极地微生物 —— 新天然药物的潜在来源

微生物是极地生态系统的重要组成部分.由于极地独特的地理、气候及环境特点,极地微生物所具有的新颖性与多样性,在科学研究、应用开发等方面都具有重要价值,并逐渐受到人们的广泛关注.有关极地微生物的资源勘探与代谢活性产物研究,已成为国际微生物学研究的热点之一.结合笔者的工作实践,对近年来极地微生物资源的勘探与收集情况进行了介绍,并着重对以医药与生物农药等为目标的极地微生物产活性化合物的研究现状进行了概述,同时还对目前一些影响研究工作开展的限制因素进行了讨论.可以预见,针对极地微生物资源的研究开发工作,将会给新型天然药物的筛选与发现带来新的机遇与突破.     

微生物太阳能燃料电池的研究进展

摘要:能源危机已经成为阻碍世界发展的主要问题之一,微生物燃料电池的出现为能源危机提供了新的解决途径。将植物和微藻等光合生物与微生物燃料电池整合为微生物太阳能燃料电池(MSCs),能够实现将太阳能转化为电能。微生物太阳能燃料电池不仅能够实现电能持续稳定的产生,而且在污水处理,生物柴油加工以及中间代谢物生产等方面具有广阔的应用前景。本文从光合生物在微生物燃料电池中的作用的角度出发,在参考大量文献的基础上对微生物太阳能电池进行较为全面的综述,并评述其中的优点及不足之处,最后对微生物燃料电池面临的挑战及研究需求做简要分析。旨在为未来微生物太阳能燃料电池的实际应用提供参考。     

香烟烟雾提取物对小鼠气管环上皮钙粘附素表达的影响

体外进行器官培养,通过免疫组织化学和原位杂交方法检测香烟烟雾提取物（CSE）作用48、72h,小鼠气管上皮细胞上皮钙粘附素（E－cd）表达的变化。结果表明,正常对照组E－cd分布于气管假复层纤毛柱状上皮细胞连接处的胞膜上,50％CSE作用后,膜上E－cd表达减少,随着作用时间延长,胞浆内E-cd表达明显增加（P＜0.05）,而细胞内E－cd mRNA含量无明显变化。提示,CSE对小鼠气管上皮细胞E-cd表达的调控在翻译后水平,胞膜上E－cd表达的下调与吸烟所致气道上皮细胞的损伤修复过程相关。     

海洋细菌生态学的若干前沿课题及其研究新进展

海洋细菌在海洋生态系统中的重要作用随着微食物环的提出被深入认识和充分肯定。本文概述了海洋细菌在微食物环中的重要生态作用及微食物环的研究进展,海洋细菌在碳的生物地球化学循环中的重要性,海洋细菌的活性及其群落结构与功能,分析了藻际环境特性和藻际微生物在赤潮多发海域的生态作用,提出了我国海洋细菌生态学研究的若干新思考与新任务,强调了基于"以菌治藻"的新理念,开展针对于赤潮灾害防除的"微食物环-赤潮-关键微生物菌群"耦合互作这一重要科学问题研究的必要性及紧迫性。     

生物组学在污染环境微生物修复研究中的应用

随着分子生物学、生物信息学和各种理化检测技术的发展,特别是人类基因组计划成功实施以来,基因组学研究取得了重大突破与进展。而包括转录组学、蛋白组学和代谢组学在内的后基因组学也相继出现,并被广泛应用在环境微生物学的各个研究领域。本文主要概述了当前基因组学、转录组学、蛋白质组学和代谢组学在污染环境生物修复研究中的最新研究进展,分析比较了各组学的优势与不足,同时结合本课题组的主要研究方向探讨了各生物组学在赤潮生消过程和有机污染物降解机理等研究中的应用。     

Effects of bacterial communities on biofuel-producing microalgae: stimulation,inhibition and harvesting

Despite the great interest in microalgae as a potential source of biofuel to substitute for fossil fuels, little information is available on the effects of bacterial symbionts in mass algal cultivation systems. The bacterial communities associated with microalgae are a crucial factor in the process of microalgal biomass and lipid production and may stimulate or inhibit growth of biofuel-producing microalgae. In addition, we discuss here the potential use of bacteria to harvest biofuel-producing microalgae. We propose that aggregation of microalgae by bacteria to achieve >90% reductions in volume followed by centrifugation could be an economic approach for harvesting of biofuel-producing microalgae. Our aims in this review are to promote understanding of the effects of bacterial communities on microalgae and draw attention to the importance of this topic in the microalgal biofuel field.     

Evaluation of the Ion Torrent Personal Genome Machine for Gene-Targeted Studies Using Amplicons of the Nitrogenase Gene nifH

The sequencing chips and kits of the Ion Torrent Personal Genome Machine (PGM), which employs semiconductor technology to measure pH changes in polymerization events, have recently been upgraded. The quality of PGM sequences has not been reassessed, and results have not been compared in the context of a gene-targeted microbial ecology study. To address this, we compared sequence profiles across available PGM chips and chemistries and with 454 pyrosequencing data by determining error types and rates and diazotrophic community structures. The PGM was then used to assess differences in nifH-harboring bacterial community structure among four corn-based cropping systems. Using our suggested filters from mock community analyses, the overall error rates were 0.62, 0.36, and 0.39% per base for chips 318 and 314 with the 400-bp kit and chip 318 with the Hi-Q chemistry, respectively. Compared with the 400-bp kit, the Hi-Q kit reduced indel rates by 28 to 59% and produced one to seven times more reads acceptable for downstream analyses. The PGM produced higher frameshift rates than pyrosequencing that were corrected by the RDP FrameBot tool. Significant differences among platforms were identified, although the diversity indices and overall site-based conclusions remained similar. For the cropping system analyses, a total of 6,182 unique NifH operational taxonomic units at 5% amino acid dissimilarity were obtained. The current crop type, as well as the crop rotation history, significantly influenced the composition of the soil diazotrophic community detected.     

Beneficial effects of <Emphasis Type="Italic">Bacillus licheniformis</Emphasis> on the intestinal microflora and immunity of the white shrimp, <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>

When Bacillus licheniformis was administered to the white shrimp, Litopenaeus vannamei, although the total bacterial counts in the intestinal tract of the shrimp remained constant, Vibrio numbers significantly decreased (P < 0.05). Haemocyte counts together with phenoloxidase and superoxide dismutase activities of the shrimp were significantly higher (P < 0.05) in treatments than in the control. Thus, administration of B. licheniformis can improve the white shrimp's intestinal microflora and its immune ability.     

不同pH和盐度下海洋细菌对赤潮藻生长和产毒的影响

研究了在可控生态条件下。一株分离自厦门西海域沉积物的海洋细菌S10在不同pH和盐度条件下对赤潮原因种塔玛亚历山大藻(Alexandrium tamarense)生长和产毒的影响．结果表明。实验用藻株适宜生长pH为6～8,适宜盐度为20～34;该藻株在不同pH及不同盐度条件下,藻细胞毒力差异显著,且随着pH升高而下降。随着盐度增加而加大,到盐度为30时达到最高值。然后逐渐下降;菌株Sl0(1．02×10^l0cells·ml^-1)在pH7～9和盐度15～34下均能有效抑藻生长和产毒。且在pH7、盐度34时其抑藻生长作用最强;在pH7时抑藻产毒效果较好,且其抑藻产毒作用强度不随盐度变化而异．