SC TO-T/A

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE TO
(Amendment No. 7)

TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)
OF THE SECURITIES EXCHANGE ACT OF 1934

MARTEK BIOSCIENCES CORPORATION
(Name of Subject Company (Issuer))

KONINKLIJKE DSM N.V.
GREENBACK ACQUISITION CORPORATION
(Name of Filing Persons (Offerors))

Common Stock, $0.10 Par Value Per Share
(Title of Class of Securities)

572901106
(CUSIP Number of Class of Securities)

Hugh C. Welsh
President and General Counsel
DSM North America
45 Waterview Boulevard
Parsippany, NJ 07054
(973) 257-8300
(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications on Behalf of Filing Persons)

Copies to:
William A. Groll
David Leinwand
Cleary Gottlieb Steen & Hamilton LLP
One Liberty Plaza
New York, New York 10006
(212) 225-2000

CALCULATION OF FILING FEE

Transaction Valuation*	Amount of Filing Fee**
$1,146,313,287	$133,086.97

*

Estimated solely for purposes of calculating the filing fee pursuant to Rule 0-11(d) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"). The Transaction Valuation was calculated on the basis of (a) 36,390,898 shares of common stock, $0.10 par value per share, of Martek Biosciences Corporation (the "Shares"), the estimated maximum number of Shares that may be acquired in this tender offer (consisting of (i) 33,522,548 Shares issued and outstanding as of December 31, 2010, (ii) 2,066,297 Shares issuable upon the exercise of outstanding options and (iii) 802,053 Shares issuable upon the exercise of outstanding restricted stock units), multiplied by (b) the offer price of $31.50 per Share.

**

The filing fee, calculated in accordance with Rule 0-11 of the Securities Exchange Act of 1934, as amended, and Fee Rate Advisory #5 for fiscal year 2011, issued December 22, 2010, by multiplying the transaction value by 0.0001161.

ý

Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

Amount Previously Paid:    $133,086.97	Filing Party: Koninklijke DSM N.V., Greenback Acquisition Corporation
Form or Registration No.: Schedule TO	Date Filed: January 13, 2011

o

Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

ý

third-party tender offer subject to Rule 14d-1.

o

issuer tender offer subject to Rule 13e-4.

o

going-private transaction subject to Rule 13e-3.

o

amendment to Schedule 13D under Rule 13d-2.

Check the following box if the filing is a final amendment reporting the results of the tender offer: ý

        This Amendment No. 7 (this "Amendment") amends and supplements the Tender Offer Statement on Schedule TO (as amended, the "Schedule TO") originally filed on January 13, 2011 in connection with the offer by Greenback Acquisition Corporation, a Delaware corporation ("Purchaser") and an indirect wholly-owned subsidiary of Koninklijke DSM N.V., a corporation organized in the Netherlands ("DSM"), to purchase all outstanding shares of common stock, par value $0.10 (the "Shares"), of Martek Biosciences Corporation, a Delaware corporation ("Martek"), at a price of $31.50 per Share, net to the seller in cash, without interest thereon and less any required withholding taxes, upon the terms and subject to the conditions set forth in the Offer to Purchase dated January 13, 2011 (the "Offer to Purchase"), which is annexed to and filed with the Schedule TO as Exhibit (a)(1)(A), and in the related Letter of Transmittal, which is annexed to and filed with the Schedule TO as Exhibit (a)(1)(B), which, together with any amendments or supplements thereto, collectively constitute the "Offer."

        All capitalized terms used in this Amendment No. 7 without definition have the meanings ascribed to them in the Schedule TO.

Items 1 - 11.

        The Offer to Purchase is hereby amended and supplemented by including the following:

        The subsequent offering period of the Offer expired at 12:00 midnight, New York City time, on Thursday, February 24, 2011. The Depositary for the Offer has advised DSM and Purchaser that, as of such time, an aggregate of approximately 262,000 additional Shares had been validly tendered in the subsequent offering period, which, together with the Shares validly tendered during the initial offering period, resulted in Purchaser holding approximately 89.5% of the outstanding Shares. Purchaser has accepted for payment all Shares that were validly tendered and not withdrawn.

        DSM intends to exercise the top-up option that was granted to DSM pursuant to the Merger Agreement to purchase additional Shares directly from Martek later today. Shortly thereafter, DSM intends to complete a short-form merger in accordance with the Merger Agreement. In the short-form merger, Purchaser will merge with and into Martek and each Share not tendered in the Offer, other than those as to which holders exercise appraisal rights under Delaware law and those held by DSM or Martek or their respective subsidiaries, will be converted in the merger into the right to receive $31.50 per Share in cash, without interest and less any required withholding taxes. This is the same price per Share paid in the Offer.

        The full text of the press release issued by DSM on February 25, 2011 in connection with the expiration of the subsequent offering period is filed as Exhibit (a)(5)(K) hereto and is incorporated herein by reference.

Item 12. Exhibits.

(a)(5)(K) Press Release issued by DSM on February 25, 2011

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SIGNATURE

        After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this Schedule TO is true, complete and correct.

Dated: February 25, 2011

KONINKLIJKE DSM N.V.
By:	/s/ HUGH C. WELSH
	Name:  Hugh C. Welsh
	Title:    President and General Counsel, DSM
	North America
GREENBACK ACQUISITION CORPORATION
By:	/s/ HUGH C. WELSH
	Name:  Hugh C. Welsh Title:    Secretary and Director

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EXHIBIT INDEX

(a)(5)(K) Press Release issued by DSM on February 25, 2011

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SIGNATURE
EXHIBIT INDEX

EX-99.(A)(5)(K)

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Exhibit (a)(5)(K)

DSM Successfully Completes Tender Offer for Martek and Expects to Complete Acquisition Today

Royal DSM N.V. (NYSE Euronext: DSM KON), the global Life Sciences and Materials Sciences company, announced today that it has successfully completed the subsequent offering period to its all-cash tender offer to purchase all of the outstanding shares of common stock of Martek Biosciences Corporation at a price of $31.50 per share.

        The previously announced subsequent offering period expired at 12:00 midnight, New York City time, on Thursday, February 24, 2011. The depositary for the tender offer has advised that, as of such time, a total of approximately 262,000 additional Martek shares of common stock had been validly tendered in the subsequent offering period, which, together with the shares validly tendered and not withdrawn during the initial offering period, resulted in DSM holding approximately 89.5% of Martek's currently outstanding shares. DSM has accepted for payment all validly tendered shares.

        DSM intends to exercise the top-up option that was granted to DSM pursuant to the merger agreement to purchase additional shares directly from Martek and to complete a short-form merger in accordance with the merger agreement later today. In the short-form merger, Greenback Acquisition Corporation will be merged with and into Martek, and each share of Martek common stock not tendered in the tender offer, other than those as to which holders exercise appraisal rights under Delaware law and those held by DSM or Martek or their respective subsidiaries, will be converted in the merger into the right to receive $31.50 per share in cash, without interest and less any required withholding taxes. This is the same price per share paid in the tender offer.

Martek

        Martek is a leader in the innovation, development, production and sale of high-value products from microbial sources that promote health and wellness through nutrition. Martek's technology platform consists of its core expertise, broad experience and proprietary technology in areas such as microbial biology, algal genomics, fermentation and downstream processing. This technology platform has resulted in Martek's development of a number of products, including the company's flagship product, life'sDHA™, a sustainable and vegetarian source of algal DHA (docosahexaenoic acid) important for brain, heart and eye health throughout life for use in infant formula, pregnancy and nursing products, foods and beverages, dietary supplements and animal feeds. Martek also produces life'sARA™ (arachidonic acid), an omega-6 fatty acid, for use in infant formula and follow-on formulas. Martek's subsidiary, Amerifit Brands, develops, markets and distributes branded consumer health and wellness products and holds leading brand positions in all of its key product categories. Amerifit products are sold in most major mass, club, drug, grocery and specialty stores and include: Culturelle®, a leading probiotic supplement; AZO, the leading OTC brand addressing symptom relief and detection of urinary tract infections; and Estroven®, the leading all-natural nutritional supplement brand addressing the symptoms of menopause.

        For more information on Martek Biosciences, visit www.martek.com. For a complete list of life'sDHA™ and life'sARA™ products, visit www.lifesdha.com. For more information about Amerifit Brands, visit http://www.amerifit.com.

DSM—Bright Science. Brighter Living.™

        Royal DSM N.V. is a global science-based company active in health, nutrition and materials. By connecting its unique competences in Life Sciences and Materials Sciences DSM is driving economic prosperity, environmental progress and social advances to create sustainable value for all stakeholders. DSM delivers innovative solutions that nourish, protect and improve performance in global markets such as food and dietary supplements, personal care, feed, pharmaceuticals, medical devices, automotive, paints, electrical and electronics, life protection, alternative energy and bio-based materials. DSM's 22,000 employees deliver annual net sales of about €9 billion. The company is listed on NYSE Euronext. More information can be found at www.dsm.com.

For more information:

DSM Corporate Communications
Herman Betten
tel. +31 (0) 45 5782017
fax +31 (0) 45 5740680
e-mail media.relations@dsm.com DSM Investor Relations
Hans Vossen
tel. +31 (0) 45 5782864
fax +31 (0) 10 4590275
e-mail investor.relations@dsm.com

Forward-looking statements

This press release may contain forward-looking statements with respect to DSM's future (financial) performance and position. Such statements are based on current expectations, estimates and projections of DSM and information currently available to the company. DSM cautions readers that such statements involve certain risks and uncertainties that are difficult to predict and therefore it should be understood that many factors can cause actual performance and position to differ materially from these statements. DSM has no obligation to update the statements contained in this press release, unless required by law. The English language version of the press release is leading.

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Exhibit (a)(5)(K)