Schematic representation of recombination to integrate (A) ter at NSI, (B) atoB, adhE2, crt, and hbd at NSII in the genome of S. elongatus. Different combinations of alternative genes nphT7, bldh, yqhD, phaJ, and phaB can replace their counterpart enzymes to recombine into NSII. (C) List of strains with different combinations of overexpressed genes used in this study.