Patent ID: 7229805

Claim:
A method for making lactic acid, comprising a) providing a microorganism exhibiting a crabtree-negative phenotype selected from the group consisting of Kluyveromyces, Pichia, and Hansenula and transformed with at least one exogenous gene encoding a naturally-occurring bovine, bacterial or fungal lactate dehydrogenase; b) culturing said crabtree-negative microorganism in a first culture medium which includes a carbon source comprising glucose and under a first set of culture conditions, including a dissolved oxygen content of at least 20 percent relative to the amount present at saturated conditions with air at atmospheric pressure, which promote cellular respiration; and c) then culturing the crabtree-negative microorganism in a culture medium which includes a carbon source comprising glucose under a second set of culture conditions, including a dissolved oxygen content of less than 2.0 percent relative to the amount present at saturated conditions with air at atmospheric pressure, which promote the production of lactic acid.