Increased Butyrate Production in Clostridium saccharoperbutylacetonicum from Lignocellulose-Derived Sugars.

Butyrate is produced by chemical synthesis based on crude oil, produced by microbial fermentation, or extracted from animal fats (M. Dwidar, J.-Y.

Deletion of glyceraldehyde-3-phosphate dehydrogenase (gapN) in Clostridium saccharoperbutylacetonicum N1-4(HMT) using CLEAVE™ increases the ATP pool and accelerates solvent production.

The development and advent of mutagenesis tools for solventogenic clostridial species in recent years has allowed for the increased refinement of industrially relevant strains. In this study we have utilised CLEAVE™, a CRISPR/Cas genome editing system developed by Green Biologics Ltd., to engineer a strain of Clostridium saccharoperbutylacetonicum N1-4(HMT) with potentially useful solvents titres and energy metabolism.

CRISPR-Cas, a highly effective tool for genome editing in Clostridium saccharoperbutylacetonicum N1-4(HMT).

The solventogenic clostridia have long been known for their ability to convert sugars from complex feedstocks into commercially important solvents. Although the acetone-butanol-ethanol process fell out of favour decades ago, renewed interest in sustainability and 'green' chemistry has re-established our appetite for reviving technologies such as these, albeit with 21st century improvements. As CRISPR-Cas genome editing tools are being developed and applied to the solventogenic clostridia, their industrial potential is growing.

Part by Part: Synthetic Biology Parts Used in Solventogenic Clostridia.

The solventogenic Clostridia are of interest to the chemical industry because of their natural ability to produce chemicals such as butanol, acetone and ethanol from diverse feedstocks. Their use as whole cell factories presents multiple metabolic engineering targets that could lead to improved sustainability and profitability of Clostridium industrial processes. However, engineering efforts have been held back by the scarcity of genetic and synthetic biology tools.

Mutations in subdomain B of the minichromosome maintenance (MCM) helicase affect DNA binding and modulate conformational transitions.

Minichromosome maintenance (MCM) proteins are believed to provide the replicative helicase activity in eukaryotes and archaea. The single MCM orthologue from Methanothermobacter thermautotrophicus (MthMCM) has been extensively characterized as a model of the eukaryotic heterohexameric MCM complex. MthMCM forms high molecular weight complexes in solution consistent with a dodecamer.

Minichromosome maintenance helicase activity is controlled by N- and C-terminal motifs and requires the ATPase domain helix-2 insert.

The minichromosome maintenance (MCM) proteins are essential conserved proteins required for DNA replication in archaea and eukaryotes. MCM proteins are believed to provide the replicative helicase activity that unwinds template DNA ahead of the replication fork. Consistent with this hypothesis, MCM proteins can form hexameric complexes that possess ATP-dependent DNA unwinding activity.