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1.
木聚糖酶高产微生物的筛选和鉴定   总被引:12,自引:2,他引:12  
利用蔗渣木聚糖为惟一碳源,从甘蔗根部泥土样口中分离得到一株产木聚糖酶活力较高的菌株,经形态、生理及生化鉴定,初步确定为蜂房芽孢杆菌;同时研究了碳源、氮源对该菌产木聚糖酶的影响。结果表明,其最适碳源为木聚糖,最适氮源为酵母浸膏和硝酸铵的混合氮源;在装料100mL的250mL三角摇瓶中于32℃、120rpm振荡培养40-44h后,发酵液中木聚糖酶活力高达3839.5Iu/mL,具有工业开发前景。  相似文献   

2.
对产β-1,3-葡聚糖酶小麦内生多黏类芽孢杆菌(Paenibacillus Polymyxa)hu-4的产酶工艺进行了研究,通过正交实验建立和优化了hu-4菌株的发酵产酶培养基,确立了最佳发酵工艺.结果表明,以蛋白胨1.8%,酵母膏0.6%,玉米浆1.2%,酵母葡聚糖0.5%,矿质元素混合溶液0.5%为其最佳发酵培养基构成,pH值7.0;在温度32℃,转速200r/min,接种量2%的工艺条件下,发酵周期为36~38h,产酶效果较好.  相似文献   

3.
通过唯一碳源法从来源于长白山森林的土壤中筛选到多株具有纤维素降解活力的细菌,选取其中的1株芽孢杆菌DS1309进行了鉴定及发酵条件的初步优化,结果显示该菌株为地衣芽孢杆菌(Bacillus licheniformis)。发酵产酶的最适条件为培养温度30℃,培养基初始p H6.0,最适碳源为葡萄糖,最适碳源为酵母粉。菌株在最适条件下培养48h达到产酶高峰,酶活力可达到1.82 IU/m L。  相似文献   

4.
以豆粕为原料固态发酵产纳豆激酶工艺的优化   总被引:1,自引:0,他引:1  
以食品级豆粕为唯一培养基成分,通过纳豆芽孢杆菌固态发酵产纳豆激酶的培养基的优化实验,确定优化条件为:接种量5%,装量为40g于250 mL锥形瓶,培养基含水量60%,浸泡水pH 7.5,发酵温度37℃.在培养24h后达到产酶高峰,产酶活力达到1 662 FU/g.比较了在相同的发酵条件下,以食品级豆粕为培养基比大豆为培...  相似文献   

5.
该文对一株巨大芽孢杆菌产胞外青霉素酰化酶的发酵条件下进行了初步研究。不同的氮源及装液量和发酵时间产酶均有影响。该菌株在27-28℃180r/min,初始PH8.0,苯乙酸浓度0.6%的最佳发酵条件下发酵60h左右,青霉素酰化酶活力可达500-700U/100ml。  相似文献   

6.
从奶粉中分离到一株同型乳酸发酵杆菌,编号TQ33,主要特点:产生芽孢,生长温度范围(20~63)℃,最适生长温度(45~50)℃,接触酶试验阳性,通气条件下生长良好,厌氧条件下发酵葡萄糖产酸不产气,主要产L(+)乳酸,菌体(G+C)为(32.45)%,生理生化性质特殊,据以上特点,将TQ33菌株鉴定为凝结芽孢杆菌(Bacilluscoagulans),LD_(50)试验表明,菌体和代谢产物属无毒物质。  相似文献   

7.
抗植物软腐病枯草芽孢杆菌的高密度发酵优化   总被引:1,自引:0,他引:1       下载免费PDF全文
为提高菌体产量,以益生菌枯草芽孢杆菌Asr作为发酵菌株,采用正交试验法和响应面法,对枯草芽孢杆菌Asr的发酵工艺进行了优化研究。结果表明,影响菌体产量最主要的3个因素为酵母浸粉、MgSO4和CaCl2;最佳发酵培养基配方为蔗糖20 g/L,蛋白胨10 g/L,酵母浸粉8.65 g/L,K2HPO4 3.0 g/L,MgSO4 0.27 g/L,CaCl2 0.53 g/L;最佳培养条件为温度37 ℃、初始pH值7.0、接种量10%、搅拌转速250 r/min;应用优化配方及工艺,枯草芽孢杆菌Asr的最高产量达到7.30×108 cfu/mL,菌体产量较优化前提高了3.95倍。研究结果可为后续菌体发酵罐的扩大培养提供技术支撑,对其他枯草芽孢杆菌发酵培养基的优化研究提供借鉴。  相似文献   

8.
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   

9.
对枯草芽孢杆菌发酵海带的条件进行优化,并以此发酵海带饲养刺参,结果表明,枯草芽孢杆菌发酵海带的优化条件为发酵温度30 ℃、适宜发酵时间96 h、接种剂量12%,发酵后海带的粗蛋白含量为14.65%,相对提高了15.17%。在36 d饲养时间内,实验组在刺参的配合饲料中添加了30%的发酵海带,刺参特定生长率、溶菌酶活性、超氧化物歧化酶活性、酸性磷酸酶活性、蛋白酶活性和淀粉酶活性皆有显著提高(P<0.05),但是,刺参体腔液细胞数量、纤维素酶活性皆无显著变化(P>0.05),此外,刺参摄食发酵海带还导致其消化道异养菌总数减少、弧菌相对数量降低、芽孢杆菌相对数量升高。由此可见,投饲枯草芽孢杆菌发酵海带能够促进刺参生长,提高消化酶活性和免疫力,调节肠道菌群结构。  相似文献   

10.
为进一步提高短小芽孢杆菌LDS33液态发酵产抗凝溶栓双活性物质的能力,采用单因素筛选法和正交筛选法对其进行优化.结果显示,短小芽孢杆菌LDS33产抗凝溶栓双活性物质的最佳发酵条件为温度26℃,初始pH值8.5,培养时间8d,最佳接种条件为接种时间2d,接种量6%,安琪酵母浓度0.4%.实验表明,短小芽孢杆菌LDS33对生长条件要求不高,容易培养,抗凝溶栓双活性物质产量较高.  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.
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   

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