Design and Activity Identification of Hybrid Peptide Based on Cecropin A and Mastoparan     

ZHAI Pei  HAN Jinhui  PAN Xiaoyu 《中国畜牧兽医》2007,47(9):3006-3013

In order to further improve mastoparan's antibacterial and antitumor activities and reduce its cytotoxicity,the molecular modification was carried out by molecular hybridization,and the biological activity of the designed peptide was identified.A novel hybrid peptide KL-21 was obtained by using the N-terminal 1-8 sequences fragment of cecropin A and the conserved sequence of mastoparan.The physicochemical parameters and structures of KL-21 were analyzed by bioinformatics method.The antibacterial activity of KL-21 was studied with MP-L as reference.In addition,the hemolysis rate of the two peptides and the activity of anti-tumor cell A549 were measured.The results showed that KL-21 could quickly kill bacteria in a shorter time.The minimum inhibitory concentration (MIC) of KL-21 to Gram-positive bacteria (S.aureus) and Gram-negative bacteria (E.coli) was 4-8 μg/mL,and the minimum bactericidal concentration (MBC) was 8-16 μg/mL.The MIC and MBC of KL-21 to fungus (C.albicans) were 32 and 64 μg/mL,respectively.The hemolytic activity of KL-21 was only 20% at 128 μg/mL,which was lower than that of MP-L.KL-21 could inhibit lung cancer cell A549 with inhibition rate in vitro about 86% at 16 μg/mL.These results indicated that KL-21 had higher antibacterial and antitumor activity and lower cytotoxicity than MP-L,which could be used as a leading peptide for further research and development.  相似文献   

Does the depletion of pentachlorophenol in root–soil interface follow a simple linear dependence on the distance to root surfaces?     

Yan He  Jianming Xu  Xiaofei Lv  Zhaohui Ma  Jianjun Wu  Jiachun Shi   《Soil biology & biochemistry》2009,41(9):1807-1813

To understand root–soil–microbe interactions in rhizo-depletion of xenobiotics, we conducted a glasshouse study using specially designed laminar rhizoboxes which allow intact layers of near- (1–5 mm) and far- (>5 mm) rhizosphere soil to be harvested separately from root surfaces without the removal of the root material itself. Plant (Lolium perenne L.) seedlings were grown for 90 days in a soil treated with PCP at 20 and 50 mg kg⁻¹. Changes in PCP depletion, soil microbial biomass and community structure (as indicated by phospholipid fatty acids (PLFAs) profiles) with increasing distance from the root surfaces were then assessed after harvesting. Surprisingly, depletion of PCP in the planted rhizoboxes exhibited a nonlinear dependence on the distance to root surfaces, with the most rapid loss in the 2 or 3 mm near-rhizosphere layers, contrasting to the well-known linear gradient of root exudates and mineral nutrients etc. (generally, the extent gradually decreased with increasing distance from the root surface). Soil microbial biomass carbon, however, decreased linearly as expected with increasing distance from the roots. The microbial community structures as indicated by PLFA profiles showed distance-dependent selective enrichment of competent species that may be responsible for efficient PCP depletion. The results suggest that root exudates induced modifications of microbial communities in the PCP contaminated rhizosphere and spatially modified the dominant species within these communities, resulting in the nonlinear PCP depletion pattern.  相似文献   

2007年上半年鱼粉市场回顾与下半年展望     

吕兆昕  李想 《饲料广角》2007,(16):10-12

2007年上半年，国内鱼粉市场在低迷中煎熬，价格一路下跌，1—6月跌幅近2000元／t，进口商和国内持货商亏损严重，归其原因还是供需矛盾的结果。下半年，国内鱼粉市场仍然面临高库存的压力，虽然市场人士对外盘的看法存在分歧，但矛盾的根源主要还在于国内鱼粉的消耗进度。[第一段]  相似文献   

光对储存期辣椒果实辣椒素含量的影响     

王金玲吕长山  于广建 《勤云标准版测试》2005,(9)

采用湘研4号(中等辣度)和景尖椒3号(高辣度)两个辣椒品种的青熟果实,以有光和无光两种不同的条件于室温下储存,就储存期辣椒果实中辣椒素含量的变化进行研究。发现有光储存利于果皮中辣椒素含量的增加,无光储存利于胎座中辣椒素含量的增加。  相似文献   

浅析天津农业信息化测评指标体系的构建     

信丽媛  宋治文  贾宝红  吕雄杰  詹嘉放 《勤云标准版测试》2008,(8)

 信息化发展水平是衡量国家和地区竞争力的重要标志之一。笔者从农业信息化测评的内涵分析出发，探讨了天津农业信息化测评指标体系构建的原则，并在系统分析天津农业信息化建设现状的基础之上，研究提出了天津农业信息化测评指标体系，共5个一级指标，20个二级指标。  相似文献   

加强管理提高质量增加经济效益     

吕沛华 《广东蚕业》2005,39(1):15-17

在体制改革后,如何在增加企业的经济效益的同时,注重抓好蚕种的质量,并且要兼顾原蚕区蚕农的经济利益,这些矛盾应如何处理确实是一个新课题.……  相似文献   

一种高效秸秆切碎器的设计研究   总被引：1，自引：0，他引：1  

吴丽丽  刘天舒  吕黄珍  董世平  黄希国  孙玉峰 《农机化研究》2011,33(5)

切碎器是秸秆切碎机的核心工作部件,它直接影响切碎机切碎质量、功率消耗和抛送性能.为此,设计了平板刀式滚筒切碎器,分析了滚筒切碎器结构参数对切碎性能和抛送性能的影响,确定了较优工作参数.经过切碎棉秆试验表明,该切碎器切碎性能优良,切段均匀,抛送性能强.  相似文献   

鸡IBD蜂胶囊毒组织灭活苗的研制与应用     

王明根  吕锦芳等 《勤云标准版测试》2005,(5)

为了预防鸡IBD的区域性流行,以当地典型发病鸡群的法氏囊为组织源,以蜂胶为佐剂,研制鸡IBD蜂胶囊毒组织灭活苗。室内试验表明,对10日龄AA肉鸡接种后,20、50d血清AGP抗体阳性率和对强毒攻击的保护率均达100%;田间试验表明,对6批7~15日龄,3万多只不同品种的雏鸡免疫,未发生一起IBD;常规检验表明,该苗安全、无毒副作用,保存期内性质稳定。  相似文献   

辽豆14号超高产纪录的创造   总被引：1，自引：0，他引：1  

董丽杰  吕桂兰  曹永强 《大豆科技》2007,(2):4-6

2000年辽宁省农科院作物所采用辽21051(辽豆14),在辽宁省海城市南台镇树林子村种植3 134.9 m2,在除去边行净667m2的面积上,实收产量为327.2 kg/667m2,是东北地区第一个大豆高产纪录.对高产的具体技术进行了总结并提出了超高产大豆的品种株型.  相似文献   

农业科技创新模型及分析   总被引：3，自引：1，他引：2  

解宗方  李海现  李锦辉 《农业现代化研究》1999,20(5):290-293

通过对农业科技创新特征的分析，指出了影响农业科技创新的障碍因素，在此基础上，构建了农业科技创新的双规三力互动模型。  相似文献