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 O29 (accession no. FN554397), isolated from leek (Allium 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)ω6 (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)).