Molecular genetic and morphological characteristics of Micractinium thermotolerans and M. inermum (Trebouxiophyceae, Chlorophyta) from pyroclastic deposits of the Kamchatka Peninsula (Russia).

During the study of algal diversity in pyroclastic deposits of the Kamchatka Peninsula, Chlorella-like green algae strains VCA-72 and VCA-93 were isolated from samples collected from along the Baydarnaya river bed on the Shiveluch volcano in 2018 and at the outlet of thermal vapors along the edge of the caldera on the southern slope of the Gorely volcano in 2020. Identification of the strains was carried out within the framework of an integrative approach using microscopic and molecular genetic methods, including preliminary taxon identification, obtaining nucleotide sequences of the small subunit and the internal transcribed spacer rRNA, reconstruction of phylogenetic trees and secondary structures of the ITS1 and ITS2 rRNA regions. On the phylogenetic tree, strain VCA-93 was clustered in the Micractinium thermotolerans species clade.

Description of Two New Species of Ehrenberg (Naviculales, Bacillariophyceae) from the Russian Far East Using an Integrative Approach.

(Naviculales, Bacillariaceae) are widespread, mostly in fresh-water habitats, and account for 343 species. They are described mainly on the basis of morphology and morphometric traits. These characteristics vary during life cycles and may overlap between species, making their identification difficult.

Study on Syntaxonomic Diversity of Algal Cenoses in Soils of the Russian Far East, Using an Integrative Taxonomic Approach.

Soil is a unique ecosystem with peculiar biodiversity that includes cyanobacteria and algae. Traditionally, cyanobacterial and algal cenoses were described mainly using the dominance approach, rarely based on the Braun-Blanquet method (floristic classification). More importantly, in both cases, the species of cyanobacteria and algae in communities were identified using classical methods (light microscopy) only.

sp. nov. (Chlorophyta, Volvocales) from the Soils of Iturup Island (Sakhalin Region, Russia).

A strain of oogamous biflagellate green alga was isolated during a study on soil algal diversity in the Russian Far East (Sakhalin Region, Iturup Island) and examined using an integrative approach. Phylogenetic analyses, based on the SSU rDNA gene, resolved the new strain as a part of the RL clade ( Watanabe and Nakada) within Oogamochlamydinia (Volvocales, Chlorophyceae). The strain was similar to members of the genus (parietal and massive cup-shaped chloroplasts; two apical contractile vacuoles), but was, however, distinguished from them based on the size and shape of the mature vegetative cells, the flagellar length, the presence of only one pyrenoid in both the mature vegetative cells and the zoospores, the anterior nucleus position, and the spermatozoids' shape.

sp. nov. (Diadesmidaceae, Naviculales)-A New Diatom from the Soil of the State Nature Reserve "Bastak" (Jewish Autonomous Region, Russia).

Diatoms inhabit different aquatic and non-aquatic environments, including soils. The naviculoid genus is widespread in various habitats and accounts for 264 species that are only based on morphological and morphometric characteristics. These parameters can greatly vary during the life cycle, making the species very similar to each other and complicating their unambiguous identification.