Filed by Diversa Corporation Pursuant to Rule 425

Under the Securities Act of 1933, as Amended

and Deemed Filed Pursuant to Rule 14a-12

Under the Securities Exchange Act of 1934, as Amended

Subject Company: Diversa Corporation

Exchange Act File No. 000-29173

This filing relates to a presentation made by members of management of Diversa Corporation (“Diversa”) and Celunol Corp. (“Celunol”). Diversa recently executed an Agreement and Plan of Merger and Reorganization, dated as of February 12, 2007, by and among Diversa, Concord Merger Sub, Inc., Celunol and William Lese, as the representative of Celunol’s stockholders.

Additional Information about the Merger and Where to Find It

Diversa intends to file with the SEC a registration statement on Form S-4 that will include a proxy statement/prospectus and other relevant documents in connection with the proposed merger between Diversa and Celunol and related transactions. Investors and securityholders of Diversa and Celunol are urged to read the proxy statement/prospectus (including any amendments or supplements to the proxy statement/prospectus) and other relevant materials when they become available, because they will contain important information about Diversa, Celunol, and the proposed merger and related transactions. Investors may obtain a free copy of these materials (when they are available) and other documents filed with the SEC at the SEC’s website at www.sec.gov. A free copy of the proxy statement/prospectus, when it becomes available, may also be obtained from Diversa by directing a request to: Diversa Corporation, 4955 Directors Place, San Diego, CA 92121, Attn: Investor Relations. In addition, investors may access copies of the documents filed with the SEC by Diversa on Diversa’s website at www.diversa.com.

Participants in the Solicitation

Diversa and its executive officers and directors and Celunol and its executive officers and directors may be deemed to be participants in the solicitation of proxies from the stockholders of Diversa in connection with the proposed merger between Diversa and Celunol and related transactions. Information regarding the special interests of these executive officers and directors in the proposed merger and related transactions will be included in the proxy statement/prospectus referred to above. Additional information regarding the executive officers and directors of Diversa is also included in Diversa’s proxy statement for its 2006 Annual Meeting of Stockholders, which was filed with the SEC on April 5, 2006. This document is available free of charge at the SEC’s website at www.sec.gov and from Investor Relations at Diversa at the address described above.

The following presentation was delivered by certain management representatives of Diversa and Celunol on February 23, 2007.

1

Accelerating the Production of Cellulosic Biofuels

February 2007

2

Forward-Looking Statements

This

discussion

will

include

forward-looking

statements

that

involve

a

high

degree

of

risk

and

uncertainty. 

These

include

statements

related

to

Diversa's

products,

product

candidates

and

business

strategies,

including

for

biofuels,

the

markets

for

Diversa's

products

and

product

candidates,

Diversa's

financial

guidance,

and

the

expected

benefits

to

the

combined

company

of

the

merger

between

Diversa

and

Celunol

and

the

likelihood

of

the

combined

company

achieving

those

benefits.

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

risks

involved

with

Diversa's

technologies,

intellectual

property

protection,

collaborative

relationships,

ability

to

develop,

receive

necessary

approvals

for

and

commercialize

its

products

and

product

candidates,

consummate

the

proposed

merger

with

Celunol,

and

achieve

the

benefits

and

synergies

expected

from

the

merger,

as

well

as

risks

involved

with

customer

adoption

of

Diversa's

products

and

product

candidates

and

competing

technologies. 

Certain

of

these

factors

and

others

are

more

fully

described

in

Diversa's

filings

with

the

Securities

and

Exchange

Commission,

including

Diversa's

Quarterly

Report

on

Form

10-Q

for

the

quarter

ended

September

30,

2006.

These

forward-looking

statements

speak

only

as

of

the

date

hereof.

Diversa

expressly

disclaims

any

intent

or

obligation

to

update

these

forward-looking

statements.

3

Making Cellulosic Biofuels

a Commercial Reality

Creating the First Company with Integrated, End-to-End

Technologies to Convert Biomass into Fuel Ethanol

4

Diversa/Celunol Merger

Creates the First Company with Integrated,

End-To-End Technologies to

Make Cellulosic Biofuels a Commercial Reality

Scientific

Talent

Proven

Processes to

Convert a Broad

Range of

Feedstocks to

Ethanol

Development

Skills

(agronomics,

engineering,

finance)

Pilot Plant

Operations

5

Diversa’s Key Technologies

> 250 Issued Patents;  > 500 Pending Patents

•

Biodiversity

–

Unique access and patented approaches to

capture nature’s enormous array of microbial

biodiversity

•

DirectEvolution

Technology

–

Patented genetic manipulation of enzymes,

proteins, and antibodies

•

High-Throughput Screening

–

Ability to rapidly screen billions of samples per day

to find the ideal enzyme (or antibody)

•

Host Engineering

–

Revolutionary heterologous over expression of

enzymes, proteins, and antibodies

•

Commercial-Scale Manufacturing

6

PARTNERS

PRODUCTS

MARKETS

FUELZYME™-CX

Amylase-T (transgenic)

FUELZYME™-LF /

Valley “Ultra-Thin”™

Phytase-T (transgenic)

Pharma

Intermediates

HEALTH &

NUTRITION

SPECIALTY

INDUSTRIAL

PROCESSES

ALTERNATIVE

FUELS

Enzyme Product Matrix

7

Diversa Strategic Focus:

Vertical Integration Within Biofuels

Cellulosic

Ethanol

Starch

Ethanol

Enzyme

Production

Enzyme

Discovery &

Evolution

Rationale

•

Accelerate development of enabling enzyme cocktails

•

Provide integrated enzyme & process engineering solutions

•

Capture greater economic value for our shareholders

8

Celunol Corp.

A science and technology-driven company with

the management experience

and expertise to become a global leader

in the production of

low-cost cellulosic

ethanol

from an array of biomass sources

9

Biofuels

Business Strategy

•

Focus on cellulosic

ethanol

•

Maintain leading-edge R&D capability

–

Pretreatment

–

Metabolic engineering

–

Process development

–

Enzyme & fermentation technology

•

Develop, own, and operate biofuels

plants

•

Strategic out-licensing deals to extend reach of technology

•

Employ well-developed project-finance structures for efficient use

of corporate equity capital

10

The Celunol Process

11

Celunol Pilot Plant, Jennings LA

•

Initially constructed 1998-99

–

First cellulosic

production facility in the

US capable of C5 fermentation

•

Upgrades completed Nov. 2006

–

On-site co-production of enzymes to

reduce costs

•

High-yield ethanol production through

fermentation of  C5 and C6 sugars

•

Pilot facility to be used as an R&D tool

on a wide range of feedstocks

12

The Next Step: Jennings Demonstration Plant

•

Demonstration-scale

cellulosic

ethanol facility

under construction

•

Design capacity of 1.4MGY

•

Feedstocks

to include

sugarcane bagasse

and

specially-bred energy cane

•

Groundbreaking: Feb. ‘07

•

Expected completion: Q4 ‘07

13

Diversa/Celunol Merger

Creates the First Company with Integrated,

End-To-End Technologies to

Make Cellulosic Biofuels a Commercial Reality

Scientific

Talent

Proven

Processes to

Convert a Broad

Range of

Feedstocks to

Ethanol

Development

Skills

(agronomics,

engineering,

finance)

Pilot Plant

Operations

14

Financial Dynamics

•

Biofuels

–

Company-sponsored commercial projects

–

Technology/process licensor to third-party

commercial projects

–

Enzyme licensor to major biofuels companies

•

Specialty Enzymes

–

Company-controlled product focus

–

Renewed plans for aggressive sales/marketing

initiatives

–

Operating leverage to drive increased margins

•

R&D

–

Focused support for biofuels and specialty enzyme

businesses

–

Strategically-focused research collaborations

15

Summary: Merger Terms

•

Diversa to issue 15 million shares of Diversa stock

•

Diversa and Celunol shareholders to own 76% and

24% of combined company, respectively

•

Diversa to provide support for Celunol’s 2007

development efforts prior to closing

–

$20 million of funding

•

Timeline

–

File S-4/Proxy by mid March 2007

–

Regulatory review/approval (SEC, HSR)

–

Stockholders’

votes  ~ May/June 2007

–

Targeted closing by end of Q2 2007

16

Making Cellulosic Biofuels

a Commercial Reality

Creating the First Company with Integrated, End-to-End

Technologies to Convert Biomass into Fuel Ethanol