Isolation of myxobacteria from the marine environment

In an attempt to isolate indigenous marine myxobacteria from coastal samples, we obtained two swarm forming bacteria. Both isolates formed cell aggregates which, at least in one isolate, developed to fruiting body-like structures consisting of a mass of myxospore-like cells. The optimum NaCl concentrations for their growth were between 2 and 3%, comparable to the NaCl concentration of seawater. This growth characteristic strongly suggests that the two isolates are specific marine bacteria. The 16S rDNA sequence studies indicated that the two isolates were related to the genus Nannocystis. Based on the phylogenetic distances between branches, we concluded that the isolates should be assigned to two new myxobacterial genera.     

中国海兽学研究概况

中国古代关于海兽知识的年代湮远,约在公元前700-200年成书的《尔雅》中就记有白鱀豚、江豚等齿鲸。但此后的2000余年间,海兽科学和其他学科一样受封建制度的束缚,进步很慢。     

Biogeographic and Evolutionary Patterns of Trace Element Utilization in Marine Microbial World

Trace elements are required by all organisms, which are key components of many enzymes catalyzing important biological reactions. Many trace element-dependent proteins have been characterized; however, little is known about their occurrence in microbial communities in diverse environments, especially the global marine ecosystem. Moreover, the relationships between trace element utilization and different types of environmental stressors are unclear. In this study, we used metagenomic data from the Global Ocean Sampling expedition project to identify the biogeographic distribution of genes encoding trace element-dependent proteins (for copper, molybdenum, cobalt, nickel, and selenium) in a variety of marine and non-marine aquatic samples. More than 56,000 metalloprotein and selenoprotein genes corresponding to nearly 100 families were predicted, becoming the largest dataset of marine metalloprotein and selenoprotein genes reported to date. In addition, samples with enriched or depleted metalloprotein/selenoprotein genes were identified, suggesting an active or inactive usage of these micronutrients in various sites. Further analysis of interactions among the elements showed significant correlations between some of them, especially those between nickel and selenium/copper. Finally, investigation of the relationships between environmental conditions and metalloprotein/selenoprotein families revealed that many environmental factors might contribute to the evolution of different metalloprotein and/or selenoprotein genes in the marine microbial world. Our data provide new insights into the utilization and biological roles of these trace elements in extant marine microbes, and might also be helpful for the understanding of how these organisms have adapted to their local environments.     

Bioprocess engineering: now and beyond 2000

Abstract: Bioprocess engineering may be defined as the translation of life-science discoveries into practical products, processes, or systems capable of serving the needs of society. It is a critical link from discovery to commercialization. Current bioprocess engineering is primarily focused on biopharmaceutical products of high dollar value per gram such as erythropoietin or growth hormones. However, other products of current interest include ethanol, amino acids, organic acids, antibiotics, and specialty chemicals. Current challenges for increased use of bioprocesses for producing bulk and semi-bulk chemicals include both technical and infrastructural barriers. Technical barriers are easy to identify and at times can be overcome by engineering improvements or changes brought about radical developments in science (e.g. recombinant DNA). Infrastructural barriers, such as raw-material substitutions or educational limitations are more difficult to define and change. Recently the National Academy of Sciences examined barriers to bioprocess engineering and issued a report entitled: "Putting Biotechnology to Work: Bioprocess Engineering". A key recommendation was the establishment of a coordinated long-range plan of research, development, training and education in bioprocess engineering involving participation by industry, academe and the federal government. The report was the first national analysis devoted entirely to bioprocess engineering and covered new topics such as space bioprocess engineering. Other topics covered by the author include the current state of the US chemical industry and future directions in three promising areas of bioprocess engineering environmental bioprocess engineering, marine bioprocess engineering and microsystem bioprocess engineering.     

Blooms of sequence-specific culturable bacteria in the sea

Abstract Using specific deoxyoligonucleotide probes we have discovered seasonally strong (up to ∼ 100%) dominance of bacteria hybridizing to a single probe, in near shore waters off Scripps pier (32°53'N; 117°15'W). The probes were designed from partially sequenced 16S rRNA (V3 domain) of isolated marine bacteria. The results indicate that this approach may be used for studies of bacterial populations in the marine environment. We have shown that a number of genotypes that at times are dominant in the natural assemblages are culturable (and not, 'viable-but-unculturable'). Additionally, our data suggests that the discrepancy between viable counts and direct counts in sea water samples can be explained by low plating efficiency.     

In-silico study of seaweed secondary metabolites as AXL kinase inhibitors

AXL kinase is an attractive cancer target for drug design and it is involved in different cancers. A set of molecule databases with 1072 secondary metabolites from seaweeds were screened against the AXL kinase active site and eight molecules were shortlisted for further studies. From the docking analysis of the complexes, four molecules GA011, BE005, BC010, and BC005 are showing prominent binging. From the 100 ns of molecular dynamics simulations and ligand-bound complex MM-PBSA free energy analysis, two molecules BC010 (ΔG = −135.38 kJ/mol) and BE005 (ΔG = −141.72 kJ/mol) are showing molecule stability in the active site also showing very strong binding free energies. It suggests these molecules could be the potent molecules for AXL kinase.     

长期复合污染胁迫下杉木林分结构变化研究

对长期复合污染胁迫下杉林林分进行了群落调查,采用比较方法着重分析了群落结构和物种组成结构等方面的变化。结果表明：长期复合污染胁迫下,杉木林分空间结构矮小化,其中乔木群体平均高度降低４．１４ｍ,平均胸高直径降低３．６９ｃｍ;杉木种群生长衰弱,密度降低７株／１００ｍ＾２,盖度减小２５％,乔木群体的不良变化为林床植物的发展创造了有利的条件。灌木层密度和盖度分别增加４３株／１００ｍ＾２和３５％。导致污染胁     

粉尘、SO2和NOx等的复合污染胁迫下马尾松林的退化特征研究

湖南省毛易林场马尾松林长期受粉尘、SO2 、NOx 等的混合污染物复合危害后 ,林相呈灰绿色 ,蒙尘量大 ,林冠不整 ,衰弱、死亡木增加 31 .4 %～ 4 7.8% ;针叶纤细 ,部分叶面有泛黄斑和坏死斑。林缘、林内松针长度分别缩短达 1 7.5 %和 1 0 .0 % ,百针重分别减少 74 .6%和 4 3.6% ;2年生松针内养分元素季节变化规律相似 ,但 N和 P含量下降 ,K和 S含量明显增高 ,显示养分循环失调。林分高和胸径生长明显受挫 ,受害最重的 A林分分别降低 2 .7m和 1 .6cm,林分胸径分布结构“左移”(小径级增多 ) ,高和胸径连年生长量退化了 1 1 .4 %和 8.1 % ;林分平均单株结球果数仅 5 .3～ 7.1个 ,成熟种子千粒重仅 6.8～8.1 g,其当年发芽率仅 31 %～ 5 2 % ,种子空粒、涩粒多。污染区 A、B林分乔木层地上部分生物量分别衰退了 1 1 9.4 %和 70 .7% ,其中最明显的是叶量 ,分别达 31 5 .1 %和 4 9.7% ;根量分别退化了 5 9.6%和38.5 % ,其中最明显的是吸收根量 ,分别降低 1 5 8.3%和 92 .2 %。草本层生物量分别衰退 75 .3%和1 5 7.8% ,但灌木层生物量未明显衰退 ;从林分物种及组织结构来看 ,长期污染胁迫未引起明显的种类组成变化 ,但种群结构发生变化 ,多样性指数 ( H′)和均匀度 ( EI)降低 ,生态优势度 ( SN)增加。文中对马尾     

海洋生物资源开发研究概况与展望

对各类主要的海洋生物资源开发研究作了简洁概述,从海洋生物体内获取的各种活性物质,除可研究海洋药物外,还可开发海洋生物功能性保健品,海洋生物化工产品等;此外,尚可利用其特异的化学结构作为先导物,设计合成治疗疑难病的创新药物。可以预言,２１世纪将是人类研究、开发、利用海洋生物资源的黄金时代