驱油生物表面活性剂生产菌的筛选与评价

目的:筛选适合油田的生物表面活性剂生产菌。方法:通过发酵培养,研究生物表面活性剂生产菌生长代谢规律;采用正交试验法,优选出其最佳培养条件;通过室内驱油实验评价生物表面活性剂驱油效果。结果:2#菌株最佳培养时间为96小时,最优发酵培养条件为:葡萄糖4.0 g、玉米浆1.6 g、Na2HPO40.1 g、KH2PO40.05 g、MgSO40.05 g、CaCl20.005 g、水100 mL、pH 7.2,培养温度35℃,摇床转速120 r/min,生物表面活性剂驱油提高采收率6.16%。结论:筛选出最优生物表面活性剂产生菌2#,菌株具备产表面活性剂的能力且产物量较高,其生物表面活性剂驱油效果良好。     

一株产生物表面活性剂菌株的筛选

目的：从大庆油田油水样中分离筛选产生物表面活性剂的菌株。方法：利用富集培养、血平板筛选、摇瓶原油乳化实验和表面张力测定等方法。结果：D2菌株能产生生物表面活性剂。结论：经初步鉴定D2菌株是产脂肽表面活性剂的芽孢杆菌,能显著降低水的表面张力．并具有良好的乳化和增溶效果。     

有机农药活性污泥中表面活性剂产生菌的筛选及鉴定

目的:筛选表面活性剂产生菌,用于降解有机农药,提高氧化塘处理效率.方法:以液体石蜡为惟一碳源进行选择性培养,通过测定发酵液的排油活性和表面张力,对有机农药厂的活性污泥进行产生物表面活性剂细菌筛选,并对筛得的细菌进行形态学、生理生化及 16SrDNA 试验和鉴定.结果:筛选出 3 株产生物表面活性剂的细菌,经鉴定均属于不动杆菌属.结论:证实了有机农药活性污泥中存在表面活性剂的产生菌,对有机农药降解存在助溶作用.     

驱油功能微生物的初步筛选

目的对大庆油田本源菌筛选得到高效驱油备用菌株。方法采用血平板实验、排油活性测定、原油凝固点测定、乳化性能测定等方法。结果筛选得到能够利用石油为唯一碳源生长的菌株13株,其中5株菌株分别在不同驱油性能方面有突出作用。结论综合筛选结果得到2株在产表面活性剂、较强的排油性能和乳化性能方面均具有较好效果的菌株。     

两种表面活性剂对玫烟色棒束孢PF904菌株侵染小菜蛾幼虫的影响

[目的]在前期筛选试验的基础上,比较表面活性剂对玫烟色棒束孢Isaria fumosoroseus PF904菌株侵染小菜蛾Plutella xylostella 3龄幼虫的增效作用,获得可提高玫烟色棒束孢PF904防治效果的助剂.[方法]通过扫描电镜观察和室内致病力试验,测定喷施分别添加表面活性剂聚二甲基硅氧烷(OF...     

高效生物表面活性剂产生菌筛选及其性质研究

目的:获得产高效生物表面活性剂的菌株并获得优化培养基。方法:通过从山东文登某加油站附近长期污染富含油质的土壤中逐步采用富集培养基和平板筛选培养基分离筛选菌株并进行优化培养寻找最优生长培养和高产生物表面活性剂的条件。结果:筛选出产表面活性剂的微生物12株,分别命名为BSF1#-BSF12#,从中筛选出1株高效表面活性剂产生菌BSF8#,优化培养结果表明BSF8#的最佳生长pH在7.5左右,最佳碳源为葡萄糖,最佳氮源为蛋白胨,BSF8#培养基中最佳NaCl浓度为2g/L。BSF8#菌株可将发酵液的表面张力由最初的48.29mN/m降到27.79 mN/m,上层乳化状发酵液的排油圈最大直径超过7.5cm,并经红外光谱分析确定其生物表面活性剂为1个糖肽类化合物。结论:BSF8#菌株产生的生物表面活性剂活性突出,有较大的开发潜力。     

生物表面活性剂的合成与提取研究进展*

生物表面活性剂（Biosurfactant）是由微生物产生的具有高表面活性的生物分子。相对于化学合成的表面活性剂,生物表面活性剂对生态系统的毒性较低,且可生物降解。因此,生物表面活性剂开始应用于环境污染治理的各个方面。中从生物表面活性剂生产菌的筛选、培养基的优化及生物表面活性剂的提取等方面对近年来生物表面活性剂的研究进展进行了总结,并对未来的发展方向作了展望。     

微生物细胞ATP释放条件研究

在ATP生物发光法微生物细胞ATP释放剂的筛选研究中,发现采用环糊精等环状化合物可以解除表面活性剂类细胞ATP释放剂对发光反应系统的抑制作用,其中,7．5g／L环糊精CD（a）能中和1．5g／L的表面活性剂Ec和Es、Et,可以完全排除Ec、Es、Et对发光反应的抑制作用。通过比较各种细胞ATP释放剂释放ATP效果,筛选、组合出以表面活性剂Ec为代表的微生物细胞ATP释放剂;通过优化实验,发现用0．25～0．50g／L的Ec处理菌液1～2min时,细胞ATP的释放效果最好,从而建立了室温条件下简便、快速的微生物细胞ATP释放方法和ATP释放剂对发光反应系统抑制的消除方法。     

泽普油田生物表面活性剂产生菌的筛选

目的:对泽普油田的9个原油样品进行生物表面活性剂产生菌株的筛选.方法:富集培养、血平板分离、摇瓶培养和排油圈测定.结果:7个样品都可溶血和排油圈,即有表面活性剂产生.结论:泽普油田有生物表面活性剂产生菌株,而且该产品具有重要的开发价值.     

生物表面活性剂在提高原油采收率方面的应用

生物表面活性剂和一般的化学表面活性剂一样,都拥有亲水和疏水基因,是微生物生长在水不溶的有机物中并以营养物而产生的代谢产物。在油田应用中,生物表面活性剂的作用是微生物提高采收率的重要机理之一,具有水溶性好、反应产物均一、安全无毒、驱油效果好等特点。本文从产生生物表面活性剂的菌种及生物表面活性剂的类型、生物表面活性剂的特性、实验研究、矿场实验及展望等五个方面综述了生物表面活性剂在提高原油采收率方面的应     

Detection of peptidoglycan in human plasma using the silkworm larvae plasma test

Silkworm larvae plasma (SLP) reagent, which is prepared from the body fluid of the silkworm, reacts with peptidoglycan (PG), a fragment of both the Gram-positive and Gram-negative bacterial cell wall, as well as with beta-glucan, a component of fungi. We developed a quantitative method for the detection of PG in human plasma from cases with bacterial infection using the SLP reagent. Tested in this way, the SLP method showed 86.2% sensitivity, 90.6% specificity, 89.3% positive predictive value, and 88.5% efficiency. The SLP method provides a valuable tool for the diagnosis of systemic infection using patients' blood.     

Potential interference of hydrogen peroxide in the 2,2'-bicinchoninic acid protein assay

At a concentration of 20-800 nmol/0.1 ml hydrogen peroxide instantly reacts with a 2,2'-bicinchoninic acid copper color reagent. It also reacts with a reformulated reagent at pH 7 but the color develops less rapidly. While the effect may interfere with protein estimations at alkaline pH, the effect of pH 7 may be used to determine the possible extent of hydrogen peroxide interference after treatment with catalase.     

Effect of physiological parameters of blood on magnetophoretic mobility of erythrocytes

Magnetophoresis is the process of the particle motion under the influence of a magnetic field. The magnetic particle and medium are considered responsive to the imposed magnetic field, and the material property that describes the response to the external magnetic field is relative magnetic permeability, and the magnetic susceptibility. The present work aims to evaluate the effect of internal and external physiological parameters on the erythrocytes' magnetophoretic mobility (MM) using Cell Tracking Velocimetry (CTV). The results of this study showed that there are a strong correlation between MM and several physiological blood parameters such as mean corpuscle hemoglobin (MCH), red blood cells distribution width (RDW), mean corpuscle hemoglobin concentration (MCHC), and fibrinogen.     

Effect of physiological parameters of blood on magnetophoretic mobility of erythrocytes

Magnetophoresis is the process of the particle motion under the influence of a magnetic field. The magnetic particle and medium are considered responsive to the imposed magnetic field, and the material property that describes the response to the external magnetic field is relative magnetic permeability, and the magnetic susceptibility. The present work aims to evaluate the effect of internal and external physiological parameters on the erythrocytes' magnetophoretic mobility (MM) using Cell Tracking Velocimetry (CTV). The results of this study showed that there are a strong correlation between MM and several physiological blood parameters such as mean corpuscle hemoglobin (MCH), red blood cells distribution width (RDW), mean corpuscle hemoglobin concentration (MCHC), and fibrinogen.     

A method for the indirect determination of trace bound selenomethionine in plants and some biological materials

An indirect method for the determination of trace bound selenomethionine (SeMet) has been developed. SeMet reacts with cyanogen bromide (CNBr) quantitatively in the presence of SnCl2 to form CH3SeCN, and after extraction with CHCl3 is acid-digested to form Se(IV). Selenium(IV) reacts with 4-nitro-o-phenylenediamine reagent to form 5-NO2-piazselenol which is then determined by gas chromatography equipped with electron capture detector. The sensitivity of this method (CNBr-piazselenol-GC method) is 6 ng SeMet/g of sample. Trace-bound SeMet in plants and some biological materials has been successfully determined by this method and its content has been compared with the total selenium in the sample.     

Construction of oligonucleotide arrays on a glass surface using a heterobifunctional reagent, N-(2-trifluoroethanesulfonatoethyl)-N-(methyl)-triethoxysilylpropyl-3-amine (NTMTA)

A rapid method for construction of oligonucleotide arrays on a glass surface, using a novel heterobifunctional reagent, N-(2-trifluoroethanesulfonatoethyl)-N-(methyl)-triethoxysilylpropyl-3-amine (NTMTA), has been described. The heterobifunctional reagent, NTMTA, carries two different thermoreactive groups. The triethoxysilyl group on one end is specific towards silanol functions on the virgin glass surface, while the trifluoroethanesulfonyl (tresyl) group on the other end of the reagent reacts specifically with aminoalkyl- or mercaptoalkyl- functionalized oligonucleotides. Immobilization of oligonucleotides on a glass surface has been realized via two routes. In the first one (A), 5′- aminoalkyl- or mercaptoalkyl-functionalized oligonucleotides were allowed to react with NTMTA to form a oligonucleotide-triethoxysilyl conjugate which, in a subsequent reaction with unmodified (virgin) glass microslide, results in surface-bound oligonucleotides. In the second route (B), the NTMTA reagent reacts first with a glass microslide whereby it generates trifluoroethanesulfonate ester functions on it, which in a subsequent step react with 5′-aminoalkyl or mercaptoalkyl oligonucleotides to generate support-bound oligonucleotides. Subsequently, the oligonucleotide arrays prepared by both routes were analyzed by hybridization experiments with complementary oligonucleotides. The constructed microarrays were successfully used in single and multiple nucleotide mismatch detection by hybridizing these with fluorescein-labeled complementary oligonucleotides. Further more, the proposed method was compared with the existing methods with respect to immobilization efficiency of oligonucleotides.     

Modeling the kinetics of acylation of insulin using a recursive method for solving the systems of coupled differential equations

This paper describes a theoretical method for solving systems of coupled differential equations that describe the kinetics of complicated reaction networks in which a molecule having multiple reaction sites reacts irreversibly with multiple equivalents of a ligand (reagent). The members of the network differ in the number of equivalents of reagent that have reacted, and in the patterns of sites of reaction. A recursive algorithm generates series, asymptotic, and average solutions describing this kinetic scheme. This method was validated by successfully simulating the experimental data for the kinetics of acylation of insulin.     

A new RNA-RNA crosslinking reagent and its application to ribosomal 5S RNA.

The synthesis of a new RNA specific bifunctional crosslinking reagent, 1.4-phenyl-diglyoxal, is described which reacts exclusively with guanosines. The properties of the crosslinked products enabled us to develop a straightforward method for identifying the reacted nucleotides. Results obtained with ribosomal 5S RNA of Escherichia coli demonstrate the formation of an intramolecular crosslink between guanosine-2 and guanosine-112 in the stem region.     

Water-soluble proteins of Pacinian corpuscles

The composition of water soluble proteins has been investigated in different parts of Pacinian corpuscles. The Pacinian corpuscles fluid proteins have been compared with the receptor homogenate proteins and blood serum of a cat. It is supposed that proteins of the Pacinian corpuscle fluid are produced from the blood system on the whole. The composition of the Pacinian corpuscle fluid as well as a great variety of glycoproteins in it allows to suppose that the Pacinian corpuscles fluid perform a transport function.     

alpha-Bromo-4-amino-3-nitroacetophenone, a new reagent for protein modification. Modification of the methionine-290 residue of porcine pepsin.

A new coloured reagent for protein modification, alpha-bromo-4-amino-3-nitroacetophenone (NH2BrNphAc), was synthesized. The reagent was found to alkylate specifically the methionine-290 residue of porcine pepsin below pH 3 at 37 degrees C, which lead to a 45% decrease of enzyme's activity towards haemoglobin. The effect of this reagent as well as that of other phenacyl bromides on the activity of pepsin appeared to be a result of steric hindrance caused by the attachment of bulky reagent residue to the edge of the cleft harbouring the enzyme active site. Only marginal reaction with the co-carboxy group of aspartic acid-315 was found under the above conditions. More pronounced esterification of carboxy groups (up to one residue per enzyme molecule) occurred when the pH was shifted to 5.2. The latter modification had no noticeable effect on enzyme activity, thus disproving a previously held assumption that pepsin inactivation by phenacyl bromide is due to the carboxy-group esterification. alpha-Bromo-4-amino-3-nitroacetophenone forms derivatives with characteristic u.v. spectra when it reacts with methionine, histidine, aspartic and glutamic acid residues, and may be recommended as a reagent for protein modification.