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EXHIBIT 10.48

M&T CREDIT SERVICES, LLC

CONTINUING GUARANTY

(Business Organization)

GUARANTOR: MARTEK BIOSCIENCES CORPORATION

6480
Dobbin Road


Columbia,
Maryland 21045




|        |                                         
|------- | ----------------------------------------
|LESSEE: | MARTEK BIOSCIENCES KINGSTREE CORPORATION

6480 Dobbin Road, Columbia, Maryland 21045


LESSOR: M&T Credit Services, LLC, One
Fountain Plaza, Buffalo, New York 14203 Attention: Office of
General Counsel

1. Guaranty.

(a) Guarantor, intending to be legally
bound, hereby unconditionally guarantees the full and prompt
payment and performance of any and all of Lessees
Obligations (as defined below) to the Lessor when due, whether
at stated maturity, by acceleration or otherwise. As used in
this Guaranty, the term Obligations shall mean any
and all obligations, indebtedness and other liabilities of
Lessee to the Lessor now or hereafter existing, of every kind
and nature and all accrued and unpaid interest thereon and all
Expenses (as defined below) including without limitation,
whether such obligations, indebtedness and other liabilities
(i) are direct, contingent, liquidated, unliquidated,
secured, unsecured, matured or unmatured; (ii) are pursuant
to a guaranty or surety in favor of the Lessor; (iii) were
originally contracted with the Lessor or with another party
(including obligations under a guaranty or surety originally in
favor of such other party); (iv) are contracted by Lessee
alone or jointly with one or more other parties; (v) are or
are not evidenced by a writing; (vi) are renewed, replaced,
modified or extended; and (vii) are periodically
extinguished and subsequently reincurred or reduced and
thereafter increased. Guarantor will pay or perform his or her
obligations under this Guaranty upon demand. This Guaranty is
and is intended to be a continuing guaranty of payment (not
collection) of the Obligations (irrespective of the aggregate
amount thereof and whether or not the Obligations from time to
time exceeds the amount of this Guaranty, if limited),
independent of, in addition and without modification to, and
does not impair or in any way affect, any other guaranty,
indorsement, or other agreement in connection with the
Obligations, or in connection with any other indebtedness or
liability to the Lessor or collateral held by the Lessor
therefor or with respect thereto, whether or not furnished by
Guarantor. Guarantor understands that the Lessor can bring an
action under this Guaranty without being required to exhaust
other remedies or demand payment first from other parties.

(b) Guarantor acknowledges the receipt of
valuable consideration for this Guaranty and acknowledges that
the Lessor is relying on this Guaranty in making a financial
accommodation to Lessee, whether a commitment to lend,
extension, modification or replacement of, or forbearance with
respect to, any Obligation, cancellation of another guaranty,
purchase of Lessees assets, or other valuable
consideration.

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2. Continuing, Absolute,
Unconditional.This Guaranty is
irrevocable, absolute, continuing, unconditional and general
without any limitation. 3. Guarantors Waivers &
Authorizations. (a) Guarantors obligations shall not
be released, impaired or affected in any way including by any of
the following, all of which Guarantor hereby waives (i) any
bankruptcy, reorganization or insolvency under any law of Lessee
or that of any other party, or by any action of a trustee in any
such proceeding; (ii) any new agreements or obligations of
Lessee or any other party with the Lessor; (iii) any
adjustment, compromise or release of any Obligations of Lessee,
by the Lessor or any other party; the existence or nonexistence
or order of any filings, exchanges, releases, impairment or sale
of, or failure to perfect or continue the perfection of a
security interest in any collateral for the Obligations,
(iv) any failure of Guarantor to receive notice of any
 intended disposition of such collateral;
(v) any fictitiousness, incorrectness, invalidity or
unenforceability, for any reason, of any instrument or other
agreement which may evidence any Obligation; (vi) any
composition, extension, stay or other statutory relief granted
to Lessee including, without limitation, the expiration of the
period of any statute of limitations with respect to any lawsuit
or other legal proceeding against Lessee or any person in any
way related to the Obligations or a part thereof or any
collateral therefor; (vii) any change in form of
organization, name, officers, directors, membership or ownership
of Lessee or Guarantor; (viii) any refusal or failure of
the Lessor or any other person prior to the date hereof or
hereafter to grant any additional loan or other credit
accommodation to Lessee or the Lessors or any other
partys receipt of notice of such refusal or failure;
(ix) any setoff, defense or counterclaim of Lessee with
respect to the obligations or otherwise arising, either directly
or indirectly, in regard to the Obligations (other than the
payment thereof); or (x) any other circumstance that might
otherwise constitute a legal or equitable defense to
Guarantors obligations under this Guaranty.


(b) The Guarantor waives acceptance, assent
and all rights of notice or demand including without limitation
(i) notice of acceptance of this Guaranty, of Lessees
default or nonpayment of any Obligation, and of changes in
Lessees financial condition; (ii) presentment,
protest, notice of protest and demand for payment;
(iii) notice that any Obligations has been incurred or of
the reliance by the Lessor upon this Guaranty; and (iv) any
other notice, demand or condition to which Guarantor might
otherwise be entitled prior to the Lessors reliance on or
enforcement of this Guaranty. Guarantor further authorizes the
Lessor, without notice, demand or additional reservation of
rights against Guarantor and without affecting Guarantors
obligations hereunder, from time to time: (i) to renew,
refinance, modify, subordinate, extend, increase, accelerate, or
otherwise change the time for payment of, the terms of or the
interest on the Obligations or any part thereof;(ii) to accept
and hold collateral from any party for the payment of the any or
all of the Obligations, and to exchange, enforce or refrain from
enforcing, or release any or all of such collateral;
(iii) to accept any indorsement or guaranty of any or all
of the Obligations or any negotiable instrument or other writing
intended to create an accord and satisfaction with respect to
any or all of the Obligations; (iv) to release, replace or
modify the obligation of any indorser or guarantor, or any party
who has given any collateral for any of all of the Obligations,
or any other party in any way obligated to pay any or all of the
Obligations, and to enforce or refrain from enforcing, or
compromise or modify, the terms of any obligation of any such
indorser, guarantor or party; (v) to dispose of any and all
collateral securing the Obligations in any commercially
reasonable manner as the Lessor, in its sole discretion, may
deem appropriate, and to direct the order and the enforcement of
any and all indorsements and guaranties relating to the
Obligations in the Lessors sole discretion; and
(vi) to determine the manner, amount and time of
application of payments and credits, if any, to be made on all
or any part of the Obligations including, without limitation, if
this Guaranty is limited in amount, to make any such application
to Obligations, if any, in excess of the amount of this Guaranty.

(c) Notwithstanding any other provision in
this Guaranty, Guarantor irrevocably waives, without notice, any
right he or she may have at law or in equity (including without
limitation any law subrogating Guarantor to the rights of the
Lessor) to seek contribution, indemnification or any other form
of reimbursement from Lessee or any other obligor or guarantor
of the Obligations for any disbursement made under this Guaranty
or otherwise until the Obligations are fully and completely
satisfied.

4. Termination.This Guaranty shall remain in full
force and effect as to each Guarantor until actual receipt by
the Lessor or the Lessors agent responsible for
Lessees relationship with the Lessor of written notice of
Guarantors intent to terminate (or Guarantors death
or incapacity) plus the lapse of a reasonable time for the
Lessor to act on such notice (the Receipt of
Notice); provided, however, this Guaranty shall remain in
full force and effect thereafter until all Obligations

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outstanding, or contracted or committed for (whether or not
outstanding), before such Receipt of Notice by the Lessor, and
any extensions, renewals or replacements thereof (whether made
before or after such Receipt of Notice), together with interest
accruing thereon after such Receipt of Notice, shall be finally
and irrevocably paid in full. Discontinuance of this Guaranty as
to one Guarantor shall not operate as a discontinuance hereof as
to any other guarantor. Payment of all of the Obligations from
time to time shall not operate as a discontinuance of this
Guaranty, unless a Receipt of Notice as provided above has been
received by the Lessor. Guarantor agrees that, to the extent that Lessee makes a payment or payments to the Lessor
on the Obligations, or the Lessor receives any proceeds of
collateral to be applied to the Obligations, which payment or
payments or any part thereof are subsequently invalidated,
declared to be fraudulent or preferential, set aside or
otherwise are required to be repaid to Lessee, its estate,
trustee, receiver or any other party, including, without
limitation, under any bankruptcy law, state or federal law,
common law or equitable cause, then to the extent of such
repayment, the obligation or part thereof which has been paid,
reduced or satisfied by such amount shall be reinstated and
continued in full force and effect as of the date such initial
payment, reduction or satisfaction occurred, notwithstanding any
contrary action which may have been taken by the Lessor in
reliance upon such payment or payments. As of the date any
payment or proceeds of collateral are returned, the statute of
limitations shall start anew with respect to any action or
proceeding by the Lessor against Guarantor under this Guaranty.


5. Expenses.Guarantor agrees to reimburse the Lessor on demand for all the
Lessors expenses, damages and losses of any kind or nature
incurred by the Lessor in attempting to enforce this Guaranty,
to collect any of the Obligations including any workout or
bankruptcy proceedings or other legal proceedings or appeal, to
realize on any collateral, and to defend any action under this
Guaranty, including without limitation costs of collection and
actual attorneys fees (of external but not internal
counsel) and disbursements (collectively, Expenses).
Expenses will accrue interest at the highest default rate in any
instrument evidencing the Obligations until payment is actually
received by the Lessor.

6. Financial and Other
Information.Guarantor shall promptly
deliver to the Lessor: (i) within forty-five days after the
end of each of its first three fiscal quarters, consolidated
statements of income and cash flows of Guarantor and its
subsidiaries for the quarter, for the corresponding quarter in
the previous fiscal year and for the period from the end of the
previous fiscal year, with a consolidated balance sheet of
Guarantor and its subsidiaries as of the quarter end; and
(ii) within ninety days after the end of each fiscal year,
consolidated statements of income and cash flows of Guarantor
and its subsidiaries and their consolidated balance sheet as of
the end of such fiscal year, setting forth comparative figures
for the preceding fiscal year and to be audited by an
independent certified public accountant acceptable to the
Lessor; all such statements shall be certified by
Guarantors chief financial officer to be correct, not
misleading and in accordance with Guarantors records and
to present fairly the results of operations and cash flows for
the Guarantor and its subsidiaries and if annual its financial
position at year end in conformity with generally accepted
accounting principles. Guarantor represents that its assets are
not subject to any liens, encumbrances or contingent liabilities
except as fully disclosed to the Lessor in such statements.
Guarantor authorizes the Lessor from time to time to obtain,
verify and review all financial data deemed appropriate by the
Lessor in connection with this Guaranty and the Obligations,
including without limitation credit reports from agencies.
Guarantor understands this Guaranty and has satisfied itself as
to its meaning and consequences and acknowledges that it has
made its own arrangements for keeping informed of changes or
potential changes affecting the Lessee including the
Lessees financial condition.

7. No Transfer of
Assets.Guarantor shall not transfer
or otherwise dispose of its assets except as permitted pursuant
to Section 6.2 of the Loan and Security Agreement dated
January 26, 2004 between Guarantor and various lenders in
their capacities as lenders or agents as amended except with
respect to any amendment thereof made without the consent of
Lessor (or any of its affiliates).

8. Nonwaiver by the Lessor;
Miscellaneous.This Guaranty is
intended by Guarantor to be the final, complete and exclusive
expression of the agreement between Guarantor and the Lessor.
This Guaranty may be assigned by the Lessor, shall inure to the
benefit of the Lessor and its successors and assigns, and shall
be binding upon Guarantor and its successors and assigns and any
participation may be granted by the Lessor herein in connection
with the assignment or granting of a participation by the Lessor
in the Obligations or any part thereof. All rights and remedies
of the Lessor are cumulative, and no such right or remedy shall
be exclusive of any other right or remedy. This Guaranty does
not supersede any other guaranty or security granted to the
Lessor by Guarantor or others (except as to Guarantors
Waiver of Subrogation rights above). No single, partial or
delayed exercise by the Lessor of any right or remedy shall
preclude exercise by the Lessor at any time at its sole option
of the same or any other right or remedy of the Lessor without
notice. Guarantor expressly disclaims any reliance on any course
of dealing or usage of trade or oral representation of the
Lessor

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including, without limitation, representations to make
loans to Lessee or enter into any other agreement with Lessee or Guarantor. No course of
dealing or other conduct, no oral agreement or representation
made by the Lessor or usage of trade shall operate as a waiver
of any right or remedy of the Lessor. No waiver or amendment of
any right or remedy of the Lessor or release by the Lessor shall
be effective unless made specifically in writing by the Lessor.
Each provision of this Guaranty shall be interpreted as
consistent with existing law and shall be deemed amended to the
extent necessary to comply with any conflicting law. If any
provision nevertheless is held invalid, the other provisions
shall remain in effect. Guarantor agrees that in any legal
proceeding, a copy of this Guaranty kept in the Lessors
course of business may be admitted into evidence as an original.
Captions are solely for convenience and not part of the
substance of this Guaranty.


9. Joint and
Several.If there is more than one
Guarantor, each Guarantor jointly and severally guarantees the
payment and performance in full of all obligations under this
Guaranty and the term Guarantor means each as well
as all of them. Guarantor also agrees that the Lessor need not
seek payment from any source other than the undersigned
Guarantor. This Guaranty is a primary obligation.
Guarantors obligations hereunder are separate and
independent of Lessees, and a separate action may be
brought against Guarantor whether or not action is brought or
joined against or with Lessee or any other party.

10. Authorization.Guarantor certifies that it is an entity in the form described
above duly organized and in good standing under the laws of the
State of its organization and duly authorized to do business in
each State material to the conduct of its business. Guarantor
has determined that the execution of this Guaranty will be in
its best interests, to its direct benefit, incidental to its
powers, and in furtherance of its duly acknowledged purposes and
objectives. Execution of this Guaranty by the persons signing
below has been authorized by all necessary corporate action,
including directors and shareholder consent or (as
appropriate) is authorized by its partnership agreement or
governing instrument. Guarantors chief executive office is
located at the above address.

11. Notices.Any demand or notice hereunder or under any applicable law
pertaining hereto shall be in writing and duly given if
delivered to Guarantor (at its address on the Lessors
records) or to the Lessor (at the address on page one and
separately to the Lessors agent responsible for
Lessees relationship with the Lessor). Such notice or
demand shall be deemed sufficiently given for all purposes when
delivered (i) by personal delivery and shall be deemed
effective when delivered, or (ii) by mail or courier and
shall be deemed effective three (3) business days after
deposit in an official depository maintained by the United
States Post Office for the collection of mail or one
(1) business day after delivery to a nationally recognized
overnight courier service (e.g.,Federal Express). Notice
by e-mail is not valid notice under this or any other agreement
between Guarantor and the Lessor.

12. Governing Law and
Jurisdiction.This Guaranty has been
delivered to and accepted by the Lessor and will be deemed to be
made in the State of New York. Unless provided otherwise under
federal law, this Guaranty will be interpreted in accordance
with the laws of the State of New York excluding its conflict of
laws rules. GUARANTOR HEREBY IRREVOCABLY CONSENTS TO THE
EXCLUSIVE JURISDICTION OF ANY STATE OR FEDERAL COURT IN ANY
JUDICIAL DISTRICT OR COUNTY IN THE STATE OF NEW YORK WHERE THE
LESSOR MAINTAINS A BRANCH AND CONSENTS THAT THE LESSOR MAY
EFFECT ANY SERVICE OF PROCESS IN THE MANNER AND AT
GUARANTORS ADDRESS SET FORTH ABOVE FOR PROVIDING NOTICE OR
DEMAND; PROVIDED THAT NOTHING CONTAINED IN THIS GUARANTY WILL
PREVENT THE LESSOR FROM BRINGING ANY ACTION, ENFORCING ANY AWARD
OR JUDGMENT OR EXERCISING ANY RIGHTS AGAINST GUARANTOR
INDIVIDUALLY, AGAINST ANY SECURITY OR AGAINST ANY PROPERTY OF
GUARANTOR WITHIN ANY OTHER COUNTY, STATE OR OTHER FOREIGN OR
DOMESTIC JURISDICTION. Guarantor acknowledges and agrees
that the venue provided above is the most convenient forum for
both the Lessor and Guarantor. Guarantor hereby waives any
objection to venue and any objection based on a more convenient
forum in any action instituted under this Guaranty.

13. Waiver of Jury Trial. GUARANTOR AND
THE LESSOR HEREBY KNOWINGLY, VOLUNTARILY, AND INTENTIONALLY
WAIVE ANY RIGHT TO TRIAL BY JURY GUARANTOR AND THE LESSOR MAY
HAVE IN ANY ACTION OR PROCEEDING, IN LAW OR IN EQUITY,
IN CONNECTION WITH THIS GUARANTY OR THE
TRANSACTIONS RELATED HERETO. GUARANTOR REPRESENTS AND WARRANTS
THAT NO REPRESENTATIVE OR AGENT OF THE LESSOR HAS REPRESENTED,
EXPRESSLY OR OTHERWISE, THAT THE LESSOR WILL NOT, IN THE EVENT
OF LITIGATION, SEEK TO ENFORCE THIS JURY TRIAL

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WAIVER. GUARANTOR
ACKNOWLEDGES THAT THE LESSOR HAS BEEN INDUCED TO ENTER INTO THIS
GUARANTY BY, AMONG OTHER THINGS, THE PROVISIONS OF THIS
SECTION.


Acknowledgment.Guarantor acknowledges that it has read and understands all the
provisions of this Guaranty, including the Governing Law,
Jurisdictionand Waiver of Jury Trial, and has been
advised by counsel as necessary or appropriate.

|               |  |  |     |   |                   |                                |        |                        |  | 
|-------------- |  |  | --- | - | ----------------- | ------------------------------ | ------ | ---------------------- |  | 
|               |  |  |     |   |                   | GUARANTOR:                    
|              
|               |  |  |     |   |                   | MARTEK BIOSCIENCES CORPORATION
|              
|Date: 10/29/04 |  |  | By: |   | /s/ Peter L. Buzy |                                | (SEAL)
|               |  |  |     |   |                   |                                |        |                        |  | 
|               |  |  |     |   |                   |                                |        | Name:    Peter L. Buzy |  | 
|               |  |  |     |   |                   |                                |        | Title:   CFO           |  | 
|               |  |  |     |   |                   |                                |        | TIN#: 52-1399362       |  | 
|              
|ACKNOWLEDGMENT |  |  |     |   |                   |                                |        |                       
|              
|STATE OF       |  |  |     | ) |                   |                                |        |                        |  | 
|               |  |  |     | : |                   | SS.                            |        |                        |  | 
|              
|COUNTY OF      |  |  |     | ) |                   |                                |        |                        |  | 

On
the ____________ day
of October, 2004, before me, the undersigned, a Notary Public in
and for said State, personally
appeared _________________,
the ______________________ of
MARTEK BIOSCIENCES CORPORATION, personally known to me or proved
to me on the basis of satisfactory evidence to be the
individual(s) whose name(s) is (are) subscribed to the
within instrument and acknowledged to me that he/she/they
executed the same in his/her/their capacity(ies), and that by
his/her/their signature(s) on the instrument, the individual(s),
or the person upon behalf of which the individual(s) acted,
executed the instrument.

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|---------------------- |  | ------------- |  | -----
|                       |  |               |  | SEAL)
|                       |  |               |  |      
|                       |  | Notary Public |  |      
|                      
|My Commission Expires: |  |               |  |      
|                       |  |               |  |      

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