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1.
In this study, the bioaccumulation of Cu(II) ions by R. delemar and their influence on growth of the microorganism were assessed, and the impact of Cu(II) ions on the activity of lipase enzyme degradation of lipids in wastewaters by enzymatic hydrolysis was received for consideration. Optimisation of Cu(II) bioaccumulation process was performed by varying three independent parameters (pH, temperature and Cu(II) concentration) using a central composite design (CCD) under response surface methodology (RSM). For the maximum Cu(II) bioaccumulation and lipase production at a desired level of the biomass concentration level, a total of 20 experimental runs were set and the experimental data fitted to the empirical second-order polynomial models. The adequacies of the predicted models for the Cu(II) bioaccumulation, lipase activity and biomass concentration were confirmed by the coefficients of multiple regression (R2), which were adjusted to be 99.6%, 94.5%, 93.4%, respectively indicating reasonably good models for practical implementation. A maximum Cu(II) bioaccumulation of 36.81 mg/L was obtained at pH 6.0, at 32.6°C, and at 50 mg/L initial Cu(II) concentration. The lipase activity of R. delemar decreased only from 505 U/L in Cu(II)-free fermentation medium to 476 U/L in the presence of Cu(II) giving 5.74% decrease in lipase activity.  相似文献   
2.
Abstract

The effects of pyrethroid pesticides (deltamethrin, permethrin and cypermethrin) and an organophosphate ester (methidation) on the activities of carp trypsin, α‐chymotrypsin, carboxypeptidase A and lipase were studied. The enzymes were isolated from the gastrointestinal tract and the effects of the pesticides were investigated during incubation for 5 min. The activity of trypsin was influenced only slightly by the presence of deltamethrin and methidation, whereas permethrin and cypermethrin caused significant inhibition. The pyrethroid pesticides at lower concentrations resulted in a slight activation of α‐chymotrypsin. Methidation inhibited the α‐chymotrypsin activity by about 20%. These pesticides modified the lipase activity to a lesser extent; the highest inhibition was measured with cypermethrin. The carboxypeptidase A activity was inhibited by both pyrethroid pesticides and methidation. The results suggest that these pesticides might interact with the active conformation of the studied hydrolytic enzymes, resulting in changes in their activities.  相似文献   
3.
非均相高效催化剂在餐厨废油转化生物柴油中的应用   总被引:1,自引:1,他引:0  
近年来,非均相催化剂在酯化和转酯化催化制备生物柴油中备受关注。综述了固体碱、固体酸、固定化酶等非均相高效催化剂在生物柴油制备中的研究进展,并展望了新型非均相催化剂在餐厨废油转化制备生物柴油的应用前景。  相似文献   
4.
利用脂肪酶提高鱼油中多不饱和脂肪酸(PUFAs)甘油酯   总被引:3,自引:0,他引:3  
利用脂肪酶选择性的水解作用研究提高鱼油中多不饱和脂肪酸(PUFAs)甘油酯的含量.通过对5种不同来源脂肪酶的筛选,以来源于米曲霉脂肪酶为最佳酶种;同时研究该酶水解鱼油的最佳工艺条件:反应温度、加酶量、反应转速、添加剂影响;最后确定最佳的富集PUFAs甘油酯时间.在此工艺条件下,鱼油中EPA由3.0%提高到9.0%,DHA由4.3%提高到16.5%,EPA DHA由7.3%提高到25.5%.图3表1参8  相似文献   
5.
沙地云杉生态型同工酶研究   总被引:3,自引:0,他引:3  
沙地云杉是内蒙古地区特有树种,只分布于浑善达克沙地东部边缘;由于长期适应干旱生态条件,分化出3种土壤生态型,即紫果型、红果型和绿果型沙地云杉,并在很多生态、生理特征上表现出明显的差异.本文采用聚丙烯酰胺凝胶电泳技术,分析了3种生态型沙地云杉的过氧化物同工酶和酯酶同工酶的酶谱特征.结果表明:不管是过氧化物同工酶还是酯酶同工酶,紫果型沙地云杉的酶带条数最多,红果型其次,绿果型酶带条数最少.在酶带强度方面也有类似的结果,紫果型沙地云杉具有较多的强、次强、中带,红果型其次,绿果型最少.这在一定程度上表明,在干旱条件下产生的3种不同生态型沙地云杉,以紫果型对干旱抗性最强,绿果型最弱,红果型居于二者之间,这一结论将为沙地云杉的经营管理及品种选择提供科学依据. 图2参21  相似文献   
6.
盐度对刺参(Apostichopus japonicus)消化酶活力的影响   总被引:1,自引:0,他引:1  
以刺参(Apostichopus japonicus)为实验对象,分别设置5个盐度水平(23、26、29、32和35),采用酶活性分析的方法比较研究了在不同盐度的养殖环境下,刺参消化道内前肠和中肠不同部位蛋白酶、淀粉酶和脂肪酶3种消化酶活性的差异.结果表明,盐度对刺参消化酶活性影响显著(P<0.05).蛋白酶活力在盐度...  相似文献   
7.
解脂耶氏酵母菌处理含油废水的研究   总被引:7,自引:2,他引:7  
利用解脂耶氏酵母菌在最佳降解条件下分别处理色拉油、餐饮油等油脂类废水和柴油、机油等石油类废水50 h.结果表明:该菌株能快速降解油脂,在油质量浓度≤2 000 mg/L时生化反应属于一级反应,对色拉油、餐饮油中油脂的降解率分别为93.30%和85.08%,同时菌体细胞大量生长,其生物量分别为1 652.7和1 940.0 mg/L,废水处理过程中pH稳定在3~4之间;但该菌对石油的降解率低,生成的生物量少,处理后废水pH维持在6~7之间.解脂耶氏酵母菌对油的降解与自身生物量的生成有关,该菌株降解油脂类和石油类物质的途径不同,产生的脂酶系统不同,使得废水的pH变化规律不相同.  相似文献   
8.
Unrefined rubber seed oil contains high levels of free fatty acids and moisture, which make the conventional chemical catalyzed transesterification unsuitable. The method of enzyme catalyzed transesterification is well suited for biodiesel production from rubber seed oil as the enzymes are insensitive to the free fatty acids. In the present work, rubber seed oil was extracted from preserved rubber seed cake by mechanical means. The extraction process was designed and optimized through 24 full factorial design. Extracted oil was subjected to enzymatic transesterification using four different lipases to identify the best one for the purpose. Transesterification process was optimized by considering three influencing variables for biodiesel production viz. methanol/oil molar ratio, catalyst concentration (% w/v) and solvent content (% v/v). A 23 full factorial design was applied to design the experiments and optimize the biodiesel production. The interactive effects of the independent variables on biodiesel yield were analyzed and regression models were developed for each set of enzyme reactions. Among the four lipases, Thermomysis Lanugonosus Lipase was found to be the most suitable for the transesterification of rubber seed oil with a biodiesel conversion of 92.83% at a molar ratio of 4% and 5% (w/v) enzyme concentration in solvent free reaction medium.  相似文献   
9.
Novel (-caprolactone)-based copolymers of different compositions were synthesized by allowing methyl iodide to react with the polycarbanion that resulted from the action of lithium diisopropylamide on poly(-caprolactone) in THF at –70°C under argon atmosphere. The copolymers were characterized by various techniques, namely 1H nuclear magnetic resonance, size exclusion chromatography, differential scanning calorimetry, x-ray diffraction and viscoelasticimetry. They were submitted to hydrolytic and lipase-catalyzed enzymatic degradation in comparison with genuine PCL. The Young modulus depended on the degree of methylation. In contrast, loss angle and glass transition temperature did not depend on this parameter. It is shown that the lipase-catalyzed degradation of methylated PCL is much slower than in the case of genuine PCL.  相似文献   
10.
从南极普利兹湾深海沉积物中筛选到一株同时产多种冷适应酶的菌株NJ197,细菌学形态鉴定及16S rDNA序列分析表明,该菌株属于假单胞菌属(Pseudomonas).生长特性研究表明,该菌株属于耐冷菌,其最适生长温度为5~15℃.NJ197菌株能利用多种单一的碳、氮源产酶,最适产酶温度为20℃,最高产酶温度为30℃.粗酶液经硫酸铵盐析、DEAE cellulose-52柱层析初步分离纯化后进行酶学性质的研究.该菌株所分泌复合酶中脂肪酶和淀粉酶的活力最高,它们的最适作用温度分别为30℃和35℃,最适pH值分别为9.0和9.5,对热敏感,是典型的碱性冷适应复合酶.Ca2 、Mn2 、Cu2 、Co2 、Fe3 对该复合酶有较为明显的激活作用,而Zn2 、Hg2 、Rb2 、Cd2 、EDTA则能抑制酶活.其中脂肪酶能在高浓度的SDS、CHAPS等变性剂中表现出较好的稳定性.图5表2参21  相似文献   
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