Catenulispora acidiphila gen. nov., sp. nov., a novel, mycelium-forming actinomycete, and proposal of Catenulisporaceae fam. nov.

A novel, Gram-positive bacterial strain was isolated from forest soil. Among species with validly published names, the 16S rRNA gene sequence is related most closely (approx. 93 % similarity) to that of Sporichthya polymorpha DSM 43042(T). However, differently from this species, it forms both vegetative and aerial mycelia. The aerial hyphae are straight to slightly flexuous, starting to septate to form chains of more than 20 cylindrical spores with a rugose surface. The strain is acidophilic, with a pH range for robust growth between 4.3 and 6.8 and an optimum around 6.0. The peptidoglycan type is A3gamma ll-Dpm-Gly. The polar lipids are phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides and two unknown phospholipids. Predominant menaquinones are MK-9(H(6)) and -9(H(4)), and iso- and anteiso-branched C(16 : 0) and C(17 : 0) are the main cellular fatty acids. The DNA G+C content is 71.9 mol%. The distinct phylogenetic position and the unusual combination of chemotaxonomic characteristics justify the proposal of Catenulispora gen. nov., with the type species Catenulispora acidiphila sp. nov. (type strain, ID139908(T) =DSM 44928(T)=NRRL B-24433(T)). Catenulisporaceae fam. nov. is also proposed.