The production of alkanes in a marine cyanobacterium possessing the α-olefin biosynthesis pathway was achieved by introducing an exogenous alkane biosynthesis pathway. Cyanobacterial hydrocarbons are synthesized via two separate pathways: the acyl-acyl carrier protein (ACP) reductase/aldehyde-deformylating oxygenase (AAR/ADO) pathway for the alkane biosynthesis and the α-olefin synthase (OLS) pathway for the α-olefin biosynthesis. Coexistence of these pathways has not yet been reported. In this study, the marine cyanobacterium Synechococcus sp. NKBG15041c was shown to produce α-olefins similar to those of Synechococcus sp. PCC7002 via the α-olefin biosynthesis pathway. The production of heptadecane in Synechococcus sp. NKBG15041c was achieved by expressing the AAR/ADO pathway genes from Synechococcus elongatus PCC 7942. The production yields of heptadecane in Synechococcus sp. NKBG15041c varied with the expression level of the aar and ado genes. The maximal yield of heptadecane was 4.2 ± 1.2 μg/g of dried cell weight in the transformant carrying a homologous promoter. Our results also suggested that the effective activation of ADO may be more important for the enhancement of alkane production by cyanobacteria.

The marine cyanobacterium Synechococcus sp. strain NKBG042902 was isolated from coastal areas in Japan. Strain NKBG042902 has four plasmids: pSY8, pSY9, pSY10, and pSY11. Moreover, the hybrid plasmid pUSY02 containing pSY11 and Escherichia coli plasmid pUC18 was constructed for this strain. The genetic manipulation technique using pUSY02 was established for this strain and used in metabolic engineering. Here, we report the draft genome sequence of this strain, which has 77 contigs comprising a total length of 3,319,479 bp, with a G+C content of 49.4%.