Microalgal lutein: Advancements in production, extraction, market potential, and applications.

Lutein, a bioactive xanthophyll, has recently attracted significant attention for numerous health benefits, e.g., protection of eye health, macular degeneration, and acute and chronic syndromes etc. Microalgae have emerged as the best platform for high-value lutein production with high productivity, lutein content, and scale-up potential. Algal lutein possesses numerous bioactivities, hence widely used in pharmaceuticals, nutraceuticals, aquaculture, cosmetics, etc. This review highlights advances in upstream lutein production enhancement and feasible downstream extraction and cell disruption techniques for a large-scale lutein biorefinery. Besides bioprocess-related advances, possible solutions for existing production challenges in microalgae-based lutein biorefinery, market potential, and emerging commercial scopes of lutein and its potential health applications are also discussed. The key enzymes involved in the lutein biosynthesizing Methyl-Erythritol-phosphate (MEP) pathway have been briefly described. This review provides a comprehensive updates on lutein research advancements covering scalable upstream and downstream production strategies and potential applications for researchers and industrialists.

Advances in oligosaccharides production from brown seaweeds: extraction, characterization, antimetabolic syndrome, and other potential applications.

Brown seaweeds are a promising source of bioactive substances, particularly oligosaccharides. This group has recently gained considerable attention due to its diverse cell wall composition, structure, and wide-spectrum bioactivities. This review article provides a comprehensive update on advances in oligosaccharides (OSs) production from brown seaweeds and their potential health applications. It focuses on advances in feedstock pretreatment, extraction, characterization, and purification prior to OS use for potential health applications. Brown seaweed oligosaccharides (BSOSs) are extracted using various methods. Among these, enzymatic hydrolysis is the most preferred, with high specificity, mild reaction conditions, and low energy consumption. However, the enzyme selection and hydrolysis conditions need to be optimized for desirable yield and oligosaccharides composition. Characterization of oligosaccharides is essential to determine their structure and properties related to bioactivities and to predict their most suitable application. This is well covered in this review. Analytical techniques such as high-performance liquid chromatography (HPLC), gas chromatography (GC), and nuclear magnetic resonance (NMR) spectroscopy are commonly applied to analyze oligosaccharides. BSOSs exhibit a range of biological properties, mainly antimicrobial, anti-inflammatory, and prebiotic properties among others. Importantly, BSOSs have been linked to possible health advantages, including metabolic syndrome management. Metabolic syndrome is a cluster of conditions, such as obesity, hypertension, and dyslipidemia, which increase the risk of cardiovascular disease and type 2 diabetes. Furthermore, oligosaccharides have potential applications in the food and pharmaceutical industries. Future research should focus on improving industrial-scale oligosaccharide extraction and purification, as well as researching their potential utility in the treatment of various health disorders.[Figure: see text].

Brown algae exhibit a great diversity to offer a wide range of OSs bioactivities.Non-enzymatic extraction yields 30-58% OSs more than enzymatic routes.Enzymatically derived OSs exhibit better bioactivity than non-enzymatic OSs.Nanofiltration/activated carbon can solve bottlenecks in large-scale purification.OSs health applications are proven at in vitro stage, clinical studies yet to be done.

Advances in oligosaccharides production from algal sources and potential applications.

In recent years, algal-derived glycans and oligosaccharides have become increasingly important in health applications due to higher bioactivities than plant-derived oligosaccharides. The marine organisms have complex, and highly branched glycans and more reactive groups to elicit greater bioactivities. However, complex and large molecules have limited use in broad commercial applications due to dissolution limitations. In comparison to these, oligosaccharides show better solubility and retain their bioactivities, hence, offering better applications opportunity. Accordingly, efforts are being made to develop a cost-effective method for enzymatic extraction of oligosaccharides from algal polysaccharides and algal biomass. Yet detailed structural characterization of algal-derived glycans is required to produce and characterize the potential biomolecules for improved bioactivity and commercial applications. Some macroalgae and microalgae are being evaluated as in vivo biofactories for efficient clinical trials, which could be very helpful in understanding the therapeutic responses. This review discusses the recent advancements in the production of oligosaccharides from microalgae. It also discusses the bottlenecks of the oligosaccharides research, technological limitations, and probable solutions to these problems. Furthermore, it presents the emerging bioactivities of algal oligosaccharides and their promising potential for possible biotherapeutic application.

Laccase: A potential biocatalyst for pollutant degradation.

In the continual march to a predominantly urbanized civilization, anthropogenic activities have increased scrupulously, industrialization have occurred, economic growth has increased, and natural resources are being exploited, causing huge waste management problems, disposal issues, and the evolution of several pollutants. In order to have a sustainable environment, these pollutants need to be removed and degraded. Bioremediation employing microorganisms or enzymes can be used to treat the pollutants by degrading and/or transforming the pollutants into different form which is less or non-toxic to the environment. Laccase is a diverse enzyme/biocatalyst belonging to the oxidoreductase group of enzymes produced by microorganisms. Due to its low substrate specificity and monoelectronic oxidation of substrates in a wide range of complexes, it is most commonly used to degrade chemical pollutants. For degradation of emerging pollutants, laccase can be efficiently employed; however, large-scale application needs reusability, thermostability, and operational stability which necessitated strategies like immobilization and engineering of robust laccase possessing desirable properties. Immobilization of laccase for bioremediation, and treatment of wastewater for degrading emerging pollutants have been focussed for sustainable development. Challenges of employing biocatalysts for these applications as well as engineering robust laccase have been highlighted in this study.

Biopharmaceutical applications of α-galactosidases.

α-Galactosidases are exoglycosidases that are active on galactose-containing side chains in oligosaccharides, polysaccharides, glycolipids, and glycoproteins. α-Galactosidases are gaining increased interest in human medicine, especially in the enzyme replacement therapy for Fabry's disease. α-Galactosidases with regioselectivity toward α-1,3-linked galactose find application in xenotransplantation and blood group transformation. The use of α-galactosidases as a therapeutic agent in alleviating the postprandial symptoms of irritable bowel syndrome is much acclaimed. The excellent therapeutic applications of α-galactosidases have led to an upwelling of worldwide research interventions to identify novel α-galactosidases with improved catalytic efficiency. In addition to these therapeutic applications, α-galactosidases also have interesting applications in the industrial sectors like food, feed, probiotics, sugar, and paper pulp. The current review focuses on the diverse therapeutic applications of α-galactosidases and their prospects.

Fucoidan from Marine Macroalgae: Biological Actions and Applications in Regenerative Medicine, Drug Delivery Systems and Food Industry.

The marine macroalgae produce a collection of bioactive polysaccharides, of which the sulfated heteropolysaccharide fucoidan produced by brown algae of the class Phaeophyceae has received worldwide attention because of its particular biological actions that confer nutritional and health benefits to humans and animals. The biological actions of fucoidan are determined by their structure and chemical composition, which are largely influenced by the geographical location, harvest season, extraction process, etc. This review discusses the structure, chemical composition and physicochemical properties of fucoidan. The biological action of fucoidan and its applications for human health, tissue engineering, regenerative medicine and drug delivery are also addressed. The industrial scenario and prospects of research depicted would give an insight into developing fucoidan as a commercially viable and sustainable bioactive material in the nutritional and pharmacological sectors.

Molecular advances in microbial α-galactosidases: challenges and prospects.

α-Galactosidase (α-D-galactosidase galactohydrolase; EC 3.2.1.22), is an industrially important enzyme that hydrolyzes the galactose residues in galactooligosaccharides and polysaccharides. The industrial production of α-galactosidase is currently insufficient owing to the high production cost, low production efficiency and low enzyme activity. Recent years have witnessed an increase in the worldwide research on molecular techniques to improve the production efficiency of microbial α-galactosidases. Cloning and overexpression of the gene sequences coding for α-galactosidases can not only increase the enzyme yield but can confer industrially beneficial characteristics to the enzyme protein. This review focuses on the molecular advances in the overexpression of α-galactosidases in bacterial and yeast/fungal expression systems. Recombinant α-galactosidases have improved biochemical and hydrolytic properties compared to their native counterparts. Metabolic engineering of microorganisms to produce high yields of α-galactosidase can also assist in the production of value-added products. Developing new variants of α-galactosidases through directed evolution can yield enzymes with increased catalytic activity and altered regioselectivity. The bottlenecks in the recombinant production of α-galactosidases are also discussed. The knowledge about the hurdles in the overexpression of recombinant proteins illuminates the emerging possibilities of developing a successful microbial cell factory and widens the opportunities for the production of industrially beneficial α-galactosidases.

Microbial α-galactosidases: Efficient biocatalysts for bioprocess technology.

Galactomannans, abundantly present in plant biomass, can be used as renewable fermentation feedstock for biorefineries working for the production of bioethanol and other value-added products. The complete and efficient bioconversion of biomass to fermentable sugars for the generation of biofuels and other value-added products require the concerted action of accessory enzymes like α-galactosidases, which can work in cohesion with other carbohydrases in an enzyme cocktail. In the paper industry, α-galactosidases enhance the bleaching effect of endo-ß-1,4-mannanases on softwood kraft pulp. Microbial α-galactosidases also find applications in the treatment of legume foods, recovery of sucrose from sugar beet syrup, improving the rheological properties of galactomannans, and synthesis of α-galactooligosaccharides to be used as functional food ingredients. Owing to their industrial applications, there is a surge in the research focused on α-galactosidases. The current review illustrates the diverse industrial applications of microbial α-galactosidases and their challenges and prospects.