南极产低温几丁质酶菌株的16S rDNA序列分析及其发酵条件及酶学性质研究

从南极深海沉积物中筛选到一株产低温几丁质酶的菌株AC444,经细菌形态观察及16S rDNA序列分析,该菌株属于假交替单胞菌属（pseudoalteromonas）,其最适与最高生长温度分别为15℃和30℃,属于兼性嗜冷菌。AC444菌株能利用多种碳源产酶,在含胶体几丁质和蛋白胨的培养基中产酶最高,达13．47U,最适产酶温度为20℃。酶的最适反应pH为7．0,最适作用温度为35℃,属中性低温酶。     

低温脂肪酶产生菌的筛选、鉴定及其部分酶学性质

从南极乔治王岛冻土来源的76株低温细菌中筛选到13株低温脂肪酶产生菌，对其中的BTsl0022菌株进行鉴定。通过生理生化特征、16s rDNA基因序列的同源性和系统发育分析发现，菌株RTsl0022属于假单胞菌属(Pseudomonas)，但与已定名的假单胞菌有一定的差异，与未定名的Pseudomonas sp．PsB的亲缘关系最接近，故将其暂定名为Pseudomonas sp．BTsl0022。对该菌脂肪酶的酶学性质初步研究表明，酶的最适作用温度为24℃，对热敏感，60℃处理30min仅残留25％酶活性，酶的适宜作用pH范围在7．0～9．0，最适pH为8．0。     

产脂肪酶海洋嗜冷菌的鉴定及酶学性质研究

从东海的深海底泥中筛选出一株产脂肪酶的海洋细菌 EastSeaG5-1415,该菌为革兰氏阴性好氧菌,短杆状,0.9～1.3μm×1.5～3.8μm,无鞭毛,无芽孢,无色素,菌落光滑不透明,过氧化氢酶和氧化酶阳性,甲基红实验阴性,氧化葡萄糖产酸,可耐受10%的NaCl.此菌最适生长温度为18℃,最高生长温度为35℃,在0℃也能生长,是典型的嗜冷菌.菌株脂肪酸种类为C17:1(28.2%),C18:1 9c(49.7%),辅酶Q-8是其主要的异戊烯醌类,DNA中G C含量为45.2mol%.以16SrRNA同源性为基础构建了相关种属细菌在内的系统发育树,在系统发育树中,分离菌株 EastSeaG5-1415 与 Psychrobacter glacincola 在同一分支,二者的序列相似性为97.6%,DNA 杂交显示与 P.glacincola 最为相近,达到87%.结合形态和生理生化试验,将其鉴定为嗜冷杆菌 P.glacincola.同时对其所产脂肪酶的性质进行了初步研究.该菌所产碱性脂肪酶最适反应温度为35℃,在5℃时仍有较高酶活,酶活达到23%,最适 pH 值为9,属低温碱性脂肪酶.     

产蛋白酶菌株的筛选鉴定及产酶优化

为筛选出高产蛋白酶的菌株,通过干酪素培养基筛选到一株高产蛋白酶的菌株BJ-4,经鉴定该菌株为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）。对菌株的产酶条件进行单因素及响应面优化,确定最佳产酶条件为：葡萄糖0.5%、牛肉膏1.5%、培养温度37.61 ℃、培养初始pH值 6.84、接种量1.36%,优化后酶活力同比增长了71.01%。菌株BJ-4在工业中具有一定的应用前景。     

米曲霉淀粉酶酶学性质的研究

对本实验室筛选的米曲霉淀粉酶的酶学性质进行了研究。该淀粉酶的最适温度为60℃,T为65．2℃,其热稳定性较差：最适pH为pH5．0,在pH4．0-8．0范围内稳定性较好。K＋对淀粉酶活性具有显著促进作用,而Ag2＋、Ph2＋、Fe3＋和Cu2＋对其活性具有强烈的抑制作用。     

大肠杆菌氨基酰化酶拆分-DL-Met的研究

报道了利用大肠杆菌氨基酰化酶Ⅰ拆分消旋体生产L氨基酸的研究结果。大肠杆菌氨基酰化酶Ⅰ ,在培养 2 0～ 2 2小时 ,酶活力可达到 89.2 μmol/ml·h- 1。用它拆分DL Met ,其最适反应温度为 6 0℃ ,最适 pH值为 7.0 ,最适底物浓度为 0 .2 5～ 0 .2 75mol/L ,催化动力学过程不符合米式方程。 0 .0 4mol /L的Co2 + 对酶有较好的激活作用 ,活力提高 8%左右     

高效降解苯胺的菌株AD9的分离、生理生化特性分析和分子鉴定

从活性污泥中分离到一株能以苯胺为唯一碳源、氮源生长的苯胺降解菌株AD9,该菌株最适生长的苯胺浓度为1000mg／L,降解效率可达90％,对苯胺耐受程度高达4500mg/L,降解苯胺的最适pH值为7．0,最适温度为30℃。以上实验结果表明,AD9具有降解苯胺速率快、耐受苯胺浓度高的特性。该菌具有氨苄青霉素、卡那霉素和利福平抗性,无氯霉素、四环素抗性,其16SrDNA序列与多株Delftia sp．菌有很高的同源性,其G＋C含量为66．8mol％,非常接近于标准菌株D．tsuruhatensis T7（66．2mol％）。另外该菌和17的DNA-DNA杂交率为83．8％。结合AD9的表型鉴定将该菌株归属为D．tsuruhatensisas。这是D．tsuruhatensis菌种苯胺降解细菌菌株的首次报道。     

绿色木霉AS3．3711的葡聚糖内切酶V基因的克隆与表达

采用RT-PCR方法克隆到绿色木霉(Trichoderma viride)AS3．3711的葡聚糖内切酶V(EGV)的cDNA基因。测序后构建到酿酒酵母诱导型表达载体pYES2上，转化酿酒酵母，同时研究了超声波处理对酵母完整细胞转化的影响。转化子用2％的β-D-半乳糖进行诱导，用Northem杂交和CMC糖化力法分别对目的基因的转录和表达产物的葡聚糖内切酶活性进行检测。结果表明，EGV的cDNA基因开放阅读框长度为741bp，编码247个氨基酸，推测的蛋白质分子量为24．99kDa。超声波处理60s的酿酒酵母的转化率最高，在相同条件下是未处理组的2倍。酶活检测显示该基因能在酿酒酵母中表达并分泌到胞外。发酵液中的酶活在培养60小时达到最高0．046U／ml。最适酶解温度为60℃，最适pH值为5．4。     

地衣芽孢杆菌培养基及培养条件优化

微生态制剂以其无毒副作用、无耐药性、无残留,能有效克服抗生素滥用等优点而为广大消费者所青睐。本文以一株地衣芽孢杆菌为研究对象,通过单因素及正交实验确定最佳培养基配比：葡萄糖1．5％,酵母抽提物1．0％,硫酸镁0．3％。最佳培养温度为35℃,最适接种量为5％,最佳初始pH6．5。     

优化米曲霉固体发酵产果胶酶及产物酶学性质

以麸皮为基质,橘皮粉添加量、氮源、培养基初始含水量和发酵时间为因子,采用响应面法的中心组合设计,对影响米曲霉(Aspergillus oryzaeJL14)固体发酵产果胶酶的条件进行了优化.结果表明,橘皮粉、硫酸铵的最适添加量分别为13.2%和2.3%,初始含水量为63.5%,发酵时间为77.0 h,米曲霉果胶酶产量最大预测值达316.4 U/g发酵产物,实验验证值为310.7 U/g发酵产物,是基础培养基酶产量的3.3倍.该米曲霉果胶酶(PG)的最适温度为50℃,Tm为55.9℃,其热稳定性较差;最适pH为4.0,属于嗜酸性果胶酶,在pH 5.0~8.0范围内稳定性较好,处理1 h后残余酶活均在80%以上.PG的Km和Vmax分别为7.06 mg/mL和62.5μmol-1.min.mL-1.PG能快速降低果胶溶液的黏度.该研究为提高橘皮利用率和酶法生产高品质果胶低聚糖奠定基础.     

凝固科学技术与材料

从凝固科学与实践发展的角度介绍了当前凝固材料体系的基本框架和凝固科学主要发展阶段的基本理论。作为材料科学与工程的基本组成，凝固科学技术正在现代科学理论的基础上针对传统材料的改性提高和新材料的发展需求，以控形、控构、控性为目标开展优质铸件的定向、晶体生长、快凝、深过冷及各种新型和超常领域凝固过程的研究，并介绍了其中某些方面和展望了可能的发展趋势。     

Creation and motion of dislocations and fracture in metal and silicon crystals

By making a step on one surface ( ) of a rectangular small paralellepiped copper crystal, dislocations could be created by the molecular dynamic method. The dislocation created was not a complete edge dislocation but a pair of Heidenreich-Shockley partial dislocations. Each time a dislocation was created, the stress on the surface was released. Small copper crystals having a notch were pulled (until fracture), compressed and buckled by use of the molecular dynamic method. An embedded atom potential was used to represent the interaction between atoms. Dislocations were created near the tip of the notch. A very sharp yield stress was observed. The results of high speed deformations of pure silicon small crystals using the molecular dynamics are presented. The results suggest that plastic deformation may be possible for the silicon with a high speed deformation even at room temperature. Another small size single crystal, the same size and the same surfaces, was compressed using molecular dynamic method. The surfaces are {110}, {112} and {111}. The compressed direction was [111]. It was found that silicon crystals are possible to be compressed with a high speed deformation. This may suggest that silicon may be plastically deformed with high speed deformation.     

江澳两地高校文创设计的协同研究与商业实践

目的 探索江门世遗文化的传承、发展和转化的新思路,践行国家在《粤港澳大湾区发展规划》纲要中要求江门承担与港澳地区文化创意合作与开发任务的分工。方法 与澳门高校紧密合作,开展专业培训课程,以开平碉楼为例,从人文视角开展设计研究,梳理开平碉楼的文化脉络,把世遗文化的元素和其背后的文化融入文创产品中,提升文创产品的附加值,推动当地文创产业结构的变革。结果 两地高校构建了稳定的科研团队,开设长期有效的设计培训课程,与景区建立了研究协作关系,帮助景区构建了一套产销研的商业模式。结论 以跨区域高校合作为平台,以文创产品为抓手,依托江澳两地的资源优势,可以构建江门世遗文化全新的品牌形象,最终推动开平世遗文化的活化。     

Development and challenges of planning and scheduling for petroleum and petrochemical production

Production planning and scheduling are becoming the core of production management, which support the decision of a petrochemical company. The optimization of production planning and scheduling is attempted by every refinery because it gains additional profit and stabilizes the daily production. The optimization problem considered in industry and academic research is of different levels of realism and complexity, thus increasing the gap. Operation research with mathematical programming is a conventional approach used to address the planning and scheduling problem. Additionally, modeling the processes, objectives, and constraints and developing the optimization algorithms are significant for industry and research. This paper introduces the perspective of production planning and scheduling from the development viewpoint.     

The Candela and Photometric and Radiometric Measurements

The national measurement system for photometric and radiometric quantities is presently based upon techniques that make these quantities traceable to a high-accuracy cryogenic radiometer. The redefinition of the candela in 1979 provided the opportunity for national measurement laboratories to base their photometric measurements on optical detector technology rather than on the emission from high-temperature blackbody optical sources. The ensuing technical developments of the past 20 years, including the significant improvements in cryogenic radiometer performance, have provided the opportunity to place the fundamental maintenance of photometric quantities upon absolute detector based technology as was allowed by the 1979 redefinition. Additionally, the development of improved photodetectors has had a significant impact on the methodology in most of the radiometric measurement areas. This paper will review the status of the NIST implementation of the technical changes mandated by the 1979 redefinition of the candela and its effect upon the maintenance and dissemination of optical radiation measurements.     

甲壳素与壳聚糖的改性及应用

甲壳素、壳聚糖及其衍生物是一种天然高分子,随着对其研究的深入发展,涉及的内容和应用范围越来越广泛.概述了甲壳素、壳聚糖的结构、性质及其化学改性和共混改性的方法,简单介绍了它们的应用领域.     

ATP-Responsive and ATP-Fueled Self-Assembling Systems and Materials

Adenosine triphosphate (ATP) is a central metabolite that plays an indispensable role in various cellular processes, from energy supply to cell-to-cell signaling. Nature has developed sophisticated strategies to use the energy stored in ATP for many metabolic and non-equilibrium processes, and to sense and bind ATP for biological signaling. The variations in the ATP concentrations from one organelle to another, from extracellular to intracellular environments, and from normal cells to cancer cells are one motivation for designing ATP-triggered and ATP-fueled systems and materials, because they show great potential for applications in biological systems by using ATP as a trigger or chemical fuel. Over the last decade, ATP has been emerging as an attractive co-assembling component for man-made stimuli-responsive as well as for fuel-driven active systems and materials. Herein, current advances and emerging concepts for ATP-triggered and ATP-fueled self-assemblies and materials are discussed, shedding light on applications and highlighting future developments. By bringing together concepts of different domains, that is from supramolecular chemistry to DNA nanoscience, from equilibrium to non-equilibrium self-assembly, and from fundamental sciences to applications, the aim is to cross-fertilize current approaches with the ultimate aim to bring synthetic ATP-dependent systems closer to living systems.     

PSD和PWELCH函数的分析改进及应用

针对MATLAB中两个内建功率谱密度计算函数psd()和pwelch()计算结果迥异的现象,在功率谱密度估计理论的基础上,根据经典的周期图理论和Welch平均周期图方法,通过详细分析源程序,解析计算方法,发现psd()计算的并不是工程单边功率谱密度,而是采样信号双边谱,故与pwelch()结果迥异,另外pwelch()不能对分段信号数据进行预处理。就上述不足提出了相应的改进措施,比较验证表明改进措施行之有效。