Low pH d-xylonate production with Pichia kudriavzevii

• Published in: Bioresource technology 2013-04, Vol.133, p.555-562
• Main Authors: Toivari, Mervi, Vehkomäki, Maija-Leena, Nygård, Yvonne, Penttilä, Merja, Ruohonen, Laura, Wiebe, Marilyn G.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biomass; Consumption; d-Xylonate; d-Xylose; Fundamental and applied biological sciences. Psychology; Genes; Glucose - pharmacology; Hydrogen-Ion Concentration - drug effects; Intracellular Space - drug effects; Intracellular Space - metabolism; Issatchenkia orientalis; Kluyveromyces - drug effects; Kluyveromyces - growth & development; Kluyveromyces - metabolism; Low pH; Pichia - drug effects; Pichia - growth & development; Pichia - metabolism; Pichia kudriavzevii; Platforms; Productivity; Pseudomonas; Recombinant; Saccharomyces cerevisiae - drug effects; Saccharomyces cerevisiae - growth & development; Saccharomyces cerevisiae - metabolism; Strain; Sugar Acids - metabolism; Xylitol - metabolism; Xylose - biosynthesis
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2013.01.157

► Pichia kudriavzevii expressing Caulobacter crescentus xylB produced 146g d-xylonate l−1 at pH 3. ► This P. kudriavzevii strain also produced 171g d-xylonate l−1 at pH 5.5. ► d-Xylonate production was less toxic to P. kudriavzevii than to Saccharomyces cerevisiae. ► P. kudriavzevii is thus an excellent production organism for d-xylonic acid. 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 171gL−1 of d-xylonate from 171gL−1d-xylose at a rate of 1.4gL−1h−1 and yield of 1.0g [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 146gL−1d-xylonate at 1.2gL−1h−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.