Contract

                                 FIRST AMENDMENT
                                       TO
                              COMMON STOCK WARRANT
                                       OF
                           DYADIC INTERNATIONAL, INC.

      This FIRST AMENDMENT (this "First  Amendment") is made and entered into as
of the 19th day of August,  2004 by and between  Dyadic  International,  Inc., a
Florida corporation (the "Company"), and X ("X").

                                    RECITALS:

      A. The Company and X are parties to that certain Common Stock Warrant (the
"Warrant"), pursuant to which the Company granted X the right to purchase shares
of Common Stock, no par value, of the Company ("Shares").  All capitalized terms
used but not otherwise  defined  herein shall have the meanings given such terms
in the Warrant.

      B. X is the holder of the Warrant and has not made any  assignment  of any
of his rights thereunder or interest therein.

      C. The Warrant was granted in  consideration  for X's  participation  in a
revolving  loan facility for the Company  evidenced by that certain $3.0 million
revolving note (as amended, the "Note").

      D. To facilitate  the Company's  ability to raise  additional  capital for
ongoing operations,  the Company and X have agreed (a) that the maturity date of
the Note be extended  from  January 1, 2005 to January 1, 2007 and (b),  that in
consideration  for such extension,  the exercise price of the Warrant be reduced
to Three Dollars and Thirty Three Cents ($3.33) per Share.

                                    AGREEMENT

      NOW THEREFORE,  in consideration of the foregoing Recitals, and other good
and  valuable  consideration  the  receipt and  sufficiency  of which are hereby
mutually and expressly acknowledged, the parties hereto agree as follows:

      1. Incorporation of Recitals.  The above Recitals are incorporated in this
First Amendment by this reference and the parties  acknowledge  them as true and
accurate.


                                       1


      2. Amendment of the Warrant. The Warrant is hereby amended by deleting the
introductory  paragraph of the Warrant in its entirety and replacing it with the
following:

      "For value received,  Dyadic  International,  Inc., a Florida  corporation
(the  "Company")  hereby  certifies  that X (the  "Holder") or his  assign(s) is
entitled to purchase  from the Company,  at any time or from time to time during
the Exercise  Period (as defined  below),  in whole or in part,  up to _________
shares of Common  Stock,  no par value,  of the Company,  at the price per share
equal to $3.33 (the "Exercise Price")."

      3. Effect of First Amendment. Except as specifically amended by this First
Amendment,  the Warrant  shall  continue in full force and effect in  accordance
with its original  terms,  and all  references  to the Warrant in any  document,
letter,  certificate,  the Warrant itself, or any  communication  issued or made
pursuant  to or with  respect  to the  Warrant,  shall be deemed to refer to the
Warrant as amended pursuant to this First Amendment.

      4.   Counterparts.   This  First  Amendment  may  be  signed  in  multiple
counterparts,  each of which shall be deemed to be an original and all of which,
taken together, shall constitute one and the same instrument.

      IN WITNESS  WHEREOF,  the Company and X have executed this First Amendment
as of the date first above-written.

DYADIC INTERNATIONAL, INC.
a Florida corporation


By:
   -----------------------------
   Name:  Mark A. Emalfarb
   Its:   CEO

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X