白洋淀附着藻类的初级生产力及其与水质的关系

附着藻类是湖泊中主要的生产者,尤其是草型湖泊。但与浮游藻类相比,针对附着藻类初级生产的研究还相对较少。采用原位调查与实验模拟相结合的方法测定2014—2015年间白洋淀附植藻类和附泥藻类的现存量和初级生产力,并对附着藻类初级生产与白洋淀水体理化参数的关系进行分析。结果表明,不同采样季节的附植藻类和附泥藻类的叶绿素a分别为34.83—245.22μg/cm~2和26.08—297.40μg/cm~2,无灰干重分别为0.46—5.21g/m~2和0.61—5.81g/m~2。两种附着藻类的生物量都在8月最高,4月和11月最低。空间分布上,南刘庄、府河入口的附着藻类生物量显著高于采蒲台和枣林庄。白洋淀附植藻类和附泥藻类的年均总初级生产分别为494.20mg C m~(-2)d~(-1)和474.45mg C m~(-2)d~(-1),呼吸速率为522.63mg C m~(-2)d~(-1)和508.98mg C m~(-2)d~(-1),净初级生产为-28.44mg C m~(-2)d~(-1)和-34.52mg C m~(-2)d~(-1)。白洋淀附着藻类初级生产力具有明显的时空分布规律,8月最高,6月次之,4月和11月最低,空间分布呈自西向东递减的趋势,在府河入淀口和南刘庄处最高,枣林庄和采蒲台最低。水质较好的区域的净初级生产力为正值,表明这些区域附着藻类以自养型群落为主,水质较差区域的净初级生产力为负值,则该区域以异养型群落为主。运用冗余分析法(RDA)探讨附着藻类与水质因子之间的关系,并采用向前引入法对水质因子进行逐步筛选,Monte Carlo置换检验结果显示,总磷、浮游植物叶绿素a、高锰酸盐指数、氨氮、水温、透明度、溶解氧和氮磷比是影响附着藻类生物量和初级生产的关键水质因子。附着藻类的总初级生产与水体富营养化程度呈正相关关系。     

碳源和氮源对彩绒革盖菌Coriolus versicolor木质纤维素酶和木质素酶分泌的影响

研究了彩绒草盖菌在不同碳源和氮源培养基中生长时,对纤维素酶、半纤维素酶、木质素酶（漆酶、多酚氧化酶、愈创木酚氧化酶）分泌的影响。结果表明不同碳源和氮源对酶类的分泌影响很大,富含淀粉的物质能明显促进木质素酶的分泌,而专一性底物（纤维素和半纤维素）对纤维素酶和半纤维素酶有诱导作用,麸皮也能诱导半纤维素酶的产生。     

我国生物多样性保护与减贫协同发展模式探索

生物多样性和贫困是全球关注的热点论题,生物多样性保护与减贫是关乎我国可持续发展、人民生活水平提高和2020年能否全面实现小康社会的重要问题。近年来,生态环境保护特别是生物多样性保护与贫困地区区域整体协调发展越来越受到社会各界的关注。本文对我国生物多样性保护与减贫的积极和消极影响关系进行了梳理和分析,采用态势分析法对我国现行的生物多样性保护与减贫的宏观政策在未来二者协同发展过程中的优势、劣势、机会和威胁进行了深入探讨。并在此基础上对以生物多样性可持续利用为核心的保护与减贫协调发展的途径进行了探索,提出了促进二者协同发展的生态移民、绿色资本带动、生态旅游、绿色考评等模式,以期对我国推进生物多样性保护与减贫协同发展提供借鉴。     

漆酶高产菌株的筛选及产酶条件研究

木质素是一种高度复杂的不定形的芳香族化合物 ,是仅次于纤维素的第二大再生有机资源 ,木质素的微生物降解及其有关酶类在制浆造纸工业和环境保护方面具有较大潜力。木质素的生物降解酶主要有木素过氧化物酶、漆酶、锰过氧化物酶和多酚氧化酶等。国外已有该方面的研究报道[5～ 7,9,10 ] ,但多集中在黄孢原毛平革菌 (Ｐｈａｎｅｒｏｃｈａｅｔｅｃｈｒｙｓｏｓｐｏｒｉｕｍ)木素过氧化物酶和锰过氧化物酶方面的研究 ;Ｓｌｏｍｃｚｙｎ ｓｋｉ等[8] 研究了Ｂｏｔｒｙｔｉｓｃｉｎｅｒｅａ的漆酶特性 ;国内有关研究报道较少[3 ,4 ] ,筛选漆酶高…     

Comparative characterization of novel ene‐reductases from cyanobacteria

The growing importance of biocatalysis in the syntheses of enantiopure molecules results from the benefits of enzymes regarding selectivity and specificity of the reaction and ecological issues of the process. Ene‐reductases (ERs) from the old yellow enzyme family have received much attention in the last years. These flavo‐enzymes catalyze the trans‐specific reduction of activated C?C bonds, which is an important reaction in asymmetric synthesis, because up to two stereogenic centers can be created in one reaction. However, limitations of ERs described in the literature such as their moderate catalytic activity and their strong preference for NADPH promote the search for novel ERs with improved properties. In this study, we characterized nine novel ERs from cyanobacterial strains belonging to different taxonomic orders and habitats. ERs were identified with activities towards a broad spectrum of alkenes. The reduction of maleimide was catalyzed with activities of up to 35.5 U mg^?1 using NADPH. Ketoisophorone and (R)‐carvone, which were converted to the highly valuable compounds (R)‐levodione and (2R,5R)‐dihydrocarvone, were reduced with reaction rates of up to 2.2 U mg^?1 with NADPH. In contrast to other homologous ERs from the literature, NADH was accepted at moderate to high rates as well: Enzyme activities of up to 16.7 U mg^?1 were obtained for maleimide and up to 1.3 U mg^?1 for ketoisophorone and (R)‐carvone. Additionally, excellent stereoselectivities were achieved in the reduction of (R)‐carvone (97–99% de). In particular, AnabaenaER3 from Anabaena variabilis ATCC 29413 and AcaryoER1 from Acaryochloris marina MBIC 11017 were identified as useful biocatalysts. Therefore, novel ERs from cyanobacteria with high catalytic efficiency were added to the toolbox for the asymmetric reduction of alkenes. Biotechnol. Bioeng. 2013; 110: 1293–1301. © 2012 Wiley Periodicals, Inc.     

甲壳动物精子学研究概况Ⅱ. 精子发生与精子的生化组成

在前文阐述了甲壳动物精子形态和结构的基础上,本文着重概述其精子发生与精子的生化组成.     

Deletion of Serum Amyloid A3 Improves High Fat High Sucrose Diet-Induced Adipose Tissue Inflammation and Hyperlipidemia in Female Mice

Serum amyloid A (SAA) increases in response to acute inflammatory stimuli and is modestly and chronically elevated in obesity. SAA3, an inducible form of SAA, is highly expressed in adipose tissue in obese mice where it promotes monocyte chemotaxis, providing a mechanism for the macrophage accumulation that occurs with adipose tissue expansion in obesity. Humans do not express functional SAA3 protein, but instead express SAA1 and SAA2 in hepatic as well as extrahepatic tissues, making it difficult to distinguish between liver and adipose tissue-specific SAA effects. SAA3 does not circulate in plasma, but may exert local effects that impact systemic inflammation. We tested the hypothesis that SAA3 contributes to chronic systemic inflammation and adipose tissue macrophage accumulation in obesity using mice deficient for Saa3 (Saa3 ^−/−). Mice were rendered obese by feeding a pro-inflammatory high fat, high sucrose diet with added cholesterol (HFHSC). Both male and female Saa3 ^−/− mice gained less weight on the HFHSC diet compared to Saa3^+/+ littermate controls, with no differences in body composition or resting metabolism. Female Saa3 ^−/− mice, but not males, had reduced HFHSC diet-induced adipose tissue inflammation and macrophage content. Both male and female Saa3 ^−/− mice had reduced liver Saa1 and Saa2 expression in association with reduced plasma SAA. Additionally, female Saa3 ^−/− mice, but not males, showed improved plasma cholesterol, triglycerides, and lipoprotein profiles, with no changes in glucose metabolism. Taken together, these results suggest that the absence of Saa3 attenuates liver-specific SAA (i.e., SAA1/2) secretion into plasma and blunts weight gain induced by an obesogenic diet. Furthermore, adipose tissue-specific inflammation and macrophage accumulation are attenuated in female Saa3 ^−/− mice, suggesting a novel sexually dimorphic role for this protein. These results also suggest that Saa3 influences liver-specific SAA1/2 expression, and that SAA3 could play a larger role in the acute phase response than previously thought.