Ravinnekuormituksen vaikutus rantavyöhykkeen leväyhteisöihin ja vaikutusten arvioinnissa käytetyt menetelmät

Tässä kirjallisuustutkimuksessa käsitellään rantavyöhykkeen eliöyhteisöjä ja niiden tutkimusmenetelmiä sekä näiden soveltuvuutta vesialueen tilan arvioimiseen. Koska sisävesistä ei tällaisia tutkimuksia juuri ole tehty, julkaisu käsittelee käytännössä pelkästään Itämeren rannikoita, ja siihen on pyritty kokoamaan kaikki löydetty alan kirjallisuus. Työ sisältää myös yhteenvedon makroskooppisten levien ravinnevaatimuksista ja ravinnekuormituksen vaikutuksista rantayhteisöihin. Julkaisu on tarkoitettu kaikille, jotka tarvitsevat tietoja pohjoisen Itämeren rantavyöhykkeen rakenteesta ja toiminnasta

The Potential of Cryptophyte Algae in Biomedical and Pharmaceutical Applications

Microalgae produce a variety of bioactive components that provide benefits to human and animal health. Cryptophytes are one of the major groups of microalgae, with more than 20 genera comprised of 200 species. Recently, cryptophytes have attracted scientific attention because of their characteristics and biotechnological potential. For example, they are rich in a number of chemical compounds, such as fatty acids, carotenoids, phycobiliproteins and polysaccharides, which are mainly used for food, medicine, cosmetics and pharmaceuticals. This paper provides a review of studies that assess protective algal compounds and introduce cryptophytes as a remarkable source of bioactive components that may be usable in biomedical and pharmaceutical sciences.Peer reviewe

Taxonomically and Functionally Distinct Ciliophora Assemblages Inhabiting Baltic Sea Ice

Ciliophora is a phylum of unicellular eukaryotes that are common and have pivotal roles in aquatic environments. Sea ice is a marine habitat, which is composed of a matrix of solid ice and pockets of saline water in which Ciliophora thrive. Here, we used phylogenetic placement to identify Ciliophora 18S ribosomal RNA reads obtained from wintertime water and sea ice, and assigned functions to the reads based on this taxonomic information. Based on our results, sea-ice Ciliophora assemblages are poorer in taxonomic and functional richness than under-ice water and water-column assemblages. Ciliophora diversity stayed stable throughout the ice-covered season both in sea ice and in water, although the assemblages changed during the course of our sampling. Under-ice water and the water column were distinctly predominated by planktonic orders Choreotrichida and Oligotrichida, which led to significantly lower taxonomic and functional evenness in water than in sea ice. In addition to planktonic Ciliophora, assemblages in sea ice included a set of moderately abundant surface-oriented species. Omnivory (feeding on bacteria and unicellular eukaryotes) was the most common feeding type but was not as predominant in sea ice as in water. Sea ice included cytotrophic (feeding on unicellular eukaryotes), bacterivorous and parasitic Ciliophora in addition to the predominant omnivorous Ciliophora. Potentially mixotrophic Ciliophora predominated the water column and heterotrophic Ciliophora sea ice. Our results highlight sea ice as an environment that creates a set of variable habitats, which may be threatened by the diminishing extent of sea ice due to changing climate.Peer reviewe

Promising Biomolecules with High Antioxidant Capacity Derived from Cryptophyte Algae Grown under Different Light Conditions

The accumulation and production of biochemical compounds in microalgae are influenced by available light quality and algal species-specific features. In this study, four freshwater cryptophyte strains (Cryptomonas ozolinii, C. pyrenoidifera, C. curvata, and C. sp. (CPCC 336)) and one marine strain (Rhodomonas salina) were cultivated under white (control), blue, and green (experimental conditions) lights. Species-specific responses to light quality were detected, i.e., the color of light significantly affected cryptophyte biomass productivity and biochemical compositions, but the optimal light for the highest chemical composition with high antioxidant capacity was different for each algal strain. Overall, the highest phycoerythrin (PE) content (345 mg g−1 dry weight; DW) was reached by C. pyrenoidifera under green light. The highest phenolic (PC) contents (74, 69, and 66 mg g−1 DW) were detected in C. curvata under control conditions, in C. pyrenoidifera under green light, and in C. ozolinii under blue light, respectively. The highest exopolysaccharide (EPS) content (452 mg g−1 DW) was found in C. curvata under the control light. In terms of antioxidant activity, the biochemical compounds from the studied cryptophytes were highly active, with IC50 -values < 50 µg mL−1. Thus, in comparison to well-known commercial microalgal species, cryptophytes could be considered a possible candidate for producing beneficial biochemical compounds

Promising Biomolecules with High Antioxidant Capacity Derived from Cryptophyte Algae Grown under Different Light Conditions

The accumulation and production of biochemical compounds in microalgae are influenced by available light quality and algal species-specific features. In this study, four freshwater cryptophyte strains (Cryptomonas ozolinii, C. pyrenoidifera, C. curvata, and C. sp. (CPCC 336)) and one marine strain (Rhodomonas salina) were cultivated under white (control), blue, and green (experimental conditions) lights. Species-specific responses to light quality were detected, i.e., the color of light significantly affected cryptophyte biomass productivity and biochemical compositions, but the optimal light for the highest chemical composition with high antioxidant capacity was different for each algal strain. Overall, the highest phycoerythrin (PE) content (345 mg g−1 dry weight; DW) was reached by C. pyrenoidifera under green light. The highest phenolic (PC) contents (74, 69, and 66 mg g−1 DW) were detected in C. curvata under control conditions, in C. pyrenoidifera under green light, and in C. ozolinii under blue light, respectively. The highest exopolysaccharide (EPS) content (452 mg g−1 DW) was found in C. curvata under the control light. In terms of antioxidant activity, the biochemical compounds from the studied cryptophytes were highly active, with IC50 -values < 50 µg mL−1. Thus, in comparison to well-known commercial microalgal species, cryptophytes could be considered a possible candidate for producing beneficial biochemical compounds

Mamiellophyceae shift in seasonal predominance in the Baltic Sea

The green algae Mamiellophyceae are a group of marine picoeukaryotes. We studied the succession of Mamiellophyceae in the Baltic Sea water column and ice from autumn to summer, using the hypervariable V4 region of the 18S ribosomal RNA (18S rRNA) gene. We show that species of Mamiellophyceae shift in seasonal predominance and that different species characterize sea ice, under-ice water, and the water column in the Baltic Sea.peerReviewe

Phases of microalgal succession in sea ice and the water column in the Baltic Sea from autumn to spring

The phytoplankton biomass in the Baltic Sea is low during the cold-water season (October to May) compared to the warm-water season(June to September). However, the sea ice is a habitat for diverse assemblages in polar and subpolar areas. These areas, including the Baltic Sea, are subject to changing environmental conditions due to global warming, and temporal and spatial studies are required to understand changes in the processes the organisms are involved in. We delineated microalgal succession in the northern Baltic Sea during the cold-water season using a weekly collected data set. Microscopy results together with molecular methods showed that 5 microbial groups could be distinguished: the sea-ice microalgal assemblage and 4 phytoplankton assemblages(fall, winter, under-ice water and spring). Based on cell enumeration, the microalgal biomass in the water column remained low until the end of the ice-covered season and was dominated by small flagellates and dinoflagellates. The young-ice assemblage in January resembled the water-column assemblage, but indicated a partly selective species-concentrating mechanism during ice formation due to lower species richness in ice than in the water column. Biomass of microalgae increased in the ice and water column during the March to May period, and the assemblage changed from flagellate-dominated to diatom-and dinoflagellate-dominated. The result that the spring phytoplankton, based on species and biomass, formed a separate as semblage indicates that sea-ice algae did not contribute to the spring bloom phytoplankton assemblage.Peer reviewe

Bioinformatic Amplicon Read Processing Strategies Strongly Affect Eukaryotic Diversity and the Taxonomic Composition of Communities

Peer reviewe