• 제목/요약/키워드: molecular evolution

검색결과 529건 처리시간 0.024초

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

  • 이혜주;배무
    • 한국미생물·생명공학회지
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    • 제20권4호
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    • pp.430-436
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    • 1992
  • 수소 생성능이 있는 Clostridium butyricum과 이 균주의 대사산물을 이용하여 수소를 생성할 수 있는 광합성 세균의 혼합 배양에 의하여 수소 생성을 할 수 있는 양 균주의 혼합 배양 동력학적 연구를 수행하였다. 혐기성 Clostridia의 발효에서 생성되는 아세트산염과 부티르산염은 Rhodopseudomonas sphaeroides에 의해 이용되어 수소를 생성하게 되었고, 이들 양 균주를 혼합 배양한 결과 수소 생성을 저해하는 아세트산염과 부티르산염의 배지내 농도는 점차 감소하였다. 이들 두 균주의 혼합 배양에서의 균체의 혼합 비율, 혼합시기, 접종량을 조사함으로써 단독 배양시와 비교하면서 최적 조건을 조사하였고, 혼합시 균체량의 비율 Clostridium 속 세균1부에 대하여 Rhodopseudomonas 속 세균 6부의 비율로 혼합할 수 있음을 확인하였다.

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Phylogenomics and its Growing Impact on Algal Phylogeny and Evolution

  • ;윤환수
    • ALGAE
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    • 제21권1호
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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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    • 제11권4호
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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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    • 한국생물공학회 2003년도 생물공학의 동향(XIII)
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    • pp.504-508
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    • 2003
  • 본 연구에서 음이온에 안정한 파파인을 얻기 위한 방법으로 방향성분자진화을 이용하였다. 변이체를 선별하기 위한 방법으로는 skin milk agar plate에 음이온성 고분자 물질은 1%농도로 첨가하여 선명한 환이 형성되는 균주를 선별하였다. 이와 같은 방법으로 선별되어진 균주 P38-10을 SDS-PAGE gel로 발현을 확인하였고, 파파인의 정량 분석방법을 통하여 활성을 측정하였다. 개량형 파파인의 발현액에 음이온성 고분자 물질을 일정하게 첨가하여 매 5시간마다 활성을 측정하였다. 이결과 개량형 파파인의 경우 wild type에 비해 10-15배의 활성과 안정성을 유지하는 것으로 확인하였다.

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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
    • 천문학회보
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    • 제40권2호
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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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