Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * EMALFARB MARK A 2. Issuer Name and Ticker or Trading Symbol DYADIC INTERNATIONAL INC [DYAI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CEO (Last) (First) (Middle) C/O DYADIC INTERNATIONAL, INC., 1044 NORTH U.S. HIGHWAY ONE, SUITE 201 3. Date of Earliest Transaction (Month/Day/Year) 12/23/2025 (Street) JUPITER, FL 33477-5094 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Senior Secured Convertible Promissory Note due March 8, 2027

$1.4

12/23/2025

D

$1,000,000(1)

(1)

03/08/2027

Common Stock

714,286

(1)

0 (1)

I

Through Mark A Emalfarb Trust U/A/ DTD 10/1/1987

Senior Secured Convertible Promissory Note due Dec 31, 2027

$1.05

12/23/2025

A

$1,000,000(1)

(1)

12/31/2027

Common Stock

952,381

(1)

$1,000,000(1)

I

Through Mark A Emalfarb Trust U/A/ DTD 10/1/1987

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
EMALFARB MARK A C/O DYADIC INTERNATIONAL, INC. 1044 NORTH U.S. HIGHWAY ONE, SUITE 201 JUPITER, FL 33477-5094	X	X	CEO

Signatures

/s/ Ping Rawson, attorney-in-fact		12/29/2025
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	On December 23, 2025, Dyadic International, Inc. (the "Company") entered into an amendment (the "Amendment") to the Form of Senior Secured Convertible Promissory Note due March 8, 2027 (the "Convertible Notes"). Following the Amendment, the Convertible Notes will mature December 31, 2027 and their conversion price is $1.05. The Amendment was approved by the Company's board of directors, and did not involve the exchange of consideration between the Company and the holders.

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