Table 1.

Previous attempts to optimize the medium or genetic background of Synechocystis sp. PCC 6803 for the production of PHB. Further approaches (also in other cyanobacteria) have been reviewed recently [19]

Genotype	PHB content (% CW)	substrate	Production condition	Polymer composition	References
WT	29	0.4% acetate	–P	PHB	[38]
overexpression phaAB (native)	35	0.4% acetate	–N	PHB	[21, 22]
overexpression phaABC (Cupriavidus necator)	11	10 mM acetate	–N	PHB	[42]
overexpression nphT7, phaB, phaC	41	0.4% acetate	Limited air exchange, –N	–	[28]
overexpression Xfpk	12	CO2	–N, –P	PHB	[5]
overexpression sigE	1.4	CO2	–N	PHB	[36]
overexpression rre37	1.2	CO2	–N	PHB	[37]