A new mesophilic isolate of Pleurastrosarcina , a genus previously only reported from arid habitats
Year: 2025
Type: article
Abstract: The genus Pleurastrosarcina with its two species P. brevispinosa and P. terriformae was exclusively found in arid soils. Despite the huge sequencing efforts, Pleurastrosarcina has not been reported elsewhere and only a few cultures are available. This genus is very difficult to identify solely by morphology especially if the typical akinetes are absent. During the evaluation of the holdings of the Algal Culture collection of the Kyiv University (ACKU), we studied a strain showing morphological similarities to both species because of the presence of akinetes. In contrast to the other strains which all originated from desert habitats, the strain ACKU 382 was isolated from a mesophilic habitat (Kaniv Nature Reserve, Ukraine). The phylogenetic analyses using a multiple gene approach (SSU, ITS, tufA, rbcL) confirmed that this strain belongs to Pleurastrosarcina. The ITS2/CBC approach revealed that ACKU 382 represents a new isolate of P. brevispinosa. Both known species are characterized by unique compensatory base changes in the secondary structure of ITS2. To find additional support for these species, we searched for molecular signatures among the two plastid-coding genes at amino acid level. The comparison of both markers showed different resolution power. Whereas tufA only confirmed the split into two species, rbcL also distinguished the varieties by unique synapomorphies similar to the SSU and ITS dataset. The strain ACKU 382 has new variants of ITS1 and ITS2 and has three unique amino acids in rbcL. As a consequence, we proposed a new variety for this strain, P. brevispinosa var. borysthenica.
Source: Phycologia
Language: English
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: hybrid
OpenAlex ID: W4408896466