Heterocyte glycolipids indicate polyphyly of stigonematalean cyanobacteria.

The cyanobacterial phylum is currently divided into five subsections (I-V), with the latter two containing no or false-branching (nostocalean) and true-branching (stigonematalean) cyanobacteria. Although morphological traits (such as cellular division and secondary branches) clearly separate both types of heterocytous cyanobacteria, molecular evidence indicates that stigonematalean cyanobacteria (Subsection V) do not form a monophyletic group but instead are interspersed and nested within the nostocalean cyanobacteria (Subsection IV). To further resolve the phylogeny of heterocytous cyanobacteria, we here analyzed the distribution of heterocyte glycolipids (HGs) in the true-branching cyanobacterium Stigonema ocellatum SAG 48.

Survey of the occurrence of desiccation-induced quenching of basal fluorescence in 28 species of green microalgae.

Desiccation-induced chlorophyll fluorescence quenching seems to be an indispensable part of desiccation resistance in the surveyed 28 green microalgal species. Lichens are desiccation tolerant meta-organisms. In the desiccated state photosynthesis is inhibited rendering the photobionts potentially sensitive to photoinhibition.

Biodiversity of green algae covering artificial hard substrate surfaces in a suburban environment: a case study using molecular approaches.

In Middle European suburban environments green algae often cover open surfaces of artificial hard substrates. Microscopy reveals the Apatococcus/Desmococcus morphotype predominant over smaller coccoid forms. Adverse conditions such as limited water availability connected with high PAR and UV irradiance may narrow the algal diversity to a few specialists in these subaerial habitats.

Biotechnological screening of microalgal and cyanobacterial strains for biogas production and antibacterial and antifungal effects.

Microalgae and cyanobacteria represent a valuable natural resource for the generation of a large variety of chemical substances that are of interest for medical research, can be used as additives in cosmetics and food production, or as an energy source in biogas plants. The variety of potential agents and the use of microalgae and cyanobacteria biomass for the production of these substances are little investigated and not exploited for the market. Due to the enormous biodiversity of microalgae and cyanobacteria, they hold great promise for novel products.

Distribution of long chain heterocyst glycolipids in N2-fixing cyanobacteria of the order Stigonematales.

N2-fixing heterocystous cyanobacteria have been shown to hold a suite of unique glycolipids, so-called heterocyst glycolipids (HGs), as part of the heterocyst cell envelope. It was also demonstrated that the distribution of these components bears a high level of chemotaxonomic information, which allows distinguishing heterocystous cyanobacteria of the order Nostocales on a family or even genus level. Here we report the heterocyst glycolipid composition of five representatives of the order Stigonematales (Fischerella muscicola, Fischerella sp.

Desiccation-induced non-radiative dissipation in isolated green lichen algae.

Lichens are able to tolerate almost complete desiccation and can quickly resume metabolic activity after rehydration. In the desiccated state, photosynthesis is completely blocked and absorbed excitation energy cannot be used for electron transport, leading to a potential strong vulnerability for high light damage. Although desiccation and high insolation often occur simultaneously and many lichens colonize exposed habitats, these organisms show surprisingly little photodamage.

NEW STREPTOPHYTE GREEN ALGAE FROM TERRESTRIAL HABITATS AND AN ASSESSMENT OF THE GENUS INTERFILUM (KLEBSORMIDIOPHYCEAE, STREPTOPHYTA)(1).

Sarcinoid aeroterrestrial green algae were isolated from three arid locations in Ukraine and the Czech Republic. Although gross morphology suggested an affinity with Desmococcus (for taxonomic authorities, see Table S1 in the supplementary material), the cellular morphological characteristics were reminiscent of those of Geminella terricola. However, the presence of a complex of ultrastructural features indicated that these isolates were members of the streptophyte lineage in the green plants.

ASSESSING PHYLOGENETIC AFFINITIES AND SPECIES DELIMITATIONS IN KLEBSORMIDIALES (STREPTOPHYTA): NUCLEAR-ENCODED rDNA PHYLOGENIES AND ITS SECONDARY STRUCTURE MODELS IN KLEBSORMIDIUM, HORMIDIELLA, AND ENTRANSIA(1).

Nuclear-encoded SSU, group I intron, and internal transcribed spacer (ITS) rDNA sequences were obtained for 16 strains of green algae representing species of Klebsormidium, Hormidiella attenuata, and Entransia fimbriata (for taxonomic authorities, see Table S1 in the supplementary material). The SSU phylogeny resolved a well-supported clade Klebsormidiales in the Streptophyta that comprised authentic Klebsormidium isolates described recently in a monograph by G. M.