鱼腥藻HB1017株化能异养生长的研究

以葡萄糖和蔗糖为碳源,检测了六株（种）鱼腥藻的化能异养生产能力。其中鱼腥藻ＨＢ１０１７株化能异养生长较快,鱼腥藻ＨＢ０株化能异养生长缓慢,其余四种鱼腥藻不能进行化能异养生长。鱼腥藻ＨＢ１０１７株能利用果糖、葡萄糖、蔗糖为底物进行化能异养生长,但生长速率依次递减,差别显著。８磅湿热灭菌的果糖和蔗糖,与过滤灭菌的相比,只能维持低得多的化能异养生长速率。然而,８磅湿热灭菌的葡萄糖能维持比过滤法灭菌的高得     

蛋白质特异性断裂试剂研究进展

蛋白质特异性断裂试剂是近年来发展起来的一些具有特异性断裂肽键功能的化学工具．这些断裂试剂可分为两类,一类通过氧化断裂机制实现蛋白空间结构特异性切割,另一类通过水解断裂机制实现序列特异性切割．蛋白质特异性断裂试剂在蛋白质序列测定,蛋白质的结构与功能研究,蛋白质与核酸相互作用研究以及新型化学治疗药物的合成等方面有着广阔的应用前景．     

The chromophore topography and binding environment of perididin.chlorophyll a.protein complexes from marine dinoflagellate algae

1. The peridinin.chlorophyll a.protein complex from Amphidinium carterae (Plymouth 450) shows spectroscopic characteristic (absorption, CD, fluorescence polarization, lifetime and energy transfer) essentially identical with peridinin.chlorophyll a.protein complexes from Glenodinium sp., Gonyaulax polyedra and Amphidinium rhyncocephaleum. 2. The apoprotein of peridinin.chlorophyll a.protein complexes is globular, with an isotropic rotational relaxation time (e.g. 33 ns for the A. caterae peridinin.chlorophyll a.protein), as deduced from the dynamic depolarization data. 3. The chromophores (4 peridinins and 1 chlorophyll a for peridinin.chlorophyll a.protein complexes from Glenodinium sp., G. polyedra and A. rhyncocephaleum and 9 and 2, respectively, for peridinin.chlorophyll a.protein of A. carterae) are accommodated in a hydrophobic crevice and not exposed to the solvent. The surface of the protein is highly hydrophilic. 4. No evidence for chlorophyll-chlorophyll interactions in the A. carterae peridinin.chlorophyll a.protein was obtained. This implies that binding crevices for two chlorophylls and half of peridinins (four to five) are located at some distance from each other. 5. The peridinin.chlorophyll a.protein complexes function as the photosynthetic antenna pigment. In addition, peridinins effectively protect chlorophyll a from photodecomposition.     

褐藻寡糖生物法制备研究进展 *

褐藻寡糖(alginate oligosaccharides,AOS)是褐藻胶的降解产物,具有抗氧化、调节免疫、调节血脂、促进细胞生长等生理活性,应用范围广泛。现有的AOS 制备法主要分为物理法、化学法和生物法。介绍AOS的生物法制备包括酶解、微生物全细胞发酵和生物合成法,基因工程的应用在改造产褐藻胶裂解酶的菌株以提高生物法效率方面具有重要意义。此外,规模化的AOS生物法制备案例进行了科学引证,并展望了未来 AOS规模化制备的发展方向,以期为 AOS 的工业化制备和应用提供参考。     

兰属(Cymbidium)5种植物叶结构特征

采用光学显微镜和体视镜,对兰属5种植物（春兰、蕙兰、建兰、寒兰、墨兰）的叶结构特征（叶脉结构、叶表皮结构、解剖结构）进行了观察和测量。结果显示,兰属5种植物的叶脉结构相似,叶表皮结构和解剖结构存在较大差异,其中最主要的差异是皮下纤维束的多少和边缘角质层锯齿形态。依据叶结构特征聚类分析结果,5种兰可分为春兰组、建兰组和墨兰组3组。本研究表明叶结构特征对兰属5种植物的分类具有重要意义。     

梵争山和张家界地区蜘蛛群落结构及多样性研究

1990年8月对梵净山和张家界两个自然保护区内蜘蛛群落进行调查,结果表明:自然保护区内蜘蛛资源极为丰富,经初步鉴定,计有蜘蛛27科85属180种,其中主要成分依次为肖蛸、园蛛、狼蛛、球蛛和皿蛛等。蜘蛛发生量折合每亩为17,585—54,000头。八个不同生境类型蜘蛛群落的种类数和密度存在明显差异;各种蜘蛛分布群在群落内的比例随栖息地结构变化而改变,因而也导致蜘蛛群落的Shannon-Wiener多样性指数,Simpson优势度和均等度等参数的变化。     

G-proteins in etiolated Avena seedlings. Possible phytochrome regulation

The molecular mechanism of light signal transduction in plants mediated by the photosensor phytochrome is not well understood. The possibility that phytochrome initiates the signal transduction chain by modulating a G-protein-like receptor is examined in the present work. Etiolated Avena seedlings contain G-proteins as examined in terms of the binding of GTP as well as by cross-reaction with mammalian G-protein antibodies. The binding of GTP was regulated in vivo by red/far-red light. The possible involvement of G-proteins in the phytochrome-mediated signal transduction in etiolated Avena seedlings has been implicated from the study of the light regulated expression of the Cab and phy genes.     

Paleolimnology of Qilu Hu,Yunnan Province,China

Qilu Hu is a large (A = 36.9 km²), shallow (z_max = 6.8 m) lake that lies at an elevation of 1797 m above msl on the Yunnan Plateau, southern China. Lake waters are hard (Mg = 3.2m eq L^–1, Ca = 1.3 meq L^–1 ), fresh (conductivity = 380 S cm ^–1), and productive (Secchi < 40 cm). An 11-m sediment core has a basal ¹⁴C age of 30960 ± 860 B.P. Sediments between 11 m and 6 m are high in % dry weight, rich in clay components Al₂O₃, Fe₂O₃, K₂O, MgO, and low in organic C (6.1%), carbonate-C (<1.0%), total N (<3.2 mg g^–1), and total S (<-1.7 mg g^–1). Diatoms and pollen indicate open-water conditions between 9.0 m and 6.0 m (1342011790 B.P.). Above 6.0 m, CaCO₃ and organic matter concentrations increase relative to clastics. The transition marks a change to shallow-water conditions as inferred from diatoms and pollen, and probably reflects a shift to drier climate. Uppermost (80-0 cm) red clays were deposited rapidly, probably as a consequence of recent (decades to centuries) riparian disturbances (e.g. agriculture, lake-bottom reclamation, urban development). Dates assigned to events in the Qilu Hu profile are tentative because of potential hard-water-lake error.     

鄂西木林子种子植物区系与邻近区系的比较研究

木林子地处武陵山脉东北端,自然地理条件优越,种子植物种系饱和度大。在2100公顷的面积内有种子植物134科~1 488属、1043种(包括亚种和变种)。本文选取11个较有代表性地区的自然种子植物区系与木林子区系进行比较分析,以求深化对木林子种子植物区系性质、起源及与邻近区系关系的认识。多区系比较研究中,优势科的确立和其相似性指标是一个指示区系特征异同的重要参数,木林子种子植物区系优势科与湖北神农架、江西庐山、广东黑石顶和海南尖峰岭区系的相似性指标分别为73.3%、46.7%、33.3%和13.3%,共有优势科下辖的各种系在各区系中具明显的替代现象。在各区系种子植物属的比较中,沿用经典的分布区类型的划分和相似性指标的比较分析,并运用数量分类方法,以11个不同种子植物区系的14个分布区类型进行聚类分析,将11个种子植物区系分为3组。实践证明数量分类方法可客观地反映各区系间的异同,以及起源上的内在同一性。