Optimization of angiotensin I-converting enzyme （ACE） inhibition by rice dregs hydrolysates using response surface methodology

INTRODUCTION Angiotensin I-converting enzyme (ACE) canconvert angiotensin I to angiotensin II which isknown to be a strong vasopressor, besides inactivat-ing bradykinin conducive to lowering blood pressure(Ondetti et al., 1977). This enzyme also playsphysiological roles in the regulation of local levels ofother endogenous peptides, such as enkephalins andsubstace P. Therefore, inhibition of ACE can reducethe activity of angiotensin II, but increase bradykininand enkephalins levels, …     

春季珊瑚树芽抗寒物质及抗氧化酶系的变化

珊瑚树芽内可溶性蛋白含量、酚类物质、POD等含量在2-4月份间呈逐渐下降的趋势，而超氧阴离子(O2^-)、SOD、MDA、脂质过氧化产物等则相反，在2—4月份间呈逐渐升高趋势。这说明：珊瑚树生长芽在开春期间可能因体内的可溶性蛋白、POD、酚类物质含量的下降而致使植物的抗寒性减弱。芽生长期间超氧阴离子产生增加，其歧化酶SOD也呈上升趋势，生长时芽内MDA以及脂质过氧化产物含量较高，表明此时生长芽的抗逆性很弱。     

蛋白质结构展示在生物化学教学中的应用

蛋白质结构的研究已成为目前生物学研究的前沿与热点,大量获得的蛋白质结构为基础教学提供了重要的教学素材。通过蛋白质结构的展示,丰富和完善了生物化学课程的知识体系,激发了学生的学习兴趣。本文将蛋白质结构的展示应用到生物化学教学中,以"蛋白质化学"和"酶"章节为例,将概念、知识点与可视的空间结构结合并引入课堂教学,有助于激发学生学习的主动性并提升课堂教学效果。     

复合菌系固体发酵产纤维素酶的影响因素研究

以B-1（Bacillaceaesp.）、B-2（Pseudomonassp.）、F-1木霉属（Trichodermasp.）、F-2木霉属（Trichodermasp.）和F-3青霉属（Penicillumsp.）组成复合菌剂,通过固体发酵培养,研究了温度、pH、时间和接种量对复合菌系固体产酶发酵的影响.实验结果得到了复合菌系的最佳产酶温度、pH、培养时间和接种量分别为32℃p、H 7.65、d、8%~10%,相对应的CMCase和Fpase的活力分别达到2501 IU/g和847 IU/g、2036 IU/g和744 IU/g、2674 IU/g和673 IU/g2、644 IU/g和578 IU/g.     

杏鲍菇菌柄中SOD活性研究

对不同温度、pH、水浴时间下杏鲍菇菌柄中SOD酶比活性及其保留率进行研究,结果表明,杏鲍菇菌柄具有较高的SOD活性,25℃下,比活性可达351.4U/mg prot,最适宜保存其活性的pH为7.80,杏鲍菇菌柄中的SOD热稳定性突出,即使在100℃下水浴15min后,其SOD酶活保留率仍然高达74.17%（以25℃时测定活性为100%）,具备优良的加工性能,但长时间的高温条件会使SOD酶活性的逐渐下降。     

体育高考前的准备工作初探

从考前的休息与训练、考前的饮食、考前准备活动、考前心理准备等四个方面探讨了考生在体育高考前的准备工作,并提出一些建议.     

Effects of different enzyme complex supplements in corn-soybean feedstuff on growth performance and nutrient utilization of broilers

A six-week experiment was conducted to investigate the effects of supplementing different enzyme cocktails in cornsoybean-byproduct diets on broiler chickens＇ growth performance and nutrient utilization. A total of 630 one-day-old Arbor Acre broiler chicks were randomly allocated to 7 experimental groups with 6 replicates of 15 chicks. The group of chicks serving as the control group were fed a basal diet made of mainly corn and soybean meal, mixed with a little fish meal, rapeseed meal and wheat bran. The other six groups were fed the same basal diet supplemented with each a different enzyme complex at the dosage of 0.75 kg enzyme in 1 t basal diet. At the same time, a metabolic trial was carded out on 42 chicks at the 27 d age. The results showed that the average daily mass gain （ADG） of chicks in the starter phase, age 1 d to 21 d, was improved by all enzyme complex supplements except the cocktail made of 230 IU/g α-amylase, 5.6 klU/g β-glucanase, 5.3 kIU/g cellulase, 15.5 kIU/g protease and 37.5 kIU/g xylanase. The enzyme cocktail made of 1.6 klU/g α-amylase, 80 klU/g protease and 1.6 kIU/g xylanase worked out the most significant difference （P〈0.05）. Enzyme supplementation decreased the feed conversion ratio （FCR） by 2.78% to 3.98% （P〉0.05）, indicating better utilization of nutritients. In the grower phase at the age from 22 d to 42 d, the enzyme cocktail made of 4.0 kIU/g β-glucanase, 3.8 kIU/g cellulase, 17.8 kIU/g protease, 4.5 kIU/g xylanase and 44 IU/g α-glactase, and that made of 240 IU/g α-amylase, 1.4.6 kIU/g β-glucanase, 2.0 kIU/g cellulase, 5.7 klU/g protease, 400 IU/g xylanase, 20 IU/g α- glactase and 200 IU/g phytase imporved chicks＇ ADG and FCR significantly （P〈0.05）. These two cocktails also were shown to improve ADG and FCR in the entire period of broiler age from 1 d to 42 d. Exogenous digesting enzymes such as protease and amylase benefited the growth and nutrition utilization in young broilers in the starter phase but barely in the grower phase, indicat     

燃油蒸发物的两相净化法处理工艺研究

针对目前汽车曲轴箱和燃油蒸发排放控制,提出活性炭吸附罐利用高效生物酶催化与活性炭进行两相组合联合处理方法,进一步处理和吸收HC化合物等污染物质,并回收利用其中的丁烷等可燃气体,节约能源.     

一株产生淀粉糖化酶的拟青霉

从土壤中分离筛选到一株降解生淀粉能力较强的菌株,通过固体发酵其生淀粉糖化酶活为2237U/g（按U/g麦麸计）,RDA值为15.25%。根据形态学特性初步鉴定该菌属于拟青霉属（Paecilomyces sp.）。其最适生长温度为30℃,最适生长起始pH5。其粗酶液24h水解生玉米淀粉的水解率为86.88%;对不同来源的生淀粉的水解能力不同,为玉米粉〉面粉〉米粉〉木薯粉〉甘薯淀粉;其最适作用pH为4,最适作用温度为70℃。     

三种鸡形目鸟类线粒体DNA的研究

采用１２种限制性内切酶分析了家鸡（Ｇａｌｕｓｇａｌｕｓｄｏｍｅｓｔｉｃｕｓ）、雉鸡（Ｐｈａｓｉａｎｕｓｃｏｌｃｈｉｃｕｓ）和普通珍珠鸡（Ｎｕｍｉｄａｍｅｌｅａｇｒｉｓ）线粒体ＤＮＡ（ｍｔＤＮＡ）。结果：①５个不同品种家鸡ｍｔＤＮＡ具有相同的限制性类型，进一步说明家鸡ｍｔＤＮＡ种内遗传变异程度很低；②雉鸡ｍｔＤＮＡ的ＢｇｌⅠ，ＥｃｏＲⅠ，ＨｉｎｄⅢ和ＰｖｕⅡ等４种限制性酶的酶切类型与云南环颈雉不相同，说明雉鸡存在ｍｔＤＮＡ种内差异；③比较家鸡、雉鸡和珍珠鸡间ｍｔＤＮＡ的ＲＦＬＰ，计算他们之间的遗传距离，家鸡与珍珠鸡的遗传距离较近（Ｐ＝０．０９６），家鸡与雉鸡以及雉鸡与珍珠鸡的遗传距离较远，分别为０．２１５和０．２２９，初步结果表明珍珠鸡是距雉科的家鸡和雉鸡亲缘关系较近的种类，和家鸡的关系相当密切。