-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 Fl5zGwSV6zw6TmpfvdQBBIcLW3V5aDZ5dM1JxhYsuaLzH7Pu/IwrZDnnMMqmCUq3
 +01DNZGmwqYumPY8fZ+BpQ==

<SEC-DOCUMENT>0001140361-08-025960.txt : 20081118
<SEC-HEADER>0001140361-08-025960.hdr.sgml : 20081118
<ACCEPTANCE-DATETIME>20081118184755
ACCESSION NUMBER:		0001140361-08-025960
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20081117
FILED AS OF DATE:		20081118
DATE AS OF CHANGE:		20081118

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PINNACLE FUND L P
		CENTRAL INDEX KEY:			0000915861
		STATE OF INCORPORATION:			TX

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32513
		FILM NUMBER:		081199393

	BUSINESS ADDRESS:	
		STREET 1:		12900 PRESTON RD STE 420
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75230

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KITT BARRY M
		CENTRAL INDEX KEY:			0001165244

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-32513
		FILM NUMBER:		081199394

	BUSINESS ADDRESS:	
		STREET 1:		4965 PRESTON PARK BLVD.
		STREET 2:		SUITE 240
		CITY:			PLANO
		STATE:			TX
		ZIP:			75093
		BUSINESS PHONE:		9729852121

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DYADIC INTERNATIONAL INC
		CENTRAL INDEX KEY:			0001213809
		STANDARD INDUSTRIAL CLASSIFICATION:	INDUSTRIAL ORGANIC CHEMICALS [2860]
		IRS NUMBER:				450486747
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		140 INTRACOASTAL POINTE DRIVE
		STREET 2:		SUITE 404
		CITY:			JUPITER
		STATE:			FL
		ZIP:			33477
		BUSINESS PHONE:		561-743-8333

	MAIL ADDRESS:	
		STREET 1:		140 INTRACOASTAL POINTE DRIVE
		STREET 2:		SUITE 404
		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>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-11-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001165244</rptOwnerCik>
            <rptOwnerName>KITT BARRY M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE PINNACLE FUND, L.P.</rptOwnerStreet1>
            <rptOwnerStreet2>4965 PRESTON PARK BLVD., SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>PLANO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75093</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000915861</rptOwnerCik>
            <rptOwnerName>PINNACLE FUND L P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4965 PRESTON PARK BLVD., SUITE 240</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PLANO</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75093</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.001 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2008-11-17</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>23400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>.1961</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1813972</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By The Pinnacle Fund, L.P.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Barry M. Kitt exercises investment discretion and control over the securities of the issuer held by The Pinnacle Fund, L.P., a Texas limited partnership (?Pinnacle?).  Mr. Kitt may be deemed to be the beneficial owner of the securities beneficially owned by Pinnacle.  Mr. Kitt hereby disclaims beneficial ownership of the securities of the issuer reported herein to the extent of his direct or indirect pecuniary interest therein, and this Form 4 shall not be deemed to be an admission that Mr. Kitt is the beneficial owner of the securities of the issuer reported herein for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.</footnote>
        <footnote id="F2">This Form 4 is filed on behalf of Pinnacle and Barry M. Kitt.  Pinnacle Advisers, L.P. (?Advisers?) is the general partner of Pinnacle.  Pinnacle Fund Management, LLC (?Management?) is the general partner of Advisers.  Mr. Kitt is the sole member of Management</footnote>
    </footnotes>

    <remarks>THE PINNACLE FUND, L.P.,
By: Pinnacle Advisers, L.P., its general partner,
By: Pinnacle Fund Management, LLC, its general partner,</remarks>

    <ownerSignature>
        <signatureName>/s/ Barry M. Kitt</signatureName>
        <signatureDate>2008-11-18</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Barry M. Kitt, its sole member</signatureName>
        <signatureDate>2008-11-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
