Ammonia → (+)-Lactose

Participants

Reaction Conditions

Reaction Steps

After pasteurizing the medium and cooling it to cultivation temperature (37° C.) in a cultivation vessel, the medium was inoculated with 1% (v/v) culture of Lactobacillus bulgaricus, strain CBS 743.84; the pH of the mixture was adjusted to a value of 6.0 by means of an ammonia solution. The pH was kept at the value of 6.0 during the cultivation by automatic metered addition of the ammonia solution, the mixture being continuously stirred. During the cultivation the conversion of the lactose was followed by measuring the consumption of ammonia. From the consumption of ammonia it was possible to calculate that if each molecule of lactose were to produce four molecules of lactic acid, 89.8% lactose had been converted after 22 hours. Enzymatic determination of the lactic acid formed indicated that after 22 hours over 85% of the quantity of lactose present at the start had in fact been converted into lactic acid, the acid being recovered by known methods.

Provenance & Evidence