-
Plants (Basel, Switzerland) Jan 2023Epigenetics, referring to heritable gene regulatory information that is independent of changes in DNA sequences, is an important mechanism involved both in organism... (Review)
Review
Epigenetics, referring to heritable gene regulatory information that is independent of changes in DNA sequences, is an important mechanism involved both in organism development and in the response to environmental events. About the epigenetic marks, DNA methylation is one of the most conserved mechanisms, playing a pivotal role in organism response to several biotic and abiotic stressors. Indeed, stress can induce changes in gene expression through hypo- or hyper-methylation of DNA at specific loci and/or in DNA methylation at the genome-wide level, which has an adaptive significance and can direct genome evolution. Exploring DNA methylation in responses to abiotic stress could have important implications for improving stress tolerance in algae. This article summarises the DNA methylation pattern in algae and its impact on abiotic stress, such as heavy metals, nutrients and temperature. Our discussion provides information for further research in algae for a better comprehension of the epigenetic response under abiotic stress, which could favour important implications to sustain algae growth under abiotic stress conditions, often related to high biosynthesis of interesting metabolites.
PubMed: 36678953
DOI: 10.3390/plants12020241 -
Frontiers in Nutrition 2022Nutritional clinical trials have reported algae such as spirulina and chlorella to have the capability to improve cardiovascular risk factors, anemia, immune function,...
Nutritional clinical trials have reported algae such as spirulina and chlorella to have the capability to improve cardiovascular risk factors, anemia, immune function, and arterial stiffness. With positive results being reported in clinical trials, researchers are investigating the potential for algae as an ergogenic aid for athletes. Initial studies found spirulina and chlorella supplementation to increase peak oxygen uptake and time to exhaustion, with the mechanistic focus on the antioxidant capabilities of both algae. However, a number of oxidative stress biomarkers reported in these studies are now considered to lack robustness and have consequently provided equivocal results. Considering the nutrient complexity and density of these commonly found edible algae, there is a need for research to widen the scope of investigation. Most recently algae supplementation has demonstrated ergogenic potential during submaximal and repeated sprint cycling, yet a confirmed primary mechanism behind these improvements is still unclear. In this paper we discuss current algae supplementation studies and purported effects on performance, critically examine the antioxidant and ergogenic differing perspectives, and outline future directions.
PubMed: 35321288
DOI: 10.3389/fnut.2022.865741 -
Bioengineered Dec 2021Hydrocolloids are a class of food additives with broad applications in the food industry to develop structure in food ingredients. Hydrocolloids can be synthetic,... (Review)
Review
Hydrocolloids are a class of food additives with broad applications in the food industry to develop structure in food ingredients. Hydrocolloids can be synthetic, plant-based, or animal-based. Increasing consumer awareness has led to the use of natural food ingredients derived from natural sources, making algae-derived hydrocolloids more appealing nowadays. Algae-derived hydrocolloids such as carrageenan, agar, and alginate are widely used in the food industry as thickening, gelling, and emulsifying agents. Carrageenans are sulfated polysaccharides with diverse structural specificities. The safety of carrageenan use in the food industry has been widely debated recently due to the reported pro-inflammatory activities of carrageenan and the probable digestion of carrageenan by the gut microbiota to generate pro-inflammatory oligosaccharides. In contrast, both agar and alginate are primarily nontoxic, and generally no dispute regarding the use of the same in food ingredients. This review provides an overview of the algae industry, the food additives, the algae-derived hydrocolloids, the applications of algae-derived hydrocolloids in food industries, health-related studies, and other sectors, along with future perspectives. Even though differences of opinion exist in the use of carrageenan, it is continued to be used by the food industry and will be used until suitable alternatives are available. In summary, algal hydrocolloids are 'label-friendly' and considered a safe option against synthetic additives.
Topics: Agar; Alginates; Carrageenan; Chlorophyta; Colloids; Food Additives; Food Industry; Phaeophyceae; Rhodophyta
PubMed: 34281484
DOI: 10.1080/21655979.2021.1946359 -
Marine Drugs 2011For photosynthesis, phototrophic organisms necessarily synthesize not only chlorophylls but also carotenoids. Many kinds of carotenoids are found in algae and, recently,... (Review)
Review
For photosynthesis, phototrophic organisms necessarily synthesize not only chlorophylls but also carotenoids. Many kinds of carotenoids are found in algae and, recently, taxonomic studies of algae have been developed. In this review, the relationship between the distribution of carotenoids and the phylogeny of oxygenic phototrophs in sea and fresh water, including cyanobacteria, red algae, brown algae and green algae, is summarized. These phototrophs contain division- or class-specific carotenoids, such as fucoxanthin, peridinin and siphonaxanthin. The distribution of α-carotene and its derivatives, such as lutein, loroxanthin and siphonaxanthin, are limited to divisions of Rhodophyta (macrophytic type), Cryptophyta, Euglenophyta, Chlorarachniophyta and Chlorophyta. In addition, carotenogenesis pathways are discussed based on the chemical structures of carotenoids and known characteristics of carotenogenesis enzymes in other organisms; genes and enzymes for carotenogenesis in algae are not yet known. Most carotenoids bind to membrane-bound pigment-protein complexes, such as reaction center, light-harvesting and cytochrome b(6)f complexes. Water-soluble peridinin-chlorophyll a-protein (PCP) and orange carotenoid protein (OCP) are also established. Some functions of carotenoids in photosynthesis are also briefly summarized.
Topics: Animals; Carotenoids; Chlorophyta; Cyanobacteria; Phaeophyceae; Phototrophic Processes; Phylogeny; Rhodophyta
PubMed: 21747749
DOI: 10.3390/md9061101 -
Microbiological Research Oct 2022Nanoscience has witnessed wide developments in various directions, in addition to its crossing through different vital medical and industrial applications. This prompted... (Review)
Review
Nanoscience has witnessed wide developments in various directions, in addition to its crossing through different vital medical and industrial applications. This prompted the development of green nanotechnology that is environmentally friendly with low toxicity, less energy use, and low eco-hazard. So, algae as green autotrophic organisms, gain increasing attention from nanotechnologists, giving a space for the arising of a new field "Algae nanotechnology", where the algae can be used either directly or via mimicry of their unique features and diversity. Algae can biosynthesis nanoparticles in intercellular or extracellular ways, depending on their cellular reactions inside the cells, their secondary metabolites, or extraction of the algal contents. The different ways of using algae for nanoparticles biosynthesis make it available to control the synthesizing of ecofriendly & biocompatible nanoparticles, with different types and morphologies. This review provides an overview of the previous efforts in this emerging field, giving a summary of the ability of algae in nanotechnology, besides future prospective of these trends in algal nanotechnology.
Topics: Biomimetics; Metal Nanoparticles; Nanoparticles; Nanotechnology; Plants
PubMed: 35834891
DOI: 10.1016/j.micres.2022.127111 -
Foods (Basel, Switzerland) Aug 2023Algae contain high-quality proteins, dietary fiber, minerals, and phenolic compounds, making them promising alternative ingredients. Since pasta is consumed worldwide,...
Algae contain high-quality proteins, dietary fiber, minerals, and phenolic compounds, making them promising alternative ingredients. Since pasta is consumed worldwide, it can be an effective vehicle for incorporating algae. This study compares the nutritional and antioxidant composition of whole-wheat pasta without and with enrichment of an algae mixture (containing and ) and ascertains the influence of the cooking procedure on their features. and were also analyzed in parallel for comparison purposes. Macronutrients, chlorides and salt, total and free amino acid profiles, and antioxidant properties (total phenolic content and ferric reducing antioxidant power) were analyzed using AOAC, Mohr's, high performance liquid chromatography with fluorescence detection, and spectrophotometric methods, respectively. The results show a significant increase in fat (70.4%), protein (29.7%), ash (26.5%), and total amino acid (except for serine, tryptophan, isoleucine, and threonine) contents in the raw algae-enriched pasta. The antioxidant activity was also higher (4.15 versus 3.68 g ferrous sulfate eq./g dw, respectively). After cooking, protein, dietary fiber, total amino acids (except threonine) and antioxidant activity were stable in the algae-enriched pasta. Thus, algae can be an excellent ingredient for food applications with health benefits.
PubMed: 37628038
DOI: 10.3390/foods12163039 -
Mathematical Biosciences and... Mar 2022Marine biology carbon sinks function is vital pathway to earned carbon neutrality object. Algae and shellfish can capture CO2 from atmosphere reducing CO2 concentration....
Marine biology carbon sinks function is vital pathway to earned carbon neutrality object. Algae and shellfish can capture CO2 from atmosphere reducing CO2 concentration. Therefore, algae and shellfish carbon sink capability investigate and forecast are important problem. The study forecast algae and shellfish carbon sinks capability trend base on 9 China coastal provinces. Fractional order accumulation grey model (FGM) is employed to forecast algae and shellfish carbon sinks capability. The result showed algae and shellfish have huge carbon sinks capability. North coastal provinces algae and shellfish carbon sinks capability trend smoothness. South and east coastal provinces carbon sinks capability trend changed drastically. The research advised coastal provinces defend algae and shellfish population, expand carbon sink capability. Algae and shellfish carbon sink resource will promote environment sustainable develop.
Topics: Carbon; Carbon Dioxide; Carbon Sequestration; Plants; Shellfish
PubMed: 35603362
DOI: 10.3934/mbe.2022254 -
Marine Drugs Oct 2021Brown algae () have been consumed by humans for hundreds of years. Current studies have shown that brown algae are rich sources of bioactive compounds with excellent... (Review)
Review
Brown algae () have been consumed by humans for hundreds of years. Current studies have shown that brown algae are rich sources of bioactive compounds with excellent nutritional value, and are considered functional foods with health benefits. Polysaccharides are the main constituents of brown algae; their diverse structures allow many unique physical and chemical properties that help to moderate a wide range of biological activities, including immunomodulation, antibacterial, antioxidant, prebiotic, antihypertensive, antidiabetic, antitumor, and anticoagulant activities. In this review, we focus on the major polysaccharide components in brown algae: the alginate, laminarin, and fucoidan. We explore how their structure leads to their health benefits, and their application prospects in functional foods and pharmaceuticals. Finally, we summarize the latest developments in applied research on brown algae polysaccharides.
Topics: Animals; Aquatic Organisms; Functional Food; Glucans; Phaeophyceae; Polysaccharides
PubMed: 34822491
DOI: 10.3390/md19110620 -
Scientific Reports Jun 2021Coral reefs experience phase shifts from coral- to algae-dominated benthic communities, which could affect the interplay between processes introducing and removing...
Coral reefs experience phase shifts from coral- to algae-dominated benthic communities, which could affect the interplay between processes introducing and removing bioavailable nitrogen. However, the magnitude of such processes, i.e., dinitrogen (N) fixation and denitrification levels, and their responses to phase shifts remain unknown in coral reefs. We assessed both processes for the dominant species of six benthic categories (hard corals, soft corals, turf algae, coral rubble, biogenic rock, and reef sands) accounting for > 98% of the benthic cover of a central Red Sea coral reef. Rates were extrapolated to the relative benthic cover of the studied organisms in co-occurring coral- and algae-dominated areas of the same reef. In general, benthic categories with high N fixation exhibited low denitrification activity. Extrapolated to the respective reef area, turf algae and coral rubble accounted for > 90% of overall N fixation, whereas corals contributed to more than half of reef denitrification. Total N fixation was twice as high in algae- compared to coral-dominated areas, whereas denitrification levels were similar. We conclude that algae-dominated reefs promote new nitrogen input through enhanced N fixation and comparatively low denitrification. The subsequent increased nitrogen availability could support net productivity, resulting in a positive feedback loop that increases the competitive advantage of algae over corals in reefs that experienced a phase shift.
Topics: Animals; Anthozoa; Coral Reefs; Denitrification; Ecosystem; Indian Ocean; Nitrogen; Nitrogen Fixation
PubMed: 34083565
DOI: 10.1038/s41598-021-90204-8 -
The Science of the Total Environment Jan 2021Improving the ecological status of water sources is a growing focus for many developed and developing nations, in particular with reducing nitrogen and phosphorus in... (Review)
Review
Improving the ecological status of water sources is a growing focus for many developed and developing nations, in particular with reducing nitrogen and phosphorus in wastewater effluent. In recent years, mixotrophic micro-algae have received increased interest in implementing them as part of wastewater treatment. This is based on their ability to utilise organic and inorganic carbon, as well as inorganic nitrogen (N) and phosphorous (P) in wastewater for their growth, with the desired results of a reduction in the concentration of these substances in the water. The aim of this review is to provide a critical account of micro-algae as an important step in wastewater treatment for enhancing the reduction of N, P and the chemical oxygen demand (COD) in wastewater, whilst utilising a fraction of the energy demand of conventional biological treatment systems. Here, we begin with an overview of the various steps in the treatment process, followed by a review of the cellular and metabolic mechanisms that micro-algae use to reduce N, P and COD of wastewater with identification of when the process may potentially be most effective. We also describe the various abiotic and biotic factors influencing micro-algae wastewater treatment, together with a review of bioreactor configuration and design. Furthermore, a detailed overview is provided of the current state-of-the-art in the use of micro-algae in wastewater treatment.
Topics: Biological Oxygen Demand Analysis; Bioreactors; Microalgae; Nitrogen; Phosphorus; Waste Disposal, Fluid; Wastewater
PubMed: 33207512
DOI: 10.1016/j.scitotenv.2020.142168