CAMBRIDGE, Mass. and SAN DIEGO
June 20, 2007

Diversa Corporation (Nasdaq: DVSA) and Celunol Corp. announced today that they have completed their previously-announced merger transaction to create a new leader in the global biofuels industry. The combined company, which has been renamed Verenium Corporation, possesses a growing portfolio of specialty enzyme products and unique technical and operational capabilities designed to enable the production of low-cost, biomass-derived sugars for a multitude of major industrial applications. The most significant near-term commercial opportunity for Verenium will be the large-scale commercial production of cellulosic ethanol derived from multiple biomass feedstocks. In connection with the corporate name change, the Company has also changed its NASDAQ ticker symbol from "DVSA" to "VRNM" and will begin trading under the new ticker symbol effective June 21, 2007.

Stockholders of both companies approved the merger and merger-related proposals earlier today, and all regulatory approvals and closing conditions have been satisfied.

"We are pleased that our respective shareholders have approved our merger and believe their support reinforces our belief in the compelling investment proposition afforded by this transaction," said Carlos A. Riva, President and Chief Executive Officer of Verenium. "After several months of diligent integration planning between the two companies, we are excited to become a single organization and are confident that the transaction represents a unique opportunity for our partners, employees, and shareholders."

"Verenium is now positioned to be a vertically-integrated leader in the rapidly-evolving worldwide biofuels industry through the unique combination of assets, technologies, and personnel resulting from this merger. We believe that commercial success in this industry requires broad R&D capabilities and asset development expertise, which we have now brought together within one, highly-focused company, Verenium Corporation."

Verenium begins operations with numerous unique attributes, including:
• Fully-integrated, end-to-end capabilities in pre-treatment, novel enzyme development, fermentation, engineering, and project development;
• One of the only operational cellulosic ethanol pilot plants in the United States;
• A 1.4 million gallon-per-year demonstration-scale facility, currently under construction, to produce cellulosic ethanol from sugarcane bagasse and specially-bred energy cane;
• A diverse and growing portfolio of commercialized industrial enzyme products; and
• Over 300 issued or in-licensed patents for its technologies and processes, as well as over 450 pending patents.

Verenium will be structured and managed as three distinct, but interdependent, organizational units: Specialty Enzymes Business Unit, Biofuels Business Unit, and Research and Development. The Specialty Enzymes Business Unit currently generates commercial revenue from multiple sources, including industrial enzyme product sales, technology licenses, strategic partnerships, and government grants. The Biofuels Business Unit will be primary focused on the commercial-scale production and sale of cellulosic ethanol from company-managed production facilities throughout the US, as well as strategic partnerships and related revenue arrangements around the world. The Research and Development organization's primary goal will be to support both Verenium Business Units, as well as various existing strategic collaborative partners. As of March 31, 2007, the Company had cash, cash-equivalents, and short-term investments on hand of approximately $125.5 million, which, together with approximately $20 million received in early April from the exercise of an over-allotment option related to the recent convertible notes offering, it believes to be sufficient to fund operations through at least 2008.

Verenium's Board of Directors will initially consist of nine members, six from Diversa and three from Celunol, including Mr. Riva. The non-employee Board members are: Dr. James Cavanaugh, who will serve as Chairman of the Board of Directors; Peter Johnson; Fernand Kaufmann, Ph.D.; Mark Leschly; Melvin Simon, Ph.D.; Cheryl Wenzinger; Joshua Ruch; and Michael Zak.

The Company's executive management team is being led by Carlos A. Riva, President, Chief Executive Officer, and Director, and John A. McCarthy, Jr., Executive Vice President and Chief Financial Officer.

Verenium will be headquartered in Cambridge, Massachusetts and have research and operations facilities in San Diego, California; Jennings, Louisiana; and Gainesville, Florida. Due to the complementary nature of the two companies and the level of development activities being pursued, the company anticipates increasing its staff in Cambridge and Jennings, as well as building additional staff over time in San Diego to support the growth of the enzyme business and research and development efforts of the Company.

In connection with the merger, Diversa will issue 15 million shares of common stock in exchange for all outstanding equity securities of Celunol, which includes shares issuable under Celunol options and warrants that will be assumed by the Company. As a result of the merger, former Celunol security holders will own approximately 24 percent of the Company, while Diversa shareholders will own approximately 76 percent. Immediately following the merger, the Company will have approximately 63 million shares outstanding.

About Verenium

Cambridge-based Verenium Corporation is a leader in the development and commercialization of cellulosic ethanol, an environmentally-friendly and renewable transportation fuel, as well as high-performance specialty enzymes for applications within the biofuels, industrial, and health and nutrition markets. The Company possesses integrated, end-to-end capabilities in pre- treatment, novel enzyme development, fermentation, engineering, and project development and is moving rapidly to commercialize its proprietary technology for the production of ethanol from a wide array of feedstocks, including sugarcane bagasse, dedicated energy crops, agricultural waste, and wood products. In addition to the vast potential for biofuels, a multitude of large-scale industrial opportunities exist for the Company for products derived from the production of low-cost, biomass-derived sugars.

Verenium's Specialty Enzyme business harnesses the power of enzymes to create a broad range of specialty products to meet high-value commercial needs. Verenium's world class R&D organization is renowned for its capabilities in the rapid screening, identification, and expression of enzymes-proteins that act as the catalysts of biochemical reactions.

Verenium recently completed a significant upgrade of one of the nation's first operational cellulosic ethanol pilot facilities located in Jennings, Louisiana and expects to achieve mechanical completion of a 1.4 million gallon-per-year, demonstration-scale facility to produce cellulosic ethanol by the end of 2007. In addition, the Company's process technology has been licensed by Tokyo-based Marubeni Corp. and Tsukishima Kikai Co., LTD and has been incorporated into BioEthanol Japan's 1.4 million liter-per-year cellulosic ethanol plant in Osaka, Japan -- the world's first commercial-scale plant to produce cellulosic ethanol from wood construction waste. For more information on Verenium, visit http://www.verenium.com.

Forward Looking Statements

Statements in this press release that are not strictly historical are "forward-looking" and involve a high degree of risk and uncertainty. These include statements related to the Company's competitive advantages and position, technical, operations, production and personnel capabilities, commercial opportunities, prospects for technical and commercial development and success, plans for expanding its cellulosic ethanol business, including by managing production facilities throughout the U.S. and through strategic partnerships and other arrangements elsewhere, and other growth, and the sufficiency of its cash equivalents to fund its operations through 2008. Such statements are only predictions, and actual events or results may differ materially from those projected in such forward-looking statements. Factors that could cause or contribute to differences include, but are not limited to, the risk that the Company may not be able to successfully integrate its businesses or achieve synergies in a timely manner or to the extent anticipated, the risk that the marketplace for the Company's products and product candidates may change or be impacted by competition, supply issues or marketplace trends, the risk that technical, regulatory or manufacturing issues, new data or intellectual property disputes may affect the Company's commercial and/or development programs or that the Company may encounter other difficulties in developing its products, product candidates, and/or processes or in gaining approval or market acceptance of new products, processes, and/or technologies and risks and other uncertainties more fully described in the Company's (formerly Diversa's) filings with the Securities and Exchange Commission, including, but not limited to, the Company's (formerly Diversa's) quarterly report on Form 10-Q for the quarter ended March 31, 2007. These forward-looking statements speak only as of the date hereof. The Company expressly disclaims any intent or obligation to update these forward-looking statements.