The phylum dictyoglomi

Abstract

The phylum Dictyoglomi consists a single genus, Dictyoglomus, with two type strains and several related pure culture isolates. All isolates are thermophilic anaerobic Gram-type negative rods. A major distinguishing phenotypic feature is the formation of spherical bodies in late stationary phase of growth, the function of which is not understood. Most isolates are fermentative using a range of simple carbohydrates, but some isolates are able to grow on crystalline cellulose and chemolithotrophy using carbon monoxide as energy source has been reported for one pure culture. There have been relatively few applications for Dictyoglomus enzymes as a result of a number of factors. Although many of their kinetic properties are exceptional, they have had to be cloned and expressed in standard fermentation strains as hosts, and their low G:C content has required significant genetic manipulation to provide expression. Some of the main applications have required inexpensive enzymes in bulk (e.g., pulp bleaching in paper manufacture), and they have had to be regarded as a replacement for well-established enzymes currently used in the industry. The major applications have involved glycosyl hydrolases, but new uses in value-added products involving drug precursor transformations have been reported recently.