This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ilmén, M.
Right arrow Articles by Penttilä, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ilmén, M.
Right arrow Articles by Penttilä, M.
Agricola
Right arrow Articles by Ilmén, M.
Right arrow Articles by Penttilä, M.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, January 2007, p. 117-123, Vol. 73, No. 1
0099-2240/07/$08.00+0     doi:10.1128/AEM.01311-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Efficient Production of L-Lactic Acid from Xylose by Pichia stipitis{triangledown}

Marja Ilmén,1* Kari Koivuranta,1 Laura Ruohonen,1 Pirkko Suominen,2 and Merja Penttilä1

VTT Technical Research Centre of Finland, Espoo, Finland,1 NatureWorks LLC, 15305 Minnetonka Blvd., Minnetonka, Minnesota2

Received 8 June 2006/ Accepted 20 October 2006

Microbial conversion of renewable raw materials to useful products is an important objective in industrial biotechnology. Pichia stipitis, a yeast that naturally ferments xylose, was genetically engineered for L-(+)-lactate production. We constructed a P. stipitis strain that expressed the L-lactate dehydrogenase (LDH) from Lactobacillus helveticus under the control of the P. stipitis fermentative ADH1 promoter. Xylose, glucose, or a mixture of the two sugars was used as the carbon source for lactate production. The constructed P. stipitis strain produced a higher level of lactate and a higher yield on xylose than on glucose. Lactate accumulated as the main product in xylose-containing medium, with 58 g/liter lactate produced from 100 g/liter xylose. Relatively efficient lactate production also occurred on glucose medium, with 41 g/liter lactate produced from 94 g/liter glucose. In the presence of both sugars, xylose and glucose were consumed simultaneously and converted predominantly to lactate. Lactate was produced at the expense of ethanol, whose production decreased to ~15 to 30% of the wild-type level on xylose-containing medium and to 70 to 80% of the wild-type level on glucose-containing medium. Thus, LDH competed efficiently with the ethanol pathway for pyruvate, even though the pathway from pyruvate to ethanol was intact. Our results show, for the first time, that lactate production from xylose by a yeast species is feasible and efficient. This is encouraging for further development of yeast-based bioprocesses to produce lactate from lignocellulosic raw material.

* Corresponding author. Mailing address: VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT, Finland. Phone: 358 20 722 4407. Fax: 358 20 722 7071. E-mail: marja.ilmen{at}vtt.fi.

{triangledown} Published ahead of print on 27 October 2006.

Applied and Environmental Microbiology, January 2007, p. 117-123, Vol. 73, No. 1
0099-2240/07/$08.00+0     doi:10.1128/AEM.01311-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.





Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»