浙江水源地河流浮游动物多样性与环境因子的通径分析

为探明水源地河流浮游动物多样性及与水环境因子的关系, 利用浮游动物多样性参数监测水质, 2010-2014年间, 我们于每年的冬季(1月)、春季(4月)、夏季(7月)和秋季(10月), 对浙江2个水源地河流采样站(H1站和H2站)展开浮游动物种类组成、丰度和多样性指数的季节性调查, 同时测定水环境因子。结果表明, H1站和H2站浮游动物平均丰度分别为1,387.4 ind./L和873.0 ind./L, 小型浮游动物(轮虫 + 桡足类无节幼体)丰度分别占92.8% (H1站)和91.5% (H2站)。两采样站轮虫、枝角类和桡足类的优势种均为针簇多肢轮虫(Polyarthra trigla)、短尾秀体溞(Diaphanosoma brachyurum)和温剑水蚤(Thermocyclops sp.)。多元逐步回归与通径分析结果表明: 冬季氮磷比是轮虫类Shannon-Wiener多样性指数(H′)波动的限制因子, 主要通过总磷含量对轮虫类H′指数产生较大的间接正向作用; 春季氮磷比是轮虫类H′指数发展的决策因子; 秋季氮磷比可通过总氮含量对轮虫类H′指数产生较大的间接正向作用。冬季氨氮、总氮含量分别是甲壳动物体积多样性指数(Hs)的决策因子和限制因子。夏季溶解氧含量是总浮游动物物种丰富度(d)波动的限制因子, 主要通过pH值对d指数产生较大的间接正向作用, 作用机制表现为轮虫类H′指数随着夏季溶解氧含量的升高呈极显著上升(P < 0.01), 而甲壳动物Hs指数则显著下降(P < 0.05)。水源地河流环境因子与浮游动物多样性之间的相互关系为浙江水源地生态学监测提供了可能性。     

“互联网+”教育在生物化学课程中应用的分析与思考

在"互联网+"教育的大力推广之下,微课、慕课、翻转课堂、手机课堂等多种教学模式应运而生。通过在生物化学课程中运用"互联网+"教学模式:教师课前准备并向学生发布相关学习资源、学生预习情况和预习效果的评价、学生成绩量化标准,取得了初步的成效。本文从我国"互联网+生物化学"教育现状、"互联网+"教育在生物化学课程中的应用以及生物化学课程与"互联网+"教育结合的未来发展等三个方面进行了阐述。     

不同碳氮源对花脸香蘑胞外酶活性的影响

以花脸香蘑Lepista sordida为材料,研究其分别在9种碳源和11种氮源液体培养条件下不同阶段pH值和葡萄糖浓度的变化,以及不同碳氮源对其所分泌的木质素过氧化物酶、羧甲基纤维素酶、锰过氧化物酶和漆酶活性的影响。结果表明,pH值在不同碳源培养后期变化显著（P<0.05）,而在不同氮源培养阶段无明显变化（P>0.05）,葡萄糖浓度和菌丝量在不同碳氮源中也无显著差异（P<0.05）。不同碳源和氮源培养基对花脸香蘑木质素过氧化物酶、羧甲基纤维素酶、锰过氧化物酶和漆酶活性均具有影响（P<0.05）。木糖和米糠有利于花脸香蘑分泌羧甲基纤维素酶（P<0.05）,红糖和牛肉浸膏有利于其分泌漆酶（P<0.05）,白砂糖和豆粉有利于其分泌锰过氧化物酶（P<0.05）,木糖和尿素有利于其分泌木质素过氧化物酶（P<0.05）。本研究为选择合适培养基以提高花脸香蘑生物转化效率提供了理论基础。     

Microbioreactor-assisted cultivation workflows for time-efficient phenotyping of protein producing Aspergillus niger in batch and fed-batch mode

In recent years, many fungal genomes have become publicly available. In combination with novel gene editing tools, this allows for accelerated strain construction, making filamentous fungi even more interesting for the production of valuable products. However, besides their extraordinary production and secretion capacities, fungi most often exhibit challenging morphologies, which need to be screened for the best operational window. Thereby, combining genetic diversity with various environmental parameters results in a large parameter space, creating a strong demand for time-efficient phenotyping technologies. Microbioreactor systems, which have been well established for bacterial organisms, enable an increased cultivation throughput via parallelization and miniaturization, as well as enhanced process insight via non-invasive online monitoring. Nevertheless, only few reports about microtiter plate cultivation for filamentous fungi in general and even less with online monitoring exist in literature. Moreover, screening under batch conditions in microscale, when a fed-batch process is performed in large-scale might even lead to the wrong identification of optimized parameters. Therefore, in this study a novel workflow for Aspergillus niger was developed, allowing for up to 48 parallel microbioreactor cultivations in batch as well as fed-batch mode. This workflow was validated against lab-scale bioreactor cultivations to proof scalability. With the optimized cultivation protocol, three different micro-scale fed-batch strategies were tested to identify the best protein production conditions for intracellular model product GFP. Subsequently, the best feeding strategy was again validated in a lab-scale bioreactor.     

2D-LC/MS techniques for the identification of proteins in highly complex mixtures

Today, 2D online or offline liquid chromatography/mass spectrometry is state of the art for the identification of proteins from complex proteome samples in many laboratories. Both 2D liquid chromatography methods use two orthogonal liquid chromatography separation techniques. The most commonly used techniques are strong cation exchange chromatography for the first dimension and reversed phase separation for the second dimension. In order to improve sensitivity the reversed phase separation is usually performed in the nanoflow scale and mass spectrometry is used as the final detection method. The high-performance liquid chromatography techniques complement the 2D-gel techniques supporting their weaknesses. This is especially true for the gel separation of hydrophobic membrane proteins, which play an important role in living cells as well as being important targets for future pharmaceutical drugs.     

Natural glycan microarrays

Glycan microarrays are emerging as increasingly used screening tools with a high potential for unraveling protein–carbohydrate interactions: probing hundreds or even thousands of glycans in parallel, they provide the researcher with a vast amount of data in a short time-frame, while using relatively small amounts of analytes. Natural glycan microarrays focus on the glycans’ repertoire of natural sources, including both well-defined structures as well as still-unknown ones. This article compares different natural glycan microarray strategies. Glycan probes may comprise oligosaccharides from glycoproteins as well as glycolipids and polysaccharides. Oligosaccharides may be purified from scarce biological samples that are of particular relevance for the carbohydrate-binding protein to be studied. We give an overview of strategies for glycan isolation, derivatization, fractionation, immobilization and structural characterization. Detection methods such as fluorescence analysis and surface plasmon resonance are summarized. The importance of glycan density and multivalency is discussed. Furthermore, some applications of natural glycan microarrays for studying lectin and antibody binding are presented.     

Characterization of seven novel mutations on the HEXB gene in French Sandhoff patients

Sandhoff disease (SD) is an autosomal recessive lysosomal storage disease caused by mutations in the HEXB gene encoding the beta subunit of hexosaminidases A and B, two enzymes involved in GM2 ganglioside degradation. Eleven French Sandhoff patients with infantile or juvenile forms of the disease were completely characterized using sequencing of the HEXB gene. A specific procedure was developed to facilitate the detection of the common 5′-end 16 kb deletion which was frequent (36% of the alleles) in our study. Eleven other disease-causing mutations were found, among which four have previously been reported (c.850C>T, c.793T>G, c.115del and c.800_817del). Seven mutations were completely novel and were analyzed using molecular modelling. Two deletions (c.176del and c.1058_1060del), a duplication (c.1485_1487dup) and a nonsense mutation (c.552T>G) were predicted to strongly alter the enzyme spatial organization. The splice mutation c.558+5G>A affecting the intron 4 consensus splice site led to a skipping of exon 4 and to a truncated protein (p.191X). Two missense mutations were found among the patients studied. The c.448A>C mutation was probably a severe mutation as it was present in association with the known c.793T>G in an infantile form of Sandhoff disease and as it significantly modified the N-terminal domain structure of the protein. The c.171G>C mutation resulting in a p.W57C amino acid substitution in the N-terminal region is probably less drastic than the other abnormalities as it was present in a juvenile patient in association with the c.176del. Finally, this study reports a rapid detection of the Sandhoff disease-causing alleles facilitating genetic counselling and prenatal diagnosis in at-risk families.