<PAGE>
                                                                   EXHIBIT 10.44
                                                                   -------------

NEITHER THIS WARRANT NOR THE SHARES OF STOCK ISSUABLE UPON EXERCISE HEREOF HAVE
BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. NO SALE, TRANSFER
OR OTHER DISPOSITION OF THIS WARRANT OR SAID SHARES MAY BE EFFECTED WITHOUT (I)
AN EFFECTIVE REGISTRATION STATEMENT RELATED THERETO, (II) AN OPINION OF COUNSEL
FOR THE HOLDER, REASONABLY SATISFACTORY TO THE COMPANY, THAT SUCH REGISTRATION
IS NOT REQUIRED OR (III) RECEIPT OF OTHER EVIDENCE REASONABLY SATISFACTORY TO
THE COMPANY AND ITS COUNSEL THAT SUCH REGISTRATION IS NOT REQUIRED.



                             PARADIGM GENETICS INC.
                   WARRANT TO PURCHASE SHARES OF COMMON STOCK
                   ------------------------------------------

                     DATE OF INITIAL ISSUANCE JULY 20, 1999


     THIS CERTIFIES THAT, for value received, TBCC Funding Trust II is entitled
to subscribe for and purchase One Hundred Sixteen Thousand Two Hundred Seventy-
Nine (116,279) shares (as adjusted pursuant to the provisions hereof, the
"Shares") of the fully paid and nonassessable Common Stock, $.01 par value, of
Paradigm Genetics Inc., a North Carolina corporation (the "Company"), at a price
per share of Two and 15/100 Dollars ($2.15) (such price and such other price as
shall result, from time to time, from adjustments specified herein is herein
referred to as the "Warrant Price"), subject to the provisions and upon the
terms and conditions hereinafter set forth. As used herein, the term "Common
Stock" shall mean the Company's presently authorized Common Stock, and any stock
into or for which Common Stock may hereafter be converted or exchanged, in
either case pursuant to the Articles of Incorporation of the Company as from
time to time amended as provided by law and in such Articles; and the term,
"Grant Date" shall mean July 20, 1999. This Warrant is issued pursuant to the
Loan and Security Agreement between Paradigm Genetics Inc. and TBCC Funding
Trust II, dated July 20, 1999 (the "Loan Agreement").

1.  Term. The purchase right represented by this Warrant is exercisable, in
    ----
whole or in part, at any time and from time to time from and after the Grant
Date to the seventh annual anniversary date of the Grant Date.

2.  Method of Exercise; Net Issue Exercise.
    --------------------------------------

     2.1   Method of Exercise; Payment: Issuance of New Warrant. The purchase
           ----------------------------------------------------
right represented by this Warrant may be exercised by the holder hereof, in
whole or in part and from time to time, by either, at the election of the holder
hereof, (a) the surrender of this Warrant (with the notice of exercise form
attached hereto as Exhibit A duly executed) at the principal office of the
Company and by the payment to the Company, by check, of an amount equal to the
then applicable Warrant Price per share multiplied by the number of Shares then
being purchased or (b) if in connection with a registered public offering of the
Company's securities, the surrender
<PAGE>

of this Warrant (with the notice of exercise form attached hereto as Exhibit A-I
duly executed) at the principal office of the Company together with notice of
arrangements reasonably satisfactory to the Company for payment to the Company
either by check or from the proceeds of the sale of shares to be sold by the
holder in such public offering of an amount equal to the then applicable Warrant
Price per share multiplied by the number of Shares then being purchased. The
person or persons in whose name(s) any certificate(s) representing shares of
Common Stock shall be issuable upon exercise of this Warrant shall be deemed to
have become the holder(s) of record of, and shall be treated for all purposes as
the record holder(s) of, the shares represented thereby (and such shares shall
be deemed to have been issued) immediately prior to the close of business on the
date or dates upon which this Warrant is exercised. In the event of any exercise
of the rights represented by this Warrant, certificates for the shares of stock
so purchased shall be delivered to the holder hereof as soon as possible and in
any event within thirty (30) days of receipt of such notice and, unless this
Warrant has been fully exercised or expired, a new Warrant representing the
portion of the Shares, if any, with respect to which this Warrant shall not then
have been exercised shall also be issued to the holder hereof as soon as
possible and in any event within such thirty (30)-day period.

     2.2  Net Issue Exercise.

          (a)  In lieu of exercising this Warrant, the holder may elect to
receive shares equal to the value of this Warrant (or the portion thereof being
canceled) by surrender of this Warrant at the principal office of the Company
together with notice of such election in which event the Company shall issue to
the holder a number of shares of the Company's Common Stock computed using the
following formula:

                                    X=Y(A-B)
                                      ------
                                       A

Where:

     X = the number of shares of Common Stock to be issued to holder

     Y = the number of shares of Common Stock purchasable under this Warrant

     A = the fair market value of one share of the Company's Common Stock

     B = Warrant Price (as adjusted to the date of such calculations)

          (b) For purposes of this Section, fair market value of one share of
the Company's Common Stock shall mean the average of the closing bid and asked
prices of the Company's Common Stock quoted in the Over-The-Counter Market
Summary or the closing price quoted on the Nasdaq National Market or any
exchange on which the Common Stock is listed, whichever is applicable, as
published in the Eastern Edition of The Wall Street Journal for the ten trading
days prior to the date of determination of fair market value. If the Common
Stock is not traded Over-The-Counter or on such market or exchange, the fair
market value of the Company's Common Stock will be the price per share which the
Company could obtain from a

                                       2
<PAGE>

willing buyer for shares sold by the Company from authorized but unissued
shares, as determined by the Company's Board of Directors in good faith.

3.  Stock Fully Paid: Reservation of Shares. All Shares that may be issued upon
    ---------------------------------------
the exercise of the rights represented by this Warrant will, upon issuance, be
fully paid and nonassessable. During the period within which the rights
represented by the Warrant may be exercised, the Company will at all times have
authorized and reserved for the purpose of issuance upon exercise of the
purchase rights evidenced by this Warrant, a sufficient number of shares of its
Common Stock to provide for the exercise of the right represented by this
Warrant.

4.  Adjustment of Warrant Price and Number of Shares. The number and kind of
    ------------------------------------------------
securities purchasable upon the exercise of this Warrant and the Warrant Price
shall be subject to adjustment from time to time upon the occurrence of certain
events, as follows:

          (a) Reclassification or Merger. In case of any reclassification,
              --------------------------
change or conversion of securities of the class issuable upon exercise of this
Warrant (other than a change in par value, or from par value to no par value, or
from no par value to par value, or as a result of a subdivision or combination),
or in case of any merger of the Company with or into another corporation (other
than a merger with another corporation in which the Company is a continuing
corporation and which does not result in any reclassification or change of
outstanding securities issuable upon exercise of this Warrant), or in case of
any sale of all or substantially all of the assets of the Company, the Company,
or such successor or purchasing corporation, as the case may be, shall execute a
new Warrant (in form and substance reasonably satisfactory to the holder of this
Warrant) providing that the holder of this Warrant shall have the right to
exercise such new Warrant and upon such exercise to receive, in lieu of each
share of Common Stock theretofore issuable upon exercise of this Warrant, the
kind and amount of shares of stock, other securities, money and property
receivable upon such reclassification, change or merger by a holder of one share
of Common Stock. Such new Warrant shall provide for adjustments that shall be as
nearly equivalent as may be practicable to the adjustments provided for in this
Section 4. The provisions of this paragraph (a) shall similarly apply to
successive reclassifications, changes, mergers and transfers.

          (b) Subdivisions or Combination of Shares. If the Company at any time
              -------------------------------------
while this Warrant remains outstanding and unexpired shall subdivide or combine
its Common Stock, the Warrant Price and the number of Shares issuable upon
exercise hereof shall be proportionately adjusted.

          (c) Stock Dividends. If the Company at any time while this Warrant is
outstanding and unexpired shall pay a dividend payable in shares of Common Stock
or other securities exercisable for or convertible into shares of Common Stock
(except any distribution specifically provided for in the foregoing
subparagraphs (a) and (b)), then the Warrant Price shall be adjusted, from and
after the date of determination of shareholders entitled to receive such
dividend or distribution, to that price determined by multiplying the Warrant
Price in effect immediately prior to such date of determination by a fraction
(a) the numerator of which shall be the total number of shares of Common Stock
outstanding immediately prior to such dividend or distribution (assuming the
conversion, exchange or exercise of all securities of the Company

                                       3
<PAGE>

which are convertible, exchangeable or exercisable) ("Fully Diluted Common
Stock"), and (b) the denominator of which shall be the total number of shares of
Fully Diluted Common Stock outstanding immediately after such dividend or
distribution, and the number of Shares subject to this Warrant shall be
proportionately adjusted.

          (d) Dilutive Issuances. If and whenever the Company should issue
              ------------------
shares of its Common Stock or other securities exercisable for or convertible
into shares of Common Stock at a price per share less than the Warrant Price, as
adjusted for stock splits, combinations, dividends and recapitalizations
pursuant to this Section 4, in effect immediately prior to such issuance (other
than shares issued or issuable to the officers or directors of or consultants to
the Company issued pursuant to a stock option or purchase plan or similar
arrangement), then the Warrant Price shall be adjusted to an amount (calculated
to the nearest cent) determined by dividing (1) the sum of (A) the total number
of shares of Fully Diluted Common Stock outstanding immediately prior to such
issuance multiplied by the then effective Warrant Price and (B) the value of the
consideration received by the Company upon such issuance as determined by the
Board of Directors by (2) the total number of shares of Fully Diluted Common
Stock outstanding immediately after such issuance. The holder of the Warrant
shall thereafter be entitled to purchase, at the Warrant Price resulting from
such adjustment, the number of shares of Common Stock (calculated to the nearest
whole share) obtained by multiplying the Warrant Price in effect immediately
prior to such adjustment by the number of shares of Fully Diluted Common Stock
issuable upon the exercise hereof immediately prior to such adjustment and
dividing the product thereof by the Warrant Price resulting from such
adjustment. For the purposes of this paragraph (d), the consideration received
for securities convertible into or exercisable or exchangeable for the Common
Stock shall be deemed to include the minimum aggregate amount payable upon
conversion, exercise or exchange of such securities. In the event the right to
convert, exercise or exchange such securities expires unexercised, the Warrant
Price of shares issuable upon the exercise hereof shall be readjusted
accordingly.

          (e) No Impairment. The Company will not, by amendment of its Articles
              -------------
of Incorporation or through any reorganization, recapitalization, transfer of
assets, consolidation, merger, dissolution, issue or sale of securities or any
other voluntary action, avoid or seek to avoid the observance or performance of
any of the terms to be observed or performed hereunder by the Company, but will
at all times in good faith assist in the carrying out of all the provisions of
this Section 4 and in the taking of all such action as may be necessary or
appropriate in order to protect the rights of the holder of this Warrant against
impairment.

          (f) Notices of Record Date. In the event of any taking by the Company
              ----------------------
of a record of its shareholders for the purpose of determining shareholders who
are entitled to receive payment of any dividend (other than a cash dividend) or
other distribution, any right to subscribe for, purchase or otherwise acquire
any share of any class or any other securities or property, or to receive any
other right, or for the purpose of determining shareholders who are entitled to
vote in connection with any proposed merger or consolidation of the Company with
or into any other corporation, or any proposed sale, lease or conveyance of all
or substantially all of the assets of the Company, or any proposed liquidation,
dissolution or winding up of the Company, the Company shall mail to the holder
of the Warrant, at least twenty (20) days prior to the date specified therein, a
notice specifying the date on which any such record is to be taken for the
purpose of such dividend, distribution or right, and the amount and character of
such dividend, distribution or right

                                       4
<PAGE>

     5.   Notice of Adjustments. Whenever the Warrant Price shall be adjusted
          ---------------------
pursuant to the provisions hereof, the Company shall within thirty (30) days
after such adjustment deliver a certificate signed by its chief financial
officer to the registered holder(s) hereof setting forth, in reasonable detail,
the event requiring the adjustment, the amount of the adjustment, the method by
which such adjustment was calculated, and the Warrant Price after giving effect
to such adjustment

     6.  Fractional Shares. No fractional shares of Common Stock will be issued
         -----------------
in connection with any exercise hereunder, but in lieu of such fractional shares
the Company shall make a cash payment therefor upon the basis of the Warrant
Price then in effect.

     7.   Compliance with Securities Act; Disposition of Warrant or Shares of
Stock.

          (a) Compliance with Securities Act. The holder of this Warrant, by
              ------------------------------
acceptance hereof, agrees that this Warrant, the shares of Common Stock to be
issued upon exercise hereof are being acquired for investment and that such
holder will not offer, sell or otherwise dispose of this Warrant, any shares of
Common Stock to be issued upon exercise hereof, except under circumstances which
will not result in a violation of the Securities Act of 1933, as amended (the
"Act"). This Warrant and all shares of Common Stock issued upon exercise of this
Warrant (unless registered under the Act) shall be stamped or imprinted with a
legend in substantially the following form:

          THIS SECURITY HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF
          1933, AS AMENDED. NO SALE, TRANSFER OR OTHER DISPOSITION MAY BE
          EFFECTED WITHOUT (i) AN EFFECTIVE REGISTRATION STATEMENT RELATED
          THERETO, (ii) AN OPINION OF COUNSEL FOR THE HOLDER, REASONABLY
          SATISFACTORY TO THE COMPANY, THAT SUCH REGISTRATION IS NOT REQUIRED OR
          (iii) RECEIPT OF OTHER EVIDENCE REASONABLY SATISFACTORY TO THE COMPANY
          AND ITS COUNSEL THAT SUCH REGISTRATION IS NOT REQUIRED.

          (b) Disposition of Warrant and Shares. With respect to any offer, sale
              ---------------------------------
or other disposition of this Warrant, or any shares of Common Stock acquired
pursuant to the exercise of this Warrant prior to registration of such shares,
the holder hereof and each subsequent holder of the Warrant agrees to give
written notice to the Company prior thereto, describing briefly the manner
thereof, together with a written opinion of such holder's counsel, if reasonably
requested by the Company, to the effect that such offer, sale or other
disposition may be effected without registration or qualification (under the Act
as then in effect or any federal or state law then in effect) of this Warrant or
such shares of Common Stock and indicating whether or not under the Act
certificates for this Warrant or such shares of Common Stock to be sold or
otherwise

                                       5
<PAGE>

disposed of require any restrictive legend as to applicable restrictions on
transferability in order to insure compliance with the Act. Each certificate
representing this Warrant or the shares of Common Stock thus transferred (except
a transfer pursuant to Rule 144) shall bear a legend as to the applicable
restrictions on transferability in order to insure compliance with the Act,
unless in the aforesaid opinion of counsel for the holder, such legend is not
required in order to insure compliance with the Act. The Company may issue stop
transfer instructions to its transfer agent in connection with the foregoing
restrictions.

     8.   Rights as Shareholders: Information. No holder of this Warrant, as
          -----------------------------------
such, shall be entitled to vote or receive dividends or be deemed the holder of
Common Stock or any other securities of the Company which may at any time be
issuable on the exercise thereof for any purpose, nor shall anything contained
herein be construed to confer upon the holder of this Warrant, as such, any of
the rights of a shareholder of the Company or any right to vote for the election
of directors or upon any matter submitted to shareholders at any meeting
thereof, or to receive notice of meetings, or to receive dividends or
subscription rights or otherwise until this Warrant shall have been exercised
and the Shares purchasable upon the exercise hereof shall have become
deliverable, as provided herein.

     9.  Registration Rights. Upon exercise of this Warrant, the holder shall
         -------------------
have and be entitled to exercise, together with all other holders of
Registerable Securities possessing registration rights under that certain
Amended and Restated Registration Rights Agreement dated as of February 12, 1998
and amended and restated as of March 12, 1999 between the Company and the
parties who have executed the counterpart signature pages thereto or are
otherwise bound thereby (the "Registration Rights Agreement"), the rights of
registration granted under the Registration Rights Agreement to Registerable
Securities with respect to the Shares. By its receipt of this Warrant, holder
agrees to be bound by the Registration Rights Agreement.

     10.  Representations and Warranties. This Warrant is issued and delivered
          ------------------------------
on the basis of the following:

          (a) this Warrant has been duly authorized and executed by the Company
and when delivered will be the valid and binding obligation of the Company
enforceable in accordance with its terms; and

          (b) the Common Stock issuable upon the exercise of this Warrant have
been duly authorized and reserved for issuance by the Company and, when issued
in accordance with the terms hereof, will be validly issued, fully paid and
nonassessable.

     11.  Modification and Waiver. This Warrant and any provision hereof may be
          -----------------------
changed, waived, discharged or terminated only by an instrument in writing
signed by the party against which enforcement of the same is sought.

     12.  Notices. Any notice, request or other document required or permitted
          -------
to be given or delivered to the holder hereof or the Company shall be delivered,
or shall be sent by certified or registered mail, postage prepaid, to each such
holder at its address as shown on the books of the Company or to the Company at
the address indicated therefor on the signature page of this Warrant

                                       6
<PAGE>

     13.  Lost Warrants or Stock Certificates. The Company covenants to the
          -----------------------------------
holder hereof that upon receipt of evidence reasonably satisfactory to the
Company of the loss, theft, destruction, or mutilation of this Warrant or any
stock certificate and, in the case of any such loss, theft or destruction, upon
receipt of an indemnity reasonably satisfactory to the Company, or in the case
of any such mutilation upon surrender and cancellation of such Warrant or stock
certificate, the Company will make and deliver a new Warrant or stock
certificate, of like tenor, in lieu of the lost, stolen, destroyed or mutilated
Warrant or stock certificate.

     14.  Governing Law. This Warrant shall be construed and enforced in
          -------------
accordance with, and the rights of the parties shall be governed by, the laws of
the State of North Carolina without reference to conflicts of laws principles.

                                       7
<PAGE>

                              [signature page to Warrant]

                              PARADIGM GENETICS INC.

                              By:       /s/ John Ryals
                                 --------------------------------
                              Name:
                              Title

                              Address:  104 Alexander Drive
                                        Building 2
                                        Research Triangle Park, NC 27709-4538

Date: July 20, 1999

                                       8
<PAGE>

                                   EXHIBIT A
                                   ---------

                               NOTICE OF EXERCISE



To:


     1.  The undersigned hereby elects to purchase ______ shares of Common Stock
of Paradigm Genetics Inc. pursuant to the terms of the attached Warrant, and
tenders herewith payment of the purchase price of such shares in full.

     2.  Please issue a certificate or certificates representing said shares in
the name of the undersigned or in such other name or names as are specified
below:


                                         --------------------------------------
                                         (Name)


                                         --------------------------------------
                                         (Address)

     3.  The undersigned represents that the aforesaid shares are being acquired
for the account of the undersigned for investment and not with a view to, or for
resale in connection with, the distribution thereof and that the undersigned has
no present intention of distributing or reselling such shares.


                                         --------------------------------------
                                         (Signature)


-------------------
(Date)

                                       9
<PAGE>

                                  EXHIBIT A-1
                                  -----------

                               NOTICE OF EXERCISE



To:


     1.  Contingent upon and effective immediately prior to the closing (the
"Closing") of the Company's public offering contemplated by the Registration
Statement on Form S-_______, filed _______(month) ______, (day) ______ (year)
the undersigned hereby elects to purchase shares of Common Stock of the Company
(or such lesser number of shares as may be sold on behalf of the undersigned at
the Closing), pursuant to the terms of the attached Warrant.

     2.  Please deliver to the custodian for the selling shareholders a stock
certificate representing such ___ shares of Common Stock.

     3.  The undersigned has instructed the custodian for the selling
shareholders to deliver to the Company $________ or, if less, the net proceeds
due the undersigned from the sale of shares in the aforesaid public offering. If
such net proceeds are less than the purchase price for such shares, the
undersigned agrees to deliver the difference to the Company prior to the
Closing.




                                        ---------------------------
                                        (Signature)



____________________
(Date)

                                       10