PRODUCTION OF L-LACTIC ACID BY RHIZOPUS-ORYZAE UNDER OXYGEN LIMITING CONDITIONS

Names are necessary to report factually on available data; however, th e USDA neither guarantees nor warrants the standard of the product, an d the use of the name by USDA implies no approval of the product to th e exclusion of others that may also be suitable. During aerobic growth , Rhizopus oryzae produces L-lactic acid from lactate dehydrogenase me diated reduction of pyruvate, while O-2 limiting conditions yield prim arily ethanol. A mutant was isolated that expressed only 5% of the wil d type alcohol dehydrogenase activity under O-2 limiting conditions an d produced nearly 40 g lactic acid/l in 70 h. This is almost a ten-fol d increase in lactic acid production when compared to the parent strai n.