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1.
从自然环境中分离、筛选出了降解橡Wan单宁能力较强的菌株,并对该菌株降解单宁的培养条件进行分析,结果表明,28-32℃、pH4.5培养8d为橡Wan单宁的最适降解条件。在此条件下,对此菌株驯化,有效提高了该菌株的耐单宁性及单宁降解率。通过研究外加碳源、氮源及碳氮比对该菌株降解单宁的影响,发现这3个因素均明显影响微生物对单宁的降解。在适宜的培养条件下,该降解菌在以葡萄糖为外加碳源,以硝酸铵为氮源,碳氮比为10:1的条件下,单宁的降解率最高,并发现在一定范围内,碳氮比高有利于菌株降解单宁,而碳氮化低则不利于单定的降解。  相似文献   

2.
产单宁酶真菌的筛选及产酶条件   总被引:2,自引:0,他引:2  
从铁冬青等4种植物的新鲜茎、叶组织中分离得到52株真菌,经平板透明圈法初筛得到18株产单宁酶菌株。初筛所得菌株经液体发酵,显示1株木霉属真菌(Trichoderma viride)(No.MYP07)酶活力最高,达0.248 μmol/(min·mL)。采用单因素结合正交实验,得到菌株MYP07的最佳发酵条件为:单宁100 g/L,蔗糖10 g/L,(NH4)2SO4 3 g/L,装液量为30 mL(250 mL锥形瓶),起始pH为5.0,温度30 ℃,转速140 r/min。在此条件下,菌株MY-P-07发酵48 h酶活力达到0392 μmol/(min·mL)。  相似文献   

3.
对粗状假丝酵母(Candida valida)产胞外脂肪酶的培养基成分和培养条件进行了优化研究.结果表明,最佳培养基组成:10 g/L葡萄糖 20 g/L橄榄油,6 g/L酵母膏 4 g/L蛋白胨,K2HPO4:2 g/L,MgSO4:2 g/L,初始pH值为7.5,培养温度为30℃,装液量为30 mL/250 mL三角瓶,接种量为1%,180 r/min摇床培养48 h,培养液酶活高达16.36 U/mL.  相似文献   

4.
张岩  吴丹  徐海洋  徐淋香 《广西科学》2021,28(6):599-606
为提高海洋细菌THN1产右旋糖酐酶的能力,本研究利用单因素试验和响应面试验对菌株THN1的发酵条件进行优化,并探究菌株THN1右旋糖酐酶的酶学性质。优化结果表明,菌株THN1的最佳产酶条件为麸皮5 g/L、胰蛋白胨20 g/L、NaCl 10 g/L、右旋糖酐T20 5 g/L,陈海水配置,pH值为8.2,30℃培养24 h。在此条件下,菌株THN1的发酵液酶活力达到3.71 U/mL,是优化前(初始酶活力为0.12 U/mL)的31倍。酶学性质分析表明,右旋糖酐酶的最适反应温度为40℃,在30℃条件下放置5 h酶活力基本保持稳定;最适反应pH值为7.5,在pH值为5.0-9.0的条件下相对酶活力能保持50%以上。本研究成果可为缩短右旋糖酐酶生产周期和降低成本提供数据支撑,并认为菌株THN1右旋糖酐酶在口腔护理方面具有良好的应用潜力。  相似文献   

5.
选育一株链霉菌Streptomyces 2036,能将阿魏酸转化为香草酸。通过培养基和发酵条件的优化,确定较适培养条件为:葡萄糖5g/L,酵母粉5g/L;最佳发酵条件为:pH5.0,摇瓶装液量50mL/250mL,转速130r/min,发酵温度30℃。在该条件下,链霉菌可在转接培养16h后添加阿魏酸溶液,经12h可将1g/L的底物阿魏酸转化为0.261g/L的香草酸,摩尔转化率为30.2%。  相似文献   

6.
从昆明某磷矿土壤中筛选出一株产木聚糖酶能力较强的菌株——MS12,通过单因素试验初步优化了该菌株的产酶条件.试验结果显示,该菌株最佳产酶培养基为玉米芯粉50 g/L、麸皮40 g/L、NH_4Cl 10 g/L、CaCl_2 5 g/L、NaHPO_42 g/L,pH自然;最佳产酶发酵条件为30℃,180 r/min,装样量30 mL/250 mL三角瓶,震荡培养96 h.经测定,菌株MS12所产木聚糖酶的最适反应温度为65℃,最适反应pH值为7.0,具有较好的pH稳定性. 1 mmol/L Na~+、Ba~(2+)和10 mmol/L Ca~(2+)、Mg~(2+)对酶活有促进作用,Ag~+对酶活有明显的抑制作用.  相似文献   

7.
通过对青霉菌产漆酶条件的优化,提高酶活,将其应用于生物制浆中。采用单因素对产酶条件进行研究,同时考察了漆酶的酶学性质。研究结果表明最佳培养条件为:麦麸16 g/L,酵母膏2 g/L,Al3+0.6 g/L,KH2PO43 g/L,30℃,pH 6.0摇瓶培养192 h。优化后漆酶的酶活提高了12.34倍。经过酶学性质的研究得出该酶的最适反应温度为30℃,而热稳定性为20~40℃,pH稳定性为3.6~4.0。  相似文献   

8.
重组毕赤酵母体系生成PlUGT1蛋白适宜条件研究   总被引:1,自引:0,他引:1  
通过单因素试验分别研究pH值和温度对重组毕赤酵母GS115/pPIZA-PlUGT1生长以及甲醇浓度、pH值和温度对诱导表达PlUGT1蛋白的影响.结果表明,pH6.5和30 ℃是培养重组毕赤酵母GS115/pPIZA-PlUGT1最佳的生长条件,重组毕赤酵母GS115/pPIZA-PlUGT1诱导表达蛋白的适宜条件为甲醇体积分数0.5%、30 ℃和pH5.0,该条件下培养72 h,培养液中的蛋白质量浓度为0.721mg/mL.  相似文献   

9.
产脂肪酶假丝酵母的筛选及其研究   总被引:5,自引:0,他引:5  
从武汉油污样中分离获得一株高产脂肪酶酶的假丝酵母R-2.发酵研究表明,最适培养基为蛋白胨20g/L,蔗糖10g/L,橄榄油5g/L,(NH4)2SO41g/L,MgSO4.7H2O1g/L,K2HPOR1g/L和吐温-801g/L,最适产酶条件为30℃,初始pH7.0,转速200r/min,培养32h ,最高产酶活力达到1437u/mL,酶作用最适温度40℃,最适pH7.5。  相似文献   

10.
以安琪活性干酵母为出发菌种,分析了培养基初始硒浓度、接种量、装液量、温度、初始pH以及转速等发酵条件对酵母生物量及富硒量的影响,并通过正交试验设计初步确定了培养的最优方案.在最佳的摇瓶培养条件下(初始硒浓度25μg/mL,接种量10%,装液量60/250 mL,温度30℃,初始pH 5.0,摇床转速160 r/min,培养40 h后),该活性干酵母的生物量及富硒量分别达到9.89 g/L、954 μg/g.  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.
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   

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.
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.
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   

19.
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   

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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