Affiliation:
1. Department of Food Technology, Iowa State University, Ames, Iowa 50010
Abstract
A recently developed differential agar medium was used to study associative growth patterns in 17 different heterologous, three-strain mixtures of
Streptococcus lactis, S. cremoris
, and
S. diacetilactis
grown in milk. Mixtures were made by combining equal volumes of 18-hr milk cultures of the three species. Relative populations of component species were followed through three successive transfers in milk after the initial mixed propagation. Direct evidence for strain dominance and compatibility was obtained. A procedure also was developed to estimate the extent of suppression of
S. lactis
and
S. diacetilactis
in a mixture containing a dominant
S. cremoris
strain. The technique described could be successfully applied in quality-control work in the dairy-starter manufacturing industry.
Publisher
American Society for Microbiology
Subject
General Pharmacology, Toxicology and Pharmaceutics,General Immunology and Microbiology,General Biochemistry, Genetics and Molecular Biology,General Medicine
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