[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-43187-en":3,"doc-seo-43187-105":30,"detail-sidebar-cat-0-en-105":91},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":20,"is_deleted":4,"is_public":21,"is_downloadable":21,"audit_status":21,"page_count":22,"language":23,"language_code":24,"site_id":25,"html_lang":24,"table_of_contents":26,"faqs":27,"seo_title":13,"seo_description":14,"update_tm":28,"read_time":29},43187,687197207639,"Asher","https://ap-avatar.wpscdn.com/davatar_a8503ba1806abce46bf441b54a3ca4cd",8,"Research & Report","Metabolic Engineering of Saccharomyces cerevisiae for Bioconversion of D-xylose to D-xylonate","An NAD+-dependent D-xylose dehydrogenase (XylB) from Caulobacter crescentus was expressed in Saccharomyces cerevisiae to convert D-xylose into D-xylonate. The engineered yeast produced 1772 g L−1 D-xylonate at 0.23 g L−1 h−1 from 23 g L−1 D-xylose with glucose and ethanol as co-substrates. D-xylonate titer and rate increased while xylitol formation decreased versus strains using alternative D-xylose dehydrogenases; GRE3 deletion reduced xylitol. XylC enhanced extracellular D-xylonate at pH 5.5 and 3, though cell vitality declined at pH 3.0; an industrial strain reached 43 g L−1 D-xylonate from 49 g L−1 D-xylose.","Metabolic Engineering 14 (2012) 427–436  \nContents lists available at SciVerse ScienceDirect Metabolic Engineering  \njournal [homepage: www.elsevier.com/locate/ymben](homepage: www.elsevier.com/locate/ymben)  \nMetabolic engineering of Saccharomyces cerevisiae for bioconversion of D-xylose to D-xylonate  \nMervi Toivaria,n, Yvonne Nyg˚arda, Esa-Pekka Kumpulaa, Maija-Leena Vehkom¨akia, Mojca Benˇcina b,c, Mari Valkonena, Hannu Maaheimoa, Martina Andberg a, Anu Koivulaa, Laura Ruohonena,  \nMerja Penttil¨aa, Marilyn G. Wiebea  \na VTT, Technical Research Centre of Finland, PO Box 1000, FI-02044 VTT, Espoo, Finland  \nb Department of Biotechnology, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia c Excellent NMR—Future Innovation for Sustainable Technologies Centre of Excellence, Ljubljana, Slovenia  \na r t i c l e i n f o  \n\n| Article history:\u003Cbr>Received 30 June 2011\u003Cbr>Received in revised form\u003Cbr>23 January 2012\u003Cbr>Accepted 5 March 2012\u003Cbr>Available online 13 March 2012 |\n| --- |\n| Keywords:\u003Cbr>D-xylose dehydrogenase\u003Cbr>D-xylonic acid\u003Cbr>D-xylose\u003Cbr>Saccharomyces cerevisiae\u003Cbr>Bioconversion |\n\na b s t r a c t  \nAn NAD þ -dependent D-xylose dehydrogenase, XylB, from Caulobacter crescentus was expressed in Saccharomyces cerevisiae, resulting in production of 1772 g D-xylonate l 􀀂 1 at 0.23 g l 􀀂 1 h 􀀂 1 from 23 g D-xylose l 􀀂 1 (with glucose and ethanol as co-substrates). D-Xylonate titre and production rate were increased and xylitol production decreased, compared to strains expressing genes encoding T. reesei or pig liver NADP þ -dependent D-xylose dehydrogenases. D-Xylonate accumulated intracellularly to 􀀃70 mg g 􀀂 1 ; xylitol to 􀀃18 mg g 􀀂 1. The aldose reductase encoding gene GRE3 was deleted to reduce xylitol production. Cells expressing D-xylonolactone lactonase xylC from C. crescentus with xylB initially produced more extracellular D-xylonate than cells lacking xylC at both pH 5.5 and pH 3, and sustained higher production at pH 3. Cell vitality and viability decreased during D-xylonate production at pH 3.0. An industrial S. cerevisiae strain expressing xylB efficiently produced 43 g D-xylonate l 􀀂 1 from 49 g D-xylose l 􀀂 1.  \n& 2012 Elsevier Inc. Open access under CC BY-NC-ND license .  \n1. Introduction  \nD-Xylose is an abundant pentose sugar present in lignocellulosic plant material, which is currently considered primarily as a potential feed-stock for ethanol or xylitol production (Akinterinwa and Cirino, 2009; Nair and Zhao, 2010; Skorupa Parachin et al., 2011). However, its oxidation product D-xylonic acid or its conjugate base D-xylonate has potential applications as chelator, dispersant, clarifying agent, antibiotic, health enhancer, polyamide or hydrogel modifier or 1,2,4-butanetriol precursor (Millner et al., 1994; Chun et al., 2006; Markham, 1991 ; Tomoda et al., 2004; Pujos, 2006; Niu et al., 2003; Zamora et al., 2000). D-Xylonate could also serve as a non-food derived replacement of D-gluconic acid.  \nMicrobial production of D-xylonate with bacteria e.g., Pseudomonas sp. or Gluconobacter oxydans has been well described (Buchert et al., 1986, 1988; Buchert, 1990). High D-xylonate yieldsand relatively high production rates from D-xylose are obtainable with bacteria, but when birch wood hydrolyzates were used as substrate, the conversion of D-xylose to D-xylonate decreased  \nn Corresponding author. Fax: þ358 20 722 7071. E-mail address: mervi.toivari@vtt.fi (M. Toivari).  \n(Buchert et al., 1989, 1990). Gluconobacter species have periplasmic, membrane bound PQQ-dependent and intracellular NAD(P) þ dependent dehydrogenases which oxidise D-xylose to D-xylonate. These enzymes are responsible for the oxidation of a variety of sugars and sugar alcohols, and the lack of specificity results in a mixture of acids when complex substrates such as lignocellulosic hydrolysate are provided (Buchert, 1991; Rauch et al., 2010; H¨olscheret al., 2009). Resently, an Escherichia coli strain was engineered to produ","cbCaihdN09Dp69y7","https://ap.wps.com/l/cbCaihdN09Dp69y7","pdf",967115,2,1,10,"English","en",105,"# Introduction\n## D-xylonate value and applications\n## Existing microbial production and limitations\n## Rationale for using yeast and NAD+-dependent dehydrogenases\n## Background on NAD+-dependent D-xylose dehydrogenases","[{\"question\":\"Which enzyme and host were engineered to produce D-xylonate from D-xylose?\",\"answer\":\"The NAD+-dependent D-xylose dehydrogenase XylB from Caulobacter crescentus was expressed in Saccharomyces cerevisiae to drive D-xylose bioconversion to D-xylonate.\"},{\"question\":\"How did the engineered strain’s D-xylonate production compare to strains using other dehydrogenases?\",\"answer\":\"D-xylonate titer and production rate increased, while xylitol production decreased compared with strains expressing genes encoding alternative D-xylose dehydrogenases dependent on other cofactors.\"},{\"question\":\"What genetic and process factors affected byproduct formation and production under different pH conditions?\",\"answer\":\"Deleting GRE3 reduced xylitol production. Expressing xylC with xylB increased extracellular D-xylonate at pH 5.5 and pH 3, and production at pH 3 remained higher, but cell vitality and viability decreased during D-xylonate production at pH 3.0.\"}]",1783378311,25,{"code":4,"msg":31,"data":32},"ok",{"site_id":25,"language":24,"slug":33,"title":13,"keywords":34,"description":14,"schema_data":35,"social_meta":86,"head_meta":88,"extra_data":90,"updated_unix":28},"metabolic-engineering-of-saccharomyces-cerevisiae-for-bioconversion-of-d-xylose-to-d-xylonate","",{"@graph":36,"@context":85},[37,53,68],{"@type":38,"itemListElement":39},"BreadcrumbList",[40,44,47,50],{"item":41,"name":42,"@type":43,"position":21},"https://docshare.wps.com","Home","ListItem",{"item":45,"name":46,"@type":43,"position":20},"https://docshare.wps.com/document/","Document",{"item":48,"name":12,"@type":43,"position":49},"https://docshare.wps.com/document/research-report/",3,{"item":51,"name":13,"@type":43,"position":52},"https://docshare.wps.com/document/metabolic-engineering-of-saccharomyces-cerevisiae-for-bioconversion-of-d-xylose-to-d-xylonate/43187/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":24,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":41,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-13","2026-07-06",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81],{"name":72,"@type":73,"acceptedAnswer":74},"Which enzyme and host were engineered to produce D-xylonate from D-xylose?","Question",{"text":75,"@type":76},"The NAD+-dependent D-xylose dehydrogenase XylB from Caulobacter crescentus was expressed in Saccharomyces cerevisiae to drive D-xylose bioconversion to D-xylonate.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"How did the engineered strain’s D-xylonate production compare to strains using other dehydrogenases?",{"text":80,"@type":76},"D-xylonate titer and production rate increased, while xylitol production decreased compared with strains expressing genes encoding alternative D-xylose dehydrogenases dependent on other cofactors.",{"name":82,"@type":73,"acceptedAnswer":83},"What genetic and process factors affected byproduct formation and production under different pH conditions?",{"text":84,"@type":76},"Deleting GRE3 reduced xylitol production. Expressing xylC with xylB increased extracellular D-xylonate at pH 5.5 and pH 3, and production at pH 3 remained higher, but cell vitality and viability decreased during D-xylonate production at pH 3.0.","https://schema.org",{"og:url":51,"og:type":87,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":89,"canonical":51},"index,follow",{"doc_id":7,"site_id":25},{"code":4,"msg":5,"data":92},[93,97,101,105,110,115,120,123,128,131,134],{"id":21,"doc_module":4,"doc_module_name":46,"category_name":94,"show_sort_weight":95,"slug":96},"Story & Novel",90,"story-novel",{"id":20,"doc_module":4,"doc_module_name":46,"category_name":98,"show_sort_weight":99,"slug":100},"Literature",80,"literature",{"id":52,"doc_module":4,"doc_module_name":46,"category_name":102,"show_sort_weight":103,"slug":104},"Exam",70,"exam",{"id":106,"doc_module":4,"doc_module_name":46,"category_name":107,"show_sort_weight":108,"slug":109},5,"Comic",60,"comic",{"id":111,"doc_module":4,"doc_module_name":46,"category_name":112,"show_sort_weight":113,"slug":114},6,"Technology",50,"technology",{"id":116,"doc_module":4,"doc_module_name":46,"category_name":117,"show_sort_weight":118,"slug":119},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":46,"category_name":12,"show_sort_weight":121,"slug":122},30,"research-report",{"id":124,"doc_module":4,"doc_module_name":46,"category_name":125,"show_sort_weight":126,"slug":127},9,"Religion & Spirituality",20,"religion-spirituality",{"id":126,"doc_module":4,"doc_module_name":46,"category_name":129,"show_sort_weight":126,"slug":130},"World Cup","world-cup",{"id":22,"doc_module":4,"doc_module_name":46,"category_name":132,"show_sort_weight":22,"slug":133},"Lifestyle","lifestyle",{"id":135,"doc_module":4,"doc_module_name":46,"category_name":136,"show_sort_weight":106,"slug":137},19,"General","general"]