不同浓度的壳聚糖处理对玉米种子萌发的影响初报

本文探讨了不同浓度壳聚糖处理对玉米种子萌发的影响，结果表明：0.5%的壳聚糖处理玉米种子的发芽率，发芽指数最高，淀粉酶的活性最强；POD维持较长时间，该处理的活性持续时间长，这些说明了适合浓度的壳聚糖处理玉米种子能提高种子的活力。     

光质和NAA组合对怀山药叶片脱分化的效应

不同光质和NAA组合对怀山药叶片脱分化的效应不同 ,结果表明 :各种光质下 ,(1)NAA浓度为2mg·L-1时 ,怀山药叶片愈伤组织形成的时间最早 ;NAA浓度为 2mg·L-1或 4mg·L-1时 ,出愈率最高 .(2 )愈伤组织中的可溶性蛋白含量和过氧化物酶 (POD)活性不同 :蓝光有利于愈伤组织中可溶性蛋白的形成 ,而黄光则有利于POD活性的提高     

多环芳烃(萘)污染对水生植物生理指标的影响

通过盆栽试验研究了萘污染对5种水生植物生理指标的影响，结果表明，萘对水生植物具有某些毒害作用，且随着浓度的增加（1.2mg/L-16.1mg/L)显示出明显的负效应，表现为呼吸强度受到抑制，叶绿素含量降低；水葫芦，水花生的过氧化物酶（POD）活性逐渐升高，浮萍，紫萍和细叶满江红的酶活性随萘浓度增加先升高后降低，叶绿素含量及POD活性可以作为水生植物受萘污染的指标。     

基于有机溶剂中的酶促反应测定血清中维生素C含量

研究了有机溶剂中辣根过氧化物酶催化维生素C的氧化反应的特性。实验发现在异丙醇-水互溶体系中,辣根过氧化物酶催化过氧化氢氧化维生素C的反应速度加快,测定灵敏度提高,基于此反应,用紫外分光光度法测定了人血清中维生素C的含量。     

红豆杉抗真菌细胞株的筛选及生理生化特性

通过胁迫筛选法筛选红豆杉抗真菌细胞变异系,并比较了该细胞系和原型在真菌诱导物处理后与抗病有关的几种酶的变化规律以及紫杉醇含量的变化．结果表明诱导物处理后抗性细胞的紫杉醇含量显著高于原型,并且过氧化物酶（ＰＯＤ）、苯丙氨酸解氨酶 （ＰＡＬ）和超氧阴离子自由基（Ｏ·－２ ）释放速率均与原型有明显区别．     

金针菇降解木质素的能力及相关酶活研究

通过对10个金针菇菌株研究发现,在液体培养下不同菌株降解木质素的能力有较大差异,其中金针菇J89-6具有一定的降解木质素的能力,降解率达46%.本文还测定了不同菌株的漆酶、木质素过氧化物酶和锰过氧化物酶三种木质素降解酶的酶活,结果显示漆酶的产量与木质素降解率呈正相关关系.     

青枯菌胞外多糖和酶对花生细胞POD及CYT的影响

用野生型青枯菌(fy7)及其胞外多糖缺失型(APT)和胞外蛋白缺失型(DF7)分别作用于青枯菌易感花生品种鄂花4号和抗性品种中花2号的悬浮培养细胞,等电聚焦分析处理后的花生细胞的过氧化物酶(POD)、酯酶(FAST)和细胞色素氧化酶(CYT)的变化．与对照组相比,fy7诱导12h时鄂花4号的3种酶都有变化,24h时只有中花2号有新POD带出现．APT诱导12h时只有FAST有变化,24h时POD和cYT均有较显著变化．DP7诱导12h时只有FAST有变化,24h时只有抗性细胞有新POD带出现．     

DyP-type peroxidases comprise a novel heme peroxidase family

Dye-decolorizing peroxidase (DyP) is produced by a basidiomycete (Thanatephorus cucumeris Dec 1) and is a member of a novel heme peroxidase family (DyP-type peroxidase family) that appears to be distinct from general peroxidases. Thus far, 80 putative members of this family have been registered in the PeroxiBase database (http://peroxibase.isbsib.ch/) and more than 400 homologous proteins have been detected via PSI-BLAST search. Although few studies have characterized the function and structure of these proteins, they appear to be bifunctional enzymes with hydrolase or oxygenase, as well as typical peroxidase activities. DyP-type peroxidase family suggests an ancient root compared with other general peroxidases because of their widespread distribution in the living world. In this review, firstly, an outline of the characteristics of DyP from T. cucumeris is presented and then interesting characteristics of the DyP-type peroxidase family are discussed. Received 14 October 2008; received after revision 12 November 2008; accepted 17 November 2008     

Enzymatic hydroxylation of aromatic compounds

Selective hydroxylation of aromatic compounds is among the most challenging chemical reactions in synthetic chemistry and has gained steadily increasing attention during recent years, particularly because of the use of hydroxylated aromatics as precursors for pharmaceuticals. Biocatalytic oxygen transfer by isolated enzymes or whole microbial cells is an elegant and efficient way to achieve selective hydroxylation. This review gives an overview of the different enzymes and mechanisms used to introduce oxygen atoms into aromatic molecules using either dioxygen (O₂) or hydrogen peroxide (H₂O₂) as oxygen donors or indirect pathways via free radical intermediates. In this context, the article deals with Rieske-type and α-keto acid-dependent dioxygenases, as well as different non-heme monooxygenases (di-iron, pterin, and flavin enzymes), tyrosinase, laccase, and hydroxyl radical generating systems. The main emphasis is on the heme-containing enzymes, cytochrome P450 monooxygenases and peroxidases, including novel extracellular heme-thiolate haloperoxidases (peroxygenases), which are functional hybrids of both types of heme-biocatalysts. Received 11 August, 2006; received after revision 28 September 2006; accepted 9 November 2006     

病圃定向筛选提高棉花品种抗枯萎病的研究

采用田间病圃筛选鉴定、过氧化物酶活性测定、过氧化物酶同工酶电泳三者相结合的方法,研究了棉花通过病圃筛选由高感品种过渡到抗病品系的过程中,其抗性变化的生化机理.结果表明：高度感病材料的抗性可以通过定向选择使其抗枯萎病性能不断增强,随着抗枯萎病性能的提高,接菌后,各材料中过氧化物酶活性也随着增强,在48～72h时可达到峰值,并且抗性不同的材料对病原物侵入的敏感程度有很大的差别.