Phylotranscriptomic relationships of the Oophila clade of green algae associated to amphibian egg masses

Green algae usually assigned to the genus Oophila are known to colonize egg capsules of amphibian egg masses across the Nearctic and Palearctic regions. We study the phylogenetic relationships of these algae using a phylotranscriptomic data set of 76 protein-coding single-copy nuclear genes. Our data set includes novel RNAseq data for six amphibian-associated and five free-living green algae, and draft genomes of two of the latter. Within the Oophila clade (nested within Moewusinia), we find samples from two European frogs (Rana dalmatina and R. temporaria) closely related to those of the North American frog R. aurora (Oophila subclade III). An isolate from the North American R. sylvatica (subclade IV) appears to be sister to the Japanese isolate from the salamander Hynobius nigrescens (subclade J1), and subclade I algae from Ambystoma maculatum are sister to all other lineages in the Oophila clade. Two free-living algae (Chlamydomonas nasuta and Cd. pseudogloeogama) are nested within the Oophila clade, and a strain of the type species of Chlorococcum (Cc. infusionum) is related to this assemblage. Our phylotranscriptomic tree suggests that recognition of different species within the Oophila clade ("clade B" of earlier studies) is warranted, and calls for a comprehensive taxonomic revision of Moewusinia.

Diversity and Distribution of Carotenogenic Algae in Europe: A Review

Microalgae are the richest source of natural carotenoids, which are valuable pigments with a high share of benefits. Often, carotenoid-producing algae inhabit specific biotopes with unfavorable or even extremal conditions. Such biotopes, including alpine snow fields and hypersaline ponds, are widely distributed in Europe. They can serve as a source of new strains for biotechnology. The number of algal species used for obtaining these compounds on an industrial scale is limited. The data on them are poor. Moreover, some of them have been reported in non-English local scientific articles and theses. This review aims to summarize existing data on microalgal species, which are known as potential carotenoid producers in biotechnology. These include Haematococcus and Dunaliella, both well-known to the scientific community, as well as less-elucidated representatives. Their distribution will be covered throughout Europe: from the Greek Mediterranean coast in the south to the snow valleys in Norway in the north, and from the ponds in Amieiro (Portugal) in the west to the saline lakes and mountains in Crimea (Ukraine) in the east. A wide spectrum of algal secondary carotenoids is reviewed: β-carotene, astaxanthin, canthaxanthin, echinenone, adonixanthin, and adonirubin. For convenience, the main concepts of biology of carotenoid-producing algae are briefly explained.

Uncovering New Diversity of Photosynthetic Microorganisms from the Mediterranean Region

In the large and morphologically diverse phylum of Chlorophyta, new taxa are discovered every year and their phylogenetic relationships are reconstructed by the incorporation of molecular phylogenetic methods into traditional taxonomy. Herein, we aim to contribute to the photosynthetic microorganisms’ diversity knowledge in the Mediterranean area, a relatively unexplored ecoregion with high diversity. Based on a polyphasic approach, 18 Chlorophyta isolates were investigated and characterized. Morphological characteristics and ultrastructure, the phylogeny based on 18S rRNA gene (small subunit ribosomal RNA), 18S–28S internal transcribed spacer (ITS region), and the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit region (rbcL gene), support establishing four new genera (Nomia, Ava, Akraea, Lilaea) and five new species (Spongiosarcinopsis limneus, N. picochloropsia, Av. limnothalassea, Ak. chliaropsychia, and L. pamvotia) belonging to orders Sphaeropleales, Chlorellales, and Chlamydomonadales. For some of them, this is the first report of their occurrence in specific aquatic environments.