This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Goh, Y. J. Articles by Hutkins, R. W. Search for Related Content PubMed PubMed Citation Articles by Goh, Y. J. Articles by Hutkins, R. W. Agricola Articles by Goh, Y. J. Articles by Hutkins, R. W.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, September 2007, p. 5716-5724, Vol. 73, No. 18
0099-2240/07/$08.00+0     doi:10.1128/AEM.00805-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Functional Analysis of the Fructooligosaccharide Utilization Operon in Lactobacillus paracasei 1195

Yong Jun Goh, Jong-Hwa Lee, and Robert W. Hutkins^*

University of Nebraska, Department of Food Science and Technology, Lincoln, Nebraska 68583-0919

Received 10 April 2007/ Accepted 11 July 2007

The fosABCDXE operon encodes components of a putative fructose/mannose phosphoenolpyruvate-dependent phosphotransferase system and a ß-fructosidase precursor (FosE) that are involved in the fructooligosaccharide (FOS) utilization pathway of Lactobacillus paracasei 1195. The presence of an N-terminal signal peptide sequence and an LPQAG cell wall anchor motif in the C-terminal region of the deduced FosE precursor amino acid sequence predicted that the enzyme is cell wall associated, indicating that FOS may be hydrolyzed extracellularly. In this study, cell fractionation experiments demonstrated that the FOS hydrolysis activity was present exclusively in the cell wall extract of L. paracasei previously grown on FOS. In contrast, no measurable FOS hydrolysis activity was detected in the cell wall extract from the isogenic fosE mutant. Induction of ß-fructosidase activity was observed when cells were grown on FOS, inulin, sucrose, or fructose but not when cells were grown on glucose. A diauxic growth pattern was observed when cells were grown on FOS in the presence of limiting glucose (0.1%). Analysis of the culture supernatant revealed that glucose was consumed first, followed by the longer-chain FOS species. Transcription analysis further showed that the fos operon was expressed only after glucose was depleted in the medium. Expression of fosE in a non-FOS-fermenting strain, Lactobacillus rhamnosus GG, enabled the recombinant strain to metabolize FOS, inulin, sucrose, and levan.

---

* Corresponding author. Mailing address: University of Nebraska, Department of Food Science and Technology, 338 FIC, Lincoln, NE 68583-0919. Phone: (402) 472-2820. Fax: (402) 472-1693. E-mail: rhutkins1{at}unl.edu

Published ahead of print on 20 July 2007.

Present address: North Carolina State University, Department of Food Science, Raleigh, NC 27695-7624.

Present address: School of Bioresource Sciences, Andong National University, Andong, South Korea.

---

Applied and Environmental Microbiology, September 2007, p. 5716-5724, Vol. 73, No. 18
0099-2240/07/$08.00+0     doi:10.1128/AEM.00805-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Lebeer, S., Vanderleyden, J., De Keersmaecker, S. C. J. (2008). Genes and Molecules of Lactobacilli Supporting Probiotic Action. Microbiol. Mol. Biol. Rev. 72: 728-764 [Abstract] [Full Text]  
• Walter, J. (2008). Ecological Role of Lactobacilli in the Gastrointestinal Tract: Implications for Fundamental and Biomedical Research. Appl. Environ. Microbiol. 74: 4985-4996 [Full Text]