Item 1.01 Entry into a Material Definitive Agreement.

On June 12, 2007, Diversa Corporation ("Diversa") and Celunol Corp. ("Celunol") entered into an Amendment No. 2 to Promissory Note (the "Amendment"), amending that certain Promissory Note, dated February 12, 2007, by and between Diversa and Celunol (as amended, the "Promissory Note"). The Amendment increased the maximum aggregate principal amount that Celunol may borrow from Diversa pursuant to the Promissory Note by $7,500,000 to $27,500,000. The original $20,000,000 maximum aggregate principal amount of the Promissory Note was intended by the parties to fund Celunol's working capital needs through May 31, 2007, which was the outside date originally estimated by the parties for the Diversa 2007 annual stockholders' meeting at which Diversa's stockholders would consider matters related to the merger of a wholly-owned subsidiary of Diversa with and into Celunol, with Celunol being the surviving corporation and a wholly-owned subsidiary of Diversa. Because the Diversa annual stockholders' meeting was scheduled for June 20, 2007, the amendment to the Promissory Note was approved by Diversa's board of directors to provide Celunol additional working capital to fund its operating activities for the time following May 31, 2007 and through the date of the Diversa stockholder meeting on June 20, 2007.

The foregoing description of the Amendment is qualified in its entirety by reference to the Amendment filed as Exhibit 10.1 hereto, and incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits 10.1 Amendment No. 2 to Promissory Note, dated June 12, 2007, between Diversa Corporation and Celunol Corp.

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