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                                                                 EXHIBIT 10.15.1

        AMENDMENT TO THE FOUNDER STOCK REPURCHASE AND VESTING AGREEMENT

     This FIRST AMENDMENT to the FOUNDER STOCK REPURCHASE AND VESTING AGREEMENT
(the "First Amendment") is dated April __, 2000 by and among PARADIGM GENETICS,
INC., a DELAWARE corporation (the "Company"), and SANDY STEWART (the "Founder").

                                  WITNESSETH:

     WHEREAS, the Company and the Founder entered into the Founder Stock
Repurchase and Vesting Agreement dated as of February 12, 1998;

     WHEREAS, the Company and the Founder agree to amend the Founder Stock
Repurchase and Vesting Agreement in order to revise certain provisions therein;
and

     NOW, THEREFORE, in consideration of the foregoing and the mutual covenants
set forth herein, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto, intending to
be legally bound, hereby amend the Founder Stock Repurchase and Vesting
Agreement and agree as follows:

     1.   The conditions of "Termination of Repurchase Rights" set forth
specifically in Section 5.3(a)(iii) is hereby deleted and replaced with the
following:

     "(iii) Upon the closing of a firm commitment underwritten public offering
     pursuant to an effective registration statement under the 1933 Act covering
     the offer and sale of the Company's Common Stock at a price per share of
     not less than $6.00 (as adjusted for stock splits and the like effected
     after the date of this Agreement) and an aggregate offering price to the
     public of not less than $20,000,000, the Founder shall acquire a vested
     interest in, and the Repurchase Right shall lapse with respect to, the
     Unvested Shares as of such closing."

     2.  This First Amendment shall be governed by and construed in accordance
with the laws of the State of Delaware, without giving effect to its conflicts
of law provisions.

     This First Amendment may be executed in multiple counterparts.

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     Executed as of the date above written.

PARADIGM GENETICS, INC.:
------------------------

By: _____________________________
Name: __________________________
Title: ___________________________

FOUNDER
-------

_________________________________
Sandy Stewart

                                       2<PAGE>

                                                                 EXHIBIT 10.16.1

        AMENDMENT TO THE FOUNDER STOCK REPURCHASE AND VESTING AGREEMENT

     This FIRST AMENDMENT to the FOUNDER STOCK REPURCHASE AND VESTING AGREEMENT
(the "First Amendment") is dated April __, 2000 by and among PARADIGM GENETICS,
INC., a DELAWARE corporation (the "Company"), and SCOTT UKNES (the "Founder").

                                  WITNESSETH:

     WHEREAS, the Company and the Founder entered into the Founder Stock
Repurchase and Vesting Agreement dated as of February 12, 1998;

     WHEREAS, the Company and the Founder agree to amend the Founder Stock
Repurchase and Vesting Agreement in order to revise certain provisions therein;
and

     NOW, THEREFORE, in consideration of the foregoing and the mutual covenants
set forth herein, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto, intending to
be legally bound, hereby amend the Founder Stock Repurchase and Vesting
Agreement and agree as follows:

     1.   The conditions of "Termination of Repurchase Rights" set forth
specifically in Section 5.3(a)(iii) is hereby deleted and replaced with the
following:

     "(iii) Upon the closing of a firm commitment underwritten public offering
     pursuant to an effective registration statement under the 1933 Act covering
     the offer and sale of the Company's Common Stock at a price per share of
     not less than $6.00 (as adjusted for stock splits and the like effected
     after the date of this Agreement) and an aggregate offering price to the
     public of not less than $20,000,000, the Founder shall acquire a vested
     interest in, and the Repurchase Right shall lapse with respect to, the
     Unvested Shares as of such closing."

     2.  This First Amendment shall be governed by and construed in accordance
with the laws of the State of Delaware, without giving effect to its conflicts
of law provisions.

     This First Amendment may be executed in multiple counterparts.

                                       1
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     Executed as of the date above written.

PARADIGM GENETICS, INC.:
------------------------

By: _____________________________
Name: __________________________
Title: ___________________________

FOUNDER
-------

_________________________________
Scott Uknes

                                       2<PAGE>

                                                                   EXHIBIT 10.17

                        AGREEMENT RELATED TO EMPLOYMENT

     I, the undersigned employee, in consideration of my employment by Paradigm
Genetics, Inc., ("Paradigm") agree:

     1.  All improvements, discoveries, or inventions, whether or not
patentable, that are conceived, devised, made, developed or perfected by me
during the period of my employment and related in any way to the business of
Paradigm, including development and research, shall be promptly disclosed to and
become the property of Paradigm.  Upon the request of Paradigm, I will execute
all documents deemed appropriate by Paradigm for obtaining the grant of patents,
both domestic and foreign, with respect to such improvements, discoveries or
inventions and for vesting title to such patents in Paradigm.

     2.  Any and all materials prepared by me for public disclosure to third
parties with respect to the business of Paradigm or its affiliates, including
publications, presentations, posters, the revision and updating of manuals and
textbooks and other public disclosures of Paradigm, shall become and remain the
property of Paradigm; and I hereby agree to assign my entire right, title and
interest in and to such materials including but not limited to, common law and
statutory rights, and Paradigm shall receive every legal protection that could
be afforded to me including the right to apply for Federal Copyright
Registration in its name as owner.  This assignment shall extend for the full
term of the copyright in said materials and any renewal thereof, and I agree not
to use any portion of said materials or to disclose to any third parties other
than in the regular course of my employment, and only after receiving permission
from Paradigm.

     3.  Any improvements, discoveries or inventions (whether or not deemed
patentable) devised, made, developed or perfected and any materials prepared by
me for disclosure with respect to the business of Paradigm or its affiliates
after I leave the employ of Paradigm are within paragraph 1 and 2 if conceived
during such employment.  Any such improvements, discoveries or inventions
devised, made, developed or perfected or materials prepared within six (6)
months after cessation of my employment shall be conclusively presumed to have
been conceived during my employment.

     4.  Paradigm will investigate any disclosures submitted by me and, if it
elects to file a patent application thereon, agrees:

         (a) to pay all expenses in connection with the preparation and
prosecution of such patent application or applications which it may decide to
file in the United States of America or in foreign countries;

         (b) to pay me an award, consistent with the policies and procedures of
Paradigm, upon issuance of a United States Letters Patent upon such invention or
improvement together with a formal assignment thereof to Paradigm:

     5.  All information of a business or technical nature imparted to or
learned by me in the course of my employment with respect to the business of
Paradigm or its affiliates or its existing or potential customers, vendors or
other business associates shall be deemed to be confidential and shall not be
disclosed by me to anyone outside the employ of Paradigm, unless

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such information has been made generally available to the trade. Such
information shall include, but not be limited to, information related to the
following:

     (a) improvements, discoveries, inventions and materials described in
paragraphs 1 through 4 above;

     (b) materials, compounds, formulations, cells and cell lines, reagents,
processes, techniques, methods, devices, apparatuses, plant and laboratory
facilities, operations, present and future business plans, all inventions,
material data, equipment design, experiments, tissue cultures, clonal material,
hybrids, embryos, genatio material or information, microorganism genetic
information, microorganism genetic material know-how, experience and trade
secrets, relating to Paradigm projects;

     (c) contents of any database proprietary to Paradigm, including AgDB;

     (d) any other research projects undertaken by Paradigm from time to time.

     If I leave the employ of Paradigm, authorization to disclose information
obtained while employed by Paradigm must be obtained in writing, and I shall not
take with me any original or copies of any drawings, notebooks, lab records,
other documents, or developments of prereproduction models whether or not they
contain or disclose confidential information. I am aware that the business and
technical information developed and acquired by Paradigm is amongst its most
valuable assets, and its value may be unwittingly destroyed by casual
dissemination.  I therefore agree to safeguard this information as carefully as
other property of Paradigm.

     6.  In my work for Paradigm, I will not use any information which I
understand to be confidential or proprietary information of my previous
employers.  I have not disclosed to any employee of Paradigm, and will not in
the future disclose to any such person any information which I understand to be
confidential or proprietary information of my previous employers.  I have not
disclosed to any employee of Paradigm, and will not in the future disclose to
any such person any information which I understand to be confidential or
proprietary information of my previous employers.

     7.  All my obligations under this agreement shall survive termination of
this agreement for any reason.  I understand that my employment is at will and
that I may leave Paradigm at any time and that I may be terminated by Paradigm
at any time, with or without cause.  Furthermore, I agree to abide by all
policies and procedures promulgated by Paradigm.

________________________________          ________________________________
         (Signature)                                   (Date)

Ian Howes
--------------------------------
(Printed Name)

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PARADIGM GENETICS, INC.

By:_______________________
    John A. Ryals
Chief Executive Officer and President

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