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1.
菌株乃从土壤中筛选得到,具有产生转糖基β-半乳糖苷酶(β-galactosidase)的特性。根据形态观察及18S rDNA序列分析;菌株乃被鉴定为扩张青霉(Penicillumexpansum)。通过单因子试验和正交试验,对菌株乃产生转糖基阻半乳糖苷酶的培养基组成及发酵条件进行了优化。优化后的培养基组成为葡萄糖2%、酵母粉1%、蛋白胨1.5%、氯化钠0.3%。在初始pH6.0,28℃培养40h时,其产酶量为2245.2U/L,比优化前提高约3倍。菌株乃产生的转糖基肛半乳糖苷酶以pH4.5缓冲液配制的30%乳糖为底物,50℃反应24h,低聚半乳糖产量为30.6%,其中80%以上为三糖。  相似文献   

2.
胶韧革菌Goleostereum incarnatum发酵产物对人体六种人细菌具有较强的抑制作用,已做过报道,采用编号为8903菌侏对该菌株的最适深层培养条件进行了研究,测定和比较了菌丝和胶韧革菌素的产量。  相似文献   

3.
实验以丝状真菌为出发菌株,采用玉米水解液为培养基质进行深层发酵培养,探索了不同糖度、氮源、温度、pH值和发酵时间等参数对丝状真菌产油脂的影响。实验确定最佳工艺参数为:玉米水解液13°Bx,2.4%NaNO3为氮源,3%玉米浆,pH值为5.5,26℃下发酵培养61h,油脂得率13.69%,菌体生物量19.45g/L。微生物油脂中主要含有16碳和18碳系脂肪酸,利用气相色谱法分析微生物油脂的脂肪酸组成如下:棕榈酸(17.16%),棕榈油酸(1.63%),硬脂酸(1.87%),油酸(58.37%),γ-亚麻酸(12.44%),α-亚麻酸(6.22%)。  相似文献   

4.
从油田污泥中分离到两株能有效降解石油烃的革兰氏染色阴性,好氧细菌。x-1菌株,呈粗杆状(1.0~1.2)×(2.2~3.7μm),两端圆,主要成连也有成对,周生鞭毛。x-3呈短粗杆状(1.0~1.3)×(1.6~3.4μm),两端圆,成对或成短连,也有单个。经初步鉴定均为无色杆菌属(Achromobacter sp.)。研究了影响菌株降油能力的主要影响因素,并确定两种菌株的适宜降油条件,其中x-1菌株在35℃,pH7.5和油浓度5000mg/L的条件下以及x-3菌株在25℃,pH7.5和油浓度1000mg/L的条件下具有较好的石油降解能力。  相似文献   

5.
产生优质脂肪酶的铜绿假单孢菌JEP-606菌株的培养成分(质量分数)为大豆1.5%,玉米浸出液3.0%,葡萄糖0.5%,橄榄油0.75%,当菌株液体培养时,细胞直径约0.4μm,长1.5~3.5μm,革兰氏阴性,产生蓝绿色素.提高菌株脂肪酶活性和生物量的培养条件是:初始pH7.0~9.0,28℃,150r/min,培养时间60~140h,装液量25mL(250mL三角瓶)和0.75%橄榄油.  相似文献   

6.
结合发酵工程实验教学改革,将实验室收集保存的产柠檬酸菌株11株,进行初筛、复筛后,选取产酸量相对较高的2112菌株进行了正交实验、稳定性实验。得到的较好发酵条件为:玉米淀粉16%,(NH4)2SO40.1%,麸皮0.6%,pH4.0。发酵温度35℃,发酵时间96h。经5次稳定性实验,该菌株产酸率最高达9.92%,已能满足实验教学的需要,为开展柠檬酸发酵系列实验提供了保证。  相似文献   

7.
研究了碳源、氮源、接种量、培养时间、培养温度、培养基初始pH等条件对产中性纤维素酶真菌菌株瓶霉菌(Phialophora sp.z8)产酶的影响.结果表明:该菌株产中性纤维素酶的适宜碳源为1%稻草粉加1%可溶性淀粉,最适氮源为0.2%的(NH4)2SO4加0.1%的牛肉膏,接种量为5%,培养时间为72h,培养温度为28℃,培养基初始pH为6~7.在最适宜的条件下,培养液中内切葡聚糖酶活力可达到2.95IU/mL,而天然纤维素酶活力和滤纸酶活力却很低。  相似文献   

8.
在发酵培养基优化研究基础上,建立了海洋低温蛋白酶茼株(Bacillus subtilis简写为BS070623)发酵最适pH值、温度、时间、接种量、通气量分别为5.5、16℃、48h、8%、200ml/500ml;在上述最适发酵条件下,BS070623菌株5L发酵低温蛋白酶活性为1189.3U/mg。  相似文献   

9.
利用基因工程手段获得的产耐酸性高温弘淀粉酶基因枯草芽孢杆菌工程菌株pWB—amyd/WB600,通过单因素筛选及正交实验进行发酵培养基优化,得到的最佳配方为(g/L):玉米粉20,蛋白胨30,CaC120.5,Na2HP048.同时对实验室摇瓶条件下液体发酵的主要影响因素初始pH、接种量、装液量、转速、温度等进行探讨,确定了最佳培养条件:37℃、pH6.5、200r/min摇床培养36h,接种量为2%,装液量为30mL/250mL.在此优化条件下,耐酸性高温弘淀粉酶活力达到3980U/mL,是未优化条件下的2.1倍.  相似文献   

10.
平菇液体菌种发酵条件的研究   总被引:1,自引:0,他引:1  
对平菇液体菌种的碳氮营养需求及培养条件进行了研究.结果表明:黑平王(平菇)菌株能利用多种碳氮源,其中碳源以玉米粉为最好,有机氮优于无机氮,豆饼粉为最佳氮源.培养基最佳组合为玉米粉2%,豆饼粉1.5%,KH2PO4 0.15%,MgSO4 0.1%,pH6.最适培养条件为25℃,摇床转速140r/min,接种量8%,装液量为100mL发酵液/300mL三角瓶,发酵时间为4d.  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.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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   

16.
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   

17.
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   

18.
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   

19.
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   

20.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

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