环境中纤维素降解菌群的筛选与降解活性分析

分别从富含腐殖质的土壤,造纸厂原料堆放处和排污口污泥中筛选得到9组纤维素分解能力强且性能稳定的纤维素混合菌群S1,S2,S3,S4,S5,J1,J2,J3,J4。它们的初始培养条件为培养基初始pH值6-8,培养温度50-60℃,静置培养。将这9组混合菌群在各自的最适温度和初始pH值下培养3天,分别于24h,48h,72h测定CMC酶活,测得的最高的三个CMC酶活分别出现在S1的72h,S2的48h和J1的48h,分别为33．1,37．7和34．1U·mL^-1。     

Physiology and Microbiological Quality of Fresh-cut Mango Cubes as Affected by High-O2 Controlled Atmospheres

Preliminary study showed that among 40‐ to 100‐kPa O₂ atmospheres, 60‐kPa O₂ reduced the respiration of fresh‐cut ‘Carabao’ mango cubes the most when held at 5 °C or 13 °C for 42 h. Therefore, the effects of 60‐kPa O₂ on the physiology and microbial quality of fresh‐cut ‘Carabao’ and ‘Nam Dokmai’ mango cubes were determined and compared with those held in air. The high‐O₂ atmosphere reduced the respiration rate of ‘Carabao’ mango cubes stored at 5 °C but stimulated the rate after 2 d of storage at 13 °C. Browning of ‘Carabao’ cubes was accelerated by 60‐kPa O₂ at 13 °C. With ‘Nam Dokmai’ cubes, the high O₂ had no effect on respiration rate, browning, and incidence of water‐soaked appearance at 5 °C and 13 °C. The high O₂ did not affect texture or ascorbic acid content of ‘Carabao’ and ‘Nam Dokmai’ mango cubes at either temperature. Counts of lactic acid bacteria and molds were below the detection level (2.4 log colony‐forming units [CFU]/g) during storage at both temperatures. However, 60‐kPa O₂ stimulated the growth of mesophilic aerobic bacteria on ‘Carabao’ cubes and yeasts of ‘Nam Dokmai’ cubes at 13 °C. The increased microbial count may have been due to the higher pH of cubes stored in 60‐kPa O₂ at 13 °C than at 5 °C or in air. Within ‘Nam Dokmai’ mango cubes, the predominant genera in mesophilic aerobic bacteria were Enterobacter, Klebsiella, and Pantoea and in the yeasts were Candida, Cryptococcus, and Rhodotorula. These results indicate that 60‐kPa O₂ is not desirable for mango cubes when held at 13 °C.     

Clinically Approved Carbon Nanoparticles with Oral Administration for Intestinal Radioprotection via Protecting the Small Intestinal Crypt Stem Cells and Maintaining the Balance of Intestinal Flora

The exploration of an old drug for new biomedical applications has an absolute predominance in shortening the clinical conversion time of drugs for clinical application. In this work, carbon nanoparticles suspension injection (CNSI), the first clinically approved carbon nanoparticles in China, is explored as a new nano‐radioprotective agent for potent intestinal radioprotection. CNSI shows powerful radioprotective performance in the intestine under oral administration, including efficient free radical scavenging ability, good biosafety, high chemical stability, and relatively long retention time. For example, CNSI shows high reactive oxygen species (ROS) scavenging activities, which effectively alleviates the mitochondrial dysfunction and DNA double‐strand breaks to protect the cells against radiation‐induced damage. Most importantly, this efficient ROS scavenging ability greatly helps restrain the apoptosis of the small intestinal epithelial and crypt stem cells, which decreases the damage of the mechanical barrier and thus relieves radiation enteritis. Moreover, CNSI helps remove the free radicals in the intestinal microenvironment and thus maintain the balance of intestinal flora so as to mitigate the radiation enteritis. The finding suggests a new application of clinically approved carbon nanoparticles, which not only promotes the development of new intestinal radioprotector, but also has a great potential for clinical transformation.     

基于Web的植物志数据库管理系统的设计与实现

根据植物的分类、特点以及植物志检索等要求,采用ASP技术设计并实现了Web植物志数据库管理系统。针对数据查询要求,使用了查询结果缓存技术和多字段匹配关键字查询的方法。系统具有专业服务和科普两方面的功能。     

中国鸭绿江口滨海湿地植物多样性分析

通过线路、样地调查法及聚类分析等研究方法,对鸭绿江口湿地的植物多样性进行分析。得出以下结论:该地区植物种类丰富多样,以被子植物、双子叶植物为主,优势科现象明显,单种属和少种属占据比率较高,表现出一定残遗性;区系分布类型多样,来源较广泛,具有一定古老性,但特有属、种匮乏;区系温带属性明显,热带成分也比较丰富,说明本区与热带植物区系亲缘关系较高,显示出过渡性,建议应加强植物多样性的保护与管理,减少干扰与破坏,为保护候鸟迁徙地和区域生态安全提供良好环境。     

桑叶生物碱对D-半乳糖诱导小鼠肠道菌群紊乱的调节作用

目的:探究桑叶生物碱对D-半乳糖诱导小鼠肠道菌群失衡的改善作用,为桑叶生物碱的开发利用提供依据.方法:采用D-半乳糖诱导建立小鼠氧化损伤模型,然后灌胃低(50?mg/kg?mb)、中(100?mg/kg?mb)、高(200?mg/kg?mb)剂量的桑叶生物碱,45?d后测定小肠组织中活性氧(reactive oxyge...     

肠道菌群与特殊环境关系的研究进展

肠道菌群的动态平衡是维持人体健康的重要标志之一,许多疾病证实与肠道菌群失调有关.环境是影响肠道菌群的重要因素,进一步可分为常规环境和特殊环境,其中关于特殊环境与肠道菌群之间相互联系的研究少之又少,而两者之间的相互作用对在特殊环境下工作的特殊人群健康具有十分重要的意义.因此,本文从特殊环境入手,重点探讨高原、航空航天、航...     

新采收稻谷与仓储稻谷的霉菌菌相分析

采用传统培养法和宏基因组学技术对比了2017年新收获稻谷和将其仓储一年后稻谷中的真菌菌相差异。结果显示,稻谷中的真菌菌群由各类田间真菌转变为曲霉类和青霉类等仓储型真菌为主的优势菌群,并且两种方法的检测结果有着高度的一致性。可为稻谷在长距离运输期间的霉变防控提供重要的指导依据。     

酒曲微生物菌群对酿造酒产品风味影响的研究进展

中国传统酿造过程中,酒曲是酿造酒必不可少的辅料,是酿酒微生物的载体,是造就酒体特征风味的关键因素。该文总结了中国以酒曲酿造的发酵酒（黄酒）和蒸馏酒（白酒）中的风味物质及各种酒曲中酿酒微生物的组成,综述酒曲中微生物对酒体风味的影响,以期为酒曲的标准化生产提供参考。     

水杨酸铬(Ⅲ)配合物对肥胖小鼠肠道菌群的影响

目的探讨水杨酸铬(Ⅲ)配合物{[Cr(Ⅲ)(5-Cl-SA)(en)2]Cl·2H2O·2CH3OH}对肥胖小鼠的减肥效果和对小鼠肠道菌群结构的影响。方法昆明种小鼠随机分为正常组、模型组和药物组,定期称重并收集其粪便;给药9周后,解剖小鼠并测定多项生理生化指标;提取粪便微生物总DNA,PCR扩增16S rDNA V3可变区,并行变性梯度凝胶电泳(DGGE),分析肠道微生物多样性,利用主成分分析(PCA)研究肠道微生物群落组成的变化。结果水杨酸铬(Ⅲ)配合物可显著控制小鼠体重增长,且有减肥功效;给药9周后,小鼠各项生理指标均趋于正常。PCR-DGGE指纹图谱分析结果显示,高脂饲料和受试药物对肠道微生物的多样性影响不大,但对菌群结构影响显著。结论本研究为开发新型减肥药物提供了依据。