DYADIC INTERNATIONAL INC

(a)None.

(b)None.

(c) During the quarter ended* June 30, 2024,the following individuals adopted Rule10b5*-1 trading arrangements, which are intended to satisfy the affirmative defense of Rule10b5-1(c) under the Exchange Act: our President and Chief Executive Officer Mark Emalfarb (adopted on* June 4, 2024);ourdirector Jack Kaye (adopted on June 6, 2024);our Vice President of Research and Business Development Ronen Tchelet (adopted on June 7, 2024);and our Chief Financial Officer Ping Wang Rawson (adopted on June 12, 2024).Each trading arrangement includes the potential sale of up to a specified number of shares of our common stock owned by the applicable individual (for Mr. Emalfarb,1 million; for Mr. Kaye,292,367; for Mr. Tchelet,250,000; and for Ms. Rawson,282,485), and expires on a specified date (for Mr. Emalfarb, December 31, 2026;for Mr. Kaye, June 2, 2026;for Mr. Tchelet, June 10, 2025;and for Ms. Rawson, June 12, 2026),*unless earlier terminated in accordance with the provisions of the arrangement.

Except as described above, for the quarter ended* June 30, 2024,none of our directors or officers (as defined in Section16* of the Exchange Act) adopted or terminated a “Rule10b5-1 trading arrangement” or a “non-Rule10b5-1 trading arrangement” (each as defined in Item408(a) and (c), respectively, of Regulation S-K).