Sandaracinus amylolyticus gen. nov., sp nov., a starch-degrading soil myxobacterium, and description of Sandaracinaceae fam. nov.

A novel starch-degrading myxobacterium designated NOSO-4(T) (new organism of the Sorangiineae strain 4) was isolated in 1995 from a soil sample containing plant residues, collected in Lucknow, Uttar Pradesh, India. The novel bacterium shows typical myxobacterial characteristics such as Gram-negative, rod-shaped vegetative cells, swarming colonies, fruiting body-like aggregates and bacteriolytic activity. The strain is mesophilic, strictly aerobic and chemoheterotrophic. Based on 16S rRNA gene sequences, NOSO-4(T) shows highest similarity (96.2%) with the unidentified bacterial strain 029 (accession no. FN554397), isolated from leek (A Ilium porrum) rhizosphere, and to the myxobacteria Jahnella thaxteri (88.9%) and Chondromyces pediculatus (88.5%). Major fatty acids are C-17:1 2-OH, C-20:4 omega 6 (arachidonic acid), and the straight-chain fatty acids C-17:0, C-15:0 and C-16:0. The genomic DNA G+C content of the novel isolate is 66.8 mol%. It is proposed that strain NOSO-4(T) represents a novel species in a new genus, i.e. Sandaracinus amylolyticus gen. nov., sp. nov., but also belongs to a new family, Sandaracinaceae fam. nov. The type strain of the type species, S. amylolyticus sp. nov., is NOSO-4(T) (=DSM 53668(T)=NCCB 100362(T)).