|Kuo, Tsung Min|
Submitted to: Enzyme and Microbial Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 5, 2006
Publication Date: March 15, 2006
Citation: Levinson, W.E., Kurtzman, C.P., Kuo, T. 2006. Production of itaconic acid by Pseudozyma antarctica NRRL Y-7808 under nitrogen-limited growth conditions. Enzyme and Microbial Technology. 39:824-827. Interpretive Summary: The American Jobs Creation Act of 2004 provides a new tax incentive for using the alternative fuel known as biodiesel. The incentive has boosted a rapid growth of biodiesel production leading to anticipated overabundance of glycerol, a major production byproduct of biodiesel derived from vegetable oils or animal fats. We are exploring new microbial processes for using glycerol to produce value-added chemicals. In this study, a number of microbial species were examined for the use of different carbon source including glycerol and the effect of various reaction parameters to produce new compounds. We found a new fungal strain that could use the sugars glucose or maltose but not glycerol or the sugar lactose effectively for producing an organic acid called itaconic acid, an important starting chemical in the polymer industry and in the manufacture of synthetic fibers, coatings, adhesives, and thickeners. The impact of this study provides basic information and technology for scientists to develop bioprocesses for producing similar types of new compounds indirectly from low cost vegetable oils.
Technical Abstract: Pseudozyma antarctica NRRL Y-7808 was found to produce itaconic acid from glucose and other sugars under nitrogen-limited growth conditions. Other Pseudozyma strains screened, including a second strain of Pseudozyma antarctica, did not produce this product; so itaconic acid production is not a common trait of the genus. Glucose and fructose were the most efficiently utilized substrates, followed by sucrose and maltose; lactose and glycerol were the poorest substrates. The maximum yield in flask experiments was 37.5% (approximately 30 g/L itaconic acid from 80 g/L glucose). The maximum rate of production in flask cultures was 248 mg L-1 hr-1 at a C/N ratio of 116, while the best combination of rate and yield was produced at a C/N ratio of 175 (230 mg L-1 hr-1 and 29%, respectively). A stirred-tank reactor process study resulted in a 20% yield and volumetric production rate of 110 mg L-1 hr-1.