一株耐冷异养硝化菌的分离鉴定及脱氮特性

利用异养硝化培养基,冬季从南四湖人工湿地底泥中分离筛选到一株具有较高脱氮性能的菌株Z01.经形态特征、生理生化特性以及16S rDNA序列分析,初步鉴定该菌株为假单胞菌属（Pseudomonas sp.）,命名为Pseudomonas sp.Z01.实验探究得到菌株Z01的最佳初始投菌量为7%,最适温度、pH和盐度分别为15℃、6.0~8.0和0.3%,最佳碳源为葡萄糖.在最适生长条件下,通过氨氮去除试验发现该菌株对模拟污水中氨氮的去除率有一定提高,是异养硝化培养基中氨氮去除效率的1.1倍.此外,该菌株对模拟废水中总氮和COD也具有较好的去除效果.研究表明,菌株Z01在冬季污水处理中硝化脱氮具有良好的应用前景和很大的发展空间.     

Correlation of the Canol Formation source rock with oil from Norman Wells

The source of the oil at Norman Wells has long been assumed to have been the Canol Formation and/or the Bluefish Member of the Hare Indian Formation. These two units are stratigraphically above and below the Kee Scarp Formation reservoir unit respectively, and are both bituminous shales. A wide range of analytical techniques including Rock-Eval pyrolysis, solvent extraction and fractionation, capillary gas chromatography, gas chromatography-mass spectrometry, and white light and fluorescence microscopy has been used to characterize core samples of these two units and two samples of crude oil from the Norman Wells field.Most of the analytical techniques were insufficiently refined to either differentiate the extracts from each other or to make a definitive oil/source rock correlation. Collision activated decomposition coupled with multiple ion detection mass spectrometry (GC-MS-MS) did provide sufficient chemical compositional detail of the oils and the two potential sources to demonstrate that the Canol Formation has been the effective source of the Norman Wells oil whereas the Bluefish Member has not. Petrological analysis of the organic fractions also indicates that although the bulk organic composition of both units may be classified as Type II organic matter, significant differences exist between them. The Bluefish Member contains substantial amounts of megaspores, whereas the organic matter in the Canol Formation is largely phytoplankton debris.The level of thermal maturity of the core samples ranges from immature to moderately mature in the vicinity of the Norman Wells field to overmature for the samples obtained to the west and north of the field. The level of thermal maturity of the oil was observed to be somewhat higher than that of the samples of the source formation directly above the field. It was thus inferred that some lateral migration from more mature areas has occurred but the extent of this migration was not necessarily more than a few to tens of kilometers.     

三种壳色硬壳蛤(Mercenaria mercenaria)的生长性状差异及通径分析

壳色是影响商品贝类经济价值的重要性状。本研究以不同壳色的硬壳蛤（Mercenaria mercenaria）群体为繁殖亲贝，采用个体间随机交配的方法，成功选育了白、红和杂3种壳色的子代群体，并在池塘培育至360日时测量了其壳长（X₁）、壳高（X₂）、壳宽（X₃）及活体质量（Y），并使用相关性分析、主成分分析和通径分析等方法，探究了不同壳色硬壳蛤在幼虫期和稚贝期的生长性状差异及壳形态性状（壳长、壳高、壳宽）对活体质量的影响。研究结果表明：在幼虫期，与白色和红色群体相比，杂色群体生长速度更快、变态率更高，但存活率低（P<0.05）；在稚贝期，白色群体表现出显著的生长优势（P<0.05）。相关性分析结果显示，3种壳色硬壳蛤的壳形态性状（X₁、X₂、X₃）与活体质量（Y）的相关系数均达极显著水平（P<0.01）。主成分分析和通径分析结果表明，硬壳蛤的壳长（X₁）是影响其活体质量（Y）的主要因素。本研究结果能够为不同壳色硬壳蛤良种选育提供重要理论依据和基础数据。     

淡水蓝藻胶被生物学功能及其分子调控研究进展

胶被是蓝藻细胞外部的功能性结构,在蓝藻形态适应性策略中发挥重要作用,影响蓝藻水华发生及其优势维持.近年来,对蓝藻胶被的特性、结构组分、影响因子、及其工业应用等方面已有较为丰富且清晰的科学认识.但对胶被生物学功能及相关分子调控机制的研究却相对较少.本文对淡水蓝藻胶被的产生、生物学功能及其分子调控机制进行了综述,总结了胶被...     

养殖波纹唇鱼雌鱼形态性状对体质量的相关性及通径分析

为确定波纹唇鱼雌性亲鱼选育标准,了解形态性状与体质量的关系,筛选出主要生长性状。本研究开展了波纹唇鱼雌性亲鱼形态性状相关性分析、通径分析和回归分析。结果显示:波纹唇鱼雌性亲鱼体质量变异系数最大;各性状之间除头长X₃与胸鳍长X₆,X₃与躯干长X₁₁和眼径X₅与腹鳍长X₇相关性不显著,其余各性状间显著相关(P<0.05)或极显著(P<0.01)相关;筛选出4个与体质量相关性最大的形态性状体长X₂、体高X₄、臀鳍长X₈、尾长X₁₂;直接作用最大的形态性状是X₂,间接作用最大的形态性状是X₄;直接决定系数最大的是形态性状X₂, X₂-X₄的间接决定系数最大;构建多元回归方程为Y=-3.402+0.016X₂+0.453X₄