Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 15, 2000
Publication Date: N/A
Technical Abstract: Lactic acid has long been used in the food and pharmaceutical industry for a diverse array of specialized purposes. Recent ecological interests have fueled the demand of lactic acid for the manufacture of the biodegradable plastic, polylactic acid (PLA), and "green-solvent," ethyl lactate. The global lactic acid market is estimated to be in excess of 100,000 tons per year and is expected to increase substantially in the next few years as ne PLA facilities become operational. However, fermentation efficiency must be improved to ensure the economic feasibility of these anticipated market expansions. The fungus Rhizopus oryzae is often preferred for industrial fermentations because of the ability to produce large amounts of optically pure L-(+)-lactic acid in a minimally defined medium. The metabolic pathways for Rhizopus are only just beginning to be understood, with some of the enzymes being partially purified and characterized. Recent work in our laboratory has taken on a more direct strategy of using molecular biology techniques to study the control and production of lactic acid, as well as several unwanted metabolites. Discussions will focus on how we have been able to metabolically engineer this fungus to produce lactic acid more efficiently.