Bioconcentration of Inorganic and Methyl Mercury by Algae Revealed Using Dual-Mass Single-Cell ICP-MS with Double Isotope Tracers

Algae are an entry point for mercury (Hg) into the food web. Bioconcentration of Hg by algae is crucial for its biogeochemical cycling and environmental risk. Herein, considering the cell heterogeneity, we investigated the bioconcentration of coexisting isotope-labeled inorganic (199IHg) and methyl Hg (201MeHg) by six typical freshwater and marine algae using dual-mass single-cell inductively coupled plasma mass spectrometry (scICP-MS). First, a universal pretreatment procedure for the scICP-MS analysis of algae was developed. Using the proposed method, the intra- and interspecies heterogeneities and the kinetics of Hg bioconcentration by algae were revealed at the single-cell level. The heterogeneity in the cellular Hg contents is largely related to cell size. The bioconcentration process reached a dynamic equilibrium involving influx/adsorption and efflux/desorption within hours. Algal density is a key factor affecting the distribution of Hg between algae and ambient water. Cellular Hg contents were negatively correlated with algal density, whereas the volume concentration factors almost remained constant. Accordingly, we developed a model based on single-cell analysis that well describes the density-driven effects of Hg bioconcentration by algae. From a novel single-cell perspective, the findings improve our understanding of algal bioconcentration governed by various biological and environmental factors.

Edible-algae base composite film containing gelatin for food packaging from macroalgae, Gracilaroid (Gracilaria fisheri)

BACKGROUND

Conventional petroleum-based packaging films cause severe environmental problems. In this work bio-edible film as a safe to replace petroleum-based polymers was introduced. A food application for edible sachets and a composite edible film (EF) from marine algae, Gracilaria fisheri (GF) extract were proposed.

RESULTS

Carbohydrates were the most prevalent component in fresh GF fronds. Under neutral conditions at 90 °C for 40 min, the extract's structure was determined by FTIR to be a carrageenan-like polysaccharide. Glycerol was the best plasticizer for EF formation since it had the highest tensile strength (TS). The integration of gelatin into the algal composite film with gelatin (CFG) was validated by significant. The best casting temperatures for 2 h were 70 and 100 °C among the four tested temperatures (25, 60, 70, and 100 °C). Temperatures did not result in significant (p ≤ 0.05) differences in any character (color values, TS, water vapor permeability, oxygen transmission, thickness, and water activity), except elongation at break. Visually, the CFG had a slightly yellow appearance. The best-to-worst order of film stability in the three tested solvents was oil, distilled water (DW), and ethanol. Its stability in ethanol (0-100%), temperature of DW (30-100 °C), and pH (3-7 in DW) demonstrated inverse variations with the concentration or different conditions, except for pH 8-10 in DW. All treatments were significantly (p ≤ 0.05) different.

CONCLUSION

The novel material made from polysaccharides from algae, G. fisheri, was used to improve EF. The edible sachet application was plausible from the EF. This article is protected by copyright. All rights reserved.

Multiparameter Sensing of Oxygen and pH at Biological Interfaces via Hyperspectral Imaging of Luminescent Sensor Nanoparticles

Chemical dynamics in biological samples are seldom stand-alone processes but represent the outcome of complicated cascades of interlinked reaction chains. In order to understand these processes and how they correlate, it is important to monitor several parameters simultaneously at high spatial and temporal resolution. Hyperspectral imaging is a promising tool for this, as it provides broad-range spectral information in each pixel, enabling the use of multiple luminescent indicator dyes, while simultaneously providing information on sample structures and optical properties. In this study, we first characterized pH- and O2-sensitive indicator dyes incorporated in different polymer matrices as optical sensor nanoparticles to provide a library for (hyperspectral) chemical imaging. We then demonstrate the successful combination of a pH-sensitive indicator dye (HPTS(DHA)3), an O2-sensitive indicator dye (PtTPTBPF), and two reference dyes (perylene and TFPP), incorporated in polymer nanoparticles for multiparameter chemical imaging of complex natural samples such as green algal biofilms (Chlorella sorokiniana) and seagrass leaves (Zostera marina) with high background fluorescence. We discuss the system-specific challenges and limitations of our approach and further optimization possibilities. Our study illustrates how multiparameter chemical imaging with hyperspectral read-out can now be applied on natural samples, enabling the alignment of several chemical parameters to sample structures.

Algae as an alternative source of protein in poultry diets for sustainable production and disease resistance: present status and future considerations

Integrating algae into poultry diets offers a promising avenue for enhancing nutrition, boosting sustainability efforts, and potentially stimulating disease resistance. This comprehensive review delves into the essence, diversity, chemical composition, and nutritional merits of algae, spotlighting their emergence as innovative nutrient sources and health supplements for poultry. The growing interest in algae within poultry nutrition stems from their diverse nutritional profile, boasting a rich array of proteins, lipids, amino acids, vitamins, minerals, and antioxidants, thus positioning them as valuable feed constituents. A key highlight of incorporating both macroalgae and microalgae lies in their elevated protein content, with microalgae varieties like Spirulina and Chlorella exhibiting protein levels of up to 50-70%, outperforming traditional sources like soybean meal. This premium protein source not only furnishes vital amino acids crucial for muscular development and overall health in poultry but also serves as an exceptional reservoir of omega-3 fatty acids, notably eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), presenting multiple health benefits for both poultry and consumers alike. Moreover, algae boast antioxidant properties attributed to bioactive compounds like phycocyanin and astaxanthin, mitigating oxidative stress and boosting the bird's immune response, thereby fostering robust health and disease resilience. Incorporating macroalgae and microalgae into poultry diets yields positive impacts on performance metrics. Research evidence underscores the enhancement of growth rates, feed conversion ratios, carcass quality, and meat attributes in broilers, while in layers, supplementation promotes increased egg production, superior egg quality, and increased concentrations of beneficial nutrients such as omega-3 fatty acids. Furthermore, algae hold promise for mitigating the environmental footprint of poultry production, though significant outcomes from trials remain sporadic, necessitating further research to elucidate optimal dosages and blends for different algae species in poultry diets. Standardizing the composition of algae utilized in research is imperative, paving the way for potential applications in poultry nutrition as growth stimulants and substitutes for antibiotics. Nonetheless, a deeper understanding of dosage, combination, and mechanism of action through rigorous scientific investigation is key to unlocking algae's full potential within poultry nutrition.

Validation of the names Cavernulicolales, Cavernulicolaceae, Cavernulicola, and Cavernulicola chilensis (Rhodophyta)

A reclassification of Cyanidium chilense under the new genus Cavernulicola was recently proposed together with a new family (Cavernulicolaceae) and a new order (Cavernulicolales). Unfortunately, due to an error in the required citation of the basionym, the name "Cavernulicola chilensis" was invalid and cannot be accepted as the generitype of Cavernulicola. This means that Cavernulicola, Cavernulicolaceae, and Cavernulicolales are likewise invalid names under the provisions of the International Code of Nomenclature for algae, fungi, and plants (ICN, Shenzhen Code). In this contribution, each of these names is validated.

Structure, biogenesis and evolution of thylakoid membranes

Cyanobacteria and chloroplasts of algae and plants harbor specialized thylakoid membranes that convert sunlight into chemical energy. These membranes house photosystems II and I, the vital protein-pigment complexes that drive oxygenic photosynthesis. In the course of their evolution, thylakoid membranes have diversified in structure. However, the core machinery for photosynthetic electron transport remained largely unchanged, with adaptations occurring primarily in the light-harvesting antenna systems. Whereas thylakoid membranes in cyanobacteria are relatively simple they become more complex in algae and plants. The chloroplasts of vascular plants contain intricate networks of stacked grana and unstacked stroma thylakoids. This review provides an in-depth view of thylakoid membrane architectures in phototrophs, and the determinants that shape their forms, as well as presenting recent insights into the spatial organization of their biogenesis and maintenance. Its overall goal is to define the underlying principles that have guided the evolution of these bioenergetic membranes.

Exploring the prokaryote-eukaryote interplay in microbial mats from an Andean athalassohaline wetland

Microbial community assembly results from the interaction between biotic and abiotic factors. However, environmental selection is thought to predominantly shape communities in extreme ecosystems. Salar de Huasco, situated in the high-altitude Andean Altiplano, represents a poly-extreme ecosystem displaying spatial gradients of physicochemical conditions. To disentangle the influence of abiotic and biotic factors, we studied prokaryotic and eukaryotic communities from microbial mats and underlying sediments across contrasting areas of this athalassohaline ecosystem. The prokaryotic communities were primarily composed of bacteria, notably including a significant proportion of photosynthetic organisms like Cyanobacteria and anoxygenic photosynthetic members of Alpha- and Gammaproteobacteria and Chloroflexi. Additionally, Bacteroidetes, Verrucomicrobia, and Deltaproteobacteria were abundantly represented. Among eukaryotes, photosynthetic organisms (Ochrophyta and Archaeplastida) were predominant, alongside relatively abundant ciliates, cercozoans, and flagellated fungi. Salinity emerged as a key driver for the assembly of prokaryotic communities. Collectively, abiotic factors influenced both prokaryotic and eukaryotic communities, particularly those of algae. However, prokaryotic communities strongly correlated with photosynthetic eukaryotes, suggesting a pivotal role of biotic interactions in shaping these communities. Co-occurrence networks suggested potential interactions between different organisms, such as diatoms with specific photosynthetic and heterotrophic bacteria or with protist predators, indicating influences beyond environmental selection. While some associations may be explained by environmental preferences, the robust biotic correlations, alongside insights from other ecosystems and experimental studies, suggest that symbiotic and trophic interactions significantly shape microbial mat and sediment microbial communities in this athalassohaline ecosystem.IMPORTANCEHow biotic and abiotic factors influence microbial community assembly is still poorly defined. Here, we explore their influence on prokaryotic and eukaryotic community assembly within microbial mats and sediments of an Andean high-altitude polyextreme wetland system. We show that, in addition to abiotic elements, mutual interactions exist between prokaryotic and eukaryotic communities. Notably, photosynthetic eukaryotes exhibit a strong correlation with prokaryotic communities, specifically diatoms with certain bacteria and other protists. Our findings underscore the significance of biotic interactions in community assembly and emphasize the necessity of considering the complete microbial community.

Toxicity and bioremediation of the lead: a critical review

Lead is a naturally occurring, bluish-gray metal that is found in small quantities in the earth's crust. The existing literature demonstrates that non-biodegradable character and continuous use results in accumulation of lead concentration in the environment and causes various ill effects such as neurotoxicity, change in psychological and behavioral development of different organisms. Nowadays the most effective technique in the revival of the environment is bioremediation and it is environmentally friendly and cost-effective. Bacterial strains such as Oceanobacillus profundus and Lactobacillus acidophilus ATCC4356 have the ability to reduce lead 97% and 73.9%, respectively. Similarly some species of algae and fungal strains also showed lead removal efficiency as 74% (spirulina), 97.1% (Chlorella kessleri), 95.5% (Penicillium janthinillum) and 86% (Aspergillus flavus). Biodegradation of lead by various microbes would be the most efficient and sustainable approach. This review focuses on toxicity, fate of lead in the environment and its microbial degradation.

Distinct regulation of two flagella by calcium during chemotaxis of male gametes in the brown alga Mutimo cylindricus (Cutleriaceae, Tilopteridales)

Brown algal male gametes show chemotaxis to the sex pheromone that is released from female gametes. The chemotactic behavior of the male gametes is controlled by the changes in the beating of two flagella known as the anterior and posterior flagellum. Our previous study using Mutimo cylindricus showed that the sex pheromone induced an increment in both the deflection angle of the anterior flagellum and sustained unilateral bend of the posterior flagellum, but the mechanisms regulating these two flagellar waveforms were not fully revealed. In this study, we analyzed the changes in swimming path and flagellar waveforms with a high-speed recording system under different calcium conditions. The extracellular Ca2+ concentration at 10-3 M caused an increment in the deflection angle of the anterior flagellum only when ionomycin was absent. No sustained unilateral bend of the posterior flagellum was induced either in the absence or presence of ionomycin in extracellular Ca2+ concentrations below 10-2 M. Real-time Ca2+ imaging revealed that there is a spot near the basal part of anterior flagellum showing higher Ca2+ than in the other parts of the cell. The intensity of the spot slightly decreased when male gametes were treated with the sex pheromone. These results suggest that Ca2+-dependent changes in the anterior and posterior flagellum are regulated by distinct mechanisms and that the increase in the anterior flagellar deflection angle and sustained unilateral bend of the posterior flagellum may not be primarily induced by the Ca2+ concentration.

How many species of algae are there? A reprise. Four kingdoms, 14 phyla, 63 classes and still growing

To date (1 November 2023), the online database AlgaeBase has documented 50,589 species of living algae and 10,556 fossil species here referred to four kingdoms (Eubacteria, Chromista, Plantae, and Protozoa), 14 phyla, and 63 classes. The algae are the third most speciose grouping of plant-like organisms after the flowering plants (≈382,000 species) and fungi (≈170,000 species, including lichens) but are the least well defined of all the botanical groupings. Priority is given to phyla and class names that are familiar to phycologists and that are nomenclaturally valid. The most species-rich phylum is the Heterokontophyta to which 18 classes are referred with 21,052 living species and which is dominated by the diatoms in three classes with 18,673 species (16,427 living; 2239 fossil). The next most species-rich phyla are the red algae (7276 living), the green algae (6851 living), the blue-green algae (Cyanobacteria, 5723 living), the charophytes (4950 living, including the Charophyceae, 511 species living, and the Zygnematophyceae, 4335 living species), Dinoflagellata (2956 living, including the Dinophyceae, 2828 extant), and haptophytes (Haptophyta 1722 species, 517 living).

The Evolutionary Origins and Ancestral Features of Septins

Septins are a family of membrane-associated cytoskeletal GTPases that play crucial roles in various cellular processes, such as cell division, phagocytosis, and organelle fission. Despite their importance, the evolutionary origins and ancestral function of septins remain unclear. In opisthokonts, septins form five distinct groups of orthologs, with subunits from multiple groups assembling into heteropolymers, thus supporting their diverse molecular functions. Recent studies have revealed that septins are also conserved in algae and protists, indicating an ancient origin from the last eukaryotic common ancestor. However, the phylogenetic relationships among septins across eukaryotes remained unclear. Here, we expanded the list of non-opisthokont septins, including previously unrecognized septins from rhodophyte red algae and glaucophyte algae. Constructing a rooted phylogenetic tree of 254 total septins, we observed a bifurcation between the major non-opisthokont and opisthokont septin clades. Within the non-opisthokont septins, we identified three major subclades: Group 6 representing chlorophyte green algae (6A mostly for species with single septins, 6B for species with multiple septins), Group 7 representing algae in chlorophytes, heterokonts, haptophytes, chrysophytes, and rhodophytes, and Group 8 representing ciliates. Glaucophyte and some ciliate septins formed orphan lineages in-between all other septins and the outgroup. Combining ancestral-sequence reconstruction and AlphaFold predictions, we tracked the structural evolution of septins across eukaryotes. In the GTPase domain, we identified a conserved GAP-like arginine finger within the G-interface of at least one septin in most algal and ciliate species. This residue is required for homodimerization of the single Chlamydomonas septin, and its loss coincided with septin duplication events in various lineages. The loss of the arginine finger is often accompanied by the emergence of the α0 helix, a known NC-interface interaction motif, potentially signifying the diversification of septin-septin interaction mechanisms from homo-dimerization to hetero-oligomerization. Lastly, we found amphipathic helices in all septin groups, suggesting that curvature-sensing is an ancestral trait of septin proteins. Coiled-coil domains were also broadly distributed, while transmembrane domains were found in some septins in Group 6A and 7. In summary, this study advances our understanding of septin distribution and phylogenetic groupings, shedding light on their ancestral features, potential function, and early evolution.

Using a Novel Multiplexed Algal Cytological Imaging (MACI) Assay and Machine Learning as a Way to Characterize Complex Phenotypes in Plant-Type Organisms

High-throughput phenotypic profiling assays, popular for their ability to characterize alternations in single-cell morphological feature data, have been useful in recent years for predicting cellular targets and mechanisms of action (MoAs) for different chemicals and novel drugs. However, this approach has not been extensively used in environmental toxicology due to the lack of studies and established methods for performing this kind of assay in environmentally relevant species. Here, we developed a multiplexed algal cytological imaging (MACI) assay, based on the subcellular structures of the unicellular microalgae, Raphidocelis subcapitata, a toxicology and ecological model species. Several different herbicides and antibiotics with unique MoAs were exposed to R. subcapitata cells, and MACI was used to characterize cellular impacts by measuring subtle changes in their morphological features, including metrics of area, shape, quantity, fluorescence intensity, and granularity of individual subcellular components. This study demonstrates that MACI offers a quick and effective framework for characterizing complex phenotypic responses to environmental chemicals that can be used for determining their MoAs and identifying their cellular targets in plant-type organisms.

Distinct function of Chlamydomonas CTRA-CTR transporters in Cu assimilation and intracellular mobilization

Successful acclimation to copper (Cu) deficiency involves a fine balance between Cu import and export. In the green alga Chlamydomonas reinhardtii, Cu import is dependent on a transcription factor, Copper Response Regulator 1 (CRR1), responsible for activating genes in Cu-deficient cells. Among CRR1 target genes are two Cu transporters belonging to the CTR/COPT gene family (CTR1 and CTR2) and a related soluble protein (CTR3). The ancestor of these green algal proteins was likely acquired from an ancient chytrid and contained conserved cysteine-rich domains (named the CTR-associated domains, CTRA) that are predicted to be involved in Cu acquisition. We show by reverse genetics that Chlamydomonas CTR1 and CTR2 are canonical Cu importers albeit with distinct affinities, while loss of CTR3 did not result in an observable phenotype under the conditions tested. Mutation of CTR1, but not CTR2, recapitulates the poor growth of crr1 in Cu-deficient medium, consistent with a dominant role for CTR1 in high-affinity Cu(I) uptake. On the other hand, the overaccumulation of Cu(I) (20 times the quota) in zinc (Zn) deficiency depends on CRR1 and both CTR1 and CTR2. CRR1-dependent activation of CTR gene expression needed for Cu over-accumulation can be bypassed by the provision of excess Cu in the growth medium. Over-accumulated Cu is sequestered into the acidocalcisome but can become remobilized by restoring Zn nutrition. This mobilization is also CRR1-dependent, and requires activation of CTR2 expression, again distinguishing CTR2 from CTR1 and consistent with the lower substrate affinity of CTR2.

ONE SENTENCE SUMMARY

Regulation of Cu uptake and sequestration by members of the CTR family of proteins in Chlamydomonas.

Chitosan-grafted salicylaldehyde/algae composite for methyl violet dye removal: adsorption modeling and optimization

In this study, a hydrothermal approach was employed to graft chitosan (Chit)/algae (ALG) with salicylaldehyde (SA), resulting in the synthesis of a biocomposite named salicylaldehyde-based chitosan Schiff base/algae (Chit-SA/ALG). The main objective of this biocomposite was to effectively remove methyl violet (MV), an organic dye, from aqueous solutions. The adsorption performance of Chit-SA/ALG toward MV was investigated in detail, considering the effects of three factors: (A) Chit-SA/ALG dose (ranging from 0.02 to 0.1 g/100 mL), (B) pH (ranging from 4 to 10), and (C) time (ranging from 10 to 120 min). The Box-Behnken design (BBD) was utilized for experimental design and analysis. The experimental results exhibited a good fit with both the pseudo-second-order kinetic model and the Freundlich isotherm, suggesting their suitability for describing the MV adsorption process on Chit-SA/ALG. The maximum adsorption capacity of Chit-SA/ALG, as calculated by the Langmuir model, was found to be 115.6 mg/g. The remarkable adsorption of MV onto Chit-SA/ALG can be primarily attributed to the electrostatic forces between Chit-SA/ALG and MV as well as the involvement of various interactions such as n-π, π-π, and H-bond interactions. This research demonstrates that Chit-SA/ALG exhibits promising potential as a highly efficient adsorbent for the removal of organic dyes from water systems.

Algal Biochar-Metal Nanocomposite Particles Tailor the Hydration Kinetics and Compressive Strength of Portland Cement Paste

Biochar can improve the mechanical properties of portland cement paste and concrete. In this work, we produced algal biochar-zinc (biochar-Zn) and algal biochar-calcium (biochar-Ca) nanocomposite particles and studied their effect on the hydration kinetics and compressive strength of cement paste. Results show that 3 wt % biochar-Zn delayed peak heat evolution during cement hydration from 8.3 to 10.0 h, while 3 wt % addition of biochar-Ca induced a minor acceleration of peak heat from 8.3 to 8.2 h. Both biochar-Zn and biochar-Ca nanocomposite particles increased the compressive strength of cement paste at 28 days by 22.6 and 17.0%, respectively. Data substantiate that retardation or minor acceleration of the reaction kinetics was due exclusively to the presence of Zn and Ca phases, respectively, while the enhanced strength was attributed to a nucleation effect induced by such phases and the internal curing effect of biochar.

Testing effects of bottom-up factors, grazing, and competition on New Zealand rocky intertidal algal communities

Top-down and bottom-up factors and their interaction highlight the interdependence of resources and consumer impacts on food webs and ecosystems. Variation in the strength of upwelling-mediated ecological controls (i.e., light availability and herbivory) between early and late succession stages is less well understood from the standpoint of influencing algal functional group composition. We experimentally tested the effect of light, grazing, and disturbance on rocky intertidal turf-forming algal communities. Studies were conducted on the South Island of New Zealand at Raramai on the east coast (a persistent downwelling region) and Twelve Mile Beach on the west coast (an intermittent upwelling region). Herbivory, light availability, and algal cover were manipulated and percent cover of major macroalgal functional groups and sessile invertebrates were measured monthly from October 2017 to March 2018. By distinguishing between algal functional groups and including different starting conditions in our design, we found that the mosaic-like pattern of bare rock intermingled with diverse turf-forming algae at Twelve Mile Beach was driven by a complex array of species interactions, including grazing, predation, preemptive competition and interference competition, colonization rates, and these interactions were modulated by light availability and other environmental conditions. Raramai results contrasted with those at Twelve Mile Beach in showing stronger effects of grazing and relatively weak effects of other interactions, low colonization rates of invertebrates, and light effects limited to crustose algae. Our study highlights the potential importance of an upwelling-mediated 3-way interaction among herbivory, light availability, and preemption in structuring contrasting low rocky intertidal macroalgal communities.

Biofilms on plastic litter in an urban river: Community composition and activity vary by substrate type

In aquatic ecosystems, plastic litter is a substrate for biofilms. Biofilms on plastic and natural surfaces share similar composition and activity, with some differences due to factors such as porosity. In freshwaters, most studies have examined biofilms on benthic substrates, while little research has compared the activity and composition of biofilms on buoyant plastic and natural surfaces. Additionally, the influence of substrate size and successional stage on biofilm composition has not been commonly assessed. We incubated three plastics of distinct textures that are buoyant in rivers, low-density polyethylene (rigid; 1.7 mm thick), low-density polyethylene film (flexible; 0.0254 mm thick), and foamed polystyrene (brittle; 6.5 mm thick), as well as wood substrates (untreated oak veneer; 0.6 mm thick) in the Chicago River. Each material was incubated at three sizes (1, 7.5, and 15 cm2 ). Substrates were incubated at 2-10 cm depths and removed weekly for 6 weeks. On each substrate we measured chlorophyll concentration, biofilm biomass, respiration, and flux of nitrogen gas. We sequenced 16S and 23S rRNA genes at Weeks 1, 3, and 6 to capture biofilm community composition across successional stages. Chlorophyll, biomass, and N2 flux were similar across substrates, but respiration was greater on wood than plastics. Bacterial and algal richness and diversity were highest on foam and wood compared to polyethylene substrates. Bacterial biofilm community composition was distinct between wood and plastic substrates, while the algal community was distinct on wood and foam, which were different from each other and polyethylene substrates. These results indicate that polymer properties influence biofilm alpha and beta diversity, which may affect transport and distribution of plastic pollution and associated microbes, as well as biogeochemical processes in urban rivers. This study provides valuable insights into the effects of substrate on biofilm characteristics, and the ecological impacts of plastic pollution on urban rivers. PRACTITIONER POINTS: Plastic physical and chemical properties act as forces of selection for biofilm. Biofilm activity was similar among three different types of plastic. Community composition between plastic and wood was different.

Chlorella Supplementation Reduces Blood Lactate Concentration and Increases O2 Pulse during Submaximal and Maximal Cycling in Young Healthy Adults

Chlorella supplementation is reported to improve V˙O2max following extended supplementation periods (~3 weeks). However, there is little research on its impact over submaximal exercise intensities and following shorter supplementation regimens. This study aimed to investigate the efficacy of 6 g/day 2-day chlorella supplementation on exercise performance in healthy young adults. Twenty young healthy adults (Males = 16, Females = 4) (Age 22 ± 6 years, V˙O2max 42.7 ± 9.6 mL/(kg·min)) were recruited for this double-blinded, randomised cross-over study. Participants ingested 6 g/day of chlorella or a placebo for 2 days, with a one-week washout period between trials. Exercise testing consisted of a 20 min submaximal cycle at 40% of their work rate max (WRmax) (watts), followed by an incremental V˙O2max test. Lactate (mmol/L), heart rate (b/min), oxygen consumption (mL/(kg·min)), O2 pulse (mL/beat), respiratory exchange ratio (RER), and WRmax were compared across conditions. Following chlorella supplementation, blood lactate levels were significantly lower (p < 0.05) during submaximal exercise (3.05 ± 0.92 mmol/L vs. 2.67 ± 0.79 mmol/L) and following V˙O2max tests (12.79 ± 2.61 mmol/L vs. 11.56 ± 3.43 mmol/L). The O2 pulse was significantly higher (p < 0.05) following chlorella supplementation during submaximal (12.6 ± 3.5 mL/beat vs. 13.1 ± 3.5 mL/beat) and maximal exercise intensity (16.7 ± 4.6 mL/beat vs. 17.2 ± 4.5 mL/beat). No differences existed between conditions for oxygen consumption, RER, V˙O2max, or WRmax. A total of 2 days of 6 g/day chlorella supplementation appears to lower the blood lactate response and increase O2 pulse during both submaximal and maximal intensity exercise but did not lead to any improvements in V˙O2max.

Association between Intake of Edible Mushrooms and Algae and the Risk of Cognitive Impairment in Chinese Older Adults

Previous studies have investigated the association between diet and cognitive impairment, yet there is limited investigation into the link between edible mushrooms and algae intake and cognitive decline. This study aims to explore the association between edible mushrooms and algae intake and the risk of cognitive impairment in individuals aged 65 years and above in China. Cross-sectional data from the 2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS) formed the basis of this study. Edible mushrooms and algae intake was evaluated using a simplified food frequency questionnaire (FFQ) and cognitive function was assessed using the Mini-Mental State Examination (MMSE). A binary logistic regression model was used to evaluate odds ratios (ORs) and 95% confidence intervals (CIs), with subgroup analysis conducted. Among 14,150 older adults, the average age was (85.33 ± 11.55), with a cognitive impairment prevalence of 22.7; multi-model adjustments showed a 25.3% lower probability of cognitive impairment for those occasionally consuming edible mushrooms and algae (OR: 0.747, 95% CI: 0.675~0.826). Furthermore, a 29% lower risk was observed in those with daily intake (OR: 0.710, 95% CI: 0.511~0.987). Subgroup analysis demonstrated significant risk reduction in women (OR: 0.589, 95% CI: 0.375~0.925, p = 0.022), individuals with disability in activities of daily living (OR: 0.568, 95% CI: 0.367~0.878, p = 0.011), and those with low social activity levels (OR: 0.671, 95% CI: 0.473~0.950, p = 0.025). This study concludes that edible mushrooms and algae intake significantly impacts the risk of cognitive impairment in older adults. These results provide insights and impetus for further research into this area. Additional cohort studies or intervention trials are necessary to confirm the potential benefits of edible mushrooms and algae in promoting cognitive health.

The effect of combining green iron nanoparticles and algae on the sustainability of broiler production under heat stress conditions

Background

Natural feed additives in broiler feed contribute to the overall health, productivity, and economic viability of broiler chickens while meeting consumer demands and preferences for natural products. The purpose of this research was to determine the effect of green iron nanoparticles (Nano-Fe) and Halimeda opuntia supplementation in broiler diets on performance, ammonia excretion in excreta, Fe retention in tissues and serum, carcass criteria, and meat quality under hot environmental conditions.

Methods

A total of 256 one-day-old male Ross 308 broiler chicks were randomly assigned to one of four feeding treatments for 42 days. Each treatment had eight replications, with eight chicks per replicate. The treatments were Negative control (CON), positive control (POS) supplemented with 1 g/kg Halimeda opuntia as a carrier, POS + 20 mg/kg Nano-Fe (NFH1), POS + 40 mg/kg Nano-Fe (NFH2).

Results

When compared to CON and POS, dietary Nano-Fe up to 40 mg/kg enhanced (p < 0.001) growth performance in terms of body weight (BW), body weight gain (BWG), and feed conversion ratio (FCR). Nano-Fe had the highest BWG and the most efficient FCR (linear, p < 0.01, and quadratic, p < 0.01) compared to POS. Without affecting internal organs, the addition of Nano-Fe and POS enhanced dressing and reduced (p < 0.001) abdominal fat compared to control (CON). Notably, the water-holding capacity of breast and leg meat was higher (p < 0.001), and cooking loss was lower in broilers given Nano-Fe and POS diets against CON. In comparison to POS, the ammonia content in excreta dropped linearly as green Nano-Fe levels increased. When compared to CON, increasing levels of Nano-Fe levels boosted Fe content in the breast, leg, liver, and serum. The birds fed on POS showed better performance than the birds fed on CON.

Conclusion

Green Nano-Fe up to 40 mg/kg fed to broiler diets using 1 g/kg Halimeda opuntia as a carrier or in single can be utilized as an efficient feed supplement for increasing broiler performance, Fe retentions, carcass characteristics, meat quality, and reducing ammonia excretions, under hot conditions.

Fabrication of spirulina based activated carbons for wastewater treatment

The lack of safe drinking water is among the main problems to be faced by many areas of the world due to climate change, unrestrained population increases, and unsustainable usage of water sources. Therefore, research projects focusing on water quality, pollution, and control for sustainable water sources are in high demand to manage any unexpected changes in water sources. Drinking water sources may be contaminated with organic and inorganic chemicals, disinfection by-products, and microorganisms. Different treatment processes to remove these contaminants from water may be limited because of their high costs and time-consuming or require a multiple-barrier approach to improving performance. Therefore, there is a great need to develop an effective process for removing impurities. The primary objective of this study is to assess the effectiveness of algae-based activated carbons and develop a unique, low-cost sustainable process for wastewater treatment. Activated carbons were produced from pelletised algae powder using carbonisation and chemical activation. Chemical activation was carried out with calcium chloride (CaCl2) and zinc chloride (ZnCl2) as chemical agents. Furthermore, Brunauer-Emmett-Teller (BET) along with scanning electron microscopy (SEM) techniques were used to analyse the morphology, surface area, as well as the porosity of the prepared activated carbons to build a water column filter. Based on the results, algae-based carbon with CaCl2 activation provided a better surface area (197.7486 m2/g) and cumulative pore volume (0.105284 cm3/g). The filtration process using algae-based activated carbon can be a promising technique for water treatment with some further improvement and modifications.

Algae in the Anthropocene: Managing, conserving, and utilizing algae in an era of rapid environmental change

The Anthropocene is defined as the current period in which humans have had a large influence over the status and trajectory of earth's climate and environment. Human-induced climate change, pollution, and coastal development have caused major changes to algal persistence, distribution, diversity, and function. This has not only brought new challenges for managing and conserving algae, but also new opportunities. This series of perspective pieces will touch on some of these challenges, potential solutions, and knowledge gaps that we must consider in supporting and understanding algae in the Anthropocene.

Investigating seed bank potential of crustose coralline algae using DNA metabarcoding

To examine the potential for the autogenic ecosystem engineers, crustose coralline algae (CCA), to serve as seed banks or refugia for life stages of other species, it is critical to develop sampling protocols that reflect the diversity of life present. In this pilot study on two shallow water species of CCA collected from Raoul Island (Kermadec Islands; Rangitāhua) New Zealand, we investigated two preservation methods (ethanol vs. silica gel), sampled inner and outer regions of the crusts, and used DNA metabarcoding and seven genes/gene regions (16S rRNA, 18S rRNA, 23S rRNA, cox1, rbcL, and tufA genes and the ITS rRNA region) to develop a protocol for taxa identification. The results revealed immense diversity, with typically more taxa identified within the inner layers than the outer layers. As highlighted in other metabarcoding studies and in earlier work on rhodoliths (nodose coralline algae), reference databases are incomplete, and to some extent, the use of multiple markers mitigates this issue. Specifically, the 23S rRNA and rbcL genes are currently more suitable for identifying algae, while the cox1 gene fares better at capturing the diversity present inclusive of algae. Further investigation of these autogenic ecosystem engineers that likely act as marine seed banks is needed.

Pathogens Associated with Bovine Mastitis: The Experience of Bosnia and Herzegovina

To obtain improved insights into the complex microbial aetiology of bovine mastitis, this study investigated the pathogens involved in cattle mastitis in Bosnia and Herzegovina. A total of 179 milk samples from cows with clinical mastitis (CM) and subclinical mastitis (SCM), as well as eight bulk tank milk (BTM) samples from 48 dairy farms, were analysed by standard bacteriological and mycological methods. Mycoplasma detection and identification were performed using culture techniques and real-time polymerase chain reaction (PCR). A total of 88 (49.2%) mastitis samples were positive for known mastitis pathogens at 32 of 47 farms (68.1%). Mycoplasma bovis was a predominant pathogen (25/187; 13.4%) in the majority of herds (14/48; 29.2%) and accounted for 48.9% of positive CM samples. Escherichia coli was the second most dominant CM pathogen (34%), followed by Streptococcus agalactiae (10.6%), whereas Staphylococcus aureus and coagulase-negative staphylococci were the most common in SCM samples (17.1%). Other mastitis pathogens included Candida spp. and Prototheca zopfii. Two BTM samples were positive for M. bovis only, and one was positive for a mixed culture of S. aureus and Streptococcus uberis. The finding of various causative agents of bovine mastitis, with M. bovis emerging as the main pathogen, emphasizes the significance of comprehensive testing that includes not only common mastitis pathogens but also mycoplasmas, fungi, and algae.

Macroscale controls determine the recovery of river ecosystem productivity following flood disturbances

River ecosystem function depends on flow regimes that are increasingly modified by changes in climate, land use, water extraction, and flow regulation. Given the wide range of variation in flow regime modifications and autotrophic communities in rivers, it has been challenging to predict which rivers will be more resilient to flow disturbances. To better understand how river productivity is disturbed by and recovers from high-flow disturbance events, we used a continental-scale dataset of daily gross primary production time series from 143 rivers to estimate growth of autotrophic biomass and ecologically relevant flow disturbance thresholds using a modified population model. We compared biomass recovery rates across hydroclimatic gradients and catchment characteristics to evaluate macroscale controls on ecosystem recovery. Estimated biomass accrual (i.e., recovery) was fastest in wider rivers with less regulated flow regimes and more frequent instances of biomass removal during high flows. Although disturbance flow thresholds routinely fell below the estimated bankfull flood (i.e., the 2-y flood), a direct comparison of disturbance flows estimated by our biomass model and a geomorphic model revealed that biomass disturbance thresholds were usually greater than bed disturbance thresholds. We suggest that primary producers in rivers vary widely in their capacity to recover following flow disturbances, and multiple, interacting macroscale factors control productivity recovery rates, although river width had the strongest overall effect. Biomass disturbance flow thresholds varied as a function of geomorphology, highlighting the need for data such as bed slope and grain size to predict how river ecosystems will respond to changing flow regimes.

Harnessing genetic engineering to drive economic bioproduct production in algae

Our reliance on agriculture for sustenance, healthcare, and resources has been essential since the dawn of civilization. However, traditional agricultural practices are no longer adequate to meet the demands of a burgeoning population amidst climate-driven agricultural challenges. Microalgae emerge as a beacon of hope, offering a sustainable and renewable source of food, animal feed, and energy. Their rapid growth rates, adaptability to non-arable land and non-potable water, and diverse bioproduct range, encompassing biofuels and nutraceuticals, position them as a cornerstone of future resource management. Furthermore, microalgae's ability to capture carbon aligns with environmental conservation goals. While microalgae offers significant benefits, obstacles in cost-effective biomass production persist, which curtails broader application. This review examines microalgae compared to other host platforms, highlighting current innovative approaches aimed at overcoming existing barriers. These approaches include a range of techniques, from gene editing, synthetic promoters, and mutagenesis to selective breeding and metabolic engineering through transcription factors.

Lipidome Plasticity Enables Unusual Photosynthetic Flexibility in Arctic vs. Temperate Diatoms

The diatom lipidome actively regulates photosynthesis and displays a high degree of plasticity in response to a light environment, either directly as structural modifications of thylakoid membranes and protein-pigment complexes, or indirectly via photoprotection mechanisms that dissipate excess light energy. This acclimation is crucial to maintaining primary production in marine systems, particularly in polar environments, due to the large temporal variations in both the intensity and wavelength distributions of downwelling solar irradiance. This study investigated the hypothesis that Arctic marine diatoms uniquely modify their lipidome, including their concentration and type of pigments, in response to wavelength-specific light quality in their environment. We postulate that Arctic-adapted diatoms can adapt to regulate their lipidome to maintain growth in response to the extreme variability in photosynthetically active radiation. This was tested by comparing the untargeted lipidomic profiles, pigmentation, specific growth rates and carbon assimilation of the Arctic diatom Porosira glacialis vs. the temperate species Coscinodiscus radiatus during exponential growth under red, blue and white light. Here, we found that the chromatic wavelength influenced lipidome remodeling and growth in each strain, with P. glacialis showing effective utilization of red light coupled with increased inclusion of primary light-harvesting pigments and polar lipid classes. These results indicate a unique photoadaptation strategy that enables Arctic diatoms like P. glacialis to capitalize on a wide chromatic growth range and demonstrates the importance of active lipid regulation in the Arctic light environment.

Metabolomic Response of Thalassiosira weissflogii to Erythromycin Stress: Detoxification Systems, Steroidal Metabolites, and Energy Metabolism

Erythromycin, a macrolide antibiotic, is a prioritized pollutant that poses a high risk to environmental health. It has been detected in different environmental matrices and can cause undesired effects in aquatic organisms, particularly freshwater algae, which are primary producers. However, the impact of erythromycin on marine algae remains largely unexplored. Erythromycin has been reported to induce hormetic effects in the marine diatom Thalassiosira weissflogii (T. weissflogii). These effects are associated with the molecular pathways and biological processes of ribosome assembly, protein translation, photosynthesis, and oxidative stress. However, the alterations in the global gene expression have yet to be validated at the metabolic level. The present study used non-targeted metabolomic analysis to reveal the altered metabolic profiles of T. weissflogii under erythromycin stress. The results showed that the increased cell density was possibly attributed to the accumulation of steroidal compounds with potential hormonic action at the metabolic level. Additionally, slight increases in the mitochondrial membrane potential (MMP) and viable cells were observed in the treatment of 0.001 mg/L of erythromycin (an environmentally realistic level). Contrarily, the 0.75 and 2.5 mg/L erythromycin treatments (corresponding to EC20 and EC50, respectively) showed decreases in the MMP, cell density, and viable algal cells, which were associated with modified metabolic pathways involving ATP-binding cassette (ABC) transporters, the metabolism of hydrocarbons and lipids, thiamine metabolism, and the metabolism of porphyrin and chlorophyll. These findings suggest that metabolomic analysis, as a complement to the measurement of apical endpoints, could provide novel insights into the molecular mechanisms of hormesis induced by antibiotic agents in algae.

Near-Native Imaging of Label-Free Silver Nanoparticles-Triggered 3D Subcellular Ultrastructural Reorganization in Microalgae

Understanding the spatial orientation of nanoparticles and the corresponding subcellular architecture events favors uncovering fundamental toxic mechanisms and predicting response pathways of organisms toward environmental stressors. Herein, we map the spatial location of label-free citrate-coated Ag nanoparticles (Cit-AgNPs) and the corresponding subcellular reorganization in microalgae by a noninvasive 3D imaging approach, cryo-soft X-ray tomography (cryo-SXT). Cryo-SXT near-natively displays the 3D maps of Cit-AgNPs presenting in rarely identified sites, namely, extracellular polymeric substances (EPS) and the cytoplasm. By comparative 3D morphological assay, we observe that Cit-AgNPs disrupt the cellular ultrastructural homeostasis, triggering a severe malformation of cytoplasmic organelles with energy-producing and stress-regulating functions. AgNPs exposure causes evident disruption of the chloroplast membrane, significant attenuation of the pyrenoid matrix and starch sheath, extreme swelling of starch granules and lipid droplets, and shrinkage of the nucleolus. In accompaniment, the number and volume occupancy of starch granules are significantly increased. Meanwhile, the spatial topology of starch granules extends from the chloroplast to the cytoplasm with a dispersed distribution. Linking the dynamics of the internal structure and the alteration of physiological properties, we derive a comprehensive cytotoxic and response pathway of microalgae exposed to AgNPs. This work provides a perspective for assessing the toxicity at subcellular scales to achieve label-free nanoparticle-caused ultrastructure remodeling of phytoplankton.

A custom 3D printed paddlewheel improves growth in flat panel photobioreactor

One of the main challenges with using flat panel photobioreactors for algal growth is uneven mixing and settling of cells in corners, especially when bubbling is the only method used for mixing. In order to improve mixing in our flat panel reactor, we designed a custom paddlewheel. Paddlewheels are frequently used in outdoor algae raceway ponds to improve mixing and we are taking advantage of the same principle for mixing in the reactor. The paddlewheel is easily integrated into our PSI FMT150 1-L flat panel photobioreactor and is printed on a 3D printer using high temperature poly lactic acid (HT-PLA). With the inclusion of an annealing step, the paddlewheel is autoclavable. Addition of the paddlewheel in the reactor minimized cell settling and improved algal growth, as evidenced by a nearly 40% increase in oxygen production rates. Nutrient dispersion and utilization in the culture was also improved as evidenced by a corresponding 38% decrease in CO2 concentration. The paddlewheel device presented here is a cost-effective method for improving algal growth in a flat panel photobioreactor.

An Update on the Chemical Constituents and Biological Properties of Selected Species of an Underpinned Genus of Red Algae: Chondrus

Macroalgae, particularly red seaweeds, have attracted significant attention due to their economic and health benefits. Chondrus, a red algae genus, despite its economic importance, seems to be undervalued. Among all its species, Chondrus crispus has been meticulously documented for its biological properties, and little is known about other species. No comprehensive review of the biological properties of this genus has been acknowledged. Thus, this review aimed to summarize the available information on the chemical constituents and biological properties of a few selected species, including Chondrus crispus, Chondrus ocellatus, Mazzaella canaliculata, and Chondrus armatus. We compiled and discovered that the genus is offering most of the important health-promoting benefits evidenced from in vitro and in vivo studies focused on antimicrobial, immunomodulation, neuroprotection, anti-atopic, anti-inflammatory, anti-viral, anti-diabetic, cytoprotective, antioxidant, anti-coagulation, nephroprotective, anti-tumor, and anti-venom activity, which speaks about the potential of this genus. Data on clinical studies are limited. Further, around 105 chemical constituents have been reported from Chondrus spp. Given its significance, further investigation is warranted, in the form of meticulously planned cell, animal, and clinical studies that concentrate on novel health-enhancing endeavors, in order to unveil the full potential of this genus. The review also outlines challenges and future directions.

Rapid diversification of a free-living protist is driven by adaptation to climate and habitat

Microbial eukaryotes (protists) have major functional roles in aquatic ecosystems, including the biogeochemical cycling of elements as well as occupying various roles in the food web. Despite their importance for ecosystem function, the factors that drive diversification in protists are not known. Here, we aimed to identify the factors that drive differentiation and, subsequently, speciation in a free-living protist, Synura petersenii (Chrysophyceae). We sampled five different geographic areas and utilized population genomics and quantitative trait analyses. Habitat and climate were the major drivers of diversification on the local geographical scale, while geography played a role over longer distances. In addition to conductivity and temperature, precipitation was one of the most important environmental drivers of differentiation. Our results imply that flushing episodes (floods) drive microalgal adaptation to different niches, highlighting the potential for rapid diversification in protists.

A Novel Phytocolorant, Neoxanthin, as a Potent Chemopreventive: Current Progress and Future Prospects

Cancer is a general term for a group of similar diseases. It is a combined process that results from an accumulation of abnormalities at different biological levels, which involves changes at both genetic and biochemical levels in the cells. Several modifiable risk factors for each type of cancer include heredity, age, and institutional screening guidelines, including colonoscopy, mammograms, prostate-specific antigen testing, etc., which an individual cannot modify. Although a wide range of resources is available for cancer drugs and developmental studies, the cases are supposed to increase by about 70% in the next two decades due to environmental factors commonly driven by the way of living. The drugs used in cancer prevention are not entirely safe, have potential side effects and are generally unsuitable owing to substantial monetary costs. Interventions during the initiation and progression of cancer can prevent, diminish, or stop the transformation of healthy cells on the way to malignancy. Diet modifications are one of the most promising lifestyle changes that can decrease the threat of cancer development by nearly 40%. Neoxanthin is a xanthophyll pigment found in many microalgae and macroalgae, having significant anti-cancer, antioxidant and chemo-preventive activity. In this review, we have focused on the anti-cancer activity of neoxanthin on different cell lines and its cancer-preventive activity concerning obesity and oxidative stress. In addition to this, the preclinical studies and future perspectives are also discussed in this review.

Biotic interactions outweigh abiotic factors as drivers of bark microbial communities in Central European forests

Bark surfaces are extensive areas within forest ecosystems, which provide an ideal habitat for microbial communities, through their longevity and seasonal stability. Here we provide a comprehensive account of the bark surface microbiome of living trees in Central European forests, and identify drivers of diversity and community composition. We examine algal, fungal, and bacterial communities and their interactions using metabarcoding on samples from over 750 trees collected in the Biodiversity Exploratories in northern, central, and southern Germany. We show that mutual biotic influence is more important than the abiotic environment with regard to community composition, whereas abiotic conditions and geography are more important for alpha diversity. Important abiotic factors are the relative humidity and light availability, which decrease the algal and bacterial alpha diversity but strongly increase fungal alpha diversity. In addition, temperature is important in shaping the microbial community, with higher temperature leading to homogeneous communities of dominant fungi, but high turnover in bacterial communities. Changes in the community dissimilarity of one organismal group occur in close relation to changes in the other two, suggesting that there are close interactions between the three major groups of the bark surface microbial communities, which may be linked to beneficial exchange. To understand the functioning of the forest microbiome as a whole, we need to further investigate the functionality of interactions within the bark surface microbiome and combine these results with findings from other forest habitats such as soil or canopy.

Pseudovampyrella gen. nov.: A genus of Vampyrella-like protoplast extractors finds its place in the Leptophryidae

Vampyrellid amoebae are predatory protists, which consume a variety of eukaryotic prey and inhabit freshwater, marine and terrestrial ecosystems. Although they have been known for almost 150 years, much of their diversity lacks an in-depth characterization. To date, environmental sequencing data hint at several uncharacterized lineages, to which no phenotype is associated. Furthermore, there are numerous historically described species without any molecular information. This study reports on two new vampyrellid strains from moorlands, which extract the protoplasts of Closterium species (Zygnematophyceae). Our data on morphology, prey range specificity and feeding strategy reveal that the studied vampyrellids are very similar to the historically described Vampyrella closterii. However, phylogenetic analyses demonstrate that the two strains do not belong to the genus Vampyrella and, instead, form a distinct clade in the family Leptophryidae. Hence, we introduce a new genus of algivorous protoplast extractors, Pseudovampyrella gen. nov., with the species P. closterii (= V. closterii) and P. minor. Our findings indicate that the genetic diversity of morphologically described vampyrellid species might be hugely underrated.

The correlation between nuts and algae-less diet and children's blood pressure: from a cross-sectional study in Chongqing

BACKGROUND

Nuts and algae have been shown to improve BP levels, but their effectiveness is controversial.

AIMS

This study aims to illustrate the effect of dietary pattern with nuts and algae-less on BP levels in children and adolescents from a cross-sectional study.

METHODS

A total of 5645 children from the Chongqing Children's Health Cohort, aged 9.34 ± 1.74 years with 52.05% males, were analyzed. Stratified analysis was conducted to explore the differences between the two dietary patterns in urban or rural areas, as well as the differences in different gender. Logistic regression was used to analyze the influence factors of increased BP. And a GLM was used to analyze the influence of the two dietary patterns on systolic blood pressure (SBP, mmHg), diastolic blood pressure (DBP, mmHg), and mean arterial pressure (MAP, mmHg).

RESULTS

Children with nuts and algae-less dietary patterns had higher SBP (104.68 ± 10.31 vs 103.81 ± 9.74, P = .006), DBP (64.27 ± 7.53 vs 63.55 ± 7.52, P = .002), and MAP (77.74 ± 7.75 vs 76.97 ± 7.52, P = .001) compared with those children with a balanced diet. After adjusting for covariates, the nuts and algae-less diet was a risk factor for hypertension in children when compared with the balanced diet(OR(95%CI):1.455(1.097,1.930), P = .009). The nuts and algae-less diet has a significant influence on SBP (104.68 ± 10.31 mmHg vs.103.81 ± 9.74 mmHg, P = .006). Stratified analysis by sex showed that nuts and algae-less dietary patterns had a more significant impact on females than males.

CONCLUSION

Nuts and algae-less dietary pattern correlated with increased BP levels in children, and a greater impact on SBP levels was found in females, suggesting that a balanced diet with appropriate nuts and algae should be proposed for children in China.

Stenotrophomonas goyi sp. nov., a novel bacterium associated with the alga Chlamydomonas reinhardtii

Background

A culture of the green algae Chlamydomonas reinhardtii was accidentally contaminated with three different bacteria in our laboratory facilities. This contaminated alga culture showed increased algal biohydrogen production. These three bacteria were independently isolated.

Methods

The chromosomic DNA of one of the isolated bacteria was extracted and sequenced using PacBio technology. Tentative genome annotation (RAST server) and phylogenetic trees analysis (TYGS server) were conducted. Diverse growth tests were assayed for the bacterium and for the alga-bacterium consortium.

Results

Phylogenetic analysis indicates that the bacterium is a novel member of the Stenotrophomonas genus that has been termed in this work as S. goyi sp. nov. A fully sequenced genome (4,487,389 base pairs) and its tentative annotation (4,147 genes) are provided. The genome information suggests that S. goyi sp. nov. is unable to use sulfate and nitrate as sulfur and nitrogen sources, respectively. Growth tests have confirmed the dependence on the sulfur-containing amino acids methionine and cysteine. S. goyi sp. nov. and Chlamydomonas reinhardtii can establish a mutualistic relationship when cocultured together.

Conclusions

S. goyi sp. nov. could be of interest for the design of biotechnological approaches based on the use of artificial microalgae-bacteria multispecies consortia that take advantage of the complementary metabolic capacities of their different microorganisms.

Stenotrophomonas goyi sp. nov., a novel bacterium associated with the alga Chlamydomonas reinhardtii

BACKGROUND

A culture of the green algae Chlamydomonas reinhardtii was accidentally contaminated with three different bacteria in our laboratory facilities. This contaminated alga culture showed increased algal biohydrogen production. These three bacteria were independently isolated.

METHODS

The chromosomic DNA of one of the isolated bacteria was extracted and sequenced using PacBio technology. Tentative genome annotation (RAST server) and phylogenetic trees analysis (TYGS server) were conducted. Diverse growth tests were assayed for the bacterium and for the alga-bacterium consortium.

RESULTS

Phylogenetic analysis indicates that the bacterium is a novel member of the Stenotrophomonas genus that has been termed in this work as S. goyi sp. nov. A fully sequenced genome (4,487,389 base pairs) and its tentative annotation (4,147 genes) are provided. The genome information suggests that S. goyi sp. nov. is unable to use sulfate and nitrate as sulfur and nitrogen sources, respectively. Growth tests have confirmed the dependence on the sulfur-containing amino acids methionine and cysteine. S. goyi sp. nov. and Chlamydomonas reinhardtii can establish a mutualistic relationship when cocultured together.

CONCLUSIONS

S. goyi sp. nov. could be of interest for the design of biotechnological approaches based on the use of artificial microalgae-bacteria multispecies consortia that take advantage of the complementary metabolic capacities of their different microorganisms.

Extraction of Cellulose from Ulva lactuca Algae and Its Use for Membrane Synthesis

Green algae are a sustainable source of biopolymers for the global demand due to their high photosynthetic efficiency. This article describes the extraction of cellulose from plant systems represented by Ulva lactuca species. In order to extract various substances, algae were finely ground with the help of solvents (liquid media). This was carried out to achieve the necessary conditions that help reduce the resistance this phase shows in regard to the transport and transfer of the species being extracted. The highest yield of extracted cellulose (20,944%) was obtained for the following factors: S/L = 1/20; conc. ethanol = 90%, conc. salts = 4 g/L. Hydrogel membranes are a unique class of macromolecular networks that contain a large fraction of aqueous solvent within their structure. With the cellulose extracted from algae, we obtained membranes which underwent the process of swelling in liquid media (ethyl alcohol) of different concentrations. The swelling of biocellulose membranes in alcoholic solutions of high concentrations was investigated. It was observed that the process of absorption of the alcoholic solution by the membrane occurred rapidly in the first part. After stabilization, the membranes continued to absorb at a slower rate until stabilization or saturation concentration was reached.

Potential Application of Marine Algae and Their Bioactive Metabolites in Brain Disease Treatment: Pharmacognosy and Pharmacology Insights for Therapeutic Advances

Seaweeds, also known as edible marine algae, are an abundant source of phytosterols, carotenoids, and polysaccharides, among other bioactive substances. Studies conducted in the past few decades have demonstrated that substances derived from seaweed may be able to pass through the blood-brain barrier and act as neuroprotectants. According to preliminary clinical research, seaweed may also help prevent or lessen the symptoms of cerebrovascular illnesses by reducing mental fatigue, preventing endothelial damage to the vascular wall of brain vessels, and regulating internal pressure. They have the ability to control neurotransmitter levels, lessen neuroinflammation, lessen oxidative stress, and prevent the development of amyloid plaques. This review aims to understand the application potential of marine algae and their influence on brain development, highlighting the nutritional value of this "superfood" and providing current knowledge on the molecular mechanisms in the brain associated with their dietary introduction.

Chloroplast genome evolution and phylogeny of the early-diverging charophycean green algae with a focus on the Klebsormidiophyceae and Streptofilum

The Klebsormidiophyceae are a class of green microalgae observed globally in both freshwater and terrestrial habitats. Morphology-based classification schemes of this class have been shown to be inadequate due to the simple morphology of these algae, the tendency of morphology to vary in culture versus field conditions, and rampant morphological homoplasy. Molecular studies revealing cryptic diversity have renewed interest in this group. We sequenced the complete chloroplast genomes of a broad series of taxa spanning the known taxonomic breadth of this class. We also sequenced the chloroplast genomes of three strains of Streptofilum, a recently discovered green algal lineage with close affinity to the Klebsormidiophyceae. Our results affirm the previously hypothesized polyphyly of the genus Klebsormidium as well as the polyphyly of the nominal species in this genus, K. flaccidum. Furthermore, plastome sequences strongly support the status of Streptofilum as a distinct, early-diverging lineage of charophytic algae sister to a clade comprising Klebsormidiophyceae plus Phragmoplastophyta. We also uncovered major structural alterations in the chloroplast genomes of species in Klebsormidium that have broad implications regarding the underlying mechanisms of chloroplast genome evolution.

Brown Seaweed Consumption as a Promising Strategy for Blood Glucose Management: A Comprehensive Meta-Analysis

Diabetes is a chronic condition that can lead to various complications; therefore, there is a need to emphasize prevention and management. Dietary interventions, such as the Mediterranean diet or calorie-restricted regimens, coupled with exercise-induced weight reduction, have been recommended for enhancing diabetes management. Seaweeds contain various functional components, such as polyphenols and fucoidan, which have been reported to exert multiple benefits, including blood glucose regulation, improved intestinal health, and enhanced of lipid profiles. The association between blood glucose and seaweed consumption has been established in previous research. We searched the PubMed, RISS, Google Scholar, ScienceDirect, and Cochrane Library databases to identify relevant studies after applying the selection/exclusion criteria, and 23 studies were ultimately included in this analysis. Comprehensive Meta-Analysis (CMA) software version 4.0 was used to assess statistical significance and heterogeneity. In this meta-analysis, postprandial blood glucose, glycated hemoglobin (HbA1c), and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) levels demonstrated significant improvements in the seaweed group compared to the control group. Conversely, fasting blood glucose and insulin levels did not show significant associations with seaweed consumption. Subgroup analysis revealed that a high dose (1000 mg or more) was more beneficial than a low dose, and seaweeds such as Laminaria digitata, Undaria pinnatifida, Acophyllum nodosum, and Fucus vesiculosus were found to be more effective at improving blood glucose levels than control treatments. Therefore, based on our research, seaweed supplementation appears to be a promising strategy for reducing postprandial blood glucose, HbA1c, and HOMA-IR levels, thereby enabling better blood glucose management and leading to a decreased risk of type 2 diabetes.

Gephyrocapsa huxleyi (Emiliania huxleyi) as a model system for coccolithophore biology

Coccolithophores are the most abundant calcifying organisms in modern oceans and are important primary producers in many marine ecosystems. Their ability to generate a cellular covering of calcium carbonate plates (coccoliths) plays a major role in marine biogeochemistry and the global carbon cycle. Coccolithophores also play an important role in sulfur cycling through the production of the climate-active gas dimethyl sulfide. The primary model organism for coccolithophore research is Emiliania huxleyi, now named Gephyrocapsa huxleyi. G. huxleyi has a cosmopolitan distribution, occupying coastal and oceanic environments across the globe, and is the most abundant coccolithophore in modern oceans. Research in G. huxleyi has identified many aspects of coccolithophore biology, from cell biology to ecological interactions. In this perspective, we summarize the key advances made using G. huxleyi and examine the emerging tools for research in this model organism. We discuss the key steps that need to be taken by the research community to advance G. huxleyi as a model organism and the suitability of other species as models for specific aspects of coccolithophore biology.

Algae Ingestion Increases Resting and Exercised Myofibrillar Protein Synthesis Rates to a Similar Extent as Mycoprotein in Young Adults

BACKGROUND

Spirulina [SPIR] (cyanobacterium) and chlorella [CHLO] (microalgae) are foods rich in protein and essential amino acids; however, their capacity to stimulate myofibrillar protein synthesis (MyoPS) in humans remains unknown.

OBJECTIVES

We assessed the impact of ingesting SPIR and CHLO compared with an established high-quality nonanimal-derived dietary protein source (fungal-derived mycoprotein [MYCO]) on plasma amino acid concentrations, as well as resting and postexercise MyoPS rates in young adults.

METHODS

Thirty-six healthy young adults (age: 22 ± 3 y; BMI: 23 ± 3 kg·m-2; male [m]/female [f], 18/18) participated in a randomized, double-blind, parallel-group trial. Participants received a primed, continuous infusion of L-[ring-2H5]-phenylalanine and completed a bout of unilateral-resistance leg exercise before ingesting a drink containing 25 g protein from MYCO (n = 12; m/f, 6/6), SPIR (n = 12; m/f, 6/6), or CHLO (n = 12; m/f, 6/6). Blood and bilateral muscle samples were collected at baseline and during a 4-h postprandial and postexercise period to assess the plasma amino acid concentrations and MyoPS rates in rested and exercised tissue.

RESULTS

Protein ingestion increased the plasma total and essential amino acid concentrations (time effects; all P < 0.001), but most rapidly and with higher peak responses following the ingestion of SPIR compared with MYCO and CHLO (P < 0.05), and MYCO compared with CHLO (P < 0.05). Protein ingestion increased MyoPS rates (time effect; P < 0.001) in both rested (MYCO, from 0.041 ± 0.032 to 0.060 ± 0.015%·h-1; SPIR, from 0.042 ± 0.030 to 0.066 ± 0.022%·h-1; and CHLO, from 0.037 ± 0.007 to 0.055 ± 0.019%·h-1, respectively) and exercised tissue (MYCO, from 0.046 ± 0.014 to 0.092 ± 0.024%·h-1; SPIR, from 0.038 ± 0.011 to 0.086 ± 0.028%·h-1; and CHLO, from 0.048 ± 0.019 to 0.090 ± 0.024%·h-1, respectively), with no differences between groups (interaction effect; P > 0.05), but with higher rates in exercised compared with rested muscle (time × exercise effect; P < 0.001).

CONCLUSIONS

The ingestion of a single bolus of algae-derived SPIR and CHLO increases resting and postexercise MyoPS rates to a comparable extent as MYCO, despite divergent postprandial plasma amino acid responses.

Removal of Algae and Algal Toxins from a Drinking Water Source Using a Two-Stage Polymeric Ultrafiltration Membrane Process

The release of algal toxins in algae-containing water sources poses a serious threat to drinking water safety and human health. The conventional water treatment processes of water plants have a limited ability to remove algae and algal toxins, especially algal toxins with a molecular weight (MW) of less than 1000 Da. To eliminate algal pollution from a water source, a two-stage ultrafiltration (UF) process with a large polysulfone hollow fiber membrane with a MW cut-off of 200 kDa and a small aromatic polyamide roll membrane with a MW cut-off of 1 kDa were applied after a traditional sand filter in a water treatment plant. UF operation conditions, including the operating time, pressure, and membrane flux, were investigated. With an operating pressure of 0.05-0.08 MPa, the polysulfone hollow fiber membrane removed algae effectively, as the influent algal cell concentration ranged from 1-30 cells/mL but exhibited a limited removal of algal toxins. With an operating pressure of 0.3-0.4 MPa, the elimination of microcystins (MCs) reached 96.3% with the aromatic polyamide roll membrane. The operating pressure, membrane flux, and operating time were selected as the experimental factors, and the effects on the UF efficiency to remove algal toxins and biodegradable dissolved organic carbon were investigated by the response surface methodology. The model showed that the order of influence on the membrane operating efficiency was operating pressure > membrane flux > running time. The optimal UF operating conditions were an operating pressure of 0.3 MPa, a membrane flux of 17.5 L/(m2·h), and a running time of 80 min.

Cellulose and JbKOBITO 1 mediate the resistance of NaHCO3-tolerant chlorella to saline-alkali stress

Carbonate stress has profound impacts on both agricultural and industrial production. Although a number of salinity-tolerant genes have been reported and applied in plants, there is a lack of research on the role of cell wall-related genes in resistance to carbonate. Likewise, in industry, current strategies have not been able to more effectively address the conflict between stress-induced microalgal biofuel accumulation and microalgal growth inhibition. It is of great significance to study the adaptation mechanism of carbonate-tolerant organisms and to explore related genes for future genetic modification. In this study, the role of the cell wall in the NaHCO3-tolerant chlorella JB17 was investigated. We found that JB17 possesses a relatively thick cell wall with a thickness of 300-600 nm, which is much higher than that of the control chlorella with a thickness of about 100 nm. Determination of the cell wall polysaccharide fractions showed that the cellulose content in the JB17 cell wall increased by 10.48% after NaHCO3 treatment, and the decrease in cellulose levels by cellulase digestion inhibited its resistance to NaHCO3. Moreover, the saccharide metabolome revealed that glucose, rhamnose, and trehalose levels were higher in JB17, especially rhamnose and trehalose, which were almost 40 times higher than in control chlorella. Gene expression detection identified an up-regulated expressed gene after NaHCO3 treatment, JbKOBITO1, overexpression of which could improve the NaHCO3 tolerance of Chlamydomonas reinhardtii. As it encodes a glycosyltransferase-like protein that is involved in cellulose synthesis, the strong tolerance of JB17 to NaHCO3 may be partly due to the up-regulated expression of JbKOBITO 1 and JbKOBITO 1-mediated cellulose accumulation. The above results revealed a critical role of cellulose in the NaHCO3 resistance of JB17, and the identified NaHCO3-tolerance gene will provide genetic resources for crop breeding in saline-alkali soils and for genetic modification of microalgae for biofuel production.