Citrate utilization in milk by Leuconostoc cremoris and Streptococcus diacetilactis.
Citrate utilization and diacetyl, acetoin and acetaldehyde production by 2 strains each of Leuconostoc cremoris and Streptococcus diacetilactis in milk were studied. With the leuconostoc bacteria no growth and little citrate utilization occurred unless a stimulant (yeast extract) was present, when complete utilization of citrate without concomitant production of diacetyl or acetoin was obtained. The additon of Mn2+ stimulated growth resulted in diacetyl and acetoin production. Destruction of diacetyl and acetoin occurred when the citric acid level fell to c.1000 and 600 mug/g in the case of Leuc. cremoris FR8-1 and CAF1, respectively. Only strain FR8-1 produced acetaldehyde. In contrast, Str. diacetilactis produced diacetyl, acetoin and acetaldehyde concomitant with citrate utilization.
D000079:Acetaldehyde / Q000378:metabolism; D000818:Animals; D002074:Butanones / Q000378:metabolism; D002951:Citrates / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D007934:Leuconostoc / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D008345:Manganese / Q000494:pharmacology; D008892:Milk / Q000382:microbiology*; D013045:Species Specificity; D013291:Streptococcus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*
D002074:Butanones; D002951:Citrates; D008345:Manganese; D000079:Acetaldehyde