• Title/Summary/Keyword: Molecular evolution

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Hydrogen Evolution by Mixed Culture of Clostridia with Rhodopseudornonas sphaeroides (Rhodopseudomonas sphaeroides와 Clostridia의 혼합)

  • Yi, Hye-Joo;Bae, Moo
    • Microbiology and Biotechnology Letters
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    • v.20 no.4
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    • pp.430-436
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    • 1992
  • Hydrogen evolution by mixed fermentation of Clostn"dium butyn"cum and photosynthetic bacteria which were capable of consuming clostridial metabolites and evolving hydrogen was investigated. Acetate and butyrate formed from anaerobic clostridial fermentation were efficiently utilized by Rhodopseudomonas sPhaeroides K-7. For complete bioconversion of clostridial metabolites such as acetate and butyrate into hydrogen, mixed culture of both anaerobic organisms forming molecular hydrogen was performed. By the mixed culture, the yield of hydrogen production increased by 20 to 75% and the levels of clostridial metabolites such as acetate, butyrate decreased in the fermentation broth. Influence of cell mixing ratio. mixing time and inoculum level on hydrogen evolution by mixed culture were examined. And then cometabolic pattern compared with in pure culture was observed as time course.

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Phylogenomics and its Growing Impact on Algal Phylogeny and Evolution

  • Adrian , Reyes-Prieto;Yoon, Hwan-Su;Bhattacharya, Debashish
    • ALGAE
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    • v.21 no.1
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    • pp.1-10
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    • 2006
  • Genomic data is accumulating in public database at an unprecedented rate. Although presently dominated by the sequences of metazoan, plant, parasitic, and picoeukaryotic taxa, both expressed sequence tag (EST) and complete genomes of free-living algae are also slowly appearing. This wealth of information offers the opportunity to clarify many long-standing issues in algal and plant evolution such as the contribution of the plastid endosymbiont to nuclear genome evolution using the tools of comparative genomics and multi-gene phylogenetics. A particularly powerful approach for the automated analysis of genome data from multiple taxa is termed phylogenomics. Phylogenomics is the convergence of genomics science (the study of the function and structure of genes and genomes) and molecular phylogenetics (the study of the hierarchical evolutionary relationships among organisms, their genes and genomes). The use of phylogenetics to drive comparative genome analyses has facilitated the reconstruction of the evolutionary history of genes, gene families, and organisms. Here we survey the available genome data, introduce phylogenomic pipelines, and review some initial results of phylogenomic analyses of algal genome data.

Study of Modern Human Evolution via Comparative Analysis with the Neanderthal Genome

  • Ahmed, Musaddeque;Liang, Ping
    • Genomics & Informatics
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    • v.11 no.4
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    • pp.230-238
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    • 2013
  • Many other human species appeared in evolution in the last 6 million years that have not been able to survive to modern times and are broadly known as archaic humans, as opposed to the extant modern humans. It has always been considered fascinating to compare the modern human genome with that of archaic humans to identify modern human-specific sequence variants and figure out those that made modern humans different from their predecessors or cousin species. Neanderthals are the latest humans to become extinct, and many factors made them the best representatives of archaic humans. Even though a number of comparisons have been made sporadically between Neanderthals and modern humans, mostly following a candidate gene approach, the major breakthrough took place with the sequencing of the Neanderthal genome. The initial genome-wide comparison, based on the first draft of the Neanderthal genome, has generated some interesting inferences regarding variations in functional elements that are not shared by the two species and the debated admixture question. However, there are certain other genetic elements that were not included or included at a smaller scale in those studies, and they should be compared comprehensively to better understand the molecular make-up of modern humans and their phenotypic characteristics. Besides briefly discussing the important outcomes of the comparative analyses made so far between modern humans and Neanderthals, we propose that future comparative studies may include retrotransposons, pseudogenes, and conserved non-coding regions, all of which might have played significant roles during the evolution of modern humans.

The development of papain which is extremely stable to anionic environment by directed molecular evolution

  • Kang, Whan-Koo;Kim, Hyoung-Sik;Hwang, Sun-Duk;Kim, Bum-Chang;Son, Jeong-Il;Lee, Byung-Ryul;Lee, Chul-Woo;Lee, Bheong-Uk
    • 한국생물공학회:학술대회논문집
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    • 2003.10a
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    • pp.504-508
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    • 2003
  • In this study, development of papain which is extremely stable to negative ionic environment was made by directed molecular evolution. The screening method to confirm papain activity was designed using anionic material and skim milk agar plate for obtaining stable modified papain. Most stable modified papain P38-10 was obtained, which shows activity 10-15 times higher compared to wild type papain in anionic environment.

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Study on the global distribution of far-ultraviolet emission in our Galaxy

  • Jo, Young-Soo;Seon, Kwang-Il;Min, Kyoung-Wook;Edelstein, Jerry
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.52.1-52.1
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    • 2015
  • FIMS/SPEAR is a dual-channel far-ultraviolet imaging spectrograph on board the Korean microsatellite STSAT-1, which was launched on 2003 September 27. The primary mission goal of FIMS was to conduct a survey of diffuse far UV emissions in our Galaxy. For this purpose, FIMS completed a survey of about 84% of the sky during its operation of a year and a half. The present study aims to analyze this survey data made in the far UV wavelengths to understand the global evolution of our Galaxy. The far UV wavelength band is known to contain important cooling lines of hot gas: hence, the study will show how the hot gas in our Galaxy, produced by stellar winds and supernova explosion, evolves globally to cool down and become mixed with ambient cooler medium. One of the main findings from previous analyses of the FIMS data is that molecular hydrogen exists ubiquitously in our Galaxy. This discovery leads to another important scientific question: how is molecular hydrogen distributed in our Galaxy and how does it affect globally the evolution of our Galaxy as a cold component? Hence, the present study will cover both the hot and cold components of the ISM, which will also provide the opportunity to investigate the interactions between the two.

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