Inacoccus terrestris sp. nov. (Chroococcaceae), a new cyanobacterium from soil of the European Russian Subarctic

Abstract

ABSTRACT A strain of an Inacoccus species (Cyanobacteria, Chroococcaceae) was isolated from a terrestrial habitat in the Murmansk Region, Russia, and characterized using a ‘polyphasic approach’ that included molecular, morphological and ecological evidence. The 16S rRNA gene phylogeny supported the strong monophyly of the genus Inacoccus, with the separation of four lineages. One of them corresponded to the recently described species Inacoccus carmineus from Brazil, while two others belonged to previously published but still taxonomically undescribed Inacoccus strains from Romania and Portugal. The fourth lineage represented a new species, Inacoccus terrestris sp. nov., from the Murmansk Region (European Russian Subarctic). Inacoccus terrestris occurred in soil and, in culture, formed microscopic, amorphous colonies. The slime contained up to four blue-green or olive-green cells, and the mucilage was more or less clearly delimited and colourless. The species is characterized by the absence of nanocytes. Its 16S rRNA gene similarity with other Inacoccus strains (with the exception of BACA0595) is lower than 98.7%, and 16S–23S ITS ITS similarity is lower than 97%, which supports its delimitation as a separate new species. Inacoccus terrestris is further characterized by unique hypothetical secondary structures of D1-D1' and Box-B helices.