The biological parts utilised for combinatorial construction of a lycopene biosynthetic pathway. a The carotenoid lycopene is produced in E. coli through a heterologous biosynthetic pathway composed of three enzymes (CrtE. CrtB and CrtI). The heterologous proteins use FPP, which is a product of MEP pathway, as a precursor. b A complete combinatorial library totalling 810 pathway configurations can be designed by varying the promoter and RBS parts and by varying the order of pathway genes and RBS parts. Through the application of statistical modelling by DoE software, the designed library was reduced to 88 representative constructs, A table displaying part information of each construct is displayed in the supplementary information ( Additional file 1: Table S1). The pathway library was assembled and expressed in E. coli DH5α to test lycopene titres. The relative effects of the different design factors had on the titres level of lycopene were modelled using JMP. The model identified biological parts which effected titre levels, this can help aid future designing of the lycopene biosynthetic pathway.