Regulation and function of lactate oxidation in Streptococcus faecium.
Regulation of the synthesis and function of an l(+)-specific lactate-oxidizing enzyme system found in a homofermentative Streptococcus was investigated. With the exception of fructose, aerobic growth at the expense of a variety of substrates resulted in the formation of a lactate oxidation system; anaerobic growth resulted in a marked reduction or complete loss of lactate-oxidizing activity. Growth on fructose, under aerobic and anaerobic conditions, invariably produced a decrease in the activity of the lactate oxidation system. A negative control, activated by an early intermediate product of glycolysis, appeared to be responsible for repression of the lactate-oxidizing enzyme(s). The enzyme system confers upon the organism the ability to grow aerobically at the expense of l(+)-lactic acid.
D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D004794:Enzyme Repression; D005632:Fructose / Q000378:metabolism; D005942:Gluconates / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D007773:Lactates / Q000378:metabolism*; D010101:Oxygen Consumption; D011773:Pyruvates / Q000378:metabolism; D012266:Ribose / Q000378:metabolism; D013291:Streptococcus / Q000201:enzymology*
D005942:Gluconates; D007773:Lactates; D011773:Pyruvates; D005632:Fructose; D012266:Ribose; D000429:Alcohol Oxidoreductases; D005947:Glucose; D005990:Glycerol