绿色木霉纤维素酶系分泌特性及酶解条件的研究

采用正交实验法分析出绿色木霉 3.3711纤素酶系各组分最适酶解条件组合分别为(pH5 .0、4 5℃ ) (C1酶 ) ,(pH3.5、5 5℃ ) (Cx 酶 )和 (pH4 .5、6 5℃ ) (βG酶 )。分析比较了分别使用纤维素粉和麦麸为单一或混合碳源时在产酶过程中各组分酶的最高酶活 ,比酶活及其形成时间和分泌特性。结果表明 ,同种碳源不同浓度所产酶系中C1比酶活相对稳定 ,C1和Cx 酶活分别形成一个和两个高峰 ,βG酶均为一个高峰。混合碳源使各组分酶活高峰期相对一致 ,高峰期稳定时间延长和酶量增加。     

Enhancing rice resistance to fungal pathogens by transformation with cell wall degrading enzyme genes from Trichoderma atroviride

INTRODUCTION Rice sheath blight (Rhizoctonia solani) and rice blast (Magnaporthe grisea) are two serious plantdiseases in China. Rice cultivars with high level and durable resistance to these two pathogens are noteasy to obtain by traditional breeding methods due to the lack of germplasm resistant to R. solani and the high genetic diversity of M. grisea. Cell wall degrading enzyme (CWDE) genes from biocontrol fungi belonging to the genus Trichoderma have been demonstrated to encode …     

Fungal genus Hypocrea/Trichoderma: from barcodes to biodiversity

Hypocrea/Trichoderma is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immuno-compromised humans and animals, while others can cause damage to cultivated mushroom. With the recent advent of a reliable, BarCode-aided identification system for all known taxa of Trichoderma and Hypocrea, it became now possible to study some of the biological fundamentals of the diversity in this fungal genus in more detail. In this article, we will therefore review recent progress in (1) the understanding of the geographic distribution of individual taxa; (2) mechanisms of speciation leading to development of mushroom diseases and facultative human mycoses; and (3) the possible correlation of specific traits of secondary metabolism and molecular phylogeny.     

克霉灵对毛木耳及绿色木霉菌丝生长的影响

采用二倍稀释法测定了克霉灵对毛木耳(Auriculariapolytricha)及绿色木霉(Trichodermaviride)菌丝生长的影响.结果表明:不同浓度的克霉灵对绿色木霉菌丝生长均表现为抑制作用,其中以1600μg/ml和3200μg/ml克霉灵对绿色木霉菌丝生长抑制作用最强,200μg/ml～1600μg/ml的克霉灵对毛木耳菌丝生长有促进作用,其中1600μg/ml的克霉灵促进作用最强,而3200μg/ml的克霉灵对毛木耳菌丝生长有抑制作用.     

Review:Global nutrient profiling by Phenotype MicroArrays:a tool complementing genomic and proteomic studies in conidial fungi

Conidial fungi or molds and mildews are widely used in modern biotechnology as producers of antibiotics and other secondary metabolites,industrially important enzymes,chemicals and food.They are also important pathogens of animals including humans and agricultural crops.These various applications and extremely versatile natural phenotypes have led to the constantly growing list of complete genomes which are now available.Functional genomics and proteomics widely exploit the genomic information to study the ...     

发酵农作物秸秆优良菌株木霉L-7发酵条件的优化

研究了木霉L-7利用稻草粉和玉米秸秆粉作为发酵基质进行的固态发酵;探讨了稻草粉和玉米秸秆粉的比例、碳源和氮源的种类、培养基含水量、培养基初始pH值、发酵温度、发酵时间及通气量对其产纤维素酶的影响。结果表明：最佳发酵培养基配方为稻草粉54.0g,玉米秸秆粉27.0g,麸皮19.0g,葡萄糖1.0g,硫酸铵1.0g,磷酸二氢钾0.1g,培养基含水量为1∶3;最优化培养条件为培养基初始pH值6.0,发酵温度30℃,发酵时间6天,通气量为60g/1000mL。在以上条件下,纤维素酶活达到最高。     

Purification and some properties of a β-glucanase from a strain,Trichoderma reesei GXC

β-glucanase was purified from a solid-state culture ofTrichoderma reesei on wheat bran in three steps which comprised ammonium sulfate precipitation, Sephadex G-100 chromatography, and DEAE-Sephadex A-50 chromatography. The molecular mass was determined to be 35.21 kilodaltons by sodium dodecyl sulfate-12.5% polyacrylamide gel electrophoresis. The β-glucanase at low pHs was more stable than that at high pHs, and optimum pH was 5.0. The optimum temperature was 60°C, and β-glucanase was relatively stable at below 40°C for 60 min. TheK _m of the enzyme on β-glucan was 10.86 mg/ml, and theV _max on β-glucan was 14286 μmol of glucose equivalents per mg of the pure enzyme per min. The β-glucanase activity was significantly inhibited by Fe³⁺ ions, and was reduced in the presence of Cu²⁺ ions, Mn²⁺ ions and Mg²⁺ ions at 5 mmol/L and 10 mmol/L, respectively. The β-glucanase activity was stimulated by Co²⁺ ions, Ca²⁺ ions, Zn²⁺ ions, and Fe²⁺ ions at 1 mmol/L and 5 mmol/L, respectively. Project supported by Foundation for University Key Teacher of the State Ministry of Education, the National Natural Science Foundation of China (No. 30000118) and Zhejiang Provincial Natural Science Foundation of China (No. 399409).     

胞外高产超氧化物歧化酶菌株的筛选及其发酵工艺条件研究

对产胞外超氧化物歧化酶的14株菌株进行筛选，其中9251菌株产酶活性最高，为绿色木霉(Trichoderma viride)．对Trichoderma viride 9251的发酵工艺进行了优化，在优化的培养条件下，发酵液产酶活性达85U／mL。同时，还考察了金属离子对9251菌株产酶活性的影响。     

Enhancing rice resistance to fungal pathogens by transformation with cell wall degrading enzyme genes from<Emphasis Type="Italic">Trichoderma atroviride</Emphasis>

Three genes encoding for fungal cell wall degrading enzymes (CWDEs),ech42, nag70 andglu78 from the biocontrol fungusTrichoderma atroviride were inserted into the binary vector pCAMBIA1305.2 singly and in all possible combinations and transformed to rice plants. More than 1800 independently regenerated plantlets in seven different populations (for each of the three genes and each of the four gene combinations) were obtained. Theech42 gene encoding for an endochitinase increased resistance to sheath blight caused byRhizoctonia solani, while the exochitinase-encoding gene,nag70, had lesser effect. The expression level of endochitinase but exochitinase was correlated with disease resistance. Nevertheless, exochitinase enhanced the effect of endochitinase on disease resistance when the two genes co-expressed in transgenics. Resistance toMagnaporthe grisea was found in all kinds of regenerated plants including that with singlegluc78. A few lines expressing eitherech42 ornag70 gene were immune to the disease. Transgenic plants are being tested to further evaluate disease resistance at field level. This is the first report of multiple of expression of genes encoding CWDEs fromTrichoderma atroviride that result in resistance to blast and sheath blight in rice. Project (No. 3997002) supported by the National Natural Science Foundation of China