绵农小麦种子巯基蛋白酶抑制剂的纯化及性质研究

绵农11号小麦种子磨粉后的胚和麸皮，经溶液浸取和硫酸铵分级沉淀获得巯基蛋白酶抑制剂（CPI）粗品，再经木瓜蛋白酶－Sepharose4B亲和层析，DEAE－Sepharose离子交换层析和SephadexG－100分子筛层析，可获得两种CPI．通过SDS－PAGE或凝胶过滤法测得其Mr分别为18800［简称CPI（H）］和10500［简称CPI（L）］．它们在PAGE，SDS－PAGE和HPLC上均为单一蛋白带．CPI（L）和CPI（H）对木瓜白酶的抑制活性（ID50）分别为7．8×10－6mol／L和3．40×10－6mol／L．对无花果蛋白酶的抑制活性分别为9．5×10－5mol／L和5．8×10－6mol／L；CPI（H）对菠萝蛋白酶有弱抑制作用，但CPI（L）则无抑制作用；无论是CPI（L）或CPI（H）对胰蛋白酶、胰凝乳蛋白酶和胃蛋白酶均无抑制作用．CPI（H）的N－末端为Ile．CPI（H）和CPI（L）在pH2．0～11．0范围内和90℃处理5min，两种CPI的抑制活性均无变化；CPI（H）和CPI（L）对木爪蛋白酶的抑制曲线经Dixon作图法，得出CPI（H）为反竞争性抑制类型，而CPI（L）为竞争性抑制类型，其Ki值为8．32×10－6mol／L．     

应用假单胞菌进行防蜡作用的研究

假单胞菌L－11菌体与其胞外产物可以作为一种很好的防蜡剂，对L－11的发酵条件进行了优化，确定了最适发酵培养基的配方，发酵培养基以葡萄糖、蛋白胨为其最适碳、氮源，防蜡剂生产的发酵条件为：前16h的发酵温度为35℃，后期将温度降至20℃，发酵液的pH=4．5为发酵终点，此时发酵液在内条件下的防蜡率为78％，将上述所得菌液在大庆油田做了防蜡实验，结果表明，注入L－11的油井洗井周期有所延长，实验证明了L－11的发酵液可以作为一种经济、有效的蜡剂。     

文南油田注水管线防污染清洗技术研究

针对文南油田注水管线内壁结垢对油田注水的危害,以及管线常规清洗中存在的环境污染和硫化氢中毒问题,进行了注水管线防污染清洗技术的研究。通过分析消除硫化氢的反应机理,配制了三种常规清洗剂和两组硫化氢抑制剂,并将清洗剂与抑制剂复配后进行脱垢实验,从而优选出最佳复配剂(MF-1-B),经过现场试验,排酸口空气中硫化氢浓度为3～5mg/m3。防污染清洗技术的开发应用使文南油田注水管网得到了及时、全面的清洗,水质达标率由清洗前的30%上升到100%。     

油井酸化缓蚀剂述评

本文扼要介绍了国内外近年来在研究和应用油井酸化缓蚀剂方面的现状和发展，并列出了美国几家公司研制的缓蚀剂的性能试验数据。对目前我国的研究工作提出了看法和建议。     

Effect of nitrification inhibitor DMPP on nitrogen leaching, nitrifying organisms, and enzyme activities in a rice-oilseed rape cropping system

DMPP （3,4-dimethylpyrazole phosphate） has been used to reduce nitrogen （N） loss from leaching or denitrification and to improve N supply in agricultural land. However, its impact on soil nitrifying organisms and enzyme activities involved in N cycling is largely unknown. Therefore, an on-farm experiment, for two years, has been conducted, to elucidate the effects of DMPP on mineral N （NH4^＋- N and NO3^--N） leaching, nitrifying organisms, and denitrifying enzymes in a rice-oilseed rape cropping system. Three treatments including urea alone （UA）, urea ＋ 1% DMPP （DP）, and no fertilizer （CK）, have been carded out. The results showed that DP enhanced the mean NH4^＋-N concentrations by 19.1%-24.3%, but reduced the mean NO3^--N concentrations by 44.9%-56.6% in the leachate, under a two-year rice-rape rotation, compared to the UA treatment. The population of ammonia oxidizing bacteria, the activity of nitrate reductase, and nitrite reductase in the DP treatment decreased about 24.5%-30.9%, 14.9%-43.5%, and 14.7%-31.6%, respectively, as compared to the UA treatment. However, nitrite oxidizing bacteria and hydroxylamine reductase remained almost unaffected by DMPP. It is proposed that DMPP has the potential to either reduce NO3^--N leaching by inhibiting ammonia oxidization or N losses from denitrification, which is in favor of the N conversations in the rice-oilseed rape cropping system.     

Comparison between inhibitor and uncoupler for minimizing excess sludge production of an activated sludge process

In order to study the minimization of excess sludge production, the reduction in the excess sludge production in the presence of an inhibitor and uncoupler was studied in this work. The experimental results show that such an addition could effectively reduce the production of excess sludge. With the energy uncoupling model established in this work, energy uncoupling coefficient (E _u) was used to evaluate the reduction in excess sludge production. The energy uncoupling coefficients in the presence of dinitrophenol (dNP), Zn²⁺, and Cu²⁺ was 0.75, 0.46, and 0.18, respectively. The analysis demonstrated that energy spilling occurred in the presence of dNP, and that dNP was an effective uncoupler for reducing the production of excess activated sludge without affecting the microbial respiration activity.     

鼓泡法对聚天冬氨酸阻垢性能的评价

用鼓泡法对六种聚天冬氨酸 (Polyasparticacid ,PASP)的阻碳酸钙垢性能进行了评价 ,考察了pH值、阻垢剂用量、温度、恒温时间等对阻垢性能的影响。研究发现 ,阻垢率随着聚天冬用量的增加而增大 ,其用量在 1 0mg/L时 ,已能获得较好的阻垢效果。另外 ,与聚丙烯酸 (PAA)和聚马来酸 (HPMA)的比较发现 ,聚天冬在高温水系统中作长时间停留 ,仍对碳酸钙垢有较强的抑制作用     

Selective redox degradation of chlorinated aliphatic compounds by Fenton reaction in pyrite suspension

Selective redox degradation of chlorinated aliphatics by Fenton reaction in pyrite suspension was investigated in a closed system. Carbon tetrachloride (CT) was used as a representative target of perchlorinated alkanes and trichloroethylene (TCE) was used as one of highly chlorinated alkenes. Degradation of CT in Fenton reaction was significantly enhanced by pyrite used as an iron source instead of soluble Fe. Pyrite Fenton showed 93% of CT removal in 140 min, while Fenton reaction with soluble Fe(II) showed 52% and that with Fe(III) 15%. Addition of 2-propanol to the pyrite Fenton system significantly inhibited degradation of TCE (99% to 44% of TCE removal), while degradation of CT was slightly improved by the 2-propanol addition (80-91% of CT removal). The result suggests that, unlike oxidative degradation of TCE by hydroxyl radical in pyrite Fenton system, an oxidation by the hydroxyl radical is not a main degradation mechanism for the degradation of CT in pyrite Fenton system but a reductive dechlorination by superoxide can rather be the one for the CT degradation. The degradation kinetics of CT in the pyrite Fenton system was decelerated (0.13-0.03 min⁻¹), as initial suspension pH decreased from 3 to 2. The formation of superoxide during the CT degradation in the pyrite Fenton system was observed by electron spin resonance spectroscopy. The formation at initial pH 3 was greater than that at initial pH 2, which supported that superoxide was a main reductant for degradation of CT in the pyrite Fenton system.     

Trypsin inhibitor,antioxidant and antimicrobial activities as well as chemical composition of potato sprouts originating from yellow- and colored-fleshed varieties

Abstract

Potato sprouts could be a valuable resource of phytochemicals such as secondary plant metabolites, potential antioxidants and nutritive compounds. In this work, potato sprout extracts of five varieties were examined; they differed in major glycoalkaloid content, trypsin inhibitor activity, total polyphenol content and antioxidant activity, as well as in antimicrobial activity against Gram?+?and G???bacteria, and yeast. Sprouts of colored-fleshed tubers were characterized by higher trypsin inhibitor activity than sprouts of yellow potatoes. The strongest microorganism growth inhibition effect was observed for macerate with sprouts from the purple-fleshed Blaue Annelise variety against B. subtilis, whereas C. albicans yeasts were sensitive to macerates with sprouts from purple-fleshed Blue Congo and yellow-fleshed Vineta potato varieties.