Reddy M S, Vedamuthu E R, Washam C J, Reinbold G W
Department of Food Technology, Iowa State University, Ames, Iowa 50010.
Appl Microbiol. 1972 Dec;24(6):953-7. doi: 10.1128/am.24.6.953-957.1972.
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.
一种最近开发的鉴别琼脂培养基被用于研究在牛奶中生长的17种不同的、由乳酸链球菌、嗜热链球菌和双乙酰乳酸链球菌组成的异源三菌株混合物的联合生长模式。混合物通过将三种菌的18小时牛奶培养物等体积混合制成。在初始混合传代后，在牛奶中连续传代三次，跟踪各组成菌株的相对数量。获得了菌株优势和相容性的直接证据。还开发了一种程序来估计在含有优势嗜热链球菌菌株的混合物中乳酸链球菌和双乙酰乳酸链球菌的抑制程度。所描述的技术可成功应用于乳制品发酵剂制造行业的质量控制工作。
