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1.
高产纤维素酶菌株的筛选及产酶条件研究   总被引:39,自引:5,他引:39  
从霉变的玉米芯中筛选到一株高产纤维素酶的菌株,经18S rRNA基因序列分析和菌株形态特性分析,确定该菌株为灰绿曲霉(Aspergillus glaucus).利用固体纤曲培养产生纤维素酶,研究了培养基起始pH值、培养温度、培养时间、接种量、氮源、稻草粉与麸皮比例、表面活性剂等对菌株产酶的影响.在最适条件下菌株培养72h后,羧甲基纤维素酶(CMCase)活力高达6812U/g(干曲.下同),滤纸酶活力(FPA)达172U/g.利用该菌株对蔗渣进行分解.其糖化率达36.4%.  相似文献   

2.
纤维素酶产生菌的筛选及其固态发酵初步研究   总被引:5,自引:0,他引:5  
用预处理的天然纤维素为碳源,从土壤中定向筛选出8株产纤维素酶能力较强的真菌,选取其中CMC糖化力(CMCase)和滤纸糖化力(FPA)均较高的JZ-H进行固态发酵实验,初步研究发现:该菌以杂草为碳源、(NH4)2SO4和蛋白胨为氮源、500mL三角瓶装干料10g、自然pH、30℃培养72h,发酵物的CMCase达128.5IU/g,FPA达75.8U/g。  相似文献   

3.
一株纤维素酶产生菌的固态发酵初步研究   总被引:2,自引:0,他引:2  
用预处理的天然纤维素为碳源,从土壤中筛选出8株产纤维素酶能力较强的真菌,选取其中CMC糖化力(CMCase)和滤纸糖化力(FPA)均较高的JZ—H进行固态发酵实验,初步研究表明,该菌以杂草为碳源,(NH4)2S04和蛋白胨为氮源,500mL三角瓶装干料10g,自然pH,30℃培养96h,发酵物的CMcase达128.5IU/g,FPA达75.8U/g,蛋白质增加13.5%.  相似文献   

4.
一株耐高温纤维素降解菌的分离筛选及鉴定   总被引:1,自引:0,他引:1  
为了分离筛选耐高温的纤维素高效降解菌,从鸡粪蘑菇渣高温堆肥中取样,采用滤纸富集培养基进行富集培养、刚果红纤维素培养基进行分离纯化培养、滤纸条培养基和刚果红纤维素培养基进行初筛培养、液体发酵测定纤维素酶活法进行复筛培养,利用形态特征观察、生理生化特征检测和基于16S rRNA基因序列的系统发育分析法进行初步鉴定,结果分离筛选到1株耐高温纤维素降解菌XD-3.该菌株在50 ℃生长良好、羧甲基纤维素酶(CMCase)活力达6.14±0.37 U/mL.综合形态特征、生理生化特性、基于16S rRNA基因序列的系统发育分析,菌株XD-3初步鉴定为解淀粉芽孢杆菌(Bacillus amyloliquefaciens).  相似文献   

5.
研究了碱性纤维素酶生产菌株镰刀霉菌(Fusarum Sp.)的产酶条件.结果表明:该菌株产碱性纤维素酶的适宜碳源为1%麦杆粉+1%可溶性淀粉,最适氮源为O.2%的(NH_4)_2SO_4加0.1%的酵母粉,接种量为5%,培养时间为72 h,培养温度为46℃,培养基初始pH为8.0.在最适宜的条件下,培养液中内切葡聚糖酶活力可达到1.29 IU/mL,而天然纤维素酶活力和滤纸酶活力却很低.具有这种组分结构的碱性纤维素酶系统在棉织品的生物整理及洗涤剂工业中具有良好的应用前景.  相似文献   

6.
产纤维素酶的解淀粉芽孢杆菌分离鉴定及酶学性质研究   总被引:1,自引:0,他引:1  
对一株产纤维素酶菌株进行分离鉴定,并对其酶学特性进行了初步研究.刚果红染色法筛选产纤维素酶菌株B16,采用形态观察、生理生化指标和16S rDNA确定其菌属来源,分析纤维素酶的最适反应pH值和温度、酸碱和热稳定性、金属离子对酶活性的影响,最后考察纤维素酶系的分布.结果表明:筛选菌株为解淀粉芽孢杆菌,其较适反应温度为30℃,较适pH 8.0,在10~60℃呈高稳定性,在pH 5~8时稳定性较强,Mn2+和Ba2+是该酶的激活因子.除微晶纤维素酶活力(16.39 U/mL)稍弱外,滤纸酶(70.37 U/mL)、β-葡萄糖苷酶(131.55 U/mL)、羧甲基纤维素酶(307.23 U/mL)活力均相对较高.结果表明,该酶在饲料添加剂方面具有应用潜力.  相似文献   

7.
纤维素分解菌——青霉和放线菌的分离选育研究   总被引:1,自引:0,他引:1  
在平凉县的一蘑菇房里采集了用来种植蘑菇的潮湿木屑粉.用纤维素刚果红鉴别培养基初筛,根据水解圈与菌落直径之比大小和水解圈清晰度分离筛选出较多的产纤维素酶菌株,进一步通过测纤维素酶活力复筛,最终筛选出滤纸酶活力和羧甲基纤维素酶活力同时都较高的菌株2株,分别是27-3F (FPA:199.12U,CMCase activity:1181U)和27-1A(FPA:110.54U,CMCase activity:908.2U).经形态学鉴定菌株27-3F是青霉。菌株27-1A是为放线菌的链霉菌属.  相似文献   

8.
为得到降解纤维素能力较强的细菌,以腐殖土壤为菌株来源筛选、分离纤维素降解细菌。对所取土样稀释一定比例进行涂布平板,以羧甲基纤维素钠(CMC-Na)为唯一碳源培养,用刚果红染色的方法筛选有透明圈的菌株,得到一株编号为YBX-52的纤维素降解细菌。在产酶培养基中以30 ℃培养48 h,用DNS法测得滤纸酶活力(FPA)为221.75 μmol/min、羧甲基纤维素酶活力(CMC)为274.56 μmol/min。以16 SrDNA通过序列对比,构建YBX-52系统发育树,结合其生理生化特征将其鉴定为苏云金芽孢杆菌(Bacillus thuringiensis)。  相似文献   

9.
为了研制高效生物增温剂和生产高温纤维酶制剂,试验采用CMC培养基和发酵培养基,从猪粪和麦秸秆自然堆肥中分离出高温纤维素分解菌,测定羧甲基纤维素酶活(CMCase)和滤纸酶活(FPase)并对分离到的菌株进行18S rRNA基因分析.结果表明HZ2菌株CMCase,Fpase都较高,通过18S rDNA序列分析发现HZ2...  相似文献   

10.
康宁木霉液态发酵高产纤维素酶和木聚糖酶的研究   总被引:2,自引:0,他引:2  
对选育的一株康宁木霉(Trichoderma koningii)QF-02进行了液态发酵生产纤维素酶和木聚糖酶的研究。实验结果表明:碳源的种类及性质是影响产酶的关键因素,价廉易得的天然稻草是其产酶的良好碳源。在培养基组成为40目稻草粉4g、Mandels营养液100mL、起始pH值4.8的优化培养条件下,摇瓶培养120h所得3种酶的平均活力分别为:滤纸酶活(FPA)1.43IU/mL, β-葡萄糖苷酶活0.36IU/mL, 木聚糖酶活176.8IU/mL。与商品纤维素酶制剂相比,在FPA载量相同(3FPU/g原料)的情况下,自制的复合酶在水解碱预处理稻草和天然稻草时,总还原糖产量比商品纤维素酶提高55%和40%,葡萄糖产量提高33%和12%。研究结果还表明木聚糖酶和纤维素酶具有协同酶解木质纤维素的作用。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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