荧光假单胞菌对重金属废水的去除特性研究

通过正交试验得到荧光假单胞菌的最佳培养条件:pH值为6、微生物接种量为1 mL、搅拌速度为150 r/min、培养时间为3 d。在适宜的培养条件下,考察了荧光假单胞菌对不同初始浓度的Cr、Pb、Cu、Cd废水的处理效果。结果表明:在不同初始重金属浓度条件下,荧光假单胞菌对Cr、Pb、Cu、Cd的平均去除率分别为89.70%、44.33%、37.54%、17.03%,差别比较明显;对Cr的去除率为68.60%～98.63%,去除效果最好,且去除率随初始浓度增大而提高,说明荧光假单胞菌适合处理高浓度的含Cr废水。     

降解甲苯的菌种分离及其固定化初步研究

在人类的生存环境中存在着大量的苯类有机污染物,它们给人体和环境带来极大危害。本文针对污染物甲苯,在实验室条件下对甲苯降解菌进行菌种的筛选、分离、驯化,最后经鉴定该菌株为假单胞菌属。利用筛选后的菌株进行实验,通过实验分析得出菌株各参数的影响顺序为：甲苯加入量〉温度〉pH〉菌液接种量。最后对该菌株作简单的固定化研究,以海藻酸钠（浓度2%、CaCl2浓度为4%-5%）为包埋载体时最易操作,效果很好。     

The structure-function relationship of the lipases from Pseudomonas aeruginosa and Bacillus subtilis

Within the BRIDGE T-project on lipases we investigate the structure-functionrelationships of the lipases from Bacillus subtilis and Pseudomonasaeruginosa. Construction of an overproducing Bacillus. strainallowed the purification of > 100 mg lipase from 30 l culturesupernatant. After testing a large variety of crystallizationconditions, the Bacillus lipase gave crystals of reasonablequality in PEG-4000 (38-45%), Na₂SO₄ and octyl-ß-glucosideat 22°C, pH 9.0. A 2.5 Å; dataset has been obtainedwhich is complete from 15 to 2.5 A resolution. P.aeruginosawild-type strain PAC1R was fermented using conditions of maximumlipase production. More than 90% of the lipase was cell boundand could be solubilized by treatment of the cells with TritonX-100. This permitted the purification of 50 mg lipase. So far,no crystals of sufficient quality were obtained. Comparisonof the model we built for the Pseudomonas lipase, on the basisof sequences and structures of various hydrolases which werefound to possess a common folding pattern (/ß hydrolasefold), with the X-ray structure of the P.glumae lipase revealedthat it is possible to correctly build the structure of thecore of a protein even in the absence of obvious sequence homologywith a protein of known 3-D structure.     

假单胞菌JW12发酵液的脂肪酶稳定性

通过对假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓｓｐ．）ＪＷ１２发酵液脂肪酶稳定性的研究，表明了发酵液脂肪的稳定性主要受蛋白酶的影响。当用吐温８０作为碳源时，通过对发酵培养基组成的调整，达到降低蛋白酶的目的，提高发酵液脂肪酶酶活。     

EDTA在化妆品中的应用

EDTA是化妆品行业常用的原料，对EDTA在化妆品中的螯合作用、抗绿脓假单胞菌作用、防腐作用等进行了总结，并对作用机理进行了分析。     

假单胞菌SJTD-1全蛋白质组学研究

近年来,石油泄漏对海洋和土壤的污染事件频发,解决这一污染问题非常重要。本实验从原油污染的土壤中分离得到一株新的铜绿假单胞菌株SJTD-1,使用SDS-PAGE-1DLC-MS和offline-2DLC-MS两种方法研究其全蛋白质组。利用这两种技术平台分别鉴定获得1453个和1623个可信蛋白,共鉴定到1912个可信蛋白。通过比较两种技术路线所鉴定到蛋白种类的差异,发现offline-2DLC-MS有利于SJTD-1菌株的膜蛋白、相对分子质量较大的蛋白和pI值不大于8的蛋白的鉴定。另外,对所有鉴定到的可信蛋白进行GO功能注释,亚细胞定位分析和代谢通路富集分析。通过对分离获得的SJTD-1菌株进行蛋白质组学分析,可为铜绿假单胞菌SJTD-1分解环烷烃以及SJTD-1在生物修复应用中的研究奠定基础。     

Isolation and identification of new strains of crude oil degrading bacteria from Kharg Island,Iran

Petroleum-degrading bacteria were isolated from polluted sites in Kharg Island, which is one of the most important ports for oil export in Iran. Both biochemical tests and 16S rRNA were applied to identify the strains. Experiments were performed in a mineral salt medium containing 2% of crude oil as the sole carbon. The results illustrated that the strains were: Brevibacillus sp., Microbacterium oxydans, Staphylococcus arlettae, Staphylococcus warneri, Methylobacterium persicinum, and Achromobacter xylosoxidans. Growth rates of these strains by its optical densities at the wavelength of 600 illustrated that Pseudomonas sp. (accession no. KC771232) had the highest growth rate (OD₆₀₀ 0.8).     

均匀设计法优化L-丝氨酸发酵培养基

为了提高假单胞菌N-13发酵液中L-丝氨酸产量,采用单因素试验法和均匀设计法对其发酵培养基进行优化.先用单因素试验法考察各培养基组分对L-丝氨酸产量的影响,再用均匀设计法进一步优化.优化后的培养基为:甘氨酸26g/L,甲醇0.8％,(NH4)2SO418g/L,玉米浆18g/L,CaCO3 26g/L.在此条件下,发酵液中L-丝氨酸的产量达到5.91g/L,较单因素实验最高值提高23.1％.     

Development of cellulose acetate membranes for bacteria immobilization to remove phenol

The objective of this study is to investigate the feasibility of developing cellulose acetate (CA) membranes to partially immobilize Pseudomonas putida (ATCC 49451) and to evaluate the inhibitory effect of phenol on the immobilized bacteria by monitoring their growth in partially immobilized and free-suspension systems. The cellulose acetate membranes used in this study were wet spun from 20 wt % of CA in 1-methyl-2-pyrrolidone (NMP)/acetone (30 : 70) solvent using water as the bore fluid as well as the external coagulant. Scanning-electron microscopy (SEM) characterization of the newly developed CA hollow fibers suggests that the fiber cross section consists of multilayer microporous structures useful for cell immobilization. Experiments were conducted using the bacteria to degrade phenol at initial phenol concentrations of 300 mg/L and 1000 mg/L. In a free suspension (no membrane) system, it was observed that the bacteria were able to grow optimally at 300 mg/L of phenol, and degraded phenol almost completely in about 26 h. However, neither cell growth nor phenol degradation occurred when initial concentration of phenol was increased to 1000 mg/L. In a cell-immobilized membrane system, the cell growth and phenol concentration profiles in the medium were very similar to those obtained in a free suspension culture if phenol concentration was 300 mg/L. However, when the initial phenol concentration was increased to 1000 mg/L, data obtained in a cell-immobilized membrane system were discernibly different from that obtained in the suspension culture. In the former case, phenol concentration decreased in the beginning of test, indicating that the carbon source has been consumed and immobilized cells within the membrane had begun to multiply. As soon as the phenol concentration decreased to about 700 mg/L (at which concentration, substrate inhibition was not as severe as 1000 mg/L), partial immobilization occurred when some cells diffused out of the membrane into the medium and optical density became measurable in the medium. It was found that cell growth continued for the next 32 h, reaching an optical density in the medium of 0.42 absorbance units and a significant amount of phenol was degraded. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1677–1688, 1998     

冷鲜猪腩肉假单胞菌生长动力学模型的分析研究

以托盘包装冷鲜猪腩肉为研究对象,研究假单胞菌的生长变化与模型的构建和验证。结果表明:Gompertz方程拟合获得假单胞菌生长预测一级模型,相关系数R2值均大于0.99,总的平均偏差因子和准确因子均在1左右;利用平方根模型研究温度对一级模型动力学参数的影响,得到温度与最大比生长速率和延滞期方程分别为姨U=0.063×[T-(-12.79)]和姨1/LPD=0.086×[T-(-12.67)],其中T∈[0,20],R2分别为0.972和0.851,F统计量检验表明方程具有显著性。结论:建立的生长预测一级和二级模型能够很好的描述0℃~20℃下假单胞菌在冷鲜猪腩肉基质上的生长。