Targeted environmental genomics for biocatalyst discovery

微生物世界蕴藏着丰富的DNA序列信息，这些信息可用于生产生物制品和酶，这些生物制品和酶调节与工业相关的化学反应。在某些情况下，这些基因产物编码的生物过程可以产生高能有机化合物，可能开始直接取代对环境有害的基于化石燃料的技术。多年来，由于无法培养微生物群落中存在的大多数微生物，获取微生物世界中丰富的遗传物质的途径一直受到阻碍。分子技术现在提供了从这种未培养的大多数微生物中获取DNA的方法；现在可以从直接从少数土壤中提取的DNA中构建基因库，然后这些库代表土壤样本中存在的每种微生物的遗传物质。这种捕获的环境DNA(元基因组)寄宿在易于培养的细菌中，可以检测和筛选捕获的基因的相应表达，以获得目标基因产品的表达。通过这种方式，可以利用来自未培养微生物的多样化和新的基因来执行所需的功能，而不需要培养的先决条件。这项提案描述了加拿大元微生物组倡议的建立，这是一个公众可访问的代表加拿大土壤微生物群落的环境DNA文库的集合。由于其无与伦比的微生物多样性和相应的代谢丰富性，来自加拿大不同生物群的土壤样本将被选中。这些DNA文库将通过强大的DNA测序技术进行表征，以确定每个样本的微生物群落多样性。与Iogen公司合作，我们将通过分离用于生物燃料和生物制品应用的木质纤维生物质转化的新基因，证明在这些环境文库中存在有意义的DNA。对酶活性和结构的详细描述将有助于开发或改进生产高附加值化学品的工艺。

The microbial world harbours a wealth of DNA sequence information that can be harnessed for the production of bioproducts and enzymes that mediate industrially relevant chemical reactions. In some cases, the biological processes encoded by these gene products can produce high-energy organic compounds that may begin to directly replace fossil fuel-based technologies that are harmful to the environment. For many years, access to the full richness of the genetic material in the microbial world has been hampered by the inability to cultivate most microbes present in microbial communities. Molecular techniques now provide the methods to access the DNA from this uncultivated microbial majority; it is now possible to construct gene libraries from DNA that is extracted directly from a handful of soil, and these libraries then represent the genetic material from each of the microorganisms present in that soil sample. This captured environmental DNA (the 'metagenome') is hosted in readily cultivated bacteria and the corresponding expression of captured genes can be detected and screened for the expression of targeted gene products. In this way, diverse and novel genes from uncultivated microorganisms that carry out desired functions may be exploited, without the prerequisite of cultivation. This proposal describes the establishment of the Canadian MetaMicroBiome Initiative, a publicly accessible collection of libraries of environmental DNA representing Canadian soil microbial communities. Soil samples from disparate Canadian biomes will be chosen due to their unparalleled microbial diversity and corresponding metabolic richness. These DNA libraries will be characterized by powerful DNA sequencing techniques to determine the microbial community diversity of each sample. In partnership with Iogen Corp., we will show that there is DNA of interest in these environmental libraries by isolating new genes for the conversion of lignocellulosic biomass for biofuel and bioproducts applications. Detailed characterization of the enzyme activities and structures will aid in the development or improvement of processes for the production of high value-added chemicals.