James L. Steele

James L. Steele

Professor, Food Science
125 Babcock Hall
jlsteele@wisc.edu
(608) 262-5960
FAX (608) 262-6872

Research Interests

My research group is examining the genetics and physiology of lactic acid bacteria. These organisms are used in a variety of food and industrial fermentations. However, a better understanding of their physiology is needed before we will be able to develop rational approaches to enhance their industrial utility. My group's primary focus is the metabolic pathways and enzymes by which these organisms produce flavor compounds in fermented foods. In particular, we are interested in the role of individual proteolytic enzymes and amino acid catabolic pathways in Cheddar cheese flavor development. For research on the contribution of proteolytic enzymes, Lactobacillus helveticus CNRZ32 was chosen as our model organism because it's ability to enhance cheese flavor development has been linked to it's proteolytic enzyme system. Amino acid catabolic pathways have been primarily examined in Lactococcus lactis, as this organism is used as the starter culture in Cheddar cheese manufacture.

I believe that conducting research in an applied field requires a strong background in both the basic sciences and in the applied field of choice. In my research area, a background in genetics, biochemistry, microbiology and food science is essential.

Education

  • B.S. Microbiology, University of Minnesota 1982
  • M.S. Food Science, University of Minnesota 1985
  • Ph.D. Genetics, University of Minnesota 1989

Scientific and Professional Organizations

  • Institute of Food Technologists
  • American Dairy Science Association
  • American Society for Microbiology

Selected Publications

Dudley, E.G. and J.L. Steele. 2005. Succinate production by Cheddar cheese non-starter lactobacilli. J. Appl. Microbiol. 98:12-23.

Sridhar, V.R., J.E. Hughes, D.L. Welker, J.R. Broadbent, and J.L. Steele. 2005. Identification of endopeptidase genes from the genomic sequence of Lactobacillus helveticus CNRZ32 and their role in hydrolysis of model bitter peptides. Appl. Environ. Microbiol. 71:3025-3032.

Broadbent, J.R., B.T. Rodríguez, P. Joseph, E.A. Smith, and J.L. Steele. 2006. Conversion of Lactococcus lactis cell envelope proteinase specificity by partial allele exchange. J. Appl. Microbiol. 100:1307-1317.

Díaz-Muñiz, I. and J.L. Steele. 2006. Limiting galactose requirement for citrate utilization by Lactobacillus casei is annulled in Cheddar cheese extract. Antonie van Leeuwenhoek 90:233-243.

Gibbs, M.J., V.V. Smeianov, and J.L. Steele. 2006. Two families of Rep-like genes that originated by inter-species recombination, are represented in viral, plasmid and parasitic protozoan genomes. Mol. Biol. Evol. 23:1097-1100

Díaz-Muñiz, I., D.S. Banavara, M.F. Budinich, S.A. Rankin, E.G. Dudley and J.L. Steele. 2006. Lactobacillus casei metabolic potential to utilize citrate as an energy source in ripening cheese: A bioinformatics approach. J. Appl. Microbiol. 101:872-882.

Steele, J.L., M.F. Buninich, H. Cai, S.C. Curtis, and J.R. Broadbent. 2006. Diversity and metabolic activity of Lactobacillus casei in ripening cheddar cheese. Aust. J. Dairy Technol. 61:53-60.

Makarova, K., A. Slesarev, Y. Wolf, A. Sorokin, B. Mirkin, E. Koonin, A. Pavlov, N. Pavlova, V. Karamychev, N. Polouchine, V. Shakhova, , I. Grigoriev, Y. Lou, D. Rohksar, S. Lucas, K. Huang, D. M. Goodstein, T. Hawkins, V. Plengvidhya, D. Welker, J. Hughes, Y. Goh, A. Benson, K. Baldwin, J.-H. Lee, I. Díaz-Muñiz, B. Dosti, V. Smeianov, W. Wechter, R. Barabote, G. Lorca, E. Altermann, R. Barrangou, B. Ganesan, Y. Xie, H. Rawsthorne, D. Tamir, C. Parker, L. McKay, F. Breidt, J. Broadbent, R. Hutkins, D. O’Sullivan, J. Steele, G. Unlu, M. Saier, T. Klaenhammer, P. Richardson, S. Kozyavkin, B. Weimer, and D. Mills. 2006. Comparative genomics of the lactic acid bacteria. Proc. Natl. Acad. Sci. 103:15611-15616.