Microlunatus soli sp. nov., isolated from soil

Abstract

A Gram-stain-positive, coccoid, non-endospore-forming actinobacterium (strain CC-12602T) was isolated from a spawn used for growing the edible mushroom Agaricus brasiliensis in the laboratory. On the basis of 16S rRNA gene sequence analysis, strain CC-12602T was shown to belong to the genus Microlunatus and was related most closely to the type strains of Microlunatus ginsengisoli (96.1 % similarity), M. phosphovorus (95.9 %), M. panaciterrae (95.8 %) and M. aurantiacus (95.5 %). The quinone system comprised menaquinone MK-9(H4) as the major component and the polyamine pattern consisted of spermidine and spermine as major compounds. The predominant polar lipids were phosphatidylglycerol and unknown phospholipid PL3. Moderate amounts of diphosphatidylglycerol, an unknown glycolipid and three unknown phospholipids and minor amounts of an unknown phospholipid and a polar lipid were detected. The peptidoglycan type was A3γ′, based on ll-2,6-diaminopimelic acid with an interpeptide bridge consisting of a single glycine residue and a second glycine residue at position 1 of the peptide subunit. Peptidoglycan structure and major fatty acids (anteiso-C15 : 0, iso-C16 : 0 and iso-C15 : 0) supported the affiliation of strain CC-12602T to the genus Microlunatus. The results of physiological and biochemical tests allowed strain CC-12602T to be differentiated phenotypically from recognized Microlunatus species. Strain CC-12602T is therefore considered to represent a novel species of the genus Microlunatus, for which the name Microlunatus soli sp. nov. is proposed. The type strain is CC-12602T (=DSM 21800T =CCM 7685T).