Metabolix’s biopolymers are based on polyhydroxyalkanoates (“PHA”) which occur naturally in micro-organisms and plants. Mirel biopolymers are biobased, uniquely biodegradable, and suitable for a wide range of product applications. Metabolix has previously demonstrated production of Mirel biopolymer resin at industrial scale. Metabolix is currently supplying Mirel biopolymer resin to customers from existing inventory of approximately 5 million pounds.About Antibióticos Antibióticos, S.A. is a world leader with more than 50 years listed among the leading producers of Active Pharmaceutical Ingredients (APIs). Its expertise lies in both fermentation and semi-synthesis processes where the company has become a global reference. Antibióticos, S.A. offers contract manufacturing services to multinational corporations, large pharmaceutical organizations and other companies outsourcing products for toll manufacturing. As a strong key partner of multinational pharmaceutical companies for the production of APIs, its products are sold in more than 50 countries worldwide. Antibióticos, S.A. facilities have a long record of operating in compliance with GMP, ISO 9001 certification and are FDA Approved. Its fermentation facilities are capable of using different kinds of microorganisms, including fungi, yeasts, and bacteria. The company is operating under new ownership since 2009 which has brought a firm commitment and support for expanding its biotechnology business. More information about Antibióticos S.A. is available at www.antibioticos-sa.com. About Metabolix Metabolix, Inc. is an innovation-driven bioscience company delivering sustainable solutions to the plastics, chemicals and energy industries. Metabolix is developing and commercializing Mirel TM and Mvera TM, a family of high-performance bioplastics which are biobased and biodegradable alternatives to many petroleum-based plastics. Metabolix’s biobased chemicals platform utilizes its novel “FAST” recovery process to enable the production of cost-effective, “drop-in” replacements for petroleum-based industrial chemicals. Metabolix is also developing a platform for co-producing plastics, chemicals and energy from crops. Metabolix has established an industry-leading intellectual property portfolio that, together with its knowledge of advanced industrial practice, provides a foundation for industry collaborations. For more information, please visit www.metabolix.com. (MBLX-E) Safe Harbor for Forward-Looking Statements This press release contains forward-looking statements which are made pursuant to the safe harbor provisions of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements in this release do not constitute guarantees of future performance. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, statements regarding the intention of the companies to successfully complete the work under the LOI and sign a contract manufacturing agreement constitute forward-looking statements. Such forward-looking statements are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated and are detailed in Metabolix's filings with the Securities and Exchange Commission, including its 10-K for the year ended December 31, 2011, which was filed on March 12, 2012. Metabolix assumes no obligation to update any forward-looking information contained in this press release or with respect to the announcements described herein.