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EXHIBIT 23.1
CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS
We consent to the incorporation by reference in the Registration Statement
(Form S-8) pertaining to the 1996 Stock Option Plan, 2000 Employee Stock
Purchase Plan and 2000 Non-Employee Directors Stock Option Plan of our report
dated March 10, 2000 (except for the first paragraph of Note 9, as to which
the date is September 28, 2000) with respect to the financial statements of
Kosan Biosciences Incorporated as of December 31, 1998 and 1999 and for each
of three years in the period ended December 31, 1999 included in its
Registration Statement (Form S-1 No. 333-33732) and related Prospectus dated
October 5, 2000, filed with the Securities and Exchange Commission.
/S/ ERNST & YOUNG LLP
Palo Alto, California
October 6, 2000
