Proteiniclasticum sediminis sp. nov., an obligate anaerobic bacterium isolated from anaerobic sludge

Antonie van Leeuwenhoek - An obligate anaerobic bacterial BAD-10 T was isolated from anaerobic acetochlor-degrading sludge. The strain was Gram-stain negative, curved rod-shaped,...     

A Multicenter Study of Viral Aetiology of Community-Acquired Pneumonia in Hospitalized Children in Chinese Mainland

Virologica Sinica - Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide. In this study, we aimed to describe the aetiology of viral...     

A chloride efflux transporter,BIG RICE GRAIN 1, is involved in mediating grain size and salt tolerance in rice

Grain size is determined by the size and number of cells in the grain. The regulation of grain size is crucial for improving crop yield; however, the genes and molecular mechanisms that control grain size remain elusive. Here, we report that a member of the detoxification efflux carrier /Multidrug and Toxic Compound Extrusion (DTX/MATE) family transporters, BIG RICE GRAIN 1 (BIRG1), negatively influences grain size in rice (Oryza sativa L.). BIRG1 is highly expressed in reproductive organs and roots. In birg1 grain, the outer parenchyma layer cells of spikelet hulls are larger than in wild-type (WT) grains, but the cell number is unaltered. When expressed in Xenopus laevis oocytes, BIRG1 exhibits chloride efflux activity. Consistent with this role of BIRG1, the birg1 mutant shows reduced tolerance to salt stress at a toxic chloride level. Moreover, grains from birg1 plants contain a higher level of chloride than those of WT plants when grown under normal paddy field conditions, and the roots of birg1 accumulate more chloride than those of WT under saline conditions. Collectively, the data suggest that BIRG1 in rice functions as a chloride efflux transporter that is involved in mediating grain size and salt tolerance by controlling chloride homeostasis.     

Differences between species in seed bank and vegetation helps to hold functional diversity in a floodable Neotropical savanna

种子库和植被物种之间的差异有助于保持新热带稀树草原的功能多样性 本研究的目的是量化种子库和建立的植被对物种组成、功能组成和多样性的贡献,并讨论这些差异对冲积平原植物群落更新和稳定性的影响。我们在巴西潘塔纳尔湿地的一个周期性洪水泛滥的稀树大草原上,在旱季和雨季对分布在5个地点的25个地块(10 m × 1 m)的1.5 m高度的地面覆盖植被和种子库进行了采样。采用出苗法对土壤种子库进行了评价。研究结果表明,种子库物种具有赋予群落更新的特征,而植被则具有稳定性特征。种子库的功能丰富度高于植被,而功能均匀度则低于植被。由于种子库和植被的植物特征不同,使得具有不同功能稳定性和更新特性的物种得以共存,这将有助于维持植物的功能多样性。这可能会让植物种群在应对干旱、火灾和洪水等不同的环境选择时更具有弹性。     

Secondary Structural Transformation of Bovine Lactoferricin Affects Its Antibacterial Activity

Probiotics and Antimicrobial Proteins - Lactoferricin (Lfcin) is a potent antibacterial peptide derived from lactoferrin by pepsin hydrolysis. It was hypothesized that structural transformation of...     

A C6/C5 co‐fermenting Saccharomyces cerevisiae strain with the alleviation of antagonism between xylose utilization and robustness

During second‐generation bioethanol production from lignocellulosic biomass, the desired traits for fermenting microorganisms, such as Saccharomyces cerevisiae, are high xylose utilization and high robustness to inhibitors in lignocellulosic hydrolysates. However, as observed previously, these two traits easily showed the antagonism, one rising and the other falling, in the C6/C5 co‐fermenting S. cerevisiae strain. In this study, LF1 obtained in our previous study is an engineered budding yeast strain with a superior co‐fermentation capacity of glucose and xylose, and was then mutated by atmospheric and room temperature plasma (ARTP) mutagenesis to improve its robustness. The ARTP‐treated cells were grown in 50% (v/v) leachate from lignocellulose pretreatment with high inhibitors content for adaptive evolution. After 30 days, the generated mutant LF1‐6 showed significantly enhanced tolerance, with a six‐fold increase in cell density in the above leachate. Unfortunately, its xylose utilization dropped markedly, indicating the recurrence of the negative correlation between xylose utilization and robustness. To alleviate this antagonism, LF1‐6 cells were iteratively mutated with ARTP mutagenesis and then anaerobically grown using xylose as the sole carbon source, and xylose utilization was restored in the resulting strain 6M‐15. 6M‐15 also exhibited increased co‐fermentation performance of xylose and glucose with the highest ethanol productivity reported to date (0.525 g g^?1 h^?1) in high‐level mixed sugars (80 g L^?1 glucose and 40 g L^?1 xylose) with no inhibitors. Meanwhile, its fermentation time was shortened by 8 h compared to that of LF1. During the fermentation of non‐detoxified lignocellulosic hydrolysate with high inhibitor concentrations at pH ~3.5, 6M‐15 can efficiently convert glucose and xylose with an ethanol yield of 0.43 g g^?1. 6M‐15 is also regarded as a potential chassis cell for further design of a customized strain suitable for production of second‐generation bioethanol or other high value‐added products from lignocellulosic biomass.     

A review of the botany,traditional uses,phytochemistry and pharmacology of Nepeta tenuifolia Briq.

Phytochemistry Reviews - Nepeta tenuifolia (N. tenuifolia) is a common aromatic herb that is widespread in East Asia. The aerial parts and spikes can be used as the traditional phytomedicines for...     

莫古礼(Floyd Alonzo McClure)在华采集和引种竹类植物的历史及其影响

竹类植物是美国采集者在我国采集和引种的一类主要植物。在众多的竹类植物采集者中, 莫古礼(Floyd Alonzo McClure)是最具代表性的一位, 他于1919-1940年在岭南大学开展竹类植物研究, 在此期间多次采集竹类植物标本并引种竹类植物到美国。本研究通过大量文献研究、档案查阅以及实地调研, 整理了莫古礼采集竹类植物的路线和采集地, 并对竹类植物学名进行校对, 分析了莫古礼在华研究、采集和引种竹类植物的历史及其影响。经统计, 莫古礼在华期间竹类植物标本采集地涉及12个省级行政区39个地级市, 主要集中在广东、海南、香港等地; 引种地涉及9个省级行政区的25个地级市; 共采集竹类植物标本727号1,840份, 隶属20属93种(含种下单位, 下同), 分别占我国竹类植物属和种的58.8%和17.4%; 共引种竹类植物255份, 隶属于17属77种, 分别占我国竹类植物属和种的50.0%和14.4%。莫古礼在华采集和引种竹类植物极大地发展了竹类植物分类学, 所采集的竹类植物标本为后人竹类植物研究提供了极大的帮助, 所引种的竹类植物极大丰富了美国竹类植物种类, 也促进了竹类植物在美国的应用。     

入侵植物三裂叶豚草在中国的潜在适生区预测

[目的] 三裂叶豚草是中国重点防控的入侵植物,研究其潜在的适生区分布格局变化对预警防控具有重要意义。[方法] 基于MaxEnt优化模型预测当前及未来（RCP2.6、RCP4.5、RCP8.5）气候情景下三裂叶豚草潜在的地理分布格局。[结果] 当调控倍频（RM）=3.5,FC（特征组合）=LQH（线性、二次型、片段化组合）时为最优模型,MaxEnt模型的预测结果较准确,受试者工作特征曲线下的面积（AUC值）达0.9287;综合8种途径评估出人类活动因子（hfp,贡献率69%）、等温性（bio3,贡献率8.9%）、温度季节变动系数（bio4,贡献率2.9%）、年降水量（bio12,贡献率7.3%）和海拔（ELEV,贡献率3.7%）是制约三裂叶豚草潜在地理分布的主要环境因子;在当前气候情景下,三裂叶豚草的高适生区主要集中在东北平原、江淮地区、京津冀、山东半岛等经济发达地区。[结论] 在未来气候变化情景下,三裂叶豚草在我国的潜在适生区范围总体呈现不同程度的缩减,即丧失率大于增加率;三裂叶豚草将有向南迁移的趋势;最冷月最低温度（bio6）是最不相似变量分析中出现频次最高的因子,表明温度因素对三裂叶豚草潜在地理分布变迁起到重要制约作用。本研究结果可为三裂叶豚草的预防和控制提供理论基础。