AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
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 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 Ashton, D. H.
Right arrow Articles by Warren, J. A.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Ashton, D. H.
Right arrow Articles by Warren, J. A.
Agricola
Right arrow Articles by Ashton, D. H.
Right arrow Articles by Warren, J. A.

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1968 April; 16(4): 628-635
Copyright © 1968 American Society for Microbiology. All Rights Reserved.

Relief of Casein Inhibition of Bacillus stearothermophilus by Iron, Calcium, and Magnesium1

D. H. Ashton2, F. F. Busta3 and J. A. Warren

Department of Food Science and Experimental Statistics, North Carolina State University, Raleigh, North Carolina 27607

ABSTRACT

Growth of Bacillus stearothermophilus strain NCA 1518 Smooth in Dextrose Tryptone Agar (DTA) was inhibited by sodium caseinate. Binding studies indicated that sodium caseinate, when present in DTA, had the capacity to effect an iron deficiency which could cause inhibition of growth. Additions of essential cations, iron (1 mM), calcium (5 mM), magnesium (10 mM), or hydrogen ion (pH 5.7), relieved inhibition. Responses to and interactions among these relief factors were analyzed statistically. Equations were fitted to the data and were used to estimate responses to all treatment combinations within the ranges tested. Results from these studies indicated that calcium, magnesium, and hydrogen ion acted by decreasing the binding capacity of the protein for iron, rendering this metal available for metabolic needs. Evidence was obtained that ferrous rather than ferric iron was the limiting factor in DTA containing sodium caseinate.

FOOTNOTES

2 Present address: Dairy Products Laboratory, Agricultural Research Service, Washington, D.C. 20250.

3 Present address: Department of Food Science and Industries, University of Minnesota, St. Paul, Minn. 55101.

1 Paper number 2544 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh.

Appl Environ Microbiol. 1968 April; 16(4): 628-635
Copyright © 1968 American Society for Microbiology. All Rights Reserved.





Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 1968 by the American Society for Microbiology. All rights reserved.