Compositions and methods for the conversion of short-chained carboxylic acids to alcohols using clostridial enzymes
View Patent ↗The invention relates to the fields of bacterial metabolism and the utilization or consumption of short-chain carboxylic acids to reduced products. Specifically, it relates to syngas fermentations using monocultures of syngas-utilizing homoacetogenic bacteria for the production of alcohols using native alcohol dehydrogenase.
1. A microorganism co-culture for butanol production by the conversion of syngas to butanol comprising: (i) a recombinant C1-fixing homoacetogen microorganism grown on a medium containing syngas as the sole carbon source under anaerobic condition wherein said C1-fixing homoacetogen microorganism is capable to convert the syngas to butanol and comprises a heterologous gene encoding an aldehyde ferredoxin oxidoreductase polypeptide modulated by a promoter, (ii) and a C4-producing butyrate microorganism, wherein the nucleotide sequence of aldehyde ferredoxin oxidoreductase gene has greater than 97% sequence identity to SEQ ID NO: 1 or SEQ ID NO: 3.
2. The co-culture of claim 1 wherein the promoter is an inducible promoter or a constitutive promoter.
3. The co-culture of claim 1 wherein the C1-fixing homoacetogen microorganism is C. ljungdahlii, C. ragsdalei, C. autoethanogenum or C. coskatii .
4. The co-culture of claim 1 wherein the C4-producing butyrate microorganism is Clostridium kluyveri, Clostridium carboxidivorans , or Butyribacterium methylotrophicum .