EXHIBIT 10.48
                                                                   -------------


                      AMENDED AND RESTATED PROMISSORY NOTE

Dated: As of March 15, 2001
$500,000.00
New York, New York

         FOR VALUE RECEIVED, the undersigned, COMMODORE APPLIED TECHNOLOGIES,
INC., a Delaware corporation ("Maker"), promises to pay to S. Brewer
Enterprises, Inc. ("Payee"), at the principal executive offices of Payee, 2121
Jamieson Avenue, Suite 1406, Alexandria, Virginia 22314, or at such commercial
bank within the United States of America as Payee may designate to Maker from
time to time, in lawful money of the United States of America and in immediately
available funds, the principal sum of Five Hundred Thousand Dollars
($500,000.00). Maker agrees to pay interest in like money at such office or
commercial bank on the unpaid aggregate principal amount hereof at a rate equal
to nine and .three quarters percent (9.750 %) per annum.

         1.  Principal and interest shall be due and payable in the manner set
forth below:

             (a) Accrued interest on the unpaid principal amount hereof shall be
paid monthly in cash on or before the 15th day of each calendar month.

             (b) Except for reductions to the principle and interest of the Note
through the Payee's exercise of its Conversion Rights as hereinafter set forth,
Maker will pay, in whole or in part, the principal balance then outstanding of
this Note, together with accrued interest, on or before the earlier of (i)
December 31, 2001 or (ii) five (5) business days following a direct or indirect
sale by the Maker of all or any portion of its interest in the
Teledyne-Commodore Limited Liability Company for which Maker receives cash
proceeds for such sale. Provided, that Maker shall not be obligated to repay the
outstanding principal balance and accrued interest in an amount in excess of the
cash proceeds for such sale of Maker's interest in the Teledyne-Commodore
Limited Liability Company.

             (c) All payments (including prepayments) made hereunder shall be
applied first to the payment of accrued and unpaid interest, with the balance
remaining applied to the payment of the unpaid principal balance of this Note.

         2. At any time before the earlier of the repayment dates specified in
Section 1 hereof, (the Conversion Right Expiration Date"), the Payee shall have
the right ("Conversion Right") to convert all or any portion of the outstanding
principal balance of this Note, and any accrued interest thereon, into common
stock of the Maker, par value $0.001 ("Common Stock") by giving notice to the
Maker that it intends to exercise its Conversion Right. Subject to the terms of
this Note, the Payee shall have the right to convert such outstanding principal



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and accrued interest into common stock at the rate equal to the average of the
closing price of the Company's Common Stock on the American Stock Exchange
("AMEX") or other public stock exchange for the five (5) trading days
immediately preceding each exercise of a Conversion Right or, if the Common
Stock is not listed on the AMEX or other public stock exchange, then the average
of the bid and ask for said Common Stock quoted on the OTC market or the pink
sheets on the five (5) trading days immediately preceding each exercise of a
Conversion Right (the "Conversion Rate") for each dollar of outstanding
principal and accrued interest. Each exercise of Payee's Conversion Right shall
be effected by giving notice to Maker at the address set forth below and shall
specify the amount of principal and accrued interest that Payee intends to
convert into Common Stock. Within thirty (30) days of receipt of each such
notice, Maker shall issue a certificate or certificate for Common Stock to Payee
in such denomination as Payee shall specify.

         3. Notwithstanding any provision to the contrary contained in this
Note, it is expressly agreed that, at the option of the Payee, the entire
principal amount outstanding at any time under this Note, and all accrued and
unpaid interest, shall immediately become due and payable (without demand for
payment, notice of non-payment, presentment, notice of dishonor, protest, notice
of protest or any other notice, all of which are hereby expressly waived by
Maker) upon the occurrence of any of the following (each an "Event of Default"):

             (a) upon the default in the payment of any interest or principal
due under this Note, which default continues uncured for a period of ten (10)
days;

             (b) if Maker shall make an assignment for the benefit of creditors;
or shall admit in writing its inability to pay its debts; or if a receiver or
trustee shall be appointed for Maker or for substantially all of its assets and,
if appointed without its consent, such appointment is not discharged or stayed
within thirty (30) days; or if proceedings under any law relating to bankruptcy,
insolvency or the reorganization or relief of debtors are instituted by or
against the Maker and, if contested by it, are not dismissed or stayed within
thirty (30) days; or if any writ of attachment or execution or any similar
process is issued or levied against Maker or any significant part of its
property and is not released, stayed, bonded or vacated within thirty (30) days
after its issue or levy; or if Maker takes corporate action in furtherance of
any of the foregoing.

         4. Maker may prepay the principal amount of this Note at any time
without incurring any penalty for prepayment. Upon any such prepayment, all
accrued interest to the date of repayment shall be paid whereupon no other
payment or penalty shall be due.

         5. All notices, requests and demands to or upon Maker or Payee to be
effective shall be in writing and shall be deemed to have been duly given or
made when delivered by hand, or when sent by certified mail, postage prepaid,
addressed as follows or to such other address as may hereafter be notified by
the respective parties hereto:


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                  Maker:
                  Commodore Applied Technologies, Inc.
                  150 East 58th Street, Suite 3238,
                  New York, New York 10151 2
                  Attn: James M. DeAngelis,
                  Vice President and Chief Financial Officer


                  Payee:
                  S. Brewer Enterprises, Inc.
                  Attn. Shelby T. Brewer
                  2121 Jamieson Avenue, Suite 1406
                  Alexandria, Virginia  22314


         6. No failure or delay on the part of Payee in exercising any of its
rights, powers or privileges hereunder shall operate as a waiver thereof, nor
shall a single or partial exercise thereof preclude any other or further
exercise of any right, power or privilege. Maker hereby waives demand for
payment, notice of non-payment, presentment, notice of dishonor, protest, notice
of protest or any other notice in connection with the delivery, acceptance,
performance or enforcement of this Note.

         7. This Note may not be changed or terminated orally, nor may any of
its provisions be waived, except by an agreement in writing signed by the party
against whom enforcement of such change or termination is sought.

         8. In case any one or more Events of Default shall occur and be
continuing, Payee may proceed to protect and enforce its rights by an action at
law, suit in equity or other appropriate proceeding. Maker shall pay all
reasonable costs of collection when incurred, including reasonable attorneys'
fees.

         9. This Note shall be governed by and construed in accordance with the
laws of the State of Delaware, without giving effect to its choice of law rules.

         IN WITNESS WHEREOF, the Maker has executed this Promissory Note as
March 15, 2001 COMMODORE APPLIED TECHNOLOGIES, INC.


                                     By:    /s/ James M. DeAngelis
                                     -----------------------------------
                                     Name: James M. DeAngelis,
                                     Chief Financial Officer



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