<SEC-DOCUMENT>0001493152-25-029409.txt : 20251229
<SEC-HEADER>0001493152-25-029409.hdr.sgml : 20251229
<ACCEPTANCE-DATETIME>20251229170032
ACCESSION NUMBER:		0001493152-25-029409
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20251223
FILED AS OF DATE:		20251229
DATE AS OF CHANGE:		20251229

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			EMALFARB MARK A
		CENTRAL INDEX KEY:			0001328287
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32513
		FILM NUMBER:		251609936

	MAIL ADDRESS:	
		STREET 1:		C/O DYADIC INTERNATIONAL, INC.
		STREET 2:		140 INTRACOASTAL POINT DRIVE, SUITE 404
		CITY:			JUPITER
		STATE:			FL
		ZIP:			33477-5094

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DYADIC INTERNATIONAL INC
		CENTRAL INDEX KEY:			0001213809
		STANDARD INDUSTRIAL CLASSIFICATION:	BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
		ORGANIZATION NAME:           	03 Life Sciences
		EIN:				450486747
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1044 NORTH U.S. HIGHWAY ONE
		STREET 2:		SUITE 201
		CITY:			JUPITER
		STATE:			FL
		ZIP:			33477
		BUSINESS PHONE:		561-743-8333

	MAIL ADDRESS:	
		STREET 1:		1044 NORTH U.S. HIGHWAY ONE
		STREET 2:		SUITE 201
		CITY:			JUPITER
		STATE:			FL
		ZIP:			33477

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CCP WORLDWIDE INC
		DATE OF NAME CHANGE:	20030110
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>ownership.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-12-23</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001213809</issuerCik>
        <issuerName>DYADIC INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>DYAI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001328287</rptOwnerCik>
            <rptOwnerName>EMALFARB MARK A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O DYADIC INTERNATIONAL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1044 NORTH U.S. HIGHWAY ONE, SUITE 201</rptOwnerStreet2>
            <rptOwnerCity>JUPITER</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>33477-5094</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Senior Secured Convertible Promissory Note due March 8, 2027</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.40</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-12-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>1000000</value>
                    <footnoteId id="F1"/>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2027-03-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>714286</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Through Mark A Emalfarb Trust U/A/ DTD 10/1/1987</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Senior Secured Convertible Promissory Note due Dec 31, 2027</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>1.05</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2025-12-23</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionTotalValue>
                    <value>1000000</value>
                    <footnoteId id="F1"/>
                </transactionTotalValue>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2027-12-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>952381</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>1000000</value>
                    <footnoteId id="F1"/>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Through Mark A Emalfarb Trust U/A/ DTD 10/1/1987</value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On December 23, 2025, Dyadic International, Inc. (the &quot;Company&quot;) entered into an amendment (the &quot;Amendment&quot;) to the Form of Senior Secured Convertible Promissory Note due March 8, 2027 (the &quot;Convertible Notes&quot;). 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.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Ping Rawson, attorney-in-fact</signatureName>
        <signatureDate>2025-12-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
