产植酸酶菌株的筛选、诱变及酶学性质初探

从富含有机质的环境中采集土样,通过植酸钙平板透明圈法初筛和维生素C-硫酸-钼酸铵-酒石酸锑钾法测定植酸酶酶活复筛,共筛选到5株产植酸酶的霉菌,对这5株菌株进行紫外线和亚硝基胍复合诱变处理,最终获得一株高产植酸酶突变株NTG-506,酶活达到112 U/mL,比原始出发菌株的酶活提高了3.2倍.突变株NTG-506在250mL三角瓶中发酵培养,在装液量60 mL,接种量2%时,培养4 d后酶活达到最高,为124.5 U/mL.植酸酶的最适反应温度35℃,经50℃处理10 min后剩余酶活为原来的57%.     

固态发酵生产饲用β-葡萄糖酶的产业化技术研究

采用黑曲霉菌株An08-752,经曲盘、发酵床(帘子床)、厚层通风制曲池进行固态发酵,产业化生产饲用β-葡萄糖酶,结果表明:通风曲池厚层通风发酵培养30～32 h,产β-葡聚糖酶最高,发酵酶活力达到1.15×105μ/g;发酵床发酵培养时间35～37 h,产β-葡聚糖酶最高,发酵酶活力达到1.28×105μ/g;曲盘发酵培养32～34 h,产β-葡聚糖酶最高,发酵酶活力达到1.36×105μ/g.     

高产胞外植酸酶酵母菌的选育

从酒糟样品中筛选得到 5株胞外植酸酶活性较高的野生型酵母菌 ,其中 1 1酵母的酶活性最高 ,胞外植酸酶活为 16 .6 8U /mL .1 1菌株经单倍体分离 ,得到单倍体Sp1 1,胞外植酸梅活为 11.2 0U/mL .以Sp1 1为出发菌株 ,经过原生质体紫外诱变和EMS诱变 ,选育得到一稳定突变体Msp 382 6 ,胞外植酸酶活性为 2 6 .6 5U /mL ,较出发菌株提高了 138%.     

不同浓度血红蛋白对小鼠骨髓瘤细胞体外培养的影响

用含不同浓度的牛源性血红蛋白细胞培养液培养小鼠骨髓瘤细胞,通过细胞计数绘制生长曲线,计算最大增殖浓度和倍增时间,并进行比较分析.结果表明:当培养液的血红蛋白浓度在1~5 mg/dL时小鼠骨髓瘤细胞生长较好,细胞最大增殖浓度在1.2×106个/mL以上,倍增时间小于20 h,当培养液的血红蛋白浓度为6 mg/dL时细胞生长抑制,细胞最大增殖浓度和倍增时间为6.7×105个/mL和21.6 h.由此可见,培养液中血红蛋白浓度≤5 mg/dL时不影响细胞生长,达到6 mg/dL时抑制细胞生长.     

植酸酶可减少磷的需要量

过去的研究表明,在生长肥育猪日粮中添加微生物植酸酶可提高玉米—豆饼日粮中磷的有效性.Guelph大学L·G·Young等做了一项试验,评价在以有机磷为主的日粮中添加微生物植酸酶对断奶仔猪的影响.试验采用3种植酸酶浓度(每克日粮合O,500,1000植酸酶单位),一个植酸酶单位的酶量相当于在pH=5和37℃条件下每分钟从植酸钠中释放出1nmol无机磷酸,试猪约为5周龄,平均初重为10.2kg,试验为期3周,日粮微生物植酸酶的反应相当于添加0.13%来源于无机磷的日粮磷.     

植酸酶高产菌株的选育

从土壤中分离到1株植酸酶高产菌株Pe0,初步鉴定为米曲霉.为了提高植酸酶活力,对Pe0菌株分别进行紫外线和亚硝基胍诱变处理,经初筛、复筛、遗传稳定性能检测,得到1株酶活相对较高、性状相对稳定的菌株Pe2#,酶活稳定在10.66U/mL,较原始菌株提高到3.34倍.另对其发酵条件进行优化,确定最适接种量为4%,最适pH为5.5,最适培养时间为6.5d.在此基础上进行培养基正交优化,结果表明:葡萄糖质量浓度为25g/L,蛋白胨质量浓度为4g/L,(NH4)2SO4质量浓度为2g/L,MgSO4.7H2O质量浓度为0.1g/L时所得菌株产酶活力最高.     

绿色木霉产纤维素酶降解各种废纸效果研究

绿色木霉3.3744菌株所产纤维素酶对草稿纸、复印纸、滤纸、包装材料和新闻纸等五种类型废纸有不同的降解效果。结果表明:包装材料作为底物时的纤维素酶酶活始终较高,因而最终降解效果也最好,酶解4小时后酶活仍为2.72U/mL。就酶解速度来说,以新闻纸为底物时最高,在酶解1小时后酶活力即达2.52U/mL。液体培养所得纤维素酶活力在2～3天时间达到最高,其中以打印纸和新闻纸作为碳源时纤维素酶活力最高,在三天后分别达到4.31U/mL和3.64U/mL。     

密码子优化的植酸酶基因appA-P在毕赤酵母中的高效表达

根据毕赤酵母(Pichia pastoris)密码子使用偏爱性,对Escherichia coli来源的高比活植酸酶基因(appA)全面地进行密码子优化,人工合成了植酸酶基因(appA-P),并将该基因克隆到毕赤酵母诱导型分泌表达载体pHBM905A上,获得重组质粒pHBM905A-appA-P,通过PEG1000转化法将线性化的重组质粒转化毕赤酵母GS115菌株,筛选得到一个高效表达植酸酶的重组菌株GS115-appA-P,在25℃摇瓶培养168 h后酶活力达到422 U/mL,该植酸酶最适反应温度为60℃,最适反应pH为4.5,在20~50℃、pH1.0~6.0范围内较稳定.     

睾丸酮丛毛单胞菌降解胆固醇的培养条件研究

利用睾丸酮丛毛单胞菌(菌株c.test act5、菌株c.test tac、菌株c.test)具有消化甾醇这一特性,以胆固醇为底物筛选其降解甾醇的培养条件,使胆固醇降解酶的活力相对提高,从而为高效降解甾醇类物质的工程菌的筛选奠定基础.研究结果:最佳诱导时间14 h,培养基最佳pH7.0、最佳诱导温度30℃、及最佳装液量50 ml(250 ml摇瓶).在此条件下胆固醇降解酶活力:菌株c.test act5为3.82×10-3U.ml-1、菌株c.test tac为3.51×10-3U.ml-1、菌株c.test为2.68×10-3U.ml-1.     

产α-半乳糖苷酶乳酸菌的鉴定及其发酵性能研究

从传统乳制品中筛选到2株高产α-半乳糖苷酶的菌株,经菌株形态和生理生化特性鉴定以及16S rRNA基因序列分析,确定为发酵乳酸杆菌和长双歧杆菌,并命名为LB21和KLDS2.0509。同时研究了2株菌在豆乳中的酶活力、产酸性能、棉子糖降解能力和蛋白水解能力。菌株LB21和KLDS2.0509表现出不同的α-半乳糖苷酶活力,其最高酶活力分别为26.8U/mL和31.5U/mL,发酵终点pH分别为5.1和5.0,两者均能有效地降解棉子糖,蛋白水解能力随着发酵时间的增加而增强。     

Markedness and its Interpretation in Language Use

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Features of Women's language

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

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.     

On Tragic Consciousness In The Works By Ernest Hemingway

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.