Clostridium kluyveri DSM 555

Clostridium kluyveri is a Gram-positive, spore-forming bacterium. It is unique among the clostridia as it grows anaerobically on ethanol and acetate as sole energy sources, and has been extensively studied. Fermentation products are butyrate, caproate, and H2. It has been used as a source of enzymes, for example phosphotransacetylase for analytical purposes and enoate reductases for stereospecific hydrogenation reactions. A membrane-bound energy-converting NADH:ferredoxin oxidoreductase and a butyryl-CoA dehydrogenase complex coupling the reduction of crotonyl-CoA to butyryl-CoA with the reduction of ferredoxin represent a new energy-conserving module in anaerobes. The genes for NAD-dependent ethanol dehydrogenase and NAD(P)-dependent acetaldehyde dehydrogenase are located next to genes for microcompartment proteins, suggesting that the two enzymes, which are isolated together in a macromolecular complex, form a carboxysome-like structure. Unique for a strict anaerobe, C. kluyveri harbors three sets of genes predicted to encode for polyketide/nonribosomal peptide synthetase hybrides and one set for a nonribosomal peptide synthetase. The latter is predicted to catalyze the synthesis of a new siderophore, which is formed under iron-deficient growth conditions (modified from PubMed:18218779).Although strains DSM 555 (CLOK5, this strain) and NBRC 12016 (CLOK1) are purportedly coidentical type strains of Clostridium kluyveri there are differences in the genomic sequences. The DNA record for CLOK1 (AC AP009049) it says; "The genome sequence of NBRC 12016 strain has the region containing phage-related genes (from 1.93 Mbp to 1.99 Mbp). A similar region occurs in DSM 555 (1.93 Mbp to 2.06 Mbp) but it is not only double the size of the NBRC12016 region, but also a duplicate." Whether these differences are due to errors in sequencing and/or assembly, or due to divergent evolution of the two strains is indeterminate at present (April 2009). (HAMAP: CLOK5)