algae
Dotaz
Zobrazit nápovědu
Cyanobacteria are prokaryotic organisms characterised by their complex structures and a wide range of pigments. With their ability to fix CO2, cyanobacteria are interesting for white biotechnology as cell factories to produce various high-value metabolites such as polyhydroxyalkanoates, pigments, or proteins. White biotechnology is the industrial production and processing of chemicals, materials, and energy using microorganisms. It is known that exposing cyanobacteria to low levels of stressors can induce the production of secondary metabolites. Understanding of this phenomenon, known as hormesis, can involve the strategic application of controlled stressors to enhance the production of specific metabolites. Consequently, precise measurement of cyanobacterial viability becomes crucial for process control. However, there is no established reliable and quick viability assay protocol for cyanobacteria since the task is challenging due to strong interferences of autofluorescence signals of intercellular pigments and fluorescent viability probes when flow cytometry is used. We performed the screening of selected fluorescent viability probes used frequently in bacteria viability assays. The results of our investigation demonstrated the efficacy and reliability of three widely utilised types of viability probes for the assessment of the viability of Synechocystis strains. The developed technique can be possibly utilised for the evaluation of the importance of polyhydroxyalkanoates for cyanobacterial cultures with respect to selected stressor-repeated freezing and thawing. The results indicated that the presence of polyhydroxyalkanoate granules in cyanobacterial cells could hypothetically contribute to the survival of repeated freezing and thawing.
- MeSH
- fluorescence MeSH
- fluorescenční barviva * metabolismus chemie MeSH
- fyziologický stres * MeSH
- mikrobiální viabilita * MeSH
- polyhydroxyalkanoáty metabolismus MeSH
- průtoková cytometrie * MeSH
- sinice metabolismus fyziologie MeSH
- Synechocystis * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
With the advent rise is in urbanization and industrialization, heavy metals (HMs) such as lead (Pb) and cadmium (Cd) contamination have increased considerably. It is among the most recalcitrant pollutants majorly affecting the biotic and abiotic components of the ecosystem like human well-being, animals, soil health, crop productivity, and diversity of prokaryotes (bacteria) and eukaryotes (plants, fungi, and algae). At higher concentrations, these metals are toxic for their growth and pose a significant environmental threat, necessitating innovative and sustainable remediation strategies. Bacteria exhibit diverse mechanisms to cope with HM exposure, including biosorption, chelation, and efflux mechanism, while fungi contribute through mycorrhizal associations and hyphal networks. Algae, especially microalgae, demonstrate effective biosorption and bioaccumulation capacities. Plants, as phytoremediators, hyperaccumulate metals, providing a nature-based approach for soil reclamation. Integration of these biological agents in combination presents opportunities for enhanced remediation efficiency. This comprehensive review aims to provide insights into joint action of prokaryotic and eukaryotic interactions in the management of HM stress in the environment.
- MeSH
- Bacteria * metabolismus účinky léků MeSH
- biodegradace * MeSH
- Eukaryota metabolismus účinky léků MeSH
- houby metabolismus MeSH
- kadmium * metabolismus toxicita MeSH
- látky znečišťující půdu * metabolismus MeSH
- olovo * metabolismus toxicita MeSH
- rostliny mikrobiologie metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
A novel Gram-stain-negative, strictly aerobic, rod-shaped, light-yellow-pigmented, and chemo-organoheterotrophic bacterium, designated DF-77T, was isolated from dense mats of filamentous algae collected in March 2004 at Okinawa in Japan. The microorganism grew at 0-2.0% NaCl concentrations (w/v), pH 6.0-9.0, and 20-30 °C. The 16S rRNA gene sequence-based phylogenetic tree demonstrated that the strain DF-77T is a novel member of the family Flavobacteriaceae and was greatly related to Flagellimonas nanhaiensis SM1704T with sequence similarity of 95.5%. The main fatty acids were iso-C15:1 G, iso-C15:0, and iso-C17:0 3-OH, and the only isoprenoid quinone was menaquinone-6. The dominant polar lipids were phosphatidylethanolamine, two unidentified aminolipids, an unidentified phosphoaminolipid, and four unidentified lipids. The genome size of strain DF-77T was 3.60 Mbp with a DNA G + C content of 47.5%. The average nucleotide identity (ANI) value between the genomes of strain DF-77T and its closely related species was 69.8-70.7%. The digital DNA - DNA hybridization (dDDH) value of strain DF-77T with the strain of F. nanhaiensis SM1704T was 16.8%. The genome of the strain DF-77T revealed that it encoded several genes involved in bio-macromolecule degradation, indicating a high potential for producing industrially useful enzymes. Consequently, the strain is described as a new species in the genus Flagellimonas, for which the name Flagellimonas algarum sp. nov., is proposed with the type strain DF-77T (= KCTC 72791T = NBRC 114251T).
- MeSH
- DNA bakterií genetika chemie MeSH
- Flavobacteriaceae * klasifikace izolace a purifikace genetika MeSH
- fosfolipidy analýza MeSH
- fylogeneze MeSH
- genom bakteriální MeSH
- hybridizace nukleových kyselin MeSH
- mastné kyseliny analýza MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- techniky typizace bakterií MeSH
- vitamin K 2 analýza analogy a deriváty MeSH
- zastoupení bazí MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Japonsko MeSH
In the presented study, the cells of the glacial alga Ancylonema alaskanum collected in the Austrian Alps were analyzed. Algae were imaged both in their natural environment and in laboratory conditions using transmitted light and fluorescence microscopy. Using appropriate fluorochromes, the cell wall and cell organelles were studied. Oval nuclei located in the middle of the cell next to the chloroplasts and active mitochondria as well as lipid thylakoids of chloroplasts were imaged. Scanning electron microscopy showed that the surface of the algal cell wall was not significantly differentiated, and atomic force microscope imaging recorded little roughness. The SEM EDS analysis revealed that carbon, nitrogen, oxygen, and magnesium were the main components of the cells. It is worth emphasizing that the analyzed living algal cells were obtained directly from the glacier surface and demonstrated normal respiratory processes i.e. undisturbed physiological functions. Additionally, the mineral material accompanying the cells in their natural environment - fragments of the rock were imaged by Differential Interference Contrast microscopy and analyzed by Fourier Transform Infrared Spectroscopy. The study provides new data on the morphology and physicochemical characteristics of A. alaskanum, contributing to a more comprehensive characterization of their place in this harsh ecosystem.
- MeSH
- ledový příkrov * MeSH
- mikroskopie elektronová rastrovací MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rakousko MeSH
Ultraviolet (UV) radiation is a significant environmental stressor that affects the growth, physiology, and biochemical integrity of various organisms. This study investigates the potential protective effects of a zinc-cysteine (Zn-Cys) complex against UV-C radiation, with a focus on its impact on selected microalgae (Coccomyxa peltigerae and Parachlorella kessleri) and maize (Zea mays L.). We demonstrate that exposure of the Zn-Cys complex to UV-C (254 nm) results in the formation of fluorescent photoproducts, which exhibit UV-protective properties. The study reveals that Zn-Cys significantly mitigates UV-induced stress. In both microalgae species, the Zn-Cys complex enhanced growth even under UV exposure, with the 20% concentration showing the most robust protective effects. Further hyperspectral imaging confirmed the protective mechanism of Zn-Cys by monitoring changes in light reflectance in Parachlorella kessleri, indicating reduced photosynthetic efficiency and structural alterations induced by UV exposure, while Zn-Cys significantly mitigated these effects. In addition, in maize plants (Zea mays L.), Zn-Cys treatment preserved chlorophyll content and reduced polyphenol accumulation, indicating reduced oxidative stress. These findings highlight the potential of the Zn-Cys complex as a sustainable and cost-effective strategy for UV protection in both terrestrial and extraterrestrial agriculture, advancing our understanding of plant adaptation to extreme environments.
- MeSH
- Chlorophyta účinky záření účinky léků MeSH
- cystein * chemie farmakologie MeSH
- fotosyntéza účinky léků účinky záření MeSH
- komplexní sloučeniny * chemie farmakologie MeSH
- kukuřice setá účinky záření účinky léků metabolismus MeSH
- mikrořasy účinky záření účinky léků MeSH
- ultrafialové záření * MeSH
- zinek * chemie farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
Food hydrocolloids, derived from natural sources such as plants, algae, and microbes, possess bioactive properties that significantly contribute to cardiovascular health. This review focuses on six key hydrocolloids: alginate, astragalus polysaccharides, carrageenan, fucoidan, lunasin, and psyllium, while also considering other important natural hydrocoloids such as short chain fatty acids (SCFAs), plant-derived food hydrocolloids, plant-derived gums, plant-derived mucilages, pectin, modified citrus pectin, inulin, naringenin, chia seeds, gelatine, whey protein, casein, microbial exopolysaccharides and gums, ulvan, and laminarin. Alginate, from brown seaweed, aids in cardiac tissue regeneration and repair. Astragalus polysaccharides, from the Astragalus plant, provide antioxidant, anti-inflammatory, and immunomodulatory benefits. Carrageenan, sourced from red seaweed, supports lipid profile balance and heart health. Fucoidan, another brown seaweed derivative, offers antihypertensive and lipid-lowering effects. Lunasin, a peptide found in soybeans, oats, and barley, is known for its cholesterol-lowering properties and anti-inflammatory effects. Psyllium, rich in soluble fiber, helps lower LDL cholesterol and improve overall cardiovascular function. These hydrocolloids, along with other mentioned compounds, are utilized in drug formulations, cosmetics, processed foods, and dietary supplements, enhancing food texture and stability while delivering health benefits. Upon consumption, they can be absorbed into the bloodstream or metabolized by gut microbiota into bioactive metabolites. This review examines their effects on cardiovascular function, highlighting their mechanisms in regulating vascular tone, blood pressure, vascular inflammation, and cardiac function. It consolidates current research, emphasizing the potential of these hydrocolloids and related compounds in the prevention and management of cardiovascular diseases (CVDs).
- MeSH
- algináty * chemie farmakologie MeSH
- karagenan * chemie farmakologie MeSH
- kardiovaskulární nemoci * prevence a kontrola MeSH
- kardiovaskulární systém * účinky léků MeSH
- koloidy chemie farmakologie MeSH
- lidé MeSH
- polysacharidy * chemie farmakologie MeSH
- psyllium * chemie farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Údolní nádrž Seč slouží jako retenční prostor při povodních, dále jako zdroj pitné vody a v posledních desetiletích i jako významná rekreační oblast. Z důvodu eutrofizace i zde opakovaně docházelo k výskytu sinicového vodního květu. V červenci roku 2024 došlo ke zcela výjimečné události, kdy po vydatných deštích proniklo do nádrže extrémní množství prvoků ze skupiny obrněnek (Dinophyta). Ty pak vytvořily povlak postupující s proudem vody po nádrži. Jev byl pozorován zhruba měsíc. Doposud nebyly zjištěny sladkovodní obrněnky (na rozdíl od mořských), které by produkovaly toxiny nebezpečné pro lidský organismus, a tak k přímému ohrožení zdraví koupajících se osob nedošlo. Ohrožena nebyla ani výroba pitné vody z nádrže.
The Seč valley reservoir serves as a retention area during floods, as a source of drinking water and in recent decades as an important recreational area. Due to eutrophication, cyanobacterial blooms have repeatedly occurred here. In July 2024, a highly exceptional event occurred when, after heavy rains, an extreme amount of protozoa from the group of giant nematodes (Dinophyta) entered the reservoir. They then formed a coating that progressed with the flow of water through the reservoir. The phenomenon was observed for about a month. So far, freshwater Dinoflagellates (as opposed to marine Dinoflagellates) have not been found to produce toxins dangerous to the human body, so there has been no direct threat to the health of bathers. Nor has the production of drinking water from the reservoir been compromised.
The effect of the antibiotic tetracycline on the growth and photosynthetic activity of the diatoms Cyclotella caspia Grunow, 1878, and Thalassiosira weissflogii (Grunow) G.A. Fryxell & Hasle, 1977, has been studied. The rate of tetracycline concentration decreases in the medium with and without has been estimated. The expediency and prospects of using diatoms as promising objects for water purification from tetracycline are shown. It was found that the rate and efficiency of tetracycline removal from the medium in the presence of algae depends on the initial content of the pollutant in the medium. The maximum efficiency of antibiotic removal is observed at concentrations of the pollutant provoking the hormesis growth of algae at 5 mg/L in C. caspia and 10 mg/L in T. weissflogii. In samples with C. caspia and tetracycline, the residual antibiotic content in the medium was 10-14% lower than in samples without algae. In the experiment with T. weissflogii, this indicator reached 15-16%. At concentrations of the pollutant, 2 and 10 mg/L in C. caspia and 2 and 5 mg/L in T. weissflogii, the effectiveness of removing the antibiotic by algae was lower. The residual content of tetracycline in the medium was on average 8-11% lower than in samples without algae. At antibiotic concentrations of 15 and 20 mg/L, the rate of its removal in samples with and without algae did not significantly differ. This result is obviously due to the toxic effect of tetracycline on cells, leading to pronounced inhibition of algae growth and/or death.
Epiphytic diatoms associated with marine macroalgae play vital ecological roles in nutrient cycling and primary production, yet their study remains limited due to the lack of standardized methodologies. This study focuses on diatom communities growing on Gelidium corneum, a key red alga in the Cantabrian coast (Spain). Samples were collected from two depths along the northern coast of Spain and processed using both morphological and molecular approaches. Morphological analysis involved diatom frustule preparation using hydrogen peroxide digestion, acid treatments, and permanent slide mounting, enabling identification through light microscopy. Molecular analysis employed DNA extraction and rbcL marker-based metabarcoding, allowing detailed taxonomic characterization. Results highlight the efficacy of combining morphological and molecular techniques to overcome the limitations of either approach individually. By standardizing procedures, we enhance the reproducibility and comparability of studies focused on diatom epiphytes. Our results highlight the ecological significance of diatom-macroalgal interactions and provide a framework for future investigations into these essential but underexplored communities.•A polyphasic method was developed for studying epiphytic diatoms on Gelidium corneum, combining morphological and molecular tools.•The approach overcomes challenges in diatom characterization, including intricate host morphology and cryptic species identification.•Standardized protocols enhance reproducibility and offer insights into diatom-macroalgal ecological interactions.
- Publikační typ
- časopisecké články MeSH
Dictyosphaerium chlorelloides is a green microalga from the Chlorella clade that produces highly viscous exocellular polysaccharides. The cell wall polysaccharides of this alga have not been studied in detail. In this article, water-soluble polysaccharides from D. chlorelloides biomass were extracted with hot water and purified by preparative chromatography. The composition, structural features and molecular masses of subsequently eluted fractions F1, F2, F3, F4 and F5 (minor) were determined. Three high-yield products F1, F3 and F4 consisted mainly of galactopyranosyl, 2-O-methyl-galactopyranosyl, rhamnopyranosyl and mannopyranosyl units at different proportions, while F2 was rich in glucose. Immunoactivity of these fractions was evidenced in a mixed population of immune cells derived from mice spleens after incubation with polysaccharides by flow cytometry, MTT and Immunospot assays. These fractions, except F2, demonstrated selective immunostimulant activity, and the F1 fraction induced the most potent effect, closely followed by the F3 and F4 fractions. The in vivo mechanism of their action is associated with the activation of innate immunity and shapes the immune response to the Th1 type.
- MeSH
- adjuvancia imunologická farmakologie chemie izolace a purifikace MeSH
- buněčná stěna * chemie MeSH
- Chlorophyta chemie MeSH
- mikrořasy * chemie MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- polysacharidy * farmakologie chemie izolace a purifikace MeSH
- slezina cytologie účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
