毛霉脂肪酶的研究

从土样中分离筛选到一株脂肪酶菌株—毛霉(Mucor sp.)M₂,其优化后的培养基组成(%);黄豆粉4.0、蔗糖0.5、橄榄油1.0、硫酸铵0.1、磷酸氢二钾0.2硫酸镤0.01、pH自然。产酶最适条件：初始pH6.5、培养温度28℃、培养周期96h.该酶最适作用温度50℃、最适pH8.0、pH稳定范围为7.0～10.0,Fe²⁺、Ca²⁺、Mg²⁺、K⁺对酶有激活作用。     

室内CO2浓度、温湿度和光照变化对碰碰香挥发物释放量的影响

碰碰香(Plectranthus hadiensis var. tomentosus)的芳香气味具有改善身心健康的作用,但其挥发物的释放易受到室内环境影响而降低效果。为探究碰碰香挥发物对常见室内环境变化的响应,并为其高效稳定地应用于构建舒适的亲生物环境提供科学依据,该研究采用混合正交设计,使用动态顶空和气相色谱质谱联用技术测定了碰碰香挥发物对温度、湿度、CO₂浓度及光照这4种常见室内环境因素的响应。结果表明:(1)在温度、湿度、CO₂浓度和光照4个环境因素中,CO₂浓度和温度对碰碰香植株挥发物释放量的影响较大,而湿度和光照的影响较弱。(2)正常光周期下培养的碰碰香,在夜晚无光照时,CO₂浓度500 μmol·mol^-1、温度25 ℃和湿度60%的环境条件最适于碰碰香植株释放挥发物。此环境条件下碰碰香挥发物的释放总量为86.23 μg·L^-1·kg^-1, 具有改善身心健康的活性成分含量为78.03 μg·L^-1·kg^-1。综上所述,应用碰碰香构建室内亲生物环境,维持或改善人员身心健康时,应主要注意控制CO₂浓度和温度相关的环境条件,从而充分高效地发挥碰碰香的园艺效益。     

芽孢杆菌O74碱性纤维素酶的纯化和性质研究

对芽孢杆菌(Bacillus)O74菌株产生的纤维素酶经过Sephadex G-100,DEAE-Sephadex A-25和疏水相互作用Agarose 4B三种层析方法,分离纯化到一个仅具有内切β-葡聚糖酶(CMC酶)活性的纯组分.提纯后酶的比活力提高了27.9倍,总回收率为40%.分子量和等电位点分别为52 500和4.1.酶在pH4-12范围内均具有较高活性.其最适反应温度为50℃,最适反应pH为7.0,属于反应pH范围较广泛的耐碱性纤维素酶.除Hg⁺,Ag⁺,Zn²⁺和Cu²⁺等少数离子及少数表面活性剂、助剂对酶活性有一定影响外,酶活性相当稳定,符合洗涤剂用酶的条件.     

藓类植物孢子生活力的快速检测方法初探

通过对温度和光照条件的实验探索,筛选出金发藓（Polytrichum commune）和细叶小羽藓（Haplocladium microphyllum）2种藓类孢子萌发的最适条件。采用碘-碘化钾染色法、TTC染色法、红墨水染色法、亚甲基蓝染色法对6种藓类植物孢子的生活力进行测定,并将测得的生活力结果与孢子萌发率进行了比较分析。结果表明,亚甲基蓝染色法测定的藓类植物孢子平均生活力百分率与孢子平均萌发率最为接近,且染色效果明显,可用于苔藓植物孢子生活力的快速测定。亚甲基蓝染色法测得的孢子生活力（x）与其离体萌发率（y）的相关性达到极显著水平（r=0.976）,其回归方程为y=-8.547+1.069x(P<0.01),可通过孢子生活力方便预测萌发率。     

光照、温度和pH值对小黑桫椤孢子萌发及早期配子体发育的影响

小黑桫椤(Alsophila metteniana)被列为我国国家二级保护植物。为探讨其种群数量下降原因, 作者采用无菌培养方法和显微观察技术, 在实验条件下研究了光照强度、光质、温度和pH值对小黑桫椤孢子萌发及早期配子体发育的影响。结果表明: 孢子萌发和配子体发育的最适光照强度为40–70 µmol;m^–2;s^–1, 全黑暗时孢子不萌发;白光、红光、黄光和蓝光下的萌发率分别为68.78%、65.66%、63.74%和7.51%; 白光和蓝光下配子体可以形成正常的心形原叶体, 红光和黄光下配子体发育一直处于丝状体阶段。孢子萌发和配子体发育需要在酸性土壤进行(pH值在3.7–6.7); 孢子萌发的适宜温度为20–30℃。从孢子接种到心形原叶体形成需要55 d左右。根据上述结果, 我们认为光照强度是小黑桫椤孢子萌发的必需条件, 光质是限制小黑桫椤孢子繁殖的重要原因; 光质、温度和pH值等环境因子的作用和配子体发育时间等是导致小黑桫椤种群数量日趋减少的主要原因。     

鄱阳湖沉水植物区不同深度土壤甲烷排放对温度水分变化的响应

采集鄱阳湖沉水植物区0-10 cm和10-30 cm土壤样品,通过设置2个温度（18℃和28℃）和2个水分（淹水2 cm和土柱取出水面后的实际土壤水分含量）处理组合,进行持续2年的甲烷（CH₄）排放室内培养实验,以探讨不同深度土壤CH₄排放对温度、水分变化的响应差异,以及温度、水分和土层对湿地土壤CH₄排放的交互影响。结果表明：0-10 cm和10-30 cm土壤CH₄排放速率变化范围分别为0.01-3.63 μgCH₄-C kg^-1d^-1、0.02-1.99 μgCH₄-C kg^-1d^-1;均值分别为0.72和0.15 μgCH₄-C kg^-1d^-1。温度、水分和土层3因素及其交互作用均对土壤CH₄排放有显著影响（P<0.01）,且土层的影响最大。两水分处理下的CH₄排放对温度变化的敏感性均表现为0-10 cm（Q₁₀为1.78、3.26）高于10-30 cm土层（Q₁₀为1.04、1.08）。CH₄平均排放速率及累计排放量均表现为0-10 cm显著高于10-30 cm土层,且培养前期高于培养后期,显示基质有效性对土壤CH₄排放的重要影响。     

竹茶混交模式对表层土壤有机碳储量及组分的影响

为探究毛竹林下种植茶树对土壤有机碳储量与碳组分的影响,该研究以毛竹纯林、竹茶混交林和常绿阔叶林为研究对象,采集这3种林分类型的表层(0～10 cm)土壤,测定土壤有机碳(SOC)、碳组分、生物与非生物因素指标。结果表明:(1)竹茶混交林林下植物多样性相较于毛竹纯林显著降低,但其土壤有机碳密度(22.54±2.09)t·hm^-2、碳组分与毛竹纯林无显著差异(P>0.05)。竹茶混交林的矿物结合态有机碳(MOC)为(20.13±1.83)g·kg^-1,占总有机碳的92.66%。常绿阔叶林土壤有机碳密度比竹茶混交林和毛竹纯林高土壤有机碳密度分别高41.15%和41.00%(P<0.05)。(2)3种林分类型土壤微生物量碳(MBC)含量范围为0.58～3.08 g·kg^-1,土壤16S rRNA丰度范围为2.18×10¹⁰ ～5.65×10¹⁰copies·g^-1,固碳基因cbbL丰度范围为0.37×10⁸～ 1.10 ×10⁸ copies·g^-1,土壤微生物碳利用效率范围为0.03～0.28; 3种林分类型之间微生物相关指标不存在显著差异(P>0.05)。(3)3种林分类型SOC与土壤pH、砂粒含量和地上凋落物生物量呈显著负相关,与土壤黏粒含量、粉粒含量、总氮、C:N、总磷和铵态氮含量呈显著正相关(P<0.05)。(4)就不同碳组分而言,颗粒有机碳(POC)和MOC均与土壤pH、砂粒含量和根系生物量呈显著负相关,与土壤含水量、黏粒含量、粉粒含量、总氮、C:N、总磷和铵态氮含量呈显著正相关(P<0.05)。综上表明,竹茶混交改造会造成原生毛竹纯林林下植被多样性下降,但并未造成土壤碳储量下降; 而相较于常绿阔叶林,毛竹经营措施需要改进,以提升其碳汇效益。     

桂林喀斯特石山50种常见植物叶片光合特性

选取桂林喀斯特石山生境中常见的50种植物为研究对象,分别测定叶片单位面积最大净光合速率（A_area）、单位质量最大净光合速率（A_mass）、气孔导度（Gs）、水分利用效率（WUE）、胞间/环境CO₂浓度比值（Ci/Ca）和蒸腾速率（Tr）等光合特性指标,探讨不同物种光合特性的差异以及光合特性之间的内在联系,以此探究不同植物适应喀斯特石山生境所表现出的光合生理特性。结果表明,50种植物叶片A_area,A_mass,Gs,WUE,Ci/Ca和Tr的平均值分别为8.35 μmol m^-2 s^-1,110.98 nmol g^-1 s^-1,0.10 mol m^-2 s^-1,94.84 μmol/mol,0.57和2.37 mmol m^-2 s^-1;方差分析表明,不同物种之间在A_area,A_mass,Gs,WUE,Ci/Ca和Tr之间存在显著差异。Pearson相关性分析表明,表征50种常见植物叶片光合特性的6个指标相关性除Ci/Ca与A_area和A_mass,WUE与A_mass不一致外,其他指标两两之间相关性均表现为一致性,其中Gs与Ci/Ca呈极显著的正相关。主成分分析表明,在6个光合特性指标中,Gs和Ci/Ca可作为反映喀斯特石山植物适应生境的重要光合指标,主要表征对水分条件的敏感程度以及耐旱性强弱,同时反映了植物叶片光合速率大小,用于衡量植物对喀斯特生境的生理生态适应性。基于Gs和Ci/Ca进行聚类分析表明,50种植物划分为3类：即中等Gs较高Ci/Ca型,较低Gs较高Ci/Ca型和较低Gs,Ci/Ca型。本研究表明,喀斯特生境植物在生理生态方面所表现出的适应策略主要为对资源利用方式及抵御外界不利环境的适应策略,这为后续选择物种加速植被恢复演替进程提供了参考。     

一株海洋来源铜绿假单胞菌Gxun-7角蛋白酶基因的克隆、表达及重组酶酶学性质

【背景】角蛋白酶是一类特异性降解角蛋白的水解酶,在动物饲料、生物肥料、医学、洗涤、制革及环境治理等方面具有重要的应用潜力。【目的】对前期从海洋环境筛选出的一株铜绿假单胞菌Gxun-7的角蛋白酶基因进行克隆、表达,并探究重组酶酶学性质,为角蛋白酶在工业生产中的应用奠定基础。【方法】以铜绿假单胞菌Gxun-7基因组推定的角蛋白酶基因为基础,设计引物克隆获得角蛋白酶基因kp2,构建重组表达质粒pET22b-kp2,并转化到E. coliRosettagamiB (DE3)中进行诱导表达,同时对重组表达菌株的表达条件进行优化。利用镍柱分离纯化重组角蛋白酶并研究其酶学性质。【结果】重组角蛋白酶的分子量约为33 kDa,最适温度和pH值分别为40 ℃和8.0,在温度30-60 ℃和pH 6.5-8.0具有较好的稳定性。金属离子Co²⁺、Cu²⁺和化学试剂十二烷基磺酸钠(sodium dodecyl sulfonate,SDS)、乙二胺四乙酸(ethylenediaminetetraacetic acid,EDTA)、苯甲基磺酰氟(phenylmethylsulfonyl fluoride,PMSF)对酶活力有抑制作用,而Mg²⁺、K⁺、巯基乙醇和二硫苏糖醇(dithiothreitol,DTT)对酶活力有促进作用。重组角蛋白酶具有良好的耐盐性,在12.5%的NaCl作用下相对酶活为87.55%。以酪蛋白为底物时,酶的K_m值为60.92 mg/mL、V_max值为9.70 U/mL。【结论】海洋来源铜绿假单胞菌Gxun-7的重组角蛋白酶具有良好的温度、碱、盐稳定性,可应用于工业生产中。     

豆乳凝固酶产生菌UV-10发酵条件及其酶学性质的研究

豆乳凝固酶产生菌Bacillussp .UV 1 0的最适产酶条件 :初始pH6 4,温度 2 6℃ ,培养时间 1 9h ,需要较大的通气量。酶的最适作用pH和温度分别为 5 8和 70℃。在最适条件下酶活力可达 1 84u/mL。pH6 0～ 7 0稳定性较好。 6 0℃下 1h残余酶活 6 0 %。Ca²⁺,Fe²⁺,Mg²⁺,Na⁺对其有较强的激活作用 ,而Zn²⁺,Al相似文献   

Systematic significance of mature embryo of bamboos

The mature embryo of seven species belonging to five genera of Indian bamboos is described. In all these the basic pattern of embryo organisation is same: the scutellar and coleoptilar bundles are not separated by an internode, the epiblast is absent, the lower portion of the scutellum and the coleorhiza are separated by a cleft and the margins of embryonic leaves overlap. The features unique to fleshy fruited bamboos are: presence of a massive scutellum, the juxtaposition of plumule and radicle and the occurrence of a bud in the axil of the coleoptile. The fleshy fruit bearing bamboos should be classified into one group, the tribeMelocanneae. Evidence is provided to recognise additional groups in the subfamilyBambusoideae.     

Taxonomic status of the species of the green algal genusNeochloris

Komárek has recently reviewed the various species assigned to the green algal genusNeochloris Starr (Chlorococcales, Chlorococcaceae) and removed those with uninucleate vegetative cells to a new genus,Ettlia. Watanabe & Floyd, unaware ofKomárek's work, also reviewed the species ofNeochloris and distributed them among three genera—Neochloris, Chlorococcopsis gen. nov., andParietochloris gen. nov.—on the basis of details of the covering of the zoospore and the arrangement of the basal bodies of the flagellar apparatus. This paper reconciles these two treatments and makes additional recommendations at the ranks of genus, family, order, and class.     

Phylogeny of cardinalfishes (Teleostei: Gobiiformes: Apogonidae) and the evolution of visceral bioluminescence

The cardinalfishes (Apogonidae) are a diverse clade of small, mostly reef-dwelling fishes, for which a variety of morphological data have not yielded a consistent phylogeny. We use DNA sequence to hypothesize phylogenetic relationships within Apogonidae and among apogonids and other acanthomorph families, to examine patterns of evolution including the distribution of a visceral bioluminescence system. In conformance with previous studies, Apogonidae is placed in a clade with Pempheridae, Kurtidae, Leiognathidae, and Gobioidei. The apogonid genus Pseudamia is recovered outside the remainder of the family, not as sister to the superficially similar genus Gymnapogon. Species sampled from the Caribbean and Western Atlantic (Phaeoptyx, Astrapogon, and some Apogon species) form a clade, as do the larger-bodied Glossamia and Cheilodipterus. Incidence of visceral bioluminescence is found scattered throughout the phylogeny, independently for each group in which it is present. Examination of the fine structure of the visceral bioluminescence system through histology shows that light organs exhibit a range of morphologies, with some composed of complex masses of tubules (Siphamia, Pempheris, Parapriacanthus) and others lacking tubules but containing chambers formed by folds of the visceral epithelium (Acropoma, Archamia, Jaydia, and Rhabdamia). Light organs in Siphamia, Acropoma, Pempheris and Parapriacanthus are distinct from but connected to the gut; those in Archamia, Jaydia, and Rhabdamia are simply portions of the intestinal tract, and are little differentiated from the surrounding tissues. The presence or absence of symbiotic luminescent bacteria does not correlate with light organ structure; the tubular light organs of Siphamia and chambered tubes of Acropoma house bacteria, those in Pempheridae and the other Apogonidae do not.     

Apoptotic Regulation of Caspase Activity

Intracellular cysteine aspartate-specific proteases (caspases) play both signaling and effector roles in realizing the program of cell death. Caspases function as proteolytic cascades unique for each cell type and signal triggering apoptosis. All parts of the proteolytic cascades are duplicated and controlled by feedback signals. Amplification cycles between pairs of caspases (the third and the sixth, the ninth and the third, the twelfth and the sixth, and others) help multiply the initial apoptotic signal. The presence of physiological inhibitors of apoptosis that directly interact with caspases creates a multilevel regulatory network of apoptosis in cell. The caspase proteolytic cascades are also regulated by sphingolipid secondary messengers, among them ceramide, sphingosine, and their phosphates. Moreover, an association of the caspase signaling with ubiquitin-dependent proteolysis is shown in cells. In particular, the use of extracellular activators and inhibitors of caspases allows irreversible activation of apoptosis in tumor cells or the prevention of apoptosis in cortical neurons under neurodegenerative diseases.     

Analysis of twin of eyeless regulation during early embryogenesis in Drosophila melanogaster

The Drosophila Pax6 homolog twin of eyeless (toy) is so far the first zygotically expressed gene involved in eye morphogenesis in Drosophila. The study of its expression during embryogenesis is therefore informative of the initial events of eye development in Drosophila. We have analyzed how the initial expression domain of toy at cellular blastoderm is regulated. We show that the three maternal patterning systems active in the cephalic region (the anterior, terminal and dorsal-ventral systems) cooperate with zygotically activated gap genes to shape the initial expression domain of toy. Whereas Bicoid, Dorsal and Torso signaling synergistically act as activators, Hunchback, Knirps and Decapentaplegic act as repressors.     

Host plants of someRhinanthoideae (Scrophulariaceae) of eastern North America

Twenty three species in 11 genera were examined in the field to determine hosts. OnlyStriga asiatica andSeymeria cassioides have a narrow host range being restricted to grasses and pines, respectively. These are the only species which cause pronounced and sometimes serious host damage. The other species attach to a great diversity of hosts.     

New species of Peruvian Orchidaceae III

Sixteen new species are proposed in the generaAckermania, Dressleria, Epidendrum, Maxillaria, Oncidium, Rodriguezia, Sigmatostalix, andTrigonidium. All new species are illustrated.Maxillaria vittariifolia L. O. Williams is newly recorded for Peru. A key is provided forTrigonidium of Peru.Trigonidium loretoense Schltr. andT. peruvianum Schltr. are lectotypified.     

A molecular phylogeny of Hebeloma species from Europe

In order to widen the scope of existing phylogenies of the ectomycorrhizal agaric genus Hebeloma a total of 53 new rDNA ITS sequences from that genus was generated, augmented by sequences retrieved from GenBank, and analysed using Bayesian, strict consensus and neighbour joining methods. The lignicolous Hebelomina neerlandica, Gymnopilus penetrans, and two species of Galerina served as outgroup taxa. Anamika indica, as well as representatives of the genera Hymenogaster and Naucoria, were included to test the monophyly of Hebeloma, which is confirmed by the results. Hebeloma, Naucoria, Hymenogaster and Anamika indica cluster in a strongly supported monophyletic hebelomatoid clade. All trees largely reflect the current infrageneric classification within Hebeloma, and divide the genus into mostly well-supported monophyletic groups surrounding H. crustuliniforme, H. velutipes, H. sacchariolens, H. sinapizans, and H. radicosum, with H. sarcophyllum being shown at an independent position; however this is not well supported. The section Indusiata divides with strong support into three groups, the position of the pleurocystidiate Hebeloma cistophilum suggests the possible existence of a third subsection within sect. Indusiata. Subsection Sacchariolentia is raised to the rank of section.     

Interaction of Synthetic Analogues of Natural Chalcones and Flavones with Guanidine

The reaction of chalcones and flavones with guanidine in ethanol results in 2-(2-aminopyrimidinyl-4)-phenols.     

广西青藓科分类学修订

通过对采自广西24个县(市)的1 147份青藓科植物标本的逐一鉴定及相关文献的查阅,确认有广西青藓科植物11属、44种,其中包括广西青藓科植物新记录属1属,即拟异叶藓属(Pseudokindbergia),新记录种7种,分别为匐枝青藓(Brachythecium procumbens)、阔叶尖喙藓(Oxyrrhynchium latifolium)、泛生尖喙藓(O. vagans)、拟异叶藓(Pseudokindbergia dumosa)、华东细喙藓(Rhynchostegiella sinensis)、长肋拟青藓(Sciurohypnum populeum)和弯叶拟青藓(S. reflexum)。该文提供了修订后的广西青藓科植物名录,并对其中的新记录属、种的主要形态学识别特征、生境和地理分布等进行了详细描述。