{"id":1036898,"date":"2013-05-29T20:00:00","date_gmt":"2013-05-30T00:00:00","guid":{"rendered":"http:\/\/www.immortalitymedicine.tv\/biotechnology\/growth-and-fermentation-of-d-xylose-by-saccharomyces-cerevisiae-expressing-a-novel-d-xylose-isomerase-originating-from-the-bacterium-prevotella-ruminicola-tc2-24.php"},"modified":"2024-08-17T16:00:45","modified_gmt":"2024-08-17T20:00:45","slug":"growth-and-fermentation-of-d-xylose-by-saccharomyces-cerevisiae-expressing-a-novel-d-xylose-isomerase-originating-from-the-bacterium-prevotella-ruminicola-tc2-24","status":"publish","type":"post","link":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/biotechnology\/growth-and-fermentation-of-d-xylose-by-saccharomyces-cerevisiae-expressing-a-novel-d-xylose-isomerase-originating-from-the-bacterium-prevotella-ruminicola-tc2-24.php","title":{"rendered":"Growth and fermentation of D-xylose by Saccharomyces cerevisiae expressing a novel D-xylose isomerase originating from the bacterium Prevotella ruminicola TC2-24"},"content":{"rendered":"

Background:
\nSaccharomyces cerevisiae strains expressing D-xylose isomerase (XI) produce some of the highest reported ethanol yields from D-xylose. Unfortunately, most bacterial XIs that have been expressed in S. cerevisiae are either not functional, require additional strain modification, or have low affinity for D-xylose. This study analyzed several XIs from rumen and intestinal microorganisms to identify enzymes with improved properties for engineering S. cerevisiae for D-xylose fermentation.
\nResults:
\nFour XIs originating from rumen and intestinal bacteria were isolated and expressed in a S. cerevisiae CEN.PK2-1C parental strain primed for D-xylose metabolism by over expression of its native D-xylulokinase. Three of the XIs were functional in S. cerevisiae, based on the strain's ability to grow in D-xylose medium. The most promising strain, expressing the XI mined from Prevotella ruminicola TC2-24, was further adapted for aerobic and fermentative growth by serial transfers of D-xylose cultures under aerobic, and followed by microaerobic conditions. The evolved strain had a specific growth rate of 0.23 h-1 on D-xylose medium, which is comparable to the best reported results for analogous S. cerevisiae strains including those expressing the Piromyces sp. E2 XI. When used to ferment D-xylose, the adapted strain produced 13.6 g\/L ethanol in 91 h with a metabolic yield of 83% of theoretical. From analysis of the P. ruminicola XI, it was determined the enzyme possessed a Vmax of 0.81 mumole\/min\/mg protein and a Km of 34 mM.
\nConclusion:
\nThis study identifies a new xylose isomerase from the rumen bacterium Prevotella ruminicola TC2-24 that has one of the highest affinities and specific activities compared to other bacterial and fungal D-xylose isomerases expressed in yeast. When expressed in S. cerevisiae and used to ferment D-xylose, very high ethanol yield was obtained. This new XI should be a promising resource for constructing other D-xylose fermenting strains, including industrial yeast genetic backgrounds.Source:
http:\/\/www.biotechnologyforbiofuels.com\/content\/6\/1\/84<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Background: Saccharomyces cerevisiae strains expressing D-xylose isomerase (XI) produce some of the highest reported ethanol yields from D-xylose. Unfortunately, most bacterial XIs that have been expressed in S. cerevisiae are either not functional, require additional strain modification, or have low … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"limit_modified_date":"","last_modified_date":"","_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[1246860],"tags":[],"class_list":["post-1036898","post","type-post","status-publish","format-standard","hentry","category-biotechnology"],"modified_by":null,"_links":{"self":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/posts\/1036898"}],"collection":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/comments?post=1036898"}],"version-history":[{"count":0,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/posts\/1036898\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/media?parent=1036898"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/categories?post=1036898"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.euvolution.com\/futurist-transhuman-news-blog\/wp-json\/wp\/v2\/tags?post=1036898"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}