不同龄期中华蜜蜂(Apis cerana cerana)消化道糖转化酶活性的研究

通过对 5组不同日龄的中华蜜蜂的消化道糖转化酶的活性进行测定 ,结果表明 ,不同日龄及消化道不同部分的糖转化酶的活性在不同的部位、不同的发育日龄都有一定的差异。

不同龄期意蜂消化道酶谱带分布及糖转化酶的研究

采用聚丙烯凝胶电泳对不同日龄的意大利蜜蜂 (Apismelliferaligustica)的消化道酶进行谱带分析 ,不同日龄意大利蜜蜂消化道酶带分布和对糖转化酶的活性有差异。 7～ 1 8日龄意大利蜜蜂糖转化酶活性最高 ,而 1～ 3日龄最低。相同日龄意大利蜜蜂消化道不同部位糖转化酶活性大小依次为中肠、前肠、后肠。

研究揭示马铃薯低温糖化的分子机制

近日，从华中农业大学获悉，该校园艺林学学院马铃薯科研团队在马铃薯加工品质改良研究方面取得新进展，研究人员首次发现能够精细调控马铃薯蔗糖转化酶活性的蛋白质复合体。该成果在线发表在《植物生理学》杂志上。 据介绍，马铃薯块茎的低温糖化现象严重影响油炸加工产品的品质，同时还会生成对人体有害的丙烯酰胺，控制低温糖化一直是马铃薯品质改良的重点和难点。该研究首次发现马铃薯中存在由蔗糖转化酶、转化酶抑制蛋白和SNRK1激酶组成的蛋白质复合体，级联式地调节马铃薯块茎在低温贮藏条件下的转化酶活性。而SNRK1α亚基的磷酸化使其β亚基失去功能，从而激活了转化酶抑制蛋白，使转化酶不能降解蔗糖，因此减少了低温下马铃薯还原糖的积累。

啤酒行业动态

10月1日《啤酒》新国标实施 《啤酒》国家标准已从10月1日起正式实施。与原国标相比，新标准修改了干啤酒等特种啤酒的定义，并增加了无醇啤酒和果蔬类啤酒的定义；酒精度的计量单位改为体积百分含量（％vol）表示；对淡色啤酒、浓色啤酒、黑色啤酒的泡持性、酒精度、原麦汁浓度、总酸、二氧化碳指标进行了调整；另增加了生啤酒的蔗糖转化酶活性要求；对出厂检验项目也进行了适当修改。

抽查发现:我国七种啤酒产品质量较差

强制性国家标准GB4927—2001《啤酒》、GB2758—2005《发酵酒卫生标准》、GB10344—1989做料酒标签标准》对特种啤酒的特征性指标（干啤酒中真正发酵度、冰啤酒中浊度、纯生啤酒的蔗糖转化酶活性）、包装（瓶装啤酒是否用绳捆扎出售、有无“B”标记）和甲醛及致病菌等项目指标有要求。

华中农大研究揭示马铃薯低温糖化的分子机制

近日，记者从华中农业大学获悉，该校园艺林学学院马铃薯科研团队在马铃薯加工品质改良研究方面取得新进展，研究人员首次发现能够精细调控马铃薯蔗糖转化酶活性的蛋白质复合体。该成果在线发表在《植物生理学》杂志上。

Soil Enzyme Activities on Eroded Slopes in the Sichuan Basin, China

Determining how soil erosion affects enzyme activity may enhance our understanding of soil degradation on eroded agricultural landscapes. This study assessed the changes in enzyme activity with slope position and erosion type by selecting water and tillage erosion-dominated slopes and performing analyses using the 1376s technique. The 137Cs data revealed that soil loss occurred in the upper section of the two eroded slope types, while soil accumulation occurred in the lower section. The invertase activity increased downslope and exhibited a pattern similar to the 137Cs data. The spatial patterns of urease and alkaline phosphatase activities were similar to the 137Cs inventories on the water and tillage erosion-dominated slopes, respectively. On both the eroded slope types, the invertase activity and soil organic carbon content were correlated, but no correlation was observed between the alkaline phosphatase activity and total phosphorus content. Nevertheless, the urease activity was correlated with the total nitrogen content only on the water erosion-dominated slopes. The enzyme activity-to-microbial biomass carbon ratios indicated high activities of invertase and urease but low activity of phosphatase on the water erosion-dominated slopes compared with the tillage erosion-dominated slopes. Both the invertase activity and the invertase activity-to-microbial biomass carbon ratio varied with the slope position. Changes in the urease activity-to-microbial biomass carbon ratio were significantly affected by the erosion type. These suggested that the dynamics of the invertase activity were linked to soil redistribution on the two eroded slope types, whereas the dynamics of the urease and alkaline phosphatase activities were associated with soil redistribution only on the water or tillage erosion-dominated slopes, respectively. The erosion type had an obvious effect on the activities of invertase, urease and alkaline phosphatase. Soil redistribution might influence the involvement of urease in the N cycle and alkaline phosphatase in the P cycle. Thus, enzyme activity-to-microbial biomass ratios may be used to better evaluate microbiological activity in eroded soils.