Exhibit 10.28  METABOLIX, INC.  EMPLOYEE NONCOMPETITION, CONFIDENTIALITY AND INVENTIONS AGREEMENT  The undersigned Richard P.
Eno [print name], in consideration and as a condition of my employment and
continued employment by Metabolix, Inc. (the Company), a Delaware
corporation, does hereby agree with the Company as follows:  1.  Noncompetition and Nonsolicitation.  During my employment by the Company and for a
period of one (1) year thereafter, I will not directly or indirectly,
alone or as a partner, joint venturer, consultant, officer, director, employee,
agent, independent contractor or stockholder be engaged in any competitive
business as hereinafter defined.  The
term competitive business (i) shall mean any business (however organized
or conducted) that competes with a business in which the Company was engaged,
or in which the Company was planning to engage, at any time during the 12-month
period immediately preceding the date on which my employment terminates, and (ii) shall
conclusively be presumed to include, but shall not be limited to, a business
engaging in metabolic engineering of polyhydroxyalkanoates
and the development and sale of biobased and/or biodegradable polymers;
provided, however, that the record or beneficial ownership by me of 1%
or less of the outstanding publicly traded capital stock of any such company or
business organization shall not be deemed, in and of itself, to be in violation
of this Section 1; or (ii) employ, or knowingly permit any company or
business organization which is directly or indirectly controlled by me to
employ, any person who is employed by the Company, or is an agent,
representative or consultant of the Company, or in any manner seek to solicit
or induce any such person to leave his or her employment with the Company or
assist in the recruitment of any such person; or (iii) directly or
indirectly solicit any customer of the Company (other than on behalf of the
Company) to terminate or negatively alter his, her or its relationship with the
Company or directly or indirectly induce any customer, supplier, vendor,
consultant or independent contractor of the Company to terminate or negatively
alter his, her or its relationship with the Company.  2.  Confidentiality.  I will not at any time, whether during or after
the termination of my employment, reveal to any person, association, company,
entity or other organization any of the trade secrets or confidential
information of the Company or of any third party to whom the Company is under
an obligation of confidentiality (including but not limited to trade secrets or
confidential information respecting inventions, products, research and
development activities, designs, methods, know-how, techniques, processes,
plans and proposals, marketing and selling, business plans, budgets and
unpublished financial statements, licenses, prices and costs, suppliers and
customers) except as may be required in the ordinary course of performing my
duties as an employee of the Company. 
Further, I shall not use any such trade secrets or confidential
information except as required in the performance of my duties for the
Company.  Without limiting the generality
of the foregoing, I shall not use any such trade secrets or confidential
information for my personal benefit or in any manner which may injure or cause
loss, whether directly or indirectly, to the Company.


Further, I agree that, during my
employment I shall not make, use or permit to be used any notes, memoranda,
drawings, specification, programs, data, lab results, lab notes, formulas,
codes or other materials of any nature relating to the business of the Company
or concerning any of its dealings or affairs otherwise than for the benefit of
the Company.  I further agree that I
shall not, after the termination of my employment, use or permit to be used any
such materials, it being agreed that all of the foregoing are and shall be
confidential information or trade secrets of the Company and shall be and
remain the sole and exclusive property of the Company, and immediately upon the
termination of my employment I shall deliver all of the foregoing, and all
copies thereof, to the Company. 
Notwithstanding anything to the contrary contained in this Section 2,
for purposes of this Agreement, confidential information does not include
information which: (i) is or was known to me prior to my employment with
the Company, (ii) is known in the trade or becomes generally known to the
public through no action on my part; (iii) is generally disclosed to third
parties by the Company without restriction on such third parties; (iv) is
approved for release by written authorization of the management or Board of
Directors of the Company; or (v) is required to be disclosed pursuant to
subpoena, order of judicial or administrative authority, or in connection with
judicial proceedings to which the Company or I am a party.  3.  Inventions and Intellectual Property.  If at any time or times during my employment
I (either alone or with others) make, conceive, discover, reduce to practice or
become possessed of any Intellectual Property, as hereinafter
defined, such Intellectual Property shall be the sole and absolute property of
the Company, as works made for hire or otherwise, and I hereby assign to the
Company all of my rights in such Intellectual Property.  For purposes hereof, Intellectual Property shall mean any invention,
modification, discovery, design, development, improvement, process, formula,
code, data, technique, know-how, trade secret, work of authorship or
intellectual property right whatsoever or any interest therein (whether or not
patentable or registrable under copyright or similar statutes) that (a) relates to 
metabolic engineering of polyhydroxyalkanoates or any other business of
the Company or any of the products or services being developed, manufactured or
sold by the Company or which may be useful in connection therewith, and (b) results
from tasks assigned to me by the Company, or (c) results from the use of
facilities owned, leased or contracted for by the Company or (d) are
authored, conceived, reduced to practice, made, developed or created (alone or
in conjunction with others, during regular hours of work or otherwise) or
otherwise obtained by me during my employment with the Company or in the
performance of my duties.  The term
Intellectual Property does not include inventions, modifications, discoveries,
designs, developments, improvements, processes, formulae, codes, data,
techniques, know-how, trade secrets, works of authorship or intellectual
property rights or any interest therein (whether or not patentable or
registrable under copyright or similar statutes) of any kind whatsoever which
were in my possession prior to my employment by the Company and which were not
obtained from or through the Company or not developed, prepared, compiled,
conceived, reduced to practice or otherwise created or made using the Companys
information, data, equipment, supplies or facilities.  I shall promptly
disclose to the Company (or any persons designated by it) all such Intellectual
Property and any information relating thereto. 
I shall also promptly disclose to the Company, and the Company hereby
agrees to receive all such disclosures in confidence, any   2


otherinvention, modification, discovery, design,
development, improvement, process, formula, code, data, technique, know-how,
trade secret, work of authorship or intellectual property right whatsoever or
any interest therein (whether or not patentable or registrable under copyright
or similar statutes) made, conceived, discovered, reduced to
practice or possessed by me (either alone or with others) at any time or times
during my employment, for the purposes of determining whether they constitute Intellectual
Property as defined above.  During my
employment and at any time thereafter I will, at the request and cost of the
Company, sign, execute, make and do all such deeds, documents, acts and things
as the Company and its duly authorized agents may reasonably require to apply
for, obtain and vest in the name of the Company alone (or as the Company
otherwise directs) and to defend, enforce and maintain any patents, patent
applications, copyrights, or other analogous protection with respect to the
Intellectual Property in any country throughout the world.  The Companyagrees to pay any and all
copyright, trademark and patent fees and expenses or other costs incurred by me
for any assistance rendered to the Company pursuant to this Section 3 and
to promptly reimburse me for all costs, fees and expenses incurred by me in
perfecting its property rights in the Intellectual Property, including, without
limitation, my attorneys fees and legal costs. 
My obligations to assign Intellectual Property shall not apply to any
Intellectual Property which I can demonstrate: 
(i) was developed entirely on my own time and effort; (ii) no
equipment, supplies, facilities, resources, trade secrets or confidential
information of the Company was used in the development of the Intellectual
Property; (iii) does not relate to the business of the Company or to the
Companys actual or anticipated research and development; and (iv) does
not result from any work otherwise performed by me for the Company.  If the Company is
unable, after reasonable effort, to secure my signature on any such application
or other document relating to any Intellectual Property, whether because of my
physical or mental incapacity or for any other reason whatsoever, I hereby
irrevocably designate and appoint the Company and its duly authorized officers
and agents as my agent and attorney-in-fact, to act for and in my behalf and
stead to execute and file any such application(s) or document(s) and
to do all other lawfully permitted acts to further the prosecution and issuance
of letters patent, copyright or other analogous protection thereon with the
same legal force and effect as if executed by me.  4.  Prior Inventions.  I represent that the inventions identified in
the pages, if any, attached hereto comprise all the inventions which I have
made or conceived prior to my employment by the Company, which inventions are
excluded from this Agreement.  I
understand that it is only necessary to list the title of such inventions and
the purposes thereof, but not the details of the invention itself.  IF THERE ARE ANY SUCH INVENTIONS TO BE EXCLUDED, THE UNDERSIGNED SHOULD
INITIAL HERE.  OTHERWISE IT WILL BE
DEEMED THAT THERE ARE NO SUCH EXCLUSIONS. 
          . The parties acknowledge that pages       
through          attached hereto are
the only pages attached in response to this Section 4.  5.  No Conflict.  Except as provided in the next paragraph of
this Section 5, I represent that my performance of the terms of this
Agreement, and my performance of my duties as an employee   3


of the Company, does not and will not breach any agreement to which I
am bound, including without limitation any agreement to keep in confidence
proprietary information acquired by me in confidence or in trust prior to my
employment by the Company.  I have not
entered into, and I agree that I will not enter into, any agreement, either
written or oral, in conflict herewith.During my employment by the Company, I will
not improperly use or disclose any confidential information or trade secrets,
if any, of any former employer or any other person to whom I have an obligation
of confidentiality, and I will not bring onto the premises of the Company any
unpublished documents or any property belonging to any former employer or any
other person to whom I have an obligation of confidentiality unless consented
to in writing by that former employer or person.  I will use in the performance of my duties
only information which is generally known and used by persons with training and
experience comparable to my own, which is common knowledge in the industry or
otherwise legally in the public domain, or which is otherwise provided or
developed by the Company.  I have attached hereto a copy of each agreement, if any, which
presently affects my compliance with the terms of this Agreement.  IF THERE ARE ANY SUCH AGREEMENTS, THE
UNDERSIGNED SHOULD INITIAL HERE. 
OTHERWISE IT WILL BE DEEMED THAT THERE ARE NO SUCH EXCLUSIONS. 
          . The parties acknowledge that pages       
through          attached hereto are
the only pages attached in response to this Section 5.  6.  Specific Performance.  I agree that any breach of this Agreement by
me will cause irreparable damage to the Company, and that in the event of such
breach and upon appropriate proof of such breach in accordance with the
applicable legal procedures the Company shall have, in addition to any and all
remedies of law, the right to an injunction, specific performance or other
equitable relief to prevent the violation of my obligations hereunder.  7.  No Employment Obligation.  I understand that this Agreement does not
create an obligation on the Company or any other person to continue my
employment.  8.  Amendments.  Any amendment to or modification of this
Agreement, and any waiver of any provision hereof, shall be in writing and
shall be signed by the parties hereto. 
Any waiver by either party of a breach of any provision of this
Agreement shall not operate or be construed as a waiver of any subsequent
breach hereof.  9.  Severability.  I hereby agree that each provision herein
shall be treated as a separate and independent clause, and the unenforceability
of any one clause shall in no way impair the enforceability of any of the other
clauses herein.  Moreover, if any one or
more of the provisions contained in this Agreement shall for any reason be held
to be excessively broad as to scope, activity or subject so as to be
unenforceable at law, such provision or provisions shall be construed by the
appropriate judicial body by limiting and reducing it or them, so as to be
enforceable to the maximum extent compatible with the applicable law as it
shall then appear.  I hereby further
agree that the language of all parts of this Agreement shall in all cases be
construed as a whole according to its fair meaning and not strictly for or
against any of the parties.   4


10.  Survival.  Except as otherwise provided in Section 1,
my obligations under this Agreement shall survive the termination of my employment,
regardless of the manner of such termination, and shall be binding upon my
heirs, executors, administrators and legal representatives.  11.  Successors.  The term Company shall include Metabolix, Inc.,
a Delaware corporation, and any of its subsidiaries, divisions, or
affiliates.  The Company shall have the
right to assign this Agreement to its successors and assigns, and all covenants
and agreements hereunder shall inure to the benefit of and be enforceable by
such successors and assigns.  12.  Governing Law.  This Agreement shall be deemed to be made and
entered into in the Commonwealth of Massachusetts, and shall in all respects be
interpreted, enforced and governed under the internal and domestic laws of such
Commonwealth without giving effect to the principles of conflict of law of such
Commonwealth.  EXECUTED
as of the 20th day of February, 2008.  /s/
  Richard P. EnoSignatureName:
  Richard
  P. EnoAddress:Accepted
  and Agreed:METABOLIX,
  INC.By:
  /s/
  Anthony J. SinskeyName:
  Anthony J. SinskeyTitle:
  Chairman of the Compensation Committee   5