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1.
分离纯化了在发酵生产中常见菌株的α-淀粉酶及中性蛋白酶,并对其相互作用进行了研究。结果发现,解淀粉芽孢杆菌BF所产的中性蛋白酶,对α-淀粉酶的失活作用强于其它菌株,黑曲霉uv-11所产α-淀粉酶对中性蛋白酶较其它菌株敏感,细菌中性蛋白酶对霉菌胞外酶的水解作用强于细菌之间的相互作用。  相似文献   

2.
地衣芽孢杆菌α-乙酰乳酸脱羧酶的纯化及酶学性质   总被引:3,自引:0,他引:3  
地衣芽孢杆菌(Bacillus licheni formis)AS10106α-乙酰乳酸脱酸酶经硫酸沉淀,聚乙二醇沉淀,DEAE-Sepharose Fast Flow离子交换,Gigapite K-100S柱层及SephadexG-100分子凝胶过滤柱等分离纯化步骤,得到SDS-PAGE电泳纯,α-乙酰乳酸脱羧酶的比活提高了53.5倍。对该酶性质的研究表明,酶单亚基分子量为32Kda,等电点为4.5;该酶的最适反应温度为40℃,最适反应pH为6.0,对热(40℃以上)敏感。在pH5.0-6.5之间稳定。酶活不需要金属阳离子,Cu^2 、Co^2 强烈抑制酶的活性。摇瓶实验表明,纯化的地衣芽孢杆菌α-乙酰乳酸脱羧酶能明显降低双乙酰的形成并缩短其还原时间。  相似文献   

3.
普洱茶渥堆发酵过程中嗜热细菌的分离和鉴定   总被引:2,自引:0,他引:2  
对普洱茶发酵全过程的茶样进行了pH检测,发现在渥堆过程中pH在前期有所下降达到4.5,中期基本趋于稳定,后期又有所回升。根据渥堆过程中高温和偏酸性的特征,采用传统培养与分子生物学方法相结合,对全过程的茶样在高温条件下进行细菌的分离、纯化及鉴定。结果发 现有大量嗜热细菌的存在,包括凝结芽孢杆菌 Bacillus coagulans,枯草芽孢杆菌 Bacillus- subtilis,地衣芽孢杆菌 Bacillus licheniformis,热嗜淀粉芽孢杆菌 Bacillus thermoamylovorans,Bacillus shackletoni,喜热噬油芽胞杆菌 Geobacillus thermoleovorans,乳酸片球菌 Pediococcus acidilactici,植物乳杆菌 Lactobacillus plantarum,等。这些嗜热细菌和嗜热真菌一起在普洱茶的发酵中起到了关键作用。  相似文献   

4.
地衣芽孢杆菌NK-27菌株可以产生胞外β-甘露聚糖酶和胞内β-甘露糖苷酶。β-甘露糖苷酶活力主要集中于细胞匀浆液中。以2.0%魔芋粉、1.0%(NH4)2SO4为碳、氮源地衣芽孢杆菌NK-27菌株经30℃振荡培养20-24h产生β-甘露糖苷酶酶活力最高。该酶于30-40℃、pH6.0时酶活力最高,在30-40℃、pH5.4-7.0酶稳定性较好。  相似文献   

5.
高温α-淀粉酶产生菌株的选育   总被引:18,自引:0,他引:18  
从西藏当雄温泉附近的土壤中,分离到一株能在55℃生长并分泌高温α-淀粉酶的菌株,经初步鉴定为凝结芽孢杆菌,命名为Bacillus coagulans LS-1。该菌株用紫外线和亚硝基胍诱变,在55℃摇瓶培养条件下,筛选到一个发酵液酶活达到100U/mL的突变株,较出发菌株的酶活提高了约25倍,发酵液经90℃处理60min,酶活性保持在90%以上。  相似文献   

6.
BT—37是从土壤中分离出的一株对多种鳞翅目昆虫有较高毒力的苏芸金芽孢杆菌。在PB培养基中振荡培养,蛋白酶活性随着细胞的生长而增强,培养36小时,芽孢晶体开始脱落时达到高峰。所产蛋白酶为中性蛋白酶。酶作用的最适条件:最适温度为50℃,60℃保温1.5小时酶活性降低70%;最适pH7.0;在pH6.0℃—10.6范围内稳定。1.5×10~3M时,Mn~+显著提高酶活。在蛋白酶活性高的培养基中获得了较高毒力的培养物。  相似文献   

7.
β-甘露聚糖酶菌株的复合诱变选育及发酵条件的优化   总被引:8,自引:0,他引:8  
利用离子注入和紫外线复合诱变,筛选到了一株产β-甘露聚糖酶的优良枯草芽孢杆菌(Bacillus subtilis)M-66,作者采用“系统全面反馈实验优化技术”优化了发酵条件,并使其发酵液酶活从出发菌株M-1的37.03U/mL提高到优化后的150.12U/mL。  相似文献   

8.
为构建1株产中性蛋白酶的工程菌株并对其发酵条件进行优化,以中性蛋白酶工业生产菌株枯草芽孢杆菌AS1.398的基因组为模板,采用PCR技术扩增获得中性蛋白酶基因npr,与高拷贝质粒pWB980连接并转入蛋白酶缺陷型菌株枯草芽孢杆菌WB600中得到重组工程菌WB600/pWB980-npr.在初筛平板上工程菌蛋白酶活力明显高于工业生产菌AS1.398,工程菌发酵活力可达1,398.3,U/mL.通过对其发酵工艺进一步优化,在接种量5%、装液量100,mL/500,mL、摇床转速180,r/min、温度34,℃的条件下发酵48,h,发酵液的酶活力可达2,487.5,U/mL,比优化前提高了78%.  相似文献   

9.
苏云金芽孢杆菌发酵技术研究进展   总被引:1,自引:0,他引:1  
苏云金芽孢杆菌(Bacillus thuringiensis简称Bt)是目前产销量最大的生物农药,其发酵过程是工业生产的关键步骤,本文对培养基成份,pH值、氧气、温度、发酵时间等发酵条件进行了综述,参考文献28篇。  相似文献   

10.
咖啡发酵过程中微生物种类、数量的变化及它们的代谢产物如酸等引起的发酵体系变化将直接影响着咖啡的最终品质。本文首次对云南小粒咖啡湿法发酵体系中的pH值和8种有机酸的含量变化进行了测定,并分离和鉴定了发酵过程中的细菌种类。结果发现在整个发酵过程中,pH值变化整体呈下降趋势;本文所测pH值变化与利用HPLC法检测的有机酸草酸、乙酸、乳酸含量变化规律相吻合,而苹果酸、柠檬酸、琥珀酸和丙酸基本上保持不变,其中丙酸含量最低。在20℃下,结合发酵过程中的pH值,采用传统的微生物培养法,对整个发酵过程的细菌进行了分离、纯化和鉴定。结果发现存在大量的产果胶酶的细菌,包括产气肠杆菌Enterobacter aerogenes、肠膜明串珠菌Leuconostoc mesenteroides、枯草芽孢杆菌Bacillus subtilis、蜡样芽孢杆菌Bacillus cereus、巨大芽孢杆菌Bacillus megaterium,冰核活性细菌Erwinia herbicola、肺炎克雷伯菌Klebsiella pneumoniae等,并对分离、鉴定出来的细菌在发酵中所起的作用进行了剖析。  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.
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   

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 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   

15.
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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