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表面活性剂对绿色木霉产纤维素酶影响 总被引:9,自引:0,他引:9
利用绿色木霉,以稻草为唯一碳源,采用液态发酵的方法,分别加入生物表面活性剂鼠李糖脂和化学表面活性剂Tween 80,重点研究了生物表面活性剂对绿色木霉产纤维素酶的影响。实验分析了加入不同浓度的表面活性剂时滤纸酶活、羧甲基纤维素酶活、微晶纤维素酶活及酶液的表面张力随时间的变化情况。结果表明,添加鼠李糖脂能够促进绿色木霉产酶,分别使滤纸酶活、羧甲基纤维素酶活、微晶纤维素酶活最大提高了1.08倍,1.6倍和1.03倍。与Tween 80相比,鼠李糖脂促进产酶的效果明显优于Tween 80。 相似文献
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里氏木霉液体发酵产纤维素酶的研究 总被引:11,自引:0,他引:11
在摇瓶试验基础上,采用里氏木霉(Trichoderma reesei)HC-415菌株进行5L自控罐产纤维素酶深层发酵试验。在通气量为 0.2—0.6vvm、搅拌速度为 400r/min、发酵液pH控制在5.8—6.1的条件下,发酵液的羧甲基纤维素(CMC)酶酶活最高为325.0mg糖/ml,滤纸糖酶(FPA)酶活最高达17.9mg糖/ml。发酵周期为108h。所得冻干纤维素酶粉CMC酶活最高3111IU/g,FPA最高135IU/g ,对发酵液得率平均6.7g/L。酶活总收率CMC酶活平均78.2%,FPA酶活平均73.5%。 相似文献
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里氏木霉产纤维素酶研究进展 总被引:1,自引:0,他引:1
木质纤维素类生物质被认为是重要且可持续的可再生能源,其主要组成部分是纤维素.纤维素酶是一种能将纤维素分解为葡萄糖的复合酶,能有效地降解木质纤维素生物质.真菌、细菌、放线菌、酵母等多种微生物均可以产生纤维素酶,其中里氏木霉具有完整的纤维素酶系结构,常作为生物技术领域中一个重要菌株,广泛应用于纤维素酶的商业生产.介绍了纤维... 相似文献
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绿色木霉纤维素酶CBHII基因的分子克隆 总被引:10,自引:0,他引:10
本文以噬菌体lambda EMBL3 DNA为载体,通过克隆绿色木酶(Trichoderma vi-ride)高分子量基因组DNA的部分酶解片段,并将重组分子进行体外包装后侵染Escheri-chia.coliK802,由此构建了绿色木霉基因文库。以李氏木霉(Trichoderma reesei)纤维素酶CBHII基因的末端片段为探针,用轮回噬菌斑原位杂交从文库中筛选出CBHII基因的阳性克隆5个 相似文献
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康宁木霉CP88329纤维素酶产生条件的研究 总被引:25,自引:2,他引:25
从生霉棉布上分离出的康宁木霉CP88105经诱变处理,获得一株高产纤维素酶的突变株CP88329。在固体培养基上,28℃培养72小时,所产纤维素酶固体曲,以羧甲基纤维素钠为底物酶活力为4880u/g;以脱脂棉为底物酶活力为480u/g。产酶活力水平均为出发菌的3倍。酶在脱脂棉上作用最适条件为pH4.5-5.0,45-50℃;45℃保温4h,pH稳定范围为3.5-6.5;60℃保温1h,酶活力剩余20%。酶可用于苎麻布抛光处理和牛仔服“石磨”处理。 相似文献
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纤维素是由β-1,4糖苷键链接而成的葡萄糖单体聚合物,广泛分布于自然界,是一类易获取且廉价的可再生资源。自然界含纤维素材料的利用和处理是目前亟待解决的问题,筛选产纤维素酶的优良菌株并实现纤维素的有效利用具有重要意义。利用纤维素酶降解纤维素是绿色、高效和可持续的利用方式,广泛应用于工业和农业领域(养殖、能源、纺织等)。因此,实现高效低成本的纤维素酶生产成为研究和发展的目标。木霉属真菌是重要的纤维素酶产生菌,具有产酶量大、酶系全和酶活性高等优点,分泌的胞外酶易于工业生产中的分离提纯。本研究以课题组前期积累和保存的25种木霉150个菌株为材料,通过刚果红平板法筛选、滤纸酶活测定和天然纤维素降解等测试,筛选出14株产纤维素酶能力较强的菌株(优于对照菌株里氏木霉QM9414),从中选取3株进行最佳产酶条件探索,如接种量、吐温80添加量、发酵培养基pH值等。初步测试结果表明,贵州木霉菌株8705在20℃条件下、摇瓶发酵9 d、在优化后的发酵培养基中产酶效果最佳,其上清液酶活可达到6.63 IU/mL。通过优化发酵温度、发酵时间和培养基成分配比等发酵条件,为资源利用打下物质基础并提供理论依据。 相似文献
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以里氏木霉及米根霉单菌固态发酵为对象,考察不同混合发酵形式对里氏木霉与米根霉混合固态发酵产纤维素酶的影响。结果表明:同时接种里氏木霉与米根霉,试验考察的两菌种接种量比1∶1(以孢子个数计)及5∶1条件下,两菌未产生明显协同产酶作用。米根霉延时(24 h)接种且菌种量比5∶1以及米根霉延时(48 h)接种且菌种量比1∶1,2种发酵形式产酶情况类似,滤纸酶活(FPA)及羧甲基纤维素酶(CMCase)酶活相对米根霉单菌发酵有所提高,而β-葡萄糖苷酶(β-GA)酶活相对里氏木霉单菌固态发酵结束时分别增加4.66及4.40倍,可以发现两菌产生一定协同作用。在米根霉延时(48 h)接种且菌种量比5∶1的发酵形式下,FPA及CMCase在发酵第7天酶活分别达到44.04 IU/g、627.14 U/g(以1 g干曲计),分别是里氏木霉固态单菌发酵产酶达到稳定期时酶活的1.36和1.63倍,两菌产生了有效的协同作用。 相似文献
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对绿色木霉产纤维素酶的固态发酵条件进行研究,显示其最优产酶条件为:稻草:麸皮=3:2,水分250%,最佳氮源为0.5%(NH4)2SO4,最佳培养时间3天,温度30℃,接种量10%,初始pH6.0~7.0,在此条件下,每克干曲酶活分别高达18.4FPAU/g,56.7CMCU/g。同时对酶解作用条件进行了初步研究,发现pH5.2时对滤纸酶活力最高,pH4.8时对脱脂棉活力最高。降解温度以滤纸55℃,脱脂棉50℃为最佳。实验还发现乙醇对酶的降解有抑制作用。 相似文献
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pH控制下绿色木霉(Trichoderma viride)流加发酵生产纤维素酶 总被引:1,自引:0,他引:1
绿色木霉(Trichodermaviride)在pH控制发酵条件下,采用流加葡萄糖发酵策略,可显著提高综合滤纸酶活力(FPA)和内切酶(endo—β—1,4-glucanase,EG)、外切酶exo—β-1,4-glucanase,CBH)、纤维二糖酶(cellobiase,CB)酶活。在5L发酵罐中采用pH控制和流加葡萄糖工艺,可提高CB酶含量,改变酶组分之间的比例,使得FPA、EG、CB和CBH酶活分别达到50.0U/mL,210.0U/mL,4.0U/mL和2.5U/mL,比摇瓶发酵分别提高了6.7.4.2、19、2.5倍。 相似文献
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利用实验室现有的纤维素酶高产菌株制备纤维素酶。考察了JFY-14菌株产酶培养过程中pH值、培养时间、氮源等条件的影响。得到了最佳产纤维素酶条件:培养时间为72~75 h,初始pH值为4.5~5.0以及最佳培养氮源为1%的硫酸铵。 相似文献
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绿色木霉代谢产物的植物毒性研究 总被引:5,自引:0,他引:5
通过人工固体培养和液体发酵研究发现绿色木霉的代谢产物对植物的幼苗生长有抑制作用,其代谢产物大量分泌到它所生长的环境中,在不同的营养基质中其代谢产物的抑制作用有差异. 相似文献
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Lalitha Pappu 《Archives Of Phytopathology And Plant Protection》2013,46(9-10):505-529
AbstractA process has been disclosed in the present investigation for the production of a formulation of mycopesticide with enhanced shelf life of Trichoderma viride. A comparative evaluation of talc-based and corn cob formulations in the form of seed coat and soil treatment brought to light that the soil treatment significantly enhanced the plant growth performance of pea, green gram and pigeon pea. Among the two formulations, the corn cob formulation proved to be better as the rhizosphere competence of corn cob formulation was superior to that of talc formulation. Our results suggest that corn cob residue is a better substrate owing to high cellulase and spore production. Solid-state fermentation in batch cultures. The biocontrol ability of both formulations was tested against Fusarium in Cajanus species and it was found that the disease incidence was reduced by 86% when the corn cob formulation was given as soil application. 相似文献
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The transport of radioactively labelled uracil into submerged mycelium of T. viride was measured by means of a membrane filtration technique. It was found to be time-dependent (up to 90 min) and concentration-dependent (up to 8 mmol l-1). Its concentration dependence was biphasic and consisted from the saturatable part (at the uracil concentration below 0.2 mmol l-1) with KM = 0.08 +/- 0.02 mmol l-1 and Vmax = 1.74 +/- 0.3 nmol (mg dry wt.)-1 h-1, and from the region at higher uracil concentration which showed only a weak saturatability with the substrate. The transport measured in the saturatable part of the curve was also pH- and temperature-dependent. The optimal pH was between 5.4 and 6.4 and the optimal temperature was at 37 degrees C. The activation energy of 54 kJ mol-1 and the temperature quotient of Q10 = 2.1 could be calculated from the temperature dependence. The entry of uracil was in part inhibited by nucleobases and their analogues, nucleosides, nucleotides and amino acids. The inhibitors had similar inhibitory efficiency about 50% at 0.2 mmol l-1. 3,3',4',5-tetrachlorosalicylanilide (TCS), the uncoupling agent, significantly inhibited the uracil transport, but its inhibitory efficiency decreased upon increasing the uracil concentration. Ionophore antibiotics valinomycin and monensin also inhibited the uracil transport. Inhibitors of RNA-polymerase, rifamycin and rifampicin were without effect. The results suggest that at low uracil concentrations (below 0.2 mmol l-1), its transport is mediated by a carrier and is driven by the electrochemical potential of protons. At higher uracil concentrations, the transport may be driven by the concentration difference of uracil with the contribution of the protonmotive force. It is feasible that inhibitors of uracil transport tested exert their inhibition by the dissipation of the driving force rather than by the direct competition with the substrate-binding site. 相似文献
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From in vitro and in vivo screening tests for antagonism by isolates of Trichoderma against postharvest pathogens of yams (Dioscorea spp.), an isolate of Trichoderma viride Pers. ex S.F. Gray was selected as the most promising candidate for the biocontrol of postharvest rot of yams. Inoculation of white yam (Dioscorea rotundata Poir.) with conidiaspores of T. viride and subsequent storage of the tubers under the ambient environment conditions of a traditional yam barn, resulted in a drastic reduction in the frequency of occurrence of the normal tuber surface mycoflora over a 4‐month (December‐April) storage period. Trichoderma viride on the other hand, maintained a high frequency of occurrence during the same period. Furthermore, whereas up to 52.0%) rot was found among groups of tubers that were artificially inoculated with the postharvest pathogens of yams, Aspergillus niger Van Tiegh., Botryodiplodia theobromae Pat. or Penicillium oxalicum Currie and Thom, and also the group that was not inoculated with any organism (control), among groups of tubers that were inoculated with T. viride the rot was either totally suppressed or only a low percentage of rot occurred. The significance of the findings is discussed in relation to yam storage especially by farmers with limited resources. 相似文献