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.
- Klíčová slova
- Dictyosphaerium chlorelloides, Immunomodulating activity, Microalgae biomass, Structure, Water-soluble polysaccharides,
- 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
- Názvy látek
- adjuvancia imunologická MeSH
- polysacharidy * MeSH
Nanoscale zero valent iron (nZVI) is used to remediate aquifers polluted by organochlorines or heavy metals and was also suggested to eliminate harmful algal blooms. nZVI can therefore affect microorganisms in the vicinity of the application area, including microalgae. However, studies on early transcriptomic effects of microalgae after exposure to nZVI are rare. Here, we described the early physiological and transcriptomic response of the freshwater ecological indicator green microalga, Raphidocelis subcapitata ATCC 22662, to 100 mg/L of reactive nZVI and non-reactive nano-magnetite (nFe3O4). The combined effect of shading and the release of total iron from nZVI posed a short-term inhibition effect leading to 15 % of deformed cells and cytosol leakage, while cells viability increased after 24 h. nZVI triggered a more pronounced transcriptomic response with (7380 differentially expressed genes [DEGs]) compared to nFe3O4 (4601 DEGs) after 1 h. nZVI, but not nFe3O4 increased the expression of genes function in DNA repair and replication, while deactivated carbohydrate-energy metabolisms, mitochondria signaling, and transmembrane ion transport. This study highlights an early fate assessment of algal cells under nZVI and nFe3O4 exposure using next-generation risk assessment methods and will serve as valuable information for safe and sustainable application of nZVI in water remediation.
- Klíčová slova
- DNA repair and replication, Iron stress, Microalgae, NZVI, Non-photochemical quenching, RNA-seq,
- MeSH
- chemické látky znečišťující vodu * toxicita MeSH
- Chlorophyceae účinky léků genetika MeSH
- mikrořasy * účinky léků MeSH
- stanovení celkové genové exprese MeSH
- transkriptom * účinky léků MeSH
- železo * toxicita chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chemické látky znečišťující vodu * MeSH
- železo * MeSH
This review summarizes the available information about potential sources of vitamin B12, especially for people who follow a vegan or vegetarian diet and inhabitants of poor countries in the developing world. Cyanobacteria and microalgae approved for food purposes can play a critical role as promising and innovative sources of this vitamin. This work involves a discussion of whether the form of vitamin B12 extracted from microalgae/cyanobacteria is biologically available to humans, specifically focusing on the genera Arthrospira and Chlorella. It describes analyses of their biomass composition, cultivation requirements, and genetic properties in B12 production. Furthermore, this review discusses the function of cobalamin in microalgae and cyanobacteria themselves and the possibility of modification and cocultivation to increase the content of B12 in their biomass.
- Klíčová slova
- Arthrospira, B12, Chlorella, cobalamin, cyanobacteria, green microalgae,
- MeSH
- biomasa MeSH
- Chlorella * MeSH
- lidé MeSH
- mikrořasy * MeSH
- sinice * MeSH
- vitamin B 12 analýza MeSH
- vitaminy MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- vitamin B 12 MeSH
- vitaminy MeSH
Arthrospira (Limnospira) maxima (A. maxima) and Chlorella vulgaris (Ch. vulgaris) are among the approved microalgae and cyanobacteria (MaC) in the food industry that are known to be safe for consumption. However, both organisms are controversial regarding their vitamin B12 content, due to the possible occurrence of pseudo-cobalamin. Concurrently, their nutrition profiles remain understudied. The main purpose of the present study was to identify their nutrition profiles, focusing mainly on vitamin B12, amino acids, and micronutrients under iron-induced hormesis (10 mg/L Fe in treated samples). Our findings indicate a higher B12 content in A. maxima compared to Ch. vulgaris (both control and treated samples). Using liquid chromatography with tandem mass spectrometry (LC-MS/MS), the cyanocobalamin content was determined as 0.42 ± 0.09 μg/g dried weight (DW) in the A. maxima control and 0.55 ± 0.02 μg/g DW in treated A. maxima, resulting in an insignificant difference. In addition, the iron-enriched medium increased the amount of iron in both tested biomasses (p < 0.01). However, a more pronounced (approximately 100×) boost was observed in Ch. vulgaris, indicating a better absorption capacity (control Ch. vulgaris 0.16 ± 0.01 mg/g Fe, treated Ch. vulgaris 15.40 ± 0.34 mg/g Fe). Additionally, Ch. vulgaris also showed a higher micronutrient content. Using both tested microalgae, meeting the sufficient recommended daily mineral allowance for an adult is possible. By combining biomass from A. maxima and Ch. vulgaris in a ratio of 6:1, we can fulfill the recommended daily allowance of vitamin B12 and iron by consuming 6 tablets/6 g. Importantly, iron hormesis stimulated amino acid composition in both organisms. The profile of amino acids may suggest these biomasses as promising potential nutrition sources.
- Klíčová slova
- Amino acids, Anemia, Cobalamin, Cyanobacteria, Deficiency, Iron, Microalgae,
- MeSH
- aminokyseliny * metabolismus analýza MeSH
- Chlorella vulgaris * chemie metabolismus růst a vývoj MeSH
- mikrořasy chemie metabolismus růst a vývoj MeSH
- mikroživiny * analýza metabolismus MeSH
- nutriční hodnota MeSH
- Spirulina * chemie metabolismus MeSH
- tandemová hmotnostní spektrometrie MeSH
- vitamin B 12 * metabolismus analýza MeSH
- železo metabolismus analýza MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- aminokyseliny * MeSH
- mikroživiny * MeSH
- vitamin B 12 * MeSH
- železo MeSH
The catastrophic loss of aquatic life in the Central European Oder River in 2022, caused by a toxic bloom of the haptophyte microalga Prymnesium parvum (in a wide sense, s.l.), underscores the need to improve our understanding of the genomic basis of the toxin. Previous morphological, phylogenetic, and genomic studies have revealed cryptic diversity within P. parvum s.l. and uncovered three clade-specific (types A, B, and C) prymnesin toxins. Here, we used state-of-the-art long-read sequencing and assembled the first haplotype-resolved diploid genome of a P. parvum type B from the strain responsible for the Oder disaster. Comparative analyses with type A genomes uncovered a genome-size expansion driven by repetitive elements in type B. We also found conserved synteny but divergent evolution in several polyketide synthase (PKS) genes, which are known to underlie toxin production in combination with environmental cues. We identified an approximately 20-kbp deletion in the largest PKS gene of type B that we link to differences in the chemical structure of types A and B prymnesins. Flow cytometry and electron microscopy analyses confirmed diploidy in the Oder River strain and revealed differences to closely related strains in both ploidy and morphology. Our results provide unprecedented resolution of strain diversity in P. parvum s.l. and a better understanding of the genomic basis of toxin variability in haptophytes. The reference-quality genome will enable us to better understand changes in microbial diversity in the face of increasing environmental pressures and provides a basis for strain-level monitoring of invasive Prymnesium in the future.
- Klíčová slova
- genomics, golden alga, haptophyte, harmful algal bloom, ploidy, polyketide synthase, prymnesin,
- MeSH
- fylogeneze MeSH
- haplotypy MeSH
- Haptophyta * genetika MeSH
- mikrořasy genetika MeSH
- mořské toxiny genetika MeSH
- polyketidsynthasy genetika metabolismus MeSH
- ryby genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- mořské toxiny MeSH
- polyketidsynthasy MeSH
Nitrogen is one of the most important nutrient sources for the growth of microalgae. We studied the effects of nitrogen starvation on the growth responses, biochemical composition, and fatty acid profile of Dunaliella tertiolecta, Phaeodactylum tricornutum, and Nannochloropsis oculata. The lack of nitrogen caused changes in carbohydrate, protein, lipid, and fatty acid composition in all examined microalgae. The carbohydrate content increased 59% in D. tertiolecta, while the lipid level increased 139% in P. tricornutum under nitrogen stress conditions compared to the control groups. Nitrogen starvation increased the oligosaccharide and polysaccharide contents of D. tertiolecta 4.1-fold and 3.6-fold, respectively. Furthermore, triacylglycerol (TAG) levels in N. oculata and P. tricornutum increased 2.3-fold and 7.4-fold, respectively. The dramatic increase in the amount of TAG is important for the use of these microalgae as raw materials in biodiesel. Nitrogen starvation increased the amounts of oligosaccharides and polysaccharides of D. tertiolecta, while increased eicosapentaenoic acid (EPA) in N. oculata and docosahexaenoic acid (DHA) content in P. tricornutum. The amount of polyunsaturated fatty acids (PUFAs), EPA, DHA, oligosaccharides, and polysaccharides in microalgal species can be increased without using the too costly nitrogen source in the culture conditions, which can reduce the most costly of living feeding.
- Klíčová slova
- Biochemical composition, Fatty acid profile, Microalgae, Nitrogen starvation,
- MeSH
- dusík * metabolismus MeSH
- mastné kyseliny * metabolismus analýza MeSH
- mikrořasy * metabolismus růst a vývoj MeSH
- triglyceridy metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- dusík * MeSH
- mastné kyseliny * MeSH
- triglyceridy MeSH
A digestibility enhancing effect of natural food on stomachless fish model (Cyprinus carpio) was verified by fluorogenic substrate assays of enzymatic activities in experimental pond carp gut flush and planktonic food over a full vegetative season. Then compared with size-matched conspecific grown artificially (tank carp) and an advanced omnivore species possessing true stomach (tilapia, Oreochromis niloticus). Results suggested activities of digestive enzymes (except amylolytic) were significantly higher in pond carp (p ≤ 0.05) than in the size-matched tank carp. Even compared to tilapia, pond carp appeared superior (p < 0.05; proteolytic or chitinolytic activities) or comparable (p > 0.05; phosphatase or cellulolytic activities). Amylolytic, chitinolytic, and phosphatases activities in pond carp gut significantly increased (p ≤ 0.01) over season. Several orders-of-magnitude higher enzymatic activities were detected in planktonic natural food than expressed in carp gut. Amino acid markers in planktonic food revealed a higher share of zooplankton (microcrustaceans), but not phytoplankton, synchronized with higher activities of complex polysaccharide-splitting enzymes (cellulolytic and chitinolytic) in fish gut. Periods of clear water phase low in chlorophyll-a and nutrients, but high in certain zooplankton (preferably cladocerans), may create a synergistic digestibility effect in pond carp. We conclude aquatic ecosystem components (natural food, water, microbiota) enhance fishes' hydrolyzing capabilities of C/N/P macromolecules and even their complex polymers such as cellulose, chitin, and maybe phytate (to be validated), to the extent that being stomachless is not an issue. Aquatic nutritional ecologists may consider that laboratory-based understandings of digestibility may underestimate digestion efficiency of free-ranging fish in ponds or lakes.
- Klíčová slova
- Bioremediation, Complex polymers, Digestibility enhancement, Enzymes, Nutrients,
- MeSH
- ekosystém * MeSH
- fytoplankton fyziologie MeSH
- kapři * fyziologie metabolismus MeSH
- plankton fyziologie MeSH
- trávení fyziologie MeSH
- zooplankton fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Rare Earth Elements (REEs) are indispensable in contemporary technologies, influencing various aspects of our daily lives and environmental solutions. The escalating demand for REEs has led to increased exploitation, resulting in the generation of diverse REE-bearing solid and liquid wastes. Recognizing the potential of these wastes as secondary sources of REEs, researchers are exploring microbial solutions for their recovery. This mini review provides insights into the utilization of microorganisms, with a particular focus on microalgae, for recovering REEs from sources such as ores, electronic waste, and industrial effluents. The review outlines the principles and distinctions of bioleaching, biosorption, and bioaccumulation, offering a comparative analysis of their potential and limitations. Specific examples of microorganisms demonstrating efficacy in REE recovery are highlighted, accompanied by successful methods, including advanced techniques for enhancing microbial strains to achieve higher REE recovery. Moreover, the review explores the environmental implications of bio-recovery, discussing the potential of these methods to mitigate REE pollution. By emphasizing microalgae as promising biotechnological candidates for REE recovery, this mini review not only presents current advances but also illuminates prospects in sustainable REE resource management and environmental remediation.
- Klíčová slova
- Algae, Bioaccumulation, Bioleaching, Microorganisms, Rare earth elements, Recovery,
- MeSH
- Bacteria metabolismus klasifikace MeSH
- bioakumulace MeSH
- biodegradace * MeSH
- biotechnologie metody MeSH
- kovy vzácných zemin * metabolismus MeSH
- mikrořasy * metabolismus MeSH
- průmyslový odpad analýza MeSH
- regenerace a remediace životního prostředí metody MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- kovy vzácných zemin * MeSH
- průmyslový odpad MeSH
In this work, microalgae cultivation trials were carried out in a membrane bioreactor to investigate fouling when the cultures of Chlorellavulgaris were grown under mixotrophic, heterotrophic, and phototrophic cultivation regimes. The Chlorella cultures were cultivated in wastewater as a source of nutrients that contained a high concentration of ammonium. In mixotrophic cultivation trials, the results showed that the elevated contents of carbohydrates in the soluble microbial product and proteins in extracellular polymeric substances probably initiated membrane fouling. In this case, the highest protein content was also found in extracellular polymeric substances due to the high nitrogen removal rate. Consequently, transmembrane pressure significantly increased compared to the phototrophic and heterotrophic regimes. The data indicated that cake resistance was the main cause of fouling in all cultivations. Higher protein content in the cake layer made the membrane surface more hydrophobic, while carbohydrates had the opposite effect. Compared to a mixotrophic culture, a phototrophic culture had a larger cell size and higher hydrophobicity, leading to less membrane fouling. Based on our previous data, the highest ammonia removal rate was reached in the mixotrophic cultures; nevertheless, membrane fouling appeared to be the fundamental problem.
- Klíčová slova
- cultivation, fouling, membrane bioreactor, microalgae, mixotrophy,
- MeSH
- amoniové sloučeniny * metabolismus MeSH
- bioreaktory * MeSH
- bioznečištění MeSH
- Chlorella růst a vývoj metabolismus MeSH
- fototrofní procesy MeSH
- heterotrofní procesy MeSH
- membrány umělé * MeSH
- mikrořasy * metabolismus růst a vývoj MeSH
- odpad tekutý - odstraňování metody MeSH
- odpadní voda * chemie MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- amoniové sloučeniny * MeSH
- membrány umělé * MeSH
- odpadní voda * MeSH
Drying is an inseparable part of industrial microalgae production. In this work, the impacts of eight different drying methods on the metabolome and lipidome of Arthrospira platensis were investigated. The studied drying methods were freeze drying (FD), sun drying (SD), air drying at 40 and 75 °C (AD' and AD″), infrared drying at 40 and 75 °C (IRD' and IRD″), and vacuum drying at 40 and 75 °C (VD' and VD″). Results gathered by reversed-phase liquid chromatography separation coupled with high-resolution tandem mass spectrometry with electrospray ionization (RP-LC-ESI-Orbitrap HRMS/MS) analysis allowed researchers to identify a total of 316 metabolites (including lipids) in aqueous and ethanolic extracts. The compounds identified in ethanolic extracts were mainly lipids, such as neutral and polar lipids, chlorophylls and carotenoids, while the compounds identified in the aqueous extracts were mainly amino acids and dipeptides. Among the identified compounds, products of enzymatic and chemical degradation, such as pyropheophytins, monoacylglycerols and lysophosphatidylcholines were also identified and their amounts depended on the drying method. The results showed that except for FD method, recognized as a control, the most protective method was AD'. Contrary to this, VD' and VD″, under the conditions used, promoted the most intense degradation of valuable metabolites.
- Klíčová slova
- Arthrospira platensis, HPLC-HRMS/MS, drying, lipidomics, metabolomics, microalgae,
- MeSH
- lipidomika * metody MeSH
- lipidy analýza MeSH
- lyofilizace MeSH
- metabolom MeSH
- metabolomika * metody MeSH
- mikrořasy metabolismus chemie MeSH
- Spirulina * metabolismus chemie MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- vysoušení * MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- lipidy MeSH
