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 HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sasaki, Y.
Right arrow Articles by Sasaki, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sasaki, Y.
Right arrow Articles by Sasaki, T.
Agricola
Right arrow Articles by Sasaki, Y.
Right arrow Articles by Sasaki, T.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, March 2004, p. 1858-1864, Vol. 70, No. 3
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.3.1858-1864.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

thyA as a Selection Marker in Construction of Food-Grade Host-Vector and Integration Systems for Streptococcus thermophilus

Yasuko Sasaki,* Yoshiyuki Ito, and Takashi Sasaki

Food Functionality Research Institute, Meiji Dairies Corporation, Odawara, Kanagawa 250-0862, Japan

Received 11 August 2003/ Accepted 10 December 2003

We constructed food-grade host-vector and integration systems for Streptococcus thermophilus by using a thymidylate synthase gene (thyA) as the selection marker. Two thyA genes, thyASt and thyALb, were cloned from S. thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, respectively. Thymidine-requiring mutants of S. thermophilus were obtained after successive cultures in the presence of trimethoprim, and one of them, TM1-1, was used as the host. Food-grade vectors were constructed by using either thyASt or thyALb as the selection marker. Transformants of TM1-1 created by using these vectors were selected for thymidine autotrophy as efficiently as for erythromycin resistance. By using the host-vector system developed in this way, a foreign amylase gene (amyA) was expressed in TM1-1 and was also integrated into the chromosome by use of a temperature-sensitive integration vector constructed with thyALb as the selection marker via a double-crossover event. The results obtained show that thyA is an efficient and safe selection marker for S. thermophilus that is suitable for food applications.

* Corresponding author. Mailing address: Food Functionality Research Institute, Meiji Dairies Corporation, 540 Naruda, Odawara, Kanagawa 250-0862, Japan. Phone: 81-465-37-5130. Fax: 81-465-36-2776. E-mail: YASUKO_SASAKI{at}MEIJI-MILK.COM.

Applied and Environmental Microbiology, March 2004, p. 1858-1864, Vol. 70, No. 3
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.3.1858-1864.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Labrie, S., Bart, C., Vadeboncoeur, C., Moineau, S. (2005). Use of an {alpha}-Galactosidase Gene as a Food-Grade Selection Marker for Streptococcus thermophilus. J DAIRY SCI 88: 2341-2347 [Abstract] [Full Text]  


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