title: Low pH D-xylonate production with Pichia kudriavzevii.
abstract: D-xylonic acid is one of the top 30 most desirable chemicals to be derived from biomass sugars identified by the US Department of Energy, being applicable as a non-food substitute for D-gluconic acid and as a platform chemical. We engineered the non-conventional yeast Pichia kudriavzevii VTT C-79090T to express a D-xylose dehydrogenase coding gene from Caulobacter crescentus. With this single modification the recombinant P. kudriavzevii strain produced up to 171 g L(-1) of D-xylonate from 171 g L(-1) D-xylose at a rate of 1.4 g L(-1) h(-1) and yield of 1.0 g [g substrate consumed](-1), which was comparable with D-xylonate production by Gluconobacter oxydans or Pseudomonas sp. The productivity of the strain was also remarkable at low pH, producing 146 g L(-1) D-xylonate at 1.2 g L(-1) h(-1) at pH 3.0. This is the best low pH production reported for D-xylonate. These results encourage further development towards industrial scale production.
authors: VTT, Technical Research Centre of Finland, VTT, Espoo, Finland. mervi.toivari@vtt.fi
authors: Mervi
authors: M
authors: Toivari
authors: Maija-Leena
authors: ML
authors: Vehkomäki
authors: Yvonne
authors: Y
authors: Nygård
authors: Merja
authors: M
authors: Penttilä
authors: Laura
authors: L
authors: Ruohonen
authors: Marilyn G
authors: MG
authors: Wiebe
mesh_terms: D018533:Biomass; D005947:Glucose / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D007716:Kluyveromyces / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D010843:Pichia / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D013400:Sugar Acids / Q000378:metabolism*; D014993:Xylitol / Q000378:metabolism; D014994:Xylose / Q000096:biosynthesis*
chemical_list: D013400:Sugar Acids; D014994:Xylose; D005947:Glucose; D014993:Xylitol