脂肪酶和酯酶指纹分析在嗜酸耐热菌快速鉴定中的应用

【目的】采用反相高效液相色谱建立嗜酸耐热菌的脂肪酶和酯酶指纹图谱,为建立基于脂肪酶和酯酶指纹分析的嗜酸耐热菌快速鉴定方法提供参考。【方法】将5个脂肪酶和酯酶底物直接与嗜酸耐热菌反应,通过反相高效液相色谱检测得到了9株嗜酸耐热菌的脂肪酶和酯酶指纹色谱图,并对色谱数据进行系统聚类分析。【结果】所得脂肪酶和酯酶指纹图谱能将脂环酸芽孢杆菌和芽孢杆菌明显分为2个类群,且同一属的2个不同种的细菌也能得到正确归类。【结论】脂肪酶和酯酶指纹分析能够用于嗜酸耐热菌的快速鉴别,且简便快速、重现性好、经济成本低,具有广阔的应用前景。     

杉木根际与非根际土壤酶活性比较

杉木根际与非根际土壤酶活性比较陈ｆ竣（中国林业科学研究院林业研究所北京１０００９１）李传涵（华中农业大学土化系武汉４３００７０）关键词杉木,根际土壤,土壤酶,杉木中毒由于林木生长的影响,使得林木根际土壤ｐＨ值、养分含量、微生物数目、生化活性等性质发生...     

不同光谱能量分布对番茄幼苗生长发育的影响#br#

 【目的】探讨不同光谱能量分布对番茄幼苗生长发育的影响,为番茄工厂化育苗的光环境调控提供理论依据。【方法】采用LED调制并获取6种不同光谱能量分布的光源,以镝灯为对照,在AGRI-LED植物培养系统内培育番茄幼苗,其它环境因子保持一致。在幼苗期测定植株株高、茎粗、叶面积等形态指标以及根系活力、糖氮物质、叶片抗氧化酶活性等生理指标,并观察叶片下表皮气孔特性。【结果】蓝光、红蓝光组合及红蓝绿光组合处理的幼苗植株矮壮、比叶面积小,根冠比及壮苗指数高,红光处理与之相反。复合光谱有利于幼苗的生长和形态建成;单一红光、黄光或绿光处理引起幼苗徒长,添加蓝光能够抑制这种效应。蓝光处理的幼苗总可溶性糖、总游离氨基酸含量以及干样质量均显著高于其它处理;红蓝绿光组合处理的幼苗根系活力、总淀粉含量最高;红蓝光组合处理的叶片光合速率及可溶性蛋白含量最高而且有利于糖氮物质在叶、茎、根中的均衡分布。蓝光、红蓝光组合、红蓝绿光组合处理的幼苗叶片的气孔密度较高,气孔面积及单位叶面积气孔面积较大;黄光处理的幼苗总的蔗糖含量虽然较高,但其它各项指标都较小,不利于幼苗生长发育。【结论】蓝光、红蓝组合光及红蓝绿组合光有利于樱桃番茄幼苗的生长发育并能降低能耗成本。     

南瓜汁的酶解法制取及其在发酵面制品中的应用

研究了南瓜酶法制汁工艺,确定了最佳酶法制汁工艺参数。结果表明:面粉中添加一定量的南瓜能够改善制品的色泽,增加制品的光泽,还能改善产品的质地和风味。但添加量过高会直接影响制品的感官品质,降低面坯的发酵速度;添加过少则失去研究的意义。500 g面粉中添加125 g南瓜汁、3 g酵母调制面团,经2 h发酵,所得制品最优。     

广东省碳汇林经营风险因素分析

在种植碳汇林增加森林碳汇成为当前全球应对气候变化重要途径之一的大背景下,通过阐述广东省碳 汇林的经营现状,根据碳汇林营造时期、经营时期以及后期市场交易的特点,将广东省碳汇林经营主体在经营时所 面临的风险总结为环境、过程和市场三大类,并加以分析,从而提出了风险控制对策院加大宣传力度,在碳汇林经营 中实现经营主体与农户双赢;增加保险投入,加强技术创新;扩充融资渠道,保障碳汇林顺利经营;完善碳汇信息平 台,建立健全碳汇市场交易制度。     

树莓品种‘Kivigold’快繁技术体系建立

以树莓（Rubus idaeus）品种‘Kivigold’带腋芽茎段为外植体,研究消毒剂HgCl2（0.1%）不同的消毒时间对外植体培养的影响,对不定芽增殖培养基和生根培养基中适宜的激素种类及浓度、生根苗移栽驯化中适宜的基质进行了筛选。结果显示,树莓品种‘Kivigold’外植体的最佳消毒时间为10 min,初代培养时只需添加6-BA即可满足外植体萌发和生长的需要;在不定芽增殖过程中,细胞分裂素主要影响不定芽的增殖,而生长素主要影响不定芽的生长,以质量浓度低于1.5 mg/L的6-BA以及质量浓度低于0.5 mg/L的NAA较为适宜,3种碳源中蔗糖更有利于不定芽的增殖和生长;经过进一步的筛选,确定适宜于‘Kivigold’不定芽增殖和生长的培养基为MS+1.00 mg/L 6-BA +0.10 mg/L NAA（含20 g/L蔗糖和5.9 g/L琼脂,pH 5.8）,适宜于‘Kivigold’不定芽生根的培养基为1/2 MS+0.10 mg/L NAA（含20 g/L蔗糖和5.9 g/L琼脂,pH 5.8）;在移栽驯化中最适宜的栽培基质为泥炭土:珍珠岩=1:1,移栽成活率可达到93.33%。     

致谢审稿专家

Two agricultural soils were collected from Dahu and Pinchen counties and swine manure compost (SMC) from Pingtung County in Taiwan, China to investigate the sorption and dissipation of three tetracyclines (TCs), i.e., oxytetracycline (OTC), tetracycline (TC) and chlortetracycline (CTC), in compost, soils and soil/compost mixtures with different organic carbon (OC) contents. There were seven treatments in total. TCs were most strongly adsorbed to SMC in all treatments due to the high OC content. When SMC was present in the soils, the sorption of TCs was significantly enhanced, which might be attributed to the increased OC content and CEC. The adsorption of TCs showed non-linear adsorption isotherms and fitted well to the Freundlich model. After 49 d of incubation at 25 oC in soils and soil/compost mixtures in the dark, TCs elapsed in all substrates, with the time required for 50% degradation (DT50) between 20 and 41 d, and the time for 90% degradation (DT90) between 68 and 137 d. Soil amended with compost enhanced the stability of TCs and reduced their mobility. The dissipation of TCs in a soil environment was slow, indicating that these compounds might be persistent in soil.     

How do hedgerows influence soil organic carbon stock in livestock‐grazed pasture?

Hedgerows have the potential to influence ecosystem function in livestock‐grazed pasture. Despite this, they are often ignored when quantifying farmland ecosystem service delivery. In this study, we assess the contribution of hedgerows to the ecosystem function of carbon (C) storage, with a particular emphasis on soil organic carbon (SOC). We measured SOC stock (kg C m^?2), on an equivalent soil mass basis, at 0–0.15 m depth in pasture adjacent to 38 hedgerows (biotic) and 16 stone walls or fences (abiotic controls) across ten farms in the county of Conwy, Wales, UK. Pasture SOC stock (~7 kg C m^?2) was similar adjacent to biotic and abiotic field boundaries, positively associated with soil moisture and negatively with soil bulk density (BD). For biotic boundaries, two further variables were significantly associated with SOC stock, distance from hedgerow (decrease in SOC stock) and slope orientation (upslope SOC stock greater than downslope). For pasture adjacent to hedgerows, a model combining the aforementioned variables (BD, soil moisture, distance from hedgerow, slope orientation) explained 78% of variation in SOC stock. This study demonstrates that whilst hedgerows do have subtle positive effects on SOC stock in adjacent pasture, SOC storage adjacent to field boundaries is influenced more by soil moisture content and BD than field boundary type.     

论“西方经济学”教学中的学生职业能力培养

随着社会经济的飞速发展,培养学生职业能力的重要性日益突出。当前＂西方经济学＂课程教学存在着课程实验内容的不足、教学活动创新性不够、教学主体参与性不强以及分析方法缺乏归纳和整理等问题,对学生专业实践、职业转换、社会交往、综合运用方面的能力培养造成不利影响,因而需要合理规划与选择,以培养出社会所需的＂一专多能＂的人才。     

基于ADAMS的随动复合平衡抽油机动力仿真

介绍了随动复合平衡抽油机的结构和基本参数,对曲柄净扭矩的计算公式进行了推导,说明了利用ADAMS进行抽油机动力仿真的基本步骤,给出了模型的建立和加载的方法,并对仿真结果进行了分析。分析结果表明,与异相型曲柄平衡抽油机相比,随动复合平衡抽油机的动力性能得以改善,具有较好的节能效果。