木霉菌Td系列菌株代谢产物的室内抑菌谱研究

利用摇床液体发酵、氯仿萃取木霉菌的代谢产物,采用菌丝生长速度法测定了3个木霉菌菌株的发酵代谢产物对禾谷类镰刀病菌、番茄枯萎病菌、苹果轮纹病菌、立枯丝核菌、苹果炭疽病菌、玉米弯胞病菌和花生网斑病菌的抑菌作用。结果表明,3个木霉菌株代谢产物对7种病原真菌均具有抑制作用,且抑菌作用强度和抑菌谱存在一定的菌株特异性。木霉菌株Td10的代谢产物对禾谷类镰刀病菌和立枯丝核菌抑制作用最强,Td31的代谢产物对苹果轮纹病菌和苹果炭疽病菌抑制作用最强,而Td100的代谢产物对禾谷类镰刀病菌和立枯丝核菌抑制作用较强;3个木霉菌株的代谢产物对花生网斑病菌抑制作用均较弱。     

木霉菌在生物防治中的研究进展

自从研究生物防治以来,木霉的防治机制为农业的健康发展奠定了重要基础,成为提升农产品产量的关键因素。木霉作为一种常用的生防菌,对于植物的抗病性,促生等方面起着十分重要的作用。近年来,随着病原菌耐药性的不断增强,传统的抗生素类药物大量失效,同时大量使用抗生素会造成环境的巨大污染。生防菌作为一种新兴的防治技术开始逐步被大面积使用。木霉作为一种常见的生防菌开始发挥巨大的作用。开发木霉以及相应的制剂对于土传病害的防治具有十分广阔的前景。因此,本文通过介绍生物防治的相关概念,木霉菌的作用机制以及其在某些病原菌中的生防应用做出了相关综述,为今后生物防治的多向化发展提供一定的借鉴。     

Structures and Biological Activities of Secondary Metabolites from Trichoderma harzianum

The biocontrol fungus Trichoderma harzianum, from both marine and terrestrial environments, has attracted considerable attention. T. harzianum has a tremendous potential to produce a variety of bioactive secondary metabolites (SMs), which are an important source of new herbicides and antibiotics. This review prioritizes the SMs of T. harzianum from 1988 to June 2022, and their relevant biological activities. Marine-derived SMs, especially terpenoids, polyketides, and macrolides compounds, occupy a significant proportion of natural products from T. harzianum, deserving more of our attention.     

Lipid components of mustard seeds (Brassica juncea L.) as influenced by cadmium levels

In a pot experiment the soil application of different levels of Cd²⁺ (0, 10, 20, 30, 40 and 60 µg g^–1 soil) affected the lipid components of mustard seeds (Brassica juncea L. Cv. RH-30) markedly. Total lipids declined with the Cd²⁺ levels regularly while phospho and glycolipids increased only at higher levels. Fatty acids profile of total, neutral and polar lipid fractions were affected considerably. Erucic acid in total and neutral lipids was observed to increase while it decreased in polar lipids with Cd²⁺ as compared to control. On the other hand palmitic, oleic and linoleic acids had reverse trend. Cadmium concentration increased consistently with increasing levels of Cd²⁺. Plant dry weight was also decreased significantly with Cd²⁺ levels.     

不同诱变方法提高绿色木霉产纤维素酶的研究

该文阐述了紫外、硫酸二乙酯和亚硝基胍三种诱变方法对发菌株绿色木霉TV-96进行诱变以提高其产酶的能力.确定了紫外、硫酸二乙酯和亚硝基胍的最佳诱变时间分别为:120秒、35分钟和2.5分钟;得到了31株菌株的HC值比出发菌株大,通过复筛,发现31株菌株中,有22株的产酶能力比出发菌株有提高,且突变菌株NTG8的产酶能力最高值为4 37 μgG/ml·min,是出发菌株的2.03倍,并具有较好的遗传稳定性.     

木霉菌在农业中的研究与应用前景

该文综述了木霉菌分类和形态特征、生物防治作用、促进植物生长作用、诱导植物产生抗病性作用、土壤和环境的生物修复作用、在生物有机肥中的应用、构建生物工程菌株以及应用前景等各个方面研究进展。     

培养基成分对木霉菌合成木聚糖酶的影响

木低聚糖可以从木质纤维的有控酶降解反应获得 .该文采用培养木霉菌 ,使其在最佳条件下比较专一性地合成木聚糖酶 ,这种最佳条件包括培养基成分的探索和培养条件的控制两方面 .期望用这种木聚糖酶降解木质纤维原料时 ,能尽可能多地得到木低聚糖 ,而较少出现木单糖 .首先就碳源、氮源、碳氮比等因素对木聚糖酶活性的影响进行了研究 .结果表明 ,以杨木粗木聚糖为碳源 ,以酵母浸膏为氮源 ,碳源浓度控制在 7g L左右 ,碳氮比在 7 8以上 ,所产生的木聚糖酶活性较高 ,且木聚糖酶与纤维素酶酶活的比值较高 ,即所产酶的选择性较好     

Transformation of Arabidopsis thaliana via Agrobacterium tumefacience with an endochitinase gene from Trichoderma, and enhanced resistance to Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is an important pathogen to many crops and is especially damaging to rape in China. As a model plant Arabidopsis thaliana (Col0) was transformed by spraying Agrobacterium tumefacience with Trichoderma endochitinase gene ThEn-42 at initial bud stage. Eleven seedlings (corresponding to about 0.22 percent transformation) exhibited resistance to hygromycin. The DNA fragment unique to endochitinase (ThEn-42) was amplified by Arabidopsis leaf-PCR or genomic DN…     

木霉对番茄种子活力及幼苗生长的影响

用不同浓度的木霉发酵液对番茄种子和幼苗进行处理,研究其对种子活力及幼苗生长的影响。结果表明:木霉在适量浓度下,可显著提高番茄种子的发芽率及幼苗鲜重,并能促进地上、地下部分的生长。     

木霉拮抗烟草赤星病菌菌株的筛选及其生防机制

 利用诱捕法从土壤中分离得到18株木霉(Trichoderma spp.)菌株,采用对峙法从中测定、筛选出一株对烟草赤星病菌(Alternaria alternata)具有极强拮抗作用的菌株(Tv－1),光学显微镜及透射电镜观察结果表明,Tv－1菌株的生防机制主要为生长竞争、重寄生作用以及产生生物活性类物质使病菌菌丝消解的直接抗菌作用,表现为Tv－1菌株菌丝生长迅速;能附着、缠绕于病菌菌丝上,并产生吸器侵入菌丝;同时还能分泌使病菌菌丝原生质浓缩、断裂、消解的物质。