Metabolic engineering for isopropanol production by an engineered cyanobacterium, Synechococcus elongatus PCC 7942, under photosynthetic conditions.
Cyanobacteria engineered for production of biofuels and biochemicals from carbon dioxide represent a promising area of research in relation to a sustainable economy. Previously, we have succeeded in producing isopropanol from cellular acetyl-CoA by means of Synechococcus elongatus PCC 7942 into which a synthetic metabolic pathway was introduced. The isopropanol production by this synthetic metabolic pathway requires acetate; therefore, the cells grown under photosynthetic conditions have to be transferred to a dark and anaerobic conditions to produce acetate. In this study, we achieved acetate production under photosynthetic conditions by S. elongatus PCC 7942 into which we introduced the pta gene encoding phosphate acetyltransferase from Escherichia coli. The metabolic modification (via pta introduction) of the isopropanol-producing strain enabled production of isopropanol under photosynthetic conditions. During 14 days of production, the titer of isopropanol reached 0.55 mM (33.1 mg/l) with an intermediate product, acetone, at 0.21 mM (12.2 mg/l).
Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, 804 Westwing, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Yasutaka
Y
Hirokawa
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Yudai
Y
Dempo
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
Eiichiro
E
Fukusaki
Laboratory for Bioinformatics, Graduate School of Systems Biosciences, Kyushu University, 804 Westwing, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. Electronic address: taizo@brs.kyushu-u.ac.jp.
Taizo
T
Hanai
D019840:2-Propanol / Q000378:metabolism*; D056804:Biofuels; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D060847:Metabolic Engineering; D010709:Phosphate Acetyltransferase / Q000235:genetics; D010788:Photosynthesis; D046940:Synechococcus / Q000235:genetics* / Q000378:metabolism*
D056804:Biofuels; D010709:Phosphate Acetyltransferase; D019840:2-Propanol
Acetate; Cyanobacteria; Isopropanol; Photosynthetic conditions; Synthetic metabolic pathway