Material Agreement (Form 8-K)

Item 1.01. Entry into a Material Definitive Agreement.

On September 15, 2025, Dyadic International, Inc. (the "Company") entered into an amendment (the "Amendment") to the Security Agreement, dated March 8, 2024 (the "Security Agreement"), with a majority of the current holders of the Company's Senior Secured Convertible Promissory Notes due March 8, 2027. Pursuant to the Amendment, Schedule A of the Security Agreement was replaced in its entirety to reflect updates to the Secured Parties (as defined in the Security Agreement) thereunder, including the addition of a trust for the benefit of the Company's CEO, Mark Emalfarb, as a result of his purchase and assignment to him of one of the Company's Senior Secured Convertible Promissory Notes due March 8, 2027 in a principal amount of $1,000,000.

The foregoing description of the Amendment is only a summary of the material terms thereof, does not purport to be complete and is qualified in its entirety by reference to the full text of the Amendment, a copy of which is attached as Exhibit 10.1 to this Current Report on Form 8-K and is incorporated herein by reference.