SBIR-STTR Award

The capability of certain fungi in synthesis of fumaric acid has been known for over 40 years. However, several major technical difficulties have prevented the biosynthetic method from being utilized in industrial scale production. Fumaric acid has long since been a product of the petrochemical industry. Research in the PI's laboratory at Purdue University, since 1993, supported by several grants including an USDA grant, has developed several new techniques for enhanced productivity of fumaric acid by bioprocessing. The PI is assisting a small business, General Resource Technology, Inc. of Indiana to propose this Phase I project to test the feasibility of incorporating these new techniques into a new bioprocess to produce fumaric acid from corn. The new bioprocess involves simultaneous fermentation and recovery of fumaric acid by absorption. Through systematic investigation, there is now an important skill of growing fungal mycelia in spherical pellets of very small sizes, which eliminates the problem of inadequate oxygen in the interior of large pellets. When oxygen is insufficient, the cells promotes the production of ethanol at the expense of fumaric acid. Another new technique involves simultaneous absorption of fumaric acid by a strong basic ion exchange resins and regeneration by an acidic zeolite. A set of five reactions including zeolite can be a generic method for recycle of acids and alkalis. Still another new skill involves the use of waste carbon dioxide as an extra carbon source for the fungal fermentation, which increases the fumaric acid yield greatly. This Phase I project is to test the feasibility of applying these new techniques together in a highly efficient bioprocess for fumaric acid production. Once successful, a new industrial use for corn in producing value added products can be developed.

Anticipated Results/Potential Commercial Applications of Research:
An approximate analysis has shown that the production cost of fumaric acid by the new bioprocess is about $0.31/LB. The current listed price for fumaric acid is $0.85/LB. Fumaric acid has many well established industrial uses. Fumaric acid is also the feedstock for several organic acids of potentially very large market volumes. Fumaric acid can be easily converted into aspartic acid which is used in the manufacture of artificial sweeteners, biodegradable polymers and detergents. Fumaric acid can also be converted into malic acid which competes with citric acid in many applications including the soft drinks. In addition, fumaric acid is the raw material for producing succinic acid which is useful as a monomer for producing a new class of polyesters. All counted, the potential market demand for fumaric acid can be as large as that of citric acid, lactic acid and glycerol with an annual market value of several billion dollars.

This Phase II proposal and the recently completed Phase I project deal with a new process of production of glycerol from cornstarch by a yeast fermentation. There are two current industrial processes for glycerol. Chemical syntheses are no longer competitive. The second method involves recovering glycerol as a byproduct from soap and other fatty acid industries. It suffers from the decline of the main products and also the large and thus restrictive 7 to 1 main-products to byproduct ratio. The byproduct simply cannot grow much without upsetting the market supply-demand balance of the main-products. Phase I work has improved the glycerol fermentation to a peak productivity of 4-5 g/l/h and a high average productivity of 3 g/l/h. The work has also improved the final glycerol concentration in the fermented broth to over 330 g/l, reducing reactor volume and evaporation costs. The overall yield has reached a high value of 1g/2g of cornstarch. Another important character of the yeast is the fact that the cells are stable and active, leaving no residual glucose at the end of batch operations. This makes the downstream operation of vacuum distillation for purifying the final product easy to do, avoiding otherwise problems of charring of residual carbohydrates. These results have led to this proposed Phase II project which will evaluate various reactor systems, as well as high vacuum distillation for glycerol purification, employing industrial grade raw materials, over wide ranges of process variables and oxygen supply levels. This proposed Phase II study will obtain enough practical data to prepare for a future Phase III project

Anticipated Results/Potential Commercial Applications of Research:
The production cost of glycerol is estimated at $0.45/lb by fermentation, comparing with a market price of $0.85lb. The large difference makes this process very profitable. It has attracted strongly industrial interests. GRT will provide follow-on funding of $275,000 from its internal resource for Phase III. Meanwhile, GRT is negotiating with two companies for licensing and for joint production ventures. Annual glycerol demand was given in an USDA report as 1.2 billion pounds. It is growing steadily. Two new potential uses will stimulate further demand growth. One is the use of glycerol in drilling mud formula for oil wells. Another is the conversion into 1,3-propanediol through a 2-step process that has been shown to be very effective. The new industry, once established, will benefit agriculture significantly.