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The New Phytologist Jun 2019Sexual reproduction is a nearly universal feature of eukaryotic organisms. Meiosis appears to have had a single ancient origin, but the mechanisms underlying male or... (Review)
Review
Sexual reproduction is a nearly universal feature of eukaryotic organisms. Meiosis appears to have had a single ancient origin, but the mechanisms underlying male or female sex determination are diverse and have emerged repeatedly and independently in the different eukaryotic groups. The brown algae are a group of multicellular photosynthetic eukaryotes that have a distinct evolutionary history compared with animals and plants, as they have been evolving independently for over 1 billion yr. Here, we review recent work using the brown alga Ectocarpus as a model organism to study haploid sex chromosomes, and highlight how the diversity of reproductive and life cycle features of the brown algae offer unique opportunities to characterize the evolutionary forces and the mechanisms underlying the evolution of sex determination.
Topics: Biological Evolution; Gene Regulatory Networks; Genetic Loci; Phaeophyceae; Sex Chromosomes
PubMed: 30667071
DOI: 10.1111/nph.15694 -
Molecules (Basel, Switzerland) May 2023Seaweeds or algae are marine autotrophic organisms. They produce nutrients (e.g., proteins, carbohydrates, etc.) essential for the survival of living organisms as they... (Review)
Review
Seaweeds or algae are marine autotrophic organisms. They produce nutrients (e.g., proteins, carbohydrates, etc.) essential for the survival of living organisms as they participate in biochemical processes and non-nutritive molecules (such as dietary fibers and secondary metabolites), which can improve their physiological functions. Seaweed polysaccharides, fatty acids, peptides, terpenoids, pigments, and polyphenols have biological properties that can be used to develop food supplements and nutricosmetic products as they can act as antibacterial, antiviral, antioxidant, and anti-inflammatory compounds. This review examines the (primary and secondary) metabolites produced by algae, the most recent evidence of their effect on human health conditions, with particular attention to what concerns the skin and hair's well-being. It also evaluates the industrial potential of recovering these metabolites from biomass produced by algae used to clean wastewater. The results demonstrate that algae can be considered a natural source of bioactive molecules for well-being formulations. The primary and secondary metabolites' upcycling can be an exciting opportunity to safeguard the planet (promoting a circular economy) and, at the same time, obtain low-cost bioactive molecules for the food, cosmetic, and pharmaceutical industries from low-cost, raw, and renewable materials. Today's lack of methodologies for recovering bioactive molecules in large-scale processes limits practical realization.
Topics: Humans; Seaweed; Aquatic Organisms; Dietary Supplements; Carbohydrates; Polysaccharides
PubMed: 37241773
DOI: 10.3390/molecules28104032 -
Toxins Jun 2021This article gives a comprehensive overview on potentially harmful algae occurring in the built environment. Man-made structures provide diverse habitats where algae can... (Review)
Review
This article gives a comprehensive overview on potentially harmful algae occurring in the built environment. Man-made structures provide diverse habitats where algae can grow, mainly aerophytic in nature. Literature reveals that algae that is potentially harmful to humans do occur in the anthropogenic environment in the air, on surfaces or in water bodies. Algae may negatively affect humans in different ways: they may be toxic, allergenic and pathogenic to humans or attack human structures. Toxin-producing alga are represented in the built environment mainly by blue green algae (Cyanoprokaryota). In special occasions, other toxic algae may also be involved. Green algae (Chlorophyta) found airborne or growing on manmade surfaces may be allergenic whereas Cyanoprokaryota and other forms may not only be toxic but also allergenic. Pathogenicity is found only in a special group of algae, especially in the genus Prototheca. In addition, rare cases with infections due to algae with green chloroplasts are reported. Algal action may be involved in the biodeterioration of buildings and works of art, which is still discussed controversially. Whereas in many cases the disfigurement of surfaces and even the corrosion of materials is encountered, in other cases a protective effect on the materials is reported. A comprehensive list of 79 taxa of potentially harmful, airborne algae supplemented with their counterparts occurring in the built environment, is given. Due to global climate change, it is not unlikely that the built environment will suffer from more and higher amounts of harmful algal species in the future. Therefore, intensified research in composition, ecophysiology and development of algal growth in the built environment is indicated.
Topics: Air Pollutants; Air Pollution, Indoor; Allergens; Animals; Bacterial Toxins; Built Environment; Chlorophyta; Cyanobacteria; Humans
PubMed: 34209446
DOI: 10.3390/toxins13070465 -
Foods (Basel, Switzerland) Apr 2017Population growth combined with increasingly limited resources of arable land and fresh water has resulted in a need for alternative protein sources. Macroalgae... (Review)
Review
Population growth combined with increasingly limited resources of arable land and fresh water has resulted in a need for alternative protein sources. Macroalgae (seaweed) and microalgae are examples of under-exploited "crops". Algae do not compete with traditional food crops for space and resources. This review details the characteristics of commonly consumed algae, as well as their potential for use as a protein source based on their protein quality, amino acid composition, and digestibility. Protein extraction methods applied to algae to date, including enzymatic hydrolysis, physical processes, and chemical extraction and novel methods such as ultrasound-assisted extraction, pulsed electric field, and microwave-assisted extraction are discussed. Moreover, existing protein enrichment methods used in the dairy industry and the potential of these methods to generate high value ingredients from algae, such as bioactive peptides and functional ingredients are discussed. Applications of algae in human nutrition, animal feed, and aquaculture are examined.
PubMed: 28445408
DOI: 10.3390/foods6050033 -
The Plant Journal : For Cell and... Aug 2014Algae are found in all aquatic and many terrestrial habitats. They are dominant in phytoplankton and biofilms thereby contributing massively to global primary... (Review)
Review
Algae are found in all aquatic and many terrestrial habitats. They are dominant in phytoplankton and biofilms thereby contributing massively to global primary production. Since algae comprise photosynthetic representatives of the various protoctist groups their physiology and appearance is highly diverse. This diversity is also mirrored in their characteristic life cycles that exhibit various facets of ploidy and duration of the asexual phase as well as gamete morphology. Nevertheless, sexual reproduction in unicellular and colonial algae usually has as common motive that two specialized, sexually compatible haploid gametes establish physical contact and fuse. To guarantee mating success, processes during sexual reproduction are highly synchronized and regulated. This review focuses on sex pheromones of algae that play a key role in these processes. Especially, the diversity of sexual strategies as well as of the compounds involved are the focus of this contribution. Discoveries connected to algal pheromone chemistry shed light on the role of key evolutionary processes, including endosymbiotic events and lateral gene transfer, speciation and adaptation at all phylogenetic levels. But progress in this field might also in the future provide valid tools for the manipulation of aquaculture and environmental processes.
Topics: Chlorophyta; Pheromones; Reproduction; Stramenopiles
PubMed: 24597605
DOI: 10.1111/tpj.12496 -
Marine Drugs Mar 2022Fucoxanthin is a brown-colored pigment from algae, with great potential as a bioactive molecule due to its numerous properties. This review aims to present current... (Review)
Review
Fucoxanthin is a brown-colored pigment from algae, with great potential as a bioactive molecule due to its numerous properties. This review aims to present current knowledge on this high added-value pigment. An accurate analysis of the biological function of fucoxanthin explains its wide photon absorption capacities in golden-brown algae. The specific chemical structure of this pigment also leads to many functional activities in human health. They are outlined in this work and are supported by the latest studies in the literature. The scientific and industrial interest in fucoxanthin is correlated with great improvements in the development of algae cultures and downstream processes. The best fucoxanthin producing algae and their associated culture parameters are described. The light intensity is a major influencing factor, as it has to enable both a high biomass growth and a high fucoxanthin content. This review also insists on the most eco-friendly and innovative extraction methods and their perspective within the next years. The use of bio-based solvents, aqueous two-phase systems and the centrifugal partition chromatography are the most promising processes. The analysis of the global market and multiple applications of fucoxanthin revealed that Asian companies are major actors in the market with macroalgae. In addition, fucoxanthin from microalgae are currently produced in Israel and France, and are mostly authorized in the USA.
Topics: Biomass; Humans; Microalgae; Seaweed; Xanthophylls
PubMed: 35447895
DOI: 10.3390/md20040222 -
Scientific Reports Mar 2022Some marine fishes are algae-feeding, and the microorganisms in their digestive tracts produce carbohydrate hydrolyzing enzymes such as agarose and fucosidase, which are...
Some marine fishes are algae-feeding, and the microorganisms in their digestive tracts produce carbohydrate hydrolyzing enzymes such as agarose and fucosidase, which are potentially interesting resource for new functional enzymes. The purpose of this study was to establish a method for identifying and utilizing characteristic bacteria from the intestines of two algae-eating fish species: Andamia tetradactylus, which exclusively eats algae on the rock surface, and stellar rockskipper Entomacrodus stellifer, which feeds on both algae and invertebrates. We tested the species composition of the intestinal bacterial flora and found that Proteobacteria were commonly found both in species as in the common gut communities of marine fish, whereas Spirochaetes and Tenericutes occupied the flora of A. tetradactylus. We then performed anaerobic and aerobic cultures and isolated 34 and 44 strains including 48 strains belonged to Vibrio species from A. tetradactylus and E. stellifer. We observed that some Vibrio strains formed a clear boundary to avoid contacting other strains of bacteria. Whole-genome sequencing of such two Vibrio alginolyticus strains revealed two cyclic chromosomes commonly found in the genome of Vibrio species, and some unique genes encoding alginate lyase, chitinases, and type I-F CRISPR-associated endoribonuclease for the first time in Vibrio alginolyticus.
Topics: Animals; Bacteria; Fishes; Gastrointestinal Microbiome; Perciformes; Vibrio; Vibrio alginolyticus
PubMed: 35301363
DOI: 10.1038/s41598-022-08511-7 -
Frontiers in Microbiology 2024A large number of microbial species tend to communicate and produce biofilm which causes numerous microbial infections, antibiotic resistance, and economic problems... (Review)
Review
A large number of microbial species tend to communicate and produce biofilm which causes numerous microbial infections, antibiotic resistance, and economic problems across different industries. Therefore, advanced anti-biofilms are required with novel attributes and targets, such as quorum sensing communication system. Meanwhile, quorum sensing inhibitors as promising anti-biofilm molecules result in the inhibition of particular phenotype expression blocking of cell-to-cell communication, which would be more acceptable than conventional strategies. Many natural products are identified as anti-biofilm agents from different plants, microorganisms, and marine extracts. Marine algae are promising sources of broadly novel compounds with anti-biofilm activity. Algae extracts and their metabolites such as sulfated polysaccharides (fucoidan), carotenoids (zeaxanthin and lutein), lipid and fatty acids (γ-linolenic acid and linoleic acid), and phlorotannins can inhibit the cell attachment, reduce the cell growth, interfere in quorum sensing pathway by blocking related enzymes, and disrupt extracellular polymeric substances. In this review, the mechanisms of biofilm formation, quorum sensing pathway, and recently identified marine algae natural products as anti-biofilm agents will be discussed.
PubMed: 38680918
DOI: 10.3389/fmicb.2024.1270174 -
Frontiers in Chemistry 2022Alginate is a water-soluble and acidic polysaccharide derived from the cell wall and intercellular substance of brown algae. It is widely distributed in brown algae,... (Review)
Review
Alginate is a water-soluble and acidic polysaccharide derived from the cell wall and intercellular substance of brown algae. It is widely distributed in brown algae, such as , and , etc. Alginate lyase can catalytically degrade alginate in a -eliminating manner, and its degradation product-alginate oligosaccharide (AOS) has been widely used in agriculture, medicine, cosmetics and other fields due to its wide range of biological activities. This article is mainly to make a brief introduction to the classification, source and application of alginate lyase. We hope this minireview can provide some inspirations for its development and utilization.
PubMed: 36157028
DOI: 10.3389/fchem.2022.1008010 -
Plants (Basel, Switzerland) Nov 2022Spirulina, a kind of blue-green algae, is one of the Earth's oldest known forms of life. Spirulina grows best in very alkaline environments, although it may flourish... (Review)
Review
Spirulina, a kind of blue-green algae, is one of the Earth's oldest known forms of life. Spirulina grows best in very alkaline environments, although it may flourish across a wide variety of pH values. There are several techniques for growing spp., ranging from open systems such as ponds and lakes, which are vulnerable to contamination by animals and extraterrestrial species, to closed systems such as photovoltaic reactors, which are not. Most contaminated toxins come from other toxic algae species that become mixed up during harvest, necessitating the study of spirulina production processes at home. Lighting, temperature, inoculation volume, stirring speed, dissolved particles, pH, water quality, and overall micronutrient richness are only a few of the environmental parameters influencing spirulina production. This review article covers the conditions required for spirulina cultivation, as well as a number of crucial factors that influence its growth and development while it is being grown. In addition, the article discusses harvesting processes, biomass measurement methods, the identification of dangerous algae, and the risk of contaminating algae as it grows on cultures. Spirulina's rising prospects as food for human consumption are a direct outcome of its prospective health and therapeutic advantages.
PubMed: 36432792
DOI: 10.3390/plants11223063