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

  
    
  
  
    
      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.
    
  
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.