Streptococcus diacetilactis

Daly, C., Sandine, W. E. and Elliker, P. R. 1972. Interactions of food starter cultures and food-borne pathogens Streptococcus diacetilactis versus food pathogens. J. Milk Food TechnoL 35, 349-357. 

Lundstedt, E. and Fogg, W. B. 1962. Citrated whey starters. II. Gradual formation of flavor and aroma in creamed cottage cheese after the addition of small quantities of citrated cottage cheese whey cultures of Streptococcus diacetilactis. J. Dairy Sci. 45, 1327-1331. 

Diacetyl reductase (acetoin dehydrogenase, 1.1.1.5) is widespread in bacteria (207, 208, 219, 220, 221), including the species (Streptococcus diacetilactis, Lactobacillus casei) used to prepare cultured dairy products. Mutants lacking diacetyl reductase also fail to synthesize diacetyl (222). The enzyme has been purified 30-fold from L. casei (223). The activity was not fully separable from an NADH oxidase activity, and the enzyme appeared to be a flavoprotein. Maximum activity was at pH 4.5. The NADH oxidase activity is associated with diacetyl reductase in other sources. 

Desmazeaud, M. J., and Zevaco, C. (1976). General properties and substrate specificity of an intracellular neutral protease from Streptococcus diacetilactis. Ann. Biol. Anim., Biochim., Biophys. 16, 851-868. 

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