(54a) Advanced Platform Strain Engineering Conference: AIChE Annual MeetingYear: 2015Proceeding: 2015 AIChE Annual MeetingGroup: Food, Pharmaceutical & Bioengineering DivisionSession: Biobased Fuels and Chemicals I: Biosynthetic Pathway Engineering Time: Monday, November 9, 2015 - 8:30am-8:50am Authors: Curran, K., Microbial platform strains are robust strains with a high capacity for production of several related biological products. The effort that goes into designing and building a platform strain for an initial product should ideally reduce the time and cost it takes to get subsequent related products to market. However, the challenges faced by scientists and engineers in taking a highly engineered strain from one product to another are different than if they were to start from scratch. For example, replacing the pathway genes for the first product with those for the new product is often not trivial both from a molecular biology perspective (i.e. multiple copies of the old genes may be present in the genome), and from the pathway perspective (i.e. upstream pathway flux must be balanced for the new enzymes to avoid intermediate toxicity). Additionally, a highly engineered strain may have developed product-specific mutations related to product toxicity and transport that are not beneficial for tolerance of the new product. This presentation will discuss some of these challenges and the solutions that have been successfully applied to Amyris' terpene-producing platform yeast strains.