Genome Sequence of the Solvent-Producing Bacterium Clostridium carboxidivorans Strain P7 ^T

Abstract

Clostridium carboxidivorans strain P7T is a strictly anaerobic acetogenic bacterium that produces acetate, ethanol, butanol, and butyrate. The C. carboxidivorans genome contains all the genes for the carbonyl branch of the Wood-Ljungdahl pathway for CO 2 fixation, and it encodes enzymes for conversion of acetyl coenzyme A into butanol and butyrate. Clostridium carboxidivorans strain P7T (equivalent to ATCC BAA-624T and DSM 15243 T ) is an obligate anaerobe that can grow autotrophically with H 2 and CO 2 or CO (fixing carbon via the Wood-Ljungdahl pathway), or it can grow chemoorganotrophically with simple sugars (1). Acetate, ethanol, butanol, and butyrate are end products of metabolism.For slow-growing strict anaerobes such as Clostridium carboxidivorans, genome sequencing provides a rapid theoretical characterization of its metabolism compared to traditional methods. We isolated and amplified genomic C. carboxidivorans DNA using the Wizard genomic DNA purification kit (Promega, Madison, WI) and the REPLI-g kit (Qiagen). A single shotgun pyrosequencing run using a Genome Sequencer FLX system (454 Life Sciences, Branford, CT) resulted in 429,680 high-quality reads (mean read length, 231.6 bp) that were assembled using Newbler software (454 Life Sciences) into 225 contigs Ͼ500 bp long. Paired-end sequencing produced 111,154 reads (mean read length, 256.3 bp). Assembly of the paired-end and shotgun reads produced 73 scaffolds containing 216 large contigs with a mean sequence depth of 16.33 reads. PCR amplification and Sanger sequencing were conducted, followed by scaffold assembly using Sequencher

Commercial Biomass Syngas Fermentation

“…Products include acetate, ethanol, butanol and butyrate. Draft genome sequences are available for C. carboxidivorans [173,174], which contain the genes of the reductive acetyl-CoA pathway as well as enzymes for the conversion of acetyl-CoA into butanol and butyrate. Bruant et al found the strain contains a plasmid and a butanol pathway similar to that of C. acetobutylicum [101].…”

“…While only a single acetogen had been sequenced before mid-2010, several genome sequences have since been released [91,101,102,144,173,174,228]. However, only very few transcriptomic studies have been published to date [54,176], looking at certain sets of genes rather than gene expression on a global basis.…”

Enhancing mass transfer and ethanol production in syngas fermentation of Clostridium carboxidivorans P7 through a monolithic biofilm reactor

“…At later culture stages, the acetic acid concentration itself was actually reduced; this was probably due to the consumption of acetic acid as a substrate for further ethanol production. The genomic analysis [33,34] revealed that C. carboxidivorans P7 contains genes that encode domains of aldehyde: ferredoxin oxidoreductase, indicating that P7 cells can metabolize acetate reduction to acetaldehyde and further to ethanol with reduced ferredoxin. Fig.…”

Clostridium carboxidivorans Strain P7T Recombinant Formate Dehydrogenase Catalyzes Reduction of CO 2 to Formate

“…Those enzymes from acetogenic and related anaerobes, such as Moorella thermoacetica and Clostridium pasteurianum, are better than other FDHs as reduction catalysts but also show similar catalytic efficiency toward formate oxidation and are considered highly oxygen labile, requiring anaerobic expression and purification as well as anoxic assay conditions (10,11). Clostridium carboxidivorans strain P7 T (equivalent to ATCC BAA-624 T and DSM 15243 T ) was isolated from the sediment of an agricultural settling lagoon after enrichment with CO as the substrate and is an obligate anaerobe that can grow autotrophically with H 2 and CO 2 or CO (fixing carbon via the Wood-Ljungdahl pathway) (12,13). Therefore, when the gene of a selenocysteine-containing formate dehydrogenase H (FDH H ) from the acetogen Clostridium carboxidivorans strain P7…”