BioChem - DOS

Reduction of CO2 to methanol by a polyenzymatic system encapsulated in phospholipids-silica nanocapsules

New journal of chemistry = Nouveau journal de chimie

Cazelles, Ré mi; Drone, Jullien; Fajula, Franç ois; Ersen, Ovidiu; Moldovan, Simona; Galarneau, Anne

<P>By reversing the biological metabolic reaction pathway of three dehydrogenases, a formate dehydrogenase, a formaldehyde dehydrogenase and an alcohol dehydrogenase, it was possible to transform CO<SUB>2</SUB> into methanol by a cascade reaction. The activity of each enzyme was examined separately and then the relative amount of each enzyme for the cascade reaction was optimized. The enzymes consume one molecule of the NADH cofactor each to run which should be regenerated for cost reasons. Three different NAD<SUP>+</SUP> regenerating systems were compared: 2 enzymes (phosphite dehydrogenase (PTDH) and glycerol dehydrogenase) and a natural photosystem extracted from spinach leaves (chloroplasts). PTDH was proven to be more efficient at neutral pH. The new polyenzymatic system (4 enzymes) was then encapsulated in silica nanocapsules (internal diameter 30 nm) nanostructured by phospholipids (NPS). This hybrid nanobioreactor showed an activity 55 times higher than the free enzymes in solution. A methanol production of 42 &mu;mol g<SUB>NPS</SUB><SUP>&minus;1</SUP> corresponding to 4.3 mmol g<SUB>commercial enzymatic powder</SUB><SUP>&minus;1</SUP> in 3 h at room temperature and 5 bar was obtained.</P><BR><BR><P>Graphic Abstract</P><P>Valorization of CO<SUB>2</SUB> by biocatalysis: a systematic study of the polyenzymatic cascade reaction of 3 dehydrogenases for the production of methanol with comparison of NADH regenerating systems.<BR><IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3nj00688c'><BR></P>

2013

The Royal Society of Chemistry

1144-0546

1369-9261

37

11

pp.3721-3730

10.1039/c3nj00688c

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART67410123