生物谷报道:5月7日丹麦诺维信公司和美国洛斯阿拉莫斯国家实验室等的科学家在Nature Biotechnology杂志在线版上发表文章说他们根据里氏木霉基因组所获得的数据分析发现,里氏木霉有一些基因能够编码产生一种特殊的酶,这种酶能够帮助把植物纤维素高效分解成单糖物质,这种单糖可作为生产生物乙醇的极佳中间原料。
研究表明,相比于其他真菌,里氏木霉在促成纤维素转换成单糖的同时,只有很少的基因会编码生成“吞噬”纤维素的酶,这样使得纤维素转换成单糖的过程相对高效。
目前生产燃料乙醇选用玉米、甘蔗等较易分解为糖类来源;而富含纤维素的木材、秸秆等,却因为缺乏将纤维素高效转换成糖类的方法而无法作为大规模工业生产生物乙醇的原料。这导致了“能源与人争粮”的矛盾,尤其在全球粮食供应日益紧张的今天,更成为发展生物燃料的一个瓶颈。
研究人员表示里氏木霉基因组中含有的信息有助于我们理解这一生物体高效转换纤维素以及能大量分泌蛋白酶的原因,利用这些信息将使利用纤维素大批量生产出生物燃料和其他化合物成为可能。”(生物谷www.bioon.com)
生物谷推荐原始出处:
Nature Biotechnology,doi:10.1038/nbt1403,Diego Martinez,Thomas S Brettin
Genome sequencing and analysis of the biomass-degrading fungus Trichoderma reesei (syn. Hypocrea jecorina)
Diego Martinez1,14,15, Randy M Berka2,15, Bernard Henrissat3,15, Markku Saloheimo4,15, Mikko Arvas4, Scott E Baker5, Jarod Chapman6, Olga Chertkov1, Pedro M Coutinho3, Dan Cullen7, Etienne G J Danchin3, Igor V Grigoriev6, Paul Harris2, Melissa Jackson1, Christian P Kubicek8, Cliff S Han1, Isaac Ho6, Luis F Larrondo9, Alfredo Lopez de Leon2, Jon K Magnuson5, Sandy Merino2, Monica Misra1, Beth Nelson2, Nicholas Putnam6, Barbara Robbertse10, Asaf A Salamov6, Monika Schmoll8, Astrid Terry6, Nina Thayer1, Ann Westerholm-Parvinen4, Conrad L Schoch10, Jian Yao11, Ravi Barbote1, Mary Anne Nelson12, Chris Detter1, David Bruce1, Cheryl R Kuske1, Gary Xie1, Paul Richardson6, Daniel S Rokhsar6, Susan M Lucas6, Edward M Rubin6, Nigel Dunn-Coleman13, Michael Ward11 & Thomas S Brettin6
Abstract
Trichoderma reesei is the main industrial source of cellulases and hemicellulases used to depolymerize biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. We assembled 89 scaffolds (sets of ordered and oriented contigs) to generate 34 Mbp of nearly contiguous T. reesei genome sequence comprising 9,129 predicted gene models. Unexpectedly, considering the industrial utility and effectiveness of the carbohydrate-active enzymes of T. reesei, its genome encodes fewer cellulases and hemicellulases than any other sequenced fungus able to hydrolyze plant cell wall polysaccharides. Many T. reesei genes encoding carbohydrate-active enzymes are distributed nonrandomly in clusters that lie between regions of synteny with other Sordariomycetes. Numerous genes encoding biosynthetic pathways for secondary metabolites may promote survival of T. reesei in its competitive soil habitat, but genome analysis provided little mechanistic insight into its extraordinary capacity for protein secretion. Our analysis, coupled with the genome sequence data, provides a roadmap for constructing enhanced T. reesei strains for industrial applications such as biofuel production.