共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
白腐真菌在碳素循环中的地位和作用李慧蓉(江苏石油化工学院,常州213016)白腐真菌是一类丝状真菌,因腐生在树木或木材上,引起木质的白色腐烂而得此名。这类真菌因能对木质素进行彻底的生物降解而在自然界的碳素循环中占有重要地位,它独特的降解能力和机制引起... 相似文献
3.
4.
白腐真菌漆酶的纯化及性质 总被引:1,自引:0,他引:1
液体发酵培养白腐真菌F9,粗酶液经盐析、透析浓缩、葡聚糖G-100柱层析、DEAE-纤维素离子交换层析四步分离纯化,得电泳纯漆酶。经SDS-PAGE法测定酶的相对分子质量约为6×104,酶活回收率达46.47%,纯度提高了18.86倍。F9漆酶最适反应温度为40℃,最适反应pH为4.8,在35℃以下、pH 4.8~5.4的范围内稳定性较强。其催化愈创木酚的Km为4.61 mmol/L,vm为6.27 mmol/(L.min)。K+对其有激活作用,而Fe2+、Fe3+对其有明显抑制作用。 相似文献
5.
白腐菌菌体对染料的生物吸附脱色及机理研究 总被引:1,自引:0,他引:1
目的:研究了白腐菌菌体吸附染料特性、影响因素及吸附机理。方法:采用分光光度法、吸附热特性、傅立叶变换红外光谱(FTIR)分析等系统地对菌体吸附特性及机理进行研究。结果:白腐菌BP对不同类型的染料有不同的吸附效果,240min内染料RBBR脱色率能达82.35%。菌体对RBBR的合适吸附条件为:温度28℃、转速100r/min、菌体粒径小于60目。吸附符合Freun-dlich模式,为多分子层吸附。菌体吸附染料主要通过菌体表面的羟基、羧基、胺基及磷酸基团与染料分子以共价键、离子交换或氢键结合来进行。结论:利用白腐菌菌体能有效的对部分染料进行吸附脱色。 相似文献
6.
7.
白腐真菌及其技术的潜在工业应用 总被引:6,自引:0,他引:6
本文概述了白腐真菌对木质素和各种结构不同的化学物的独特降解能力及其在降解机制,以及白腐真菌技术在石油化学工业,煤炭工业,纸浆造纸工业,纺织印染工业,酶制品生产和环境工程等方面潜在的工业应用前景。 相似文献
8.
白腐真菌原生质体制备和再生条件的研究 总被引:5,自引:2,他引:5
对影响白腐真菌(5.776)原生质体制备和再生的条件:包括菌龄、水解酶液的种类及浓度、酶解温度、酶解时间、再生培养基的稳渗剂的选择进行了研究。通过单因素比较分析和正交实验得到最适合的白腐真菌原生质体制备和再生条件。结果表明:当菌龄为58h,采用1%纤维素酶和1%蜗牛酶(2:1)混合液,酶解温度30℃,酶解时间180min,用0.7mol/L氯化钠作渗透压稳压剂,白腐真菌(5.776)原生质体的形成数和再生率均比优化前大为提高,原生质体形成量为8.36×10~5个/mL,原生质体再生率为9.12%。 相似文献
9.
10.
11.
Regis-Olivier Benech Xiaoming Li Donald Patton Justin Powlowski Reginald Storms Robert Bourbonnais Michael Paice Adrian Tsang 《Enzyme and microbial technology》2007,41(6-7):740-747
A Phanerochaete chrysosporium cDNA predicted to encode endo-1,4-β-d-mannanase, man5D, was cloned and expressed in Aspergillus niger. The coding region of the gene man5D was predicted to contain, in order from the N-terminal: a secretory signal peptide, cellulose-binding domain, linker region, and glycosyl hydrolase family 5 catalytic site. The enzyme was purified from culture filtrate of A. niger transformants that carried the recombinant man5D. Recombinant Man5D had an apparent molecular size of about 65 kDa by SDS-PAGE, and optimal activity at pH 4.0–6.0 and 60 °C. It was stable from pH 4.0 to 8.0 and up to 60 °C. The enzyme showed affinity for Avicel cellulose, suggesting that the predicted cellulose-binding domain is biologically functional. The specific activities of Man5D on mannan, galactomannan, and glucomannan at pH 5 and 60 °C ranged from 160 to 460 μmol/(min mg), with apparent Km values from 0.54 to 2.3 mg/mL. Product analysis results indicated that Man5D catalyzes endo-cleavage, and appears to have substantial transglycosylase activity. When used to treat softwood kraft pulp, Man5D hydrolyzed mainly glucomannan and exhibited a positive effect as a prebleaching agent. Compared to a commercial prebleaching with xylanase, the prebleaching effect of Man5D was weaker but with reduced loss of fibre yield as determined by the release of solubilized sugars. 相似文献
12.
13.
Bonnarme P Delattre M Drouet H Corrieu G Asther M 《Biotechnology and bioengineering》1993,41(4):440-450
Phanerochaete chrysosporium and cultivated both mechanically agitated and pneumatic bioreactors. In the pneumatic devices, the yields of lignin and manganese peroxidases as well as extracellular protein, were considerably increased as compared with mechanically agitated bioreactors. Lignin peroxidase and manganese peroxidase activities as high as 4500 U . L(-1) and 1812 U . L(-1) respectively, were produced in an airlift bioreactor. By using enzyme markers, the secretion pathway and the respiration were shown to be dramatically activated in pneumatic bioreactors. The general metabolism of the fungus, when cultivated in the conventional fermentors, is oriented toward the synthesis of biomass at the expense of the synthesis of peroxidases. The use of pneumatic devices for the production of extracellular peroxidases by P. chrysosporium, avoids shear effects due to turbine agitator in the conventional fermentors, and provides a good example for the production of shear-sensitive metabolites. (c) 1993 John Wiley & Sons, Inc. 相似文献
14.
Degradation of chlorophenols by P. chrysosporium in static cultures has been studied. The influences of mycelium acclimation, co-substrate concentration and nitrogen source on phenol degradation were analyzed. With non-acclimated mycelium the maximal concentrations degraded were 150 ppm of o-chorophenol and 100 ppm of the isomers m- and p-chlorophenol. The substituted ortho-position on the aromatic ring was the preferred attack position. Meta- and para-positions were less reactive and resulted in a slower degradation rate than the ortho position. Nevertheless, with acclimated mycelium, an increase in the ability to degrade chlorophenol and a higher reactivity in meta- and para-positions were observed (degraded chlorophenol increased by up to 70% for the o-isomer and 50% for the m- and p-isomers with respect to non-acclimated mycelium). A decrease in glucose concentration caused a decrease in chlorophenol degradation rate. Twelve days were needed for complete degradation of o-chlorophenol with 10 g/l of glucose and 22 days when glucose concentration was decreased to 2.5 g/l. The reduction of ammonium tartrate caused a greater lag time, but not a decrease in chlorophenol degradation rate. Replacement of ammonium tartrate by ammonium chloride caused a decrease in chlorophenol degradation rate. 相似文献
15.
锰过氧化物酶的结构与功能 总被引:6,自引:0,他引:6
综述了木素降解的关键酶之一锰过氧化物酶的三维分子结构和催化反应性能,综合概述了通过定点诱变等方法对锰过氧化物酶的结构和功能的研究进展。 相似文献
16.
We investigated the contributions of lipoteichoic acid and M protein to reversible and irreversible adhesion of group A streptococci and the effects of such adhesion on release of interleukin-6. Streptococci in which lipoteichoic acid was masked by the hyaluronate capsule were readily washed from HEp-2 cells, indicating no attachment. Unencapsulated, M-negative streptococci in which lipoteichoic acid was exposed were removed more slowly, indicating loose attachment. Only unencapsulated streptococci that expressed both lipoteichoic acid and M protein remained stably adherent to HEp-2 cells throughout multiple washes. Streptococci expressing both M protein and lipoteichoic acid induced release of interleukin-6 from HEp-2 cells, whereas an isogenic, M-negative mutant failed to induce release of interleukin-6. These data suggest that lipoteichoic acid mediates reversible adhesion and that M protein is required for irreversible adhesion and for inducing release of interleukin-6 from HEp-2 cells. 相似文献
17.
Segula Masaphy Dan Levanon Yigal Henis K. Venkateswarlu Steven L. Kelly 《FEMS microbiology letters》1996,135(1):51-55
Abstract The presence of cytochrome P-450 and P-450-mediated benzo(a)pyrene hydroxylase activity in both microsomal and soluble fractions of the white rot fungus Phanerochaete chrysosporium was shown. The reduced carbon monoxide difference spectrum showed maxima at 448–450 and 452–454 nm for microsomal and cytosolic fractions, respectively. Both P-450 fractions produced a Type I substrate binding spectrum on addition of benzo(a)pyrene. Activity for benzo(a)pyrene hydroxylation was NADPH-dependent and inhibited by carbon monoxide. K m values for activity showed a difference between the cellular fractions with a K m of 89 μM for microsomal P-450 and 400 μM for cytosolic P-450. The V max values observed were 0.83 nmol min− (nmol microsomal P-450) −1 and 0.4 nmol min−1 (nmol cytosolic P-450)−1 . The results indicate that P-450-mediated benzo(a)pyrene hydroxylase activity could play a role in xenobiotic transformation by this fungus beside the known ligninolytic exocellular enzymes. 相似文献
18.
黄孢原毛平革菌生产锰过氧化物酶的发酵条件研究 总被引:2,自引:0,他引:2
目的 :研究黄孢原毛平革菌产锰过氧化物酶的发酵条件。方法 :对培养条件进行优化 ,采用正交设计法对培养基组分进行优化。结果与结论 :优化培养条件为 :接种量 1 6× 10 6 个孢子 L ,pH 4 4~ 4 8,温度 36℃~ 4 0℃ ,转数 12 0r/min。优化培养基参数为 :葡萄糖 5g L ,酒石酸铵 1 3mmol L ,吐温 - 80 1 2g L ,Mn2 + 0 9mmol L。 相似文献
19.
Bakshi Dapinder K. Gupta K.G. Sharma Prince 《World journal of microbiology & biotechnology》1999,15(4):507-509
Biodecolorization of a synthetic commercial textile dye effluent (0.1 gl–1) by Phanerochaete chrysosporium was enhanced by improving the original Kirk's medium with respect to buffer, C:N ratio, Mg2+ and Zn2+ ions, inoculum, temperature shifts, agitation and sunflower oil additon. An increase of 6.7-fold in lignin peroxidase (LIP) level, 4-fold in biomass and 45.5% enhanced decolorization of effluent was achieved. Degradation was both enzymatic (47.2%) and by biosorption (61.67%). 相似文献
20.
Lidy E. Fratila-Apachitei Jennifer A. Hirst Maarten A. Siebel Huub J. Gijzen 《Biotechnology letters》1999,21(2):147-154
When incubated in synthetic (N-limited) medium and on ashwood chips, Phanerochaete chrysosporium BKM-F-1767 degraded 14 and 10 mg/l diuron, respectively. The wood chips were used as support and sole nutrient source for the fungus. A higher degradation efficiency was found in ashwood culture as compared to the liquid culture, probably as a result of the synergetic effect of attached fungal growth, presence of limiting-substrate conditions and the microenvironment provided by ashwood, all favorable for production of high extracellular enzyme titres. Diuron degradation occured during the idiophasic growth, in the presence of manganese peroxidase, detected as dominant enzyme in both cultures. 相似文献