Analysis of Capsule Production in Streptococcus Thermophilus by Comparative Genomics

Principal Investigators:  Jeffrey R. Broadbent, Utah State University

Co-Investigators:            Dr. Dennis L Welker, Utah State University

                                             Dr. Craig J Oberg, Weber State University

Project Summary:

Our group has shown that encapsulated, but not ropy, exopolysaccharide-producing (EPS) S. Thermophilus strains can significantly increase cheese yield and improve functionality without deleteriously affecting cheese quality, whey viscosity, or UF concentration time.  We have also identified genes that may be involved in capsule attachment through genetic comparisons of EPS genes in very closely related encapsulated and ropy S. thermophilus strains.  In this project, we will create isogenic derivatives of these strains to investigate the role of these genes in cell capsule attachment.


Broadbent, J. R., D. J. McMahon, D. Welker, C. J. Oberg, and S. Moineau.  2003.  Biochemistry, genetics, and applications of exopolysaccharide production in Streptococcus thermophilus:  a review.  J. Dairy Sci. 86:407-423.



Published Abstract:

Broadbent, J. R., and J. L. Steele.  Recent developments in cheese flavor and functionality.  Invited oral presentation for Chr. Hansen, Inc., March 19, 2004.  Copenhagen, Denmark.

McMahon, D. J., C. J. Oberg, and J.R. Broadbent.  Cultures and functionality of Mozzarella cheese.  Invited oral presentation for the 7th Teagasc Dairy Products Research Centre Cheese Symposium.  October 20-21, 2003.  Cork, Ireland.