DYADIC ENTERS INTO RESEARCH AND DEVELOPMENT AGREEMENT WITH ABENGOA BIOENERGY IN THE AREA OF CELLULOSIC ETHANOL PRODUCTION

DYADIC ENTERS INTO RESEARCH AND DEVELOPMENT AGREEMENT WITH ABENGOA BIOENERGY IN THE AREA OF CELLULOSIC ETHANOL PRODUCTION

ABENGOA BIOENERGY TO PURCHASE $10 MILLION OF DYADIC COMMON STOCK

Jupiter, Florida, October 27, 2006. Dyadic International, Inc. (AMEX: DIL), a biotechnology company, today announced that it has signed a three-year research and development (R&D) agreement and a stock purchase agreement with Abengoa Bioenergy R&D, Inc. (ABRD), an Abengoa Bioenergy Company focusing on research and development. Under the terms of the purchase agreement, Abengoa Bioenergy has agreed to invest $10 million in Dyadic, for which it will be issued 2,136,752 shares of Dyadic Common Stock at $4.68 per share (based on the closing sales price on October 25, 2006, as reported on the American Stock Exchange). The closing of the sale of the common shares is subject to approval of the listing of the shares by the American Stock Exchange and other customary closing conditions. After the closing, under certain circumstances, additional securities may be issuable to ABRD. Cowen and Company, LLC, acted as an advisor to Dyadic.

Dyadic will use the proceeds from this private sale to fund its R&D obligations under the R&D agreement, which has as its objective the development of a cost-effective enzyme production system for commercial application in Abengoa Bioenergy’s bioethanol (cellulosic ethanol) production process. The R&D agreement, which does not become effective until the private sale closes, calls upon Dyadic to use its proprietary technologies to develop one or more enzyme mixture manufacturing systems customized to ABRD’s proprietary biomass substrates. The R&D agreement contemplates that Dyadic will perform both foundational research of general application to the cellulosic ethanol field and specific applications research for the achievement of the goals of ABRD’s program. Under the terms of the R&D agreement, if Dyadic successfully develops one or more enzyme manufacturing systems for Abengoa Bioenergy, Dyadic may be entitled to receive license fees, technology transfer fees and royalties on ethanol sales. Other financial terms were not disclosed.

“Abengoa Bioenergy is considered to be the second largest ethanol producer in the world and a leader in the fields of both corn-derived and cellulose-derived ethanol production. We are extremely pleased to partner with Abengoa Bioenergy to leverage Dyadic’s patented C1 platform enzyme technology to enable commercial developme