松香基功能高分子金属离子配合物固定化淀粉酶(英文)

分别以聚马来松香己二醇酯、马来松香乙二醇丙烯酯聚合物和马来松香乙二醇丙烯酯-丙烯酸共聚物为载体,金属离子为桥键配位离子固定化淀粉酶。测定了固定化淀粉酶的性能,探讨了固定化酶反应机理。结果表明金属离子作为桥键配离子的固定化淀粉酶中,PMGAECa(Ⅱ)En和poly(MGAE-AA)Ca(Ⅱ)En效果较好,重复使用5次后,每5 min的活性分别为11.33、9.44 mg/g,相对保留活性为32.78%、37.59%,最适宜温度为60、50℃,最适宜pH值为6.03、5.00。     

Non-timber forest products and household incomes in Bonga forest area,southwestern Ethiopia

We identified the major non-timber forest products （NTFPs）, their contributions to household incomes, and the determinants influenc-ing engagement of households in using NTFPs in the Bonga forest area of Gimbo and Decha Districts of Kaffa Zone, southwest Ethiopia. Six Kebeles （the lowest administrative unit in Ethiopia） were sampled from two Districts and 150 households were randomly sampled using propor-tional-to-size techniques based on the number of farm households in each Kebele. Secondary data were collected from and focus group discussions were conducted with selected individuals. The farmers diversified liveli-hood activities such as crop and livestock production, collection of NTFPs and off-farm activities. NTFPs played a significant role in household incomes. The contribution from the major NTFPs （forest coffee, honey and spices） accounted for 47% of annual household in-come. The role of NTFPs was influenced by a number of factors. Vari-ables including being native to the area （＋）, total land holding （＋）, pos-session of livestock （＋） and access to extension （＋） significantly affected forest coffee production. Age of household head （-）, land holding （＋） and distance of the market from the residence （-） significantly affected honey production. Size of landholding （＋）, distance to market （-） and distance of the forest from the residence （-） were significant variables determining the NTFP incomes derived by the households. Attention is needed in the design of policies and strategies for the well-being of households to the contribution of NTFPs to local incomes and the variables that affect the collection of NTFPs must be considered.     

接骨木果油的超临界 CO2萃取及其生物活性的研究进展

接骨木果油中富含人体必需的脂肪酸,营养保健价值很高,具有降血脂,抗癌,抗病毒,抗菌,提高学习记忆力等作用。主要综述了接骨木果油的超临界C O2萃取方法,以及它的理化特性和生物活性,并对接骨木果油的发展前景进行了展望,为接骨木果油的进一步开发和利用提供科学的依据。     

The effect of strain, growth stage, and cultivating condition of Ganoderma lucidum on 5α-reductase inhibition

The inhibitory effects of 102 methanol extracts of 40 mycelia, 9 culture fluids, and 53 fruiting bodies of 40 strains of Ganoderma lucidum on 5-reductase were investigated. The methanol extract of the fruiting body of each strain was found to show the strongest 5-reductase inhibitory activity among the extracts tested.     

生物质炭配施有机肥对旱地红壤酶活性及其微生物群落组成的影响

研究生物质炭配施有机肥对旱地的土壤养分的影响,可为旱地农作物的土壤改良提供理论依据.针对中亚热带第四纪红黏土发育的旱地红壤,本研究通过室内培养试验,向土壤中施用生物质炭配施有机肥,探索土壤微生物生物量碳和氮(MBC、MBN)、酶活性(脲酶、蔗糖酶、过氧化氢酶)和微生物群落组成的变化.试验共设置5种处理,分别为对照(CK...     

饥饿与再投喂对褶皱臂尾轮虫几种消化酶活力的影响

25℃下就饥饿与再投喂对褶皱臂尾轮虫几种消化酶活力的影响进行了研究。结果表明：整个试验过程淀粉酶和纤维素酶活力一直保持较高水平。饥饿条件下,淀粉酶和纤维素酶活力在最初的1～2d下降最为明显,此后保持在一定水平;类胰蛋白酶和胃蛋白酶活力总体下降不大。饥饿条件下带卵率<0.09时,轮虫消化酶活力显著低于正常水平。恢复投喂1d后,褶皱臂尾轮虫带卵率从0增加到0.21,类胰蛋白酶和纤维素酶活力恢复正常水平,而胃蛋白酶和淀粉酶活力高于正常水平;活体观察显示褶皱臂尾轮虫胃和胃腺在再投喂1d内恢复正常结构。投喂条件下,这几种消化酶活力的高低与与带卵率大小没有直接关系。     

受人类活动影响的牛栏江洪水计算对策

牛栏江流域内水利工程众多,人类活动频繁,致使干流上各水文站的实测洪水资料缺乏一致性。由于不具备采用水量平衡法、上下游站洪水相关法和暴雨径流等常用方法的条件,因此亟需从另一个角度来寻求解决该问题的办法。就试图通过综合考虑上游水库群对洪水的削减作用,对水文站实测洪水资料计算的结果进行修正,使最终成果接近天然状况,更合理可靠。     

Drying-rewetting cycles and γ-irradiation effects on enzyme activities of distinct layers from a Quercus ilex L. litter

In a Mediterranean climate, water stress is one of the principal constraints on proper forest ecosystem functioning. Drought influences rates of organic matter degradation by affecting microbial growth and enzyme activities. The objectives of this study were: (i) to evaluate the effect of repeated drying-rewetting cycles on cellulase, alkaline phosphatase and fluorescein diacetate (FDA) hydrolase activities of three distinct Quercus ilex L. litter layers, and (ii) to investigate the effect of these cycles on γ-irradiated litters in order to distinguish the abiotic influence on the fluctuations observed. Results, for all three layers, showed high correlations between litter water content and enzyme activities. Under mesocosm conditions, and using non-sterilized litter samples, cellulase, alkaline phosphatase, and FDA activities significantly decreased or increased during drying or rewetting cycles respectively. Significant differences were also found when evaluating the effect of litter depth on enzyme activities, the intermediate depth (OLv layer) generally being the most active. For γ-sterilized samples, FDA activity still fluctuated with drying-rewetting cycles. Assays showed that pre-humidification of γ-irradiated litter increased FDA activity two-fold in the first 30 min. All these results have shown that, following drying-rewetting cycles, some of the fluctuations occur independently of microbial growth, suggesting abiotic interactions, such as desorption, in combination with both solvatation status and conformational changes of enzymes.     

汀江流域长汀段水沙变化特征及其影响因素

河流水沙变化直接反映流域的生态环境状况和土壤侵蚀程度.为探讨南方典型水土流失治理区水沙变化特征及其驱动机制,以汀江流域长汀段1982年1月至2014年12月径流、输沙数据为研究对象,采用CEEMDAN法、Mann-Kendall检验法、Pettitt检验法及构建水沙关系模型分析水沙的变化特征,通过双累积曲线法定量研究降...     

Effect of organic and inorganic sources of nutrients on soil microbial activity and soil organic carbon build-up under rice in west coast of India

The effect of medium-term (5 years) application of organic and inorganic sources of nutrients (as mineral or inorganic fertilizers) on soil organic carbon (SOC), SOC stock, carbon (C) build-up rate, microbial and enzyme activities in flooded rice soils was tested in west coast of India. Compared to the application of vermicompost, glyricidia (Glyricidia maculate) (fresh) and eupatorium (Chromolaena adenophorum) (fresh) and dhaincha (Sesbania rostrata) (fresh), the application of farmyard manure (FYM) and combined application of paddy straw (dry) and water hyacinth (PsWh) (fresh) improved the SOC content significantly (p < 0.05). The lowest (p < 0.05) SOC content (0.81%) was observed in untreated control. The highest (p < 0.05) SOC stock (23.7 Mg C ha^?1) was observed in FYM-treated plots followed by recommended dose of mineral fertilizer (RDF) (23.2 Mg C ha^?1) and it was lowest (16.5 Mg C ha^?1) in untreated control. Soil microbial biomass carbon (C_mb) (246 µg g^?1 soil) and C_mb/SOC (1.92%) were highest (p < 0.05) in FYM-treated plot. The highest (p < 0.05) value of metabolic quotient (qCO₂) was recorded under RDF (19.7 µg CO₂-C g^?1 C_mb h^?1) and untreated control (19.6 µg CO₂-C g^?1 C_mb h^?1). Application of organic and inorganic sources of nutrients impacted soil enzyme activities significantly (p < 0.05) with FYM causing highest dehydrogenase (20.5 µg TPF g^?1 day^?1), phosphatase (659 µg PNP g^?1 h^?1) and urease (0.29 µg urea g^?1 h^?1) activities. Application of organic source of nutrients especially FYM improved the microbial and enzyme activities in flooded and transplanted rice soils. Although the grain yield was higher with the application of RDF, but the use of FYM as an organic agricultural practice is more useful when efforts are intended to conserve more SOC and improved microbial activity.