低温生淀粉糖化酶菌株RS01分离及其酶学性质

自渤海湾海泥中分离得到一株产低温生淀粉糖化酶能力较强的菌株RS01,经形态学、生理生化特性及16S rRNA分析将其鉴定为气单胞菌属。对该菌株产的低温生淀粉糖化酶酶学性质进行初步研究,结果表明其最适酶反应温度为30℃,酶的热稳定性比较差,最适pH为5.4,经TLC鉴定酶解产物中有葡萄糖,表明该分离菌株具有产低温生淀粉糖化酶的能力。     

链霉菌产木聚糖酶条件和酶学性质以及重离子诱变对产酶的影响研究

以一株由青藏高原牦牛粪中分离出的链霉菌为出发菌株,对其培养特性、产酶条件和酶学性质进行初步研究.通过重离子诱变,筛选出遗传稳定的高产菌株.结果表明,该菌以玉米芯和麸皮(1∶1)为碳源能高效地诱导木聚糖酶的胞外分泌,其最适培养基和培养条件氮源为酵母膏、初始pH7、培养温度为25℃,在此条件下,第4天酶活力达到峰值3480.25 U/mL.说明该酶能够利用农业废弃物高效生产木聚糖酶.该菌株所产木聚糖酶的最适反应温度为15℃、pH4,属低温酸性木聚糖酶.经重离子诱变后,筛选出一株高产菌株SZ10-7,其酶活力可达5 338.42 U/mL.     

紫外线和60Co-γ联合诱变褐色高温单孢菌及产酶特性研究

本研究以褐色高温单孢菌(Thermomonospora fusca)为出发菌株,通过紫外线和60Co-γ射线联合诱变,获得了一株纤维素酶高产菌株AV8,CMC酶活力达到0.679 IU/mL,与出发菌株相比,其产酶能力提高3.53倍。通过对AV8产纤维素酶的培养条件进行测定,结果显示:产纤维素酶最适应温度为55℃;该菌的最适产CMC酶初始PH值为7.0,最适产FPA酶初始PH值为8.0;当培养到第7天时,产CMC酶达到高峰。当培养到第8天时产FPA酶达到高峰。     

高温蛋白酶产生菌的筛选及其产酶条件和酶学性质分析

从徂徕山温泉附近土样中分离到9株产高温蛋白酶菌株,选取一株碱性蛋白酶高产菌株L7为出发菌株,进行显微形态、16S rRNA基因序列分析,将其初步鉴定为短芽孢杆菌(Brevibacillus sp.)。研究该菌株发酵条件,确定产酶的最佳培养基组成为葡萄糖40 g/L,蛋白胨20 g/L,磷酸氢二钠1.4 g/L,氯化钙0.6 g/L,硫酸镁0.4 g/L,通过培养基优化,酶活达到103.08 U/mL。最佳培养条件为250 mL三角烧瓶中装液量50 mL、pH8.0、培养温度为55℃、培养时间为24 h。对该菌株酶学性质研究,L7菌株所产高温蛋白酶的最适温度为55℃,最适pH为10,并且具有良好的温度稳定性和pH稳定性,酶活性受PMSF强烈抑制。     

一株产高温蛋白酶嗜热菌A-2的筛选鉴定及酶学特性分析

本研究为从云南腾冲热泉中分离纯化得到一株产高温蛋白酶的菌株并对其进行驯化培养,用以探究该菌株的生长条件及酶学特性,通过选择培养基筛选能够分解脱脂奶粉产蛋白酶的菌株,应用常规方法液体培养菌体,探究温度、pH、碳源、氮源对菌株生长情况的影响,并采用福林酚法测蛋白酶活性。并提取蛋白酶液对酶的最适pH、温度以及热稳定性、pH稳定性进行研究。结果发现通过含脱脂奶粉的固体培养基筛选得到一株产蛋白酶菌株A-2,经过生理生化试验和16S rDNA鉴定知该菌种属于Aneurinibacillus属。酵母粉、葡萄糖、55℃、pH值7.5分别为菌株生长的最适氮源、碳源、温度和pH。此外该菌株所产的蛋白酶最适温度为60℃,在pH值7~9具有较好的酶活性。因此,该菌株为嗜热芽孢杆菌,所产的碱性蛋白酶具有较高的耐受温度和pH稳定性,为进一步开发利用提供参考的价值。     

一株产生淀粉分解酶犁头霉的分离鉴定及其酶学性质

从保宁麸醋醋曲中定向筛选得到一株产生淀粉分解酶的菌株CQB43,其酶活力为105.2 U/mL,RDA值达到27.9%。通过形态观察和分子生物学鉴定确定该菌株为伞枝犁头霉Absidia corymbifera。对该菌株分泌生淀粉酶酶学性质的研究结果表明,该酶在pH为4.0-5.6的范围相对稳定,最适pH是5.0;在60°C以下的范围内具有较好的热稳定性,最适作用温度为40°C。研究金属离子对其活力影响的结果表明,Co2+对该生淀粉糖化酶有激活作用,Fe3+和Ca2+对该酶有抑制作用。     

低温淀粉酶菌株C2的分离鉴定及其产低温淀粉酶的酶学性质

获得低温淀粉酶高产菌株,确定该菌株所产淀粉酶的酶学性质.从大黑山(大连)污泥中筛选菌株,通过菌株的形态特征、生理生化和16S rDNA序列鉴定确定其种属,对其酶学性质进行初步研究.获得1株低温淀粉酶高产菌株C2,经鉴定其为微小杆菌属,C2所产低温淀粉酶最适反应温度为25℃,酶的热稳定性比较差,最适pH为7.5,Ca2+和Fe2+对该酶有激活作用,Cu2+、Ni2+、Go2+等抑制酶活性.经薄层层析(TLC)鉴定酶解产物为葡萄糖,说明该菌株具有产生低温淀粉糖化酶的能力.菌株C2所产淀粉酶符合低温淀粉酶性质,值得进一步研究.     

蒙氏假单胞菌Pseudomonas monteilii对食用油脂的利用效率研究

筛选具有利用食用油脂功能的菌株,为废弃食用油脂的资源化应用开展基础性前期研究。利用油脂中性红平板筛选法筛选到1株具有脂类降解能力的菌株鉴定为蒙氏假单胞菌。通过菌株形态特征扫描、生理生化特性,进而利用分光光度法探索了该菌株最适温度、最适pH等生长条件。并研究其在最适生长条件下的生长曲线及其在不同油脂作唯一碳源条件下的生长情况。结果表明,该菌株生长的最适温度为28℃、最适pH值为7.0、最适盐度为2g/L,达到最大培养生物量的时间为7h。对玉米油、动物油、花生油、芝麻油、椰子油、橄榄油共7种食用油脂具有相应的利用能力。     

米曲霉木聚糖酶生产菌的理性选育及发酵优化

目的：米曲霉木聚糖酶生产菌的理性选育及发酵优化。方法：以米曲霉FS018为出发菌株,采用紫外和激光诱变先后处理3代,以抗高浓度葡萄糖阻遏效应为筛选模型获得一株高产木聚糖酶菌株FST036,并对该菌株的发酵培养基进行了初步优化。结果：突变株FST036产酶水平可达4200．57U／mL,产酶水平比出发菌株提高了24％。对该菌株的发酵培养基初步优化结果表明：培养基的最适氮源为牛肉膏;最适碳源为麸皮与玉米芯组合,总浓度为4％。二者最适比例为7：3;对该菌株的发酵条件初步优化结果表明：最适接种量1％,初始pH6．78,250mL三角瓶装液量为45mL,培养72h酶活可达5404．24U／mL。结论：反复多次诱变处理,并结合抗高浓度葡萄糖阻遏效应作为一种理性筛选模型,为通过诱变育种来获得曲霉木聚糖酶高产菌株提供了一条有效的途径。     

耐盐碱菌株的分离筛选及生物学特性和盐碱去除效率的研究

将采集于黑龙江省大庆市盐碱地的土壤样品经适当稀释后,涂布于高盐碱的培养基中,分离纯化获得41株菌。经过不断分别或同时提高培养基的盐、碱浓度进行耐盐碱菌株的筛选,获得1株耐盐碱菌株7,其在pH值13且盐(NaCl)浓度达到200g.L-1的培养基中仍可生长,该菌株既属于极端嗜盐微生物又属于极端嗜碱微生物。分别于不同碳源、氮源、碳氮比、初始pH值和培养温度条件下,对菌株7的生物学特性和盐、碱去除能力进行研究。结果表明,该菌株生长和去除盐碱的最佳碳源为牛肉膏;最佳氮源为蛋白胨;碳氮比为4:1时,最有利于菌株的生长和对盐、碱的去除;菌株生长的最适初始pH值为9.5,最适温度为20℃,而盐、碱去除的最佳温度则为30～35℃。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.     

（鱼句）亚科花（鱼骨）型鱼类骨骼系统的比较

对我国花型Hemibarbuspattern鱼类作了骨骼系统比较,结果表明,此类型鱼类脑颅较长,副蝶骨平直或稍弯曲,眶蝶骨腹纵嵴发达(铜鱼Coreius septentrionalis例外),下颞窝和咽突中等大,基枕骨后突发达;脑颅中的上筛骨的后突、侧筛骨的外筛突,蝶耳骨的外突、上耳骨的后突、围眶骨和后颞窝等均有明显的差异;咽颅中的舌颌骨、尾舌骨、鳃盖骨和下咽齿的列数等又有显著的区别;附肢骨骼中的腰带骨、脊椎骨中的复合神经骨和第4椎骨腹侧的悬器等也有不同之处。据此,这些差异和区别可作为属间或种间的分类依据。