Dyadic Closes $10 Million R&D and Stock Purchase Agreement with Abengoa Bioenergy in the Area of Cellulosic Ethanol Production

Business Wire, Nov 9, 2006

JUPITER, Fla. -- Dyadic International, Inc. (AMEX:DIL), a biotechnology company, announced today that it has closed the previously announced three-year research and development (R&D) agreement and stock purchase agreement with Abengoa Bioenergy R&D, Inc. (Abengoa), an Abengoa Bioenergy Company. Under the terms of the stock purchase agreement, Abengoa Bioenergy has purchased 2,136,752 shares of Dyadic Common Stock at $4.68 per share, or a total of $10 million.

The securities offered in the private sale were not registered under the Securities Act of 1933, as amended (the "Act") or any state securities laws, and may not be offered or sold in the United States absent registration, or an applicable exemption from registration, under the Act and applicable state securities laws.

For additional information regarding Dyadic's stock purchase agreement and R&D agreement with Abengoa, reference is made to Dyadic's Current Report on Form 8-K dated October 26, 2006, as filed with the U.S. Securities and Exchange Commission on November 1, 2006.

About Dyadic

Dyadic International, Inc. is engaged in the development, manufacture and sale of biological products using a number of proprietary fungal strains to produce enzymes and other biomaterials, principally focused on a system for protein production based on the patented Chrysosporium lucknowense fungus, known as C1. Dyadic is applying its technologies to produce enzymes for use in converting various agricultural products (e.g. corn) and waste products (e.g. switch grass, wheat straw, sugar cane bagasse, etc.) into fermentable sugars, which can then be used in the production of traditional and cellulosic ethanol as well as other products currently derived from petroleum. Dyadic's C1 technology also is being developed to facilitate the discovery, development and large-scale production of human antibodies and other high-value therapeutic proteins. Dyadic currently sells more than 45 liquid and dry enzyme products to more than 200 industrial customers in approximately 50 countries for the textile, pulp & paper and animal feed industries.

About Abengoa Bioenergy

Abengoa Bioenergy is considered to be the second largest ethanol producer in the world with production facilities located in Europe and the USA. Abengoa Bioenergy is one of the five business units of Abengoa, S.A. (ABG:MC), a technology company that applies innovative solutions for sustainable development in the infrastructures, environment and energy sectors. Abengoa, S.A. is a listed company on the Madrid Stock Exchange with 2005 revenues of approximately two billion euros, and is present in more than seventy countries where it operates with its five business units; Solar, Bioenergy, Environmental Services, Information Technologies, and Industrial Engineering and Construction. (www.abengoa.com)

Cautionary Statement for Forward-Looking Statements

Certain statements contained in this press release are "forward-looking statements." These forward-looking statements involve risks and uncertainties that could cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. For a discussion of these risks and uncertainties, please see our filings from time to time with the Securities and Exchange Commission, which are available free of charge on the SEC's web site at http://www.sec.gov, including our Annual Report on Form 10-KSB for the year ended December 31, 2005, and our subsequent filings with the SEC. Except as required by law, we expressly disclaim any intent or obligation to update any forward-looking statements.