Cloning, functional expression and characterization of a bifunctional 3-hydroxybutanal dehydrogenase /reductase involved in acetone metabolism by Desulfococcus biacutus.
BMC Microbiol
; 16(1): 280, 2016 11 25.
Article
in En
| MEDLINE
| ID: mdl-27884109
ABSTRACT
BACKGROUND:
The strictly anaerobic, sulfate-reducing bacterium Desulfococcus biacutus can utilize acetone as sole carbon and energy source for growth. Whereas in aerobic and nitrate-reducing bacteria acetone is activated by carboxylation with CO2 to acetoacetate, D. biacutus involves CO as a cosubstrate for acetone activation through a different, so far unknown pathway. Proteomic studies indicated that, among others, a predicted medium-chain dehydrogenase/reductase (MDR) superfamily, zinc-dependent alcohol dehydrogenase (locus tag DebiaDRAFT_04514) is specifically and highly produced during growth with acetone.RESULTS:
The MDR gene DebiaDRAFT_04514 was cloned and overexpressed in E. coli. The purified recombinant protein required zinc as cofactor, and accepted NADH/NAD+ but not NADPH/NADP+ as electron donor/acceptor. The pH optimum was at pH 8, and the temperature optimum at 45 °C. Highest specific activities were observed for reduction of C3 - C5-aldehydes with NADH, such as propanal to propanol (380 ± 15 mU mg-1 protein), butanal to butanol (300 ± 24 mU mg-1), and 3-hydroxybutanal to 1,3-butanediol (248 ± 60 mU mg-1), however, the enzyme also oxidized 3-hydroxybutanal with NAD+ to acetoacetaldehyde (83 ± 18 mU mg-1).CONCLUSION:
The enzyme might play a key role in acetone degradation by D. biacutus, for example as a bifunctional 3-hydroxybutanal dehydrogenase/reductase. Its recombinant production may represent an important step in the elucidation of the complete degradation pathway.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oxidoreductases
/
Acetone
/
Cloning, Organism
/
Deltaproteobacteria
/
Aldehydes
Language:
En
Journal:
BMC Microbiol
Journal subject:
MICROBIOLOGIA
Year:
2016
Document type:
Article
Affiliation country:
Germany