了编码RND外排泵czcCBA基因的作用机制,以期为下一步工作奠定基础。     

烃的微生物摄取机制研究进展

综述了近期在烃的微生物摄取机制方面的研究进展。对提高环境生物整治效果而言,微生物对非水溶性底物,尤其是烃的摄取机制是重要的课题。随着理论认识的深入和研究手段的丰富,在该领域已有了更多发现和结论。介绍了表面活性剂对烃摄取的影响,细胞表面性质的调整和烃的跨膜输送等方面的近期研究结果;同时,提供了细胞亚微结构分析,细胞趋化性等相关证据,指出了在该领域尚待解决的问题。     

Uptake and metabolism of methylammonium by Pseudomonas aeruginosa

The mechanism of ammonium uptake was studied in Pseudomonas aeruginosa, measuring the uptake (transport and metabolism) of [14C]methylammonium (MA). This ammonium analogue was not utilized for growth, but unmetabolized MA was accumulated to intracellular concentrations about 30 times higher than those in the medium. Most of the MA taken up, however, was rapidly metabolized to gamma-N-methylglutamine, which could be removed from the cells by the addition of ammonium. Uptake of MA exhibited distinct optima at pH 7.0 and 35 to 40 degrees C and depended on metabolic energy, as indicated by the inhibitory effect of various metabolic poisons. Growth with ammonium as nitrogen source resulted in the repression of MA uptake, whereas high uptake rates were observed with nitrate or after incubation without nitrogen source. These results suggested that the ammonium/MA uptake system is subject to nitrogen control in P. aeruginosa.     

Optimization and characterization of rhamnolipid production by Pseudomonas aeruginosa NY3 using waste frying oil as the sole carbon

Yield and cost are two major factors limiting the widespread use of rhamnolipids (RLs). In the present study, waste frying oil (WFO) was used as the sole carbon source to produce environmentally friendly RLs by Pseudomonas aeruginosa NY3. The Plackett–Burman design (PBD) and Box–Behnken design (BBD) methods were used to maximize the production yield of RL. The PBD results showed that the concentrations of NaNO₃, Na₂HPO₄, and trace elements were the key factors affecting the yield of RL. Furthermore, the BBD results showed that at NaNO₃, Na₂HPO₄, and trace elements concentrations were 4.95, 0.66, and 0.64 mL/L, respectively, the average RL yield reached 9.15 ± 0.52 g/L, 1.58-fold higher than that observed before optimization. Fourier transform infrared spectroscopy (FTIR) and liquid chromatography-ion trap-time of flight mass spectrometry (LCMS-IT-TOF) were used to elucidate the diversity of RL congeners. The results showed that, after optimization, the RL congener diversity increased, and the major RL constituent was converted from di-RLs (64.04%) to mono-RLs (60.44%). These results suggested that the concentrations of the components contained in the culture medium of P. aeruginosa NY3 influenced not only the yield of RL, but also its congener distribution.     

Comparative hydrocarbon utilization by hydrophobic and hydrophilic variants of Pseudomonas aeruginosa

Aims: To investigate hydrocarbon degradation by hydrophobic, hydrophilic and parental strains of Pseudomonas aeruginosa. Methods and Results: Partitioning of hydrocarbon‐degrading P. aeruginosa strain in a solvent/aqueous system yielded hydrophobic and hydrophilic fractions. Exhaustive partitioning of aqueous‐phase cells yielded the hydrophilic variants (L), while sequential fractionation of the hydrophobic phase cells yielded successive fractions exhibiting increasing cell‐surface hydrophobicity (CSH). In hydrocarbon adherence assays (bacterial attachment to hydrocarbon), L had a value of 20%, which increased from 61·7% in first hydrophobic fraction (H₁) to 72·2% in the third (H₃). Crude oil degradation by L was 70%, but increased from 82% in H₁ to 93% in H₃. L variant produced most exopolysaccharides and reduced surface tension from about 73 to 49 mN m^?1. Rhamnolipid production was highest in L, but was not detected in all crude oil cultures. Conclusions: Hydrophobic subpopulations of hydrocarbon‐degrading P. aeruginosa exhibited greater hydrocarbon‐utilizing ability than hydrophilic ones, or the parental strain. Significance and Impact of the Study: Results demonstrate that a population of P. aeruginosa consists of cells with different CSH which affect hydrocarbon utilization. This potentially provides the population with the capacity to utilize different hydrophobic substrates found in petroleum. Judicious selection of such hydrophobic subpopulations can enhance hydrocarbon pollution bioremediation.     

Saccharides of seven Pseudomonas aeruginosa immunotypes

Abstract The structures of O-specific polysaccharides obtained by mild acid degredation of lipopolysaccharides (LPS) from seven Pseudomonas aeruginosa Fisher's immunotypes have been studied. The polysaccharides consist mainly of monoamino and diamino sugars, frequently also carrying acidic functions. Some of the sugars were detected in nature for the O-specific polysaccharides of the immunotypes 2, 3, 4, 5 and 6 are identical to those of the polysaccharides of the 011; 0(2a)2c; 01; 010a, 10b and 07a, 7d Lányi-Bergan serological subgroups respectively, whereas no analogues have been found for the immunotypes 1 and 7. Some cross-reactions between the LPS of different immunotypes were observed in passive haemagglutination tests; the results of inhibition of passive haemagglutination and agar gel immunoprecipitation point, however, to a specificity of the LPS. Many of the LPS of the seven Pseudomonas aeruginosa immunotypes manifest rather a high cross-protective activity in active immunization tests in mice. The nature of the cross-protective activity of the LPS is discussed.     

铜绿假单胞菌产蛋白酶的发酵条件优化

【目的】鉴定一株来源于酱油曲能够分泌蛋白酶的铜绿假单胞菌CAU342A,优化其产蛋白酶的发酵条件。【方法】采用形态学观察、16S r RNA基因序列比对和生理生化方法鉴定菌株CAU342A;通过碳源、氮源、初始pH、温度、表面活性剂及发酵时间的单因素优化和正交试验获得最适发酵条件。【结果】菌株CAU342A被鉴定为铜绿假单胞菌(Pseudomonas aeruginosa),其最适发酵产酶条件为(质量体积比):3%酒糟,1.5%酵母浸提物,0.05%吐温-80,0.5%NaCl,0.7%K_2HPO_4,0.3%KH_2PO_4,0.04%MnSO_4,培养基初始pH 7.5,30°C培养72 h。在最适发酵条件下,该菌株最大产酶水平达到2 653.5 U/m L。蛋白酶酶谱分析表明该菌株能够产生至少4种具有蛋白酶活性的同工酶,其中两个主要酶谱带对应分子量分别为32 k D和50 k D。【结论】铜绿假单胞菌CAU342A高产蛋白酶,具有很大的工业应用潜力。     

钌化合物对铜绿假单胞菌的光动力杀伤作用

【摘 要】 目的 探讨光动力疗法（PDT）对体外培养的铜绿假单胞杆菌的杀伤效应。方法 以多重耐药铜绿假单胞杆菌（P. aeruginosa）为对象,用457 nm和532 nm的激光作为光源,对不同浓度钌化合物孵育的细菌悬液进行光照,用菌落计数法观测PDT对铜绿假单胞杆菌的杀伤作用;同时观察了铜绿假单胞菌临床耐药菌与标准菌株对相同PDT作用的敏感性差异。结果 PDT处理组具有剂量－效应关系,在光照剂量相同的情况下,457 nm激光作为光源有更好的PDT杀伤效果;对多重耐药的铜绿假单胞菌,光动力同样有效,其作用甚至强于标准株。结论 钌化合物介导的光动力作用对体外培养的铜绿假单胞杆菌具有很强的杀伤作用,其效果和剂量关系密切。     

光声光谱技术用于绿脓杆菌的鉴定

【目的】探索一种无创、快速、可靠、经济地鉴定绿脓杆菌的新方法。【方法】利用光声光谱技术分别对大肠杆菌、绿脓杆菌在35°C下培养24 h后产生的挥发性代谢产物(Bacterial volatile compounds,BVCs)进行连续检测,获得各细菌挥发性气体的光声光谱图谱,并用“逆向思维”的方法对其检测结果进行分析。【结果】利用光声光谱技术对绿脓杆菌、大肠杆菌的挥发性代谢产物进行检测分析,发现绿脓杆菌产生了较高浓度的氰化氢(HCN),而大肠杆菌并未检测出HCN,据此可以对绿脓杆菌进行初步鉴定。【结论】光声光谱技术为绿脓杆菌的鉴定提供了一种简单、快速、经济的方法。为加速其在临床中的应用,提出了“三步走”方案:建立“大数据”、完善“比对算法”、创建“自动检测-比对-校对-鉴定”系统。