A novel strategy for isolation and purification of fucoxanthinol and fucoxanthin from the diatom Nitzschia laevis

Production and purification of fucoxanthins and β-carotenes from Halopteris scoparia and their effects on digestive enzymes and harmful bacteria

ABSTRACTAlgae constitute a significant part of marine biodiversity. They represent a renewable source of bioactive metabolites from drug development and therapeutic fields. Fucoxanthin and β-carotene from the brown macroalgae Halopteris scoparia, were extracted using conventional organic solvent extraction, then purified, to homogeneity, based on various chromatographic principles. Their effects on digestive enzymes and harmful bacteria were investigated. The capacities of both purified pigments to inhibit α-amylase and trypsin enzymes were evaluated. Purified fucoxanthin and β-carotene exhibited interesting α-amylase inhibition activities, with IC50 of 300 and 500 µg/mL, respectively. Moreover, trypsin inhibition activities were detected using purified these two pigments. The antibacterial potential of the purified pigments was evaluated. β-carotene showed to be a great antibacterial natural compound against gram-positive and gram-negative bacteria such as Listeria monocytogenes, Staphylococcus aureus and Salmonella enterica with Minimal Inhibitory Concentration (MIC) of about 0.225, 0.1125, 0.225 µg/mL, respectively. Those findings are in favor of the exploitation of H. scoparia pigments in therapeutic fields as an antidiabetic source directly by the inhibition of α-amylase and trypsin as well as antibacterial agents against gastrointestinal infections.

Synthetic biology in microalgae towards fucoxanthin production for pharmacy and nutraceuticals

Synthetic biology has emerged as a powerful tool for engineering biological systems to produce valuable compounds, including pharmaceuticals and nutraceuticals. Microalgae, in particular, offer a promising platform for the production of bioactive compounds due to their high productivity, low land and water requirements, and ability to perform photosynthesis. Fucoxanthin, a carotenoid pigment found predominantly in brown seaweeds and certain microalgae, has gained significant attention in recent years due to its numerous health benefits, such as antioxidation, antitumor effect and precaution osteoporosis. This review provides an overview of the principles and applications of synthetic biology in the microbial engineering of microalgae for enhanced fucoxanthin production. Firstly, the fucoxanthin bioavailability and metabolism in vivo was introduced for the beneficial roles, followed by the biological functions of anti-oxidant activity, anti-inflammatory activity, antiapoptotic role antidiabetic and antilipemic effects. Secondly, the cultivation condition and strategy were summarized for fucoxanthin improvement with low production costs. Thirdly, the genetic engineering of microalgae, including gene overexpression, knockdown and knockout strategies were discussed for further improving the fucoxanthin production. Then, synthetic biology tools of CRISPR-Cas9 genome editing, transcription activator-like effector nucleases as well as modular assembly and chassis engineering were proposed to precise modification of microalgal genomes to improve fucoxanthin production. Finally, challenges and future perspectives were discussed to realize the industrial production and development of functional foods of fucoxanthin from microalgae.

Towards sustainable diatom biorefinery: Recent trends in cultivation and applications

Diatoms, with their complex cellular architecture, have been recognized as a source of limitless potential. These microbes are common in freshwater and marine habitats and are essential for primary production and carbon sequestration. They are excellent at utilizing nutrients, providing a sustainable method of treating wastewater while also producing biomass rich in beneficial substances like vitamins, carotenoids, polysaccharides, lipids, omega-3 fatty acids, pigments, and novel bioactive molecules. Additionally, they are highly efficient organisms that can be employed to monitor the environment by acting as trustworthy indicators of water quality. This comprehensive review explores the multifaceted applications of diatoms in a variety of fields, such as bioremediation, aquaculture, value-added products, and other applications. The review set out on a path towards greener, more sustainable methods amicable to both industry and the environment by utilizing theenormous diverse biotechnological potentials of diatoms.

Description and Characterization of the Odontella aurita OAOSH22, a Marine Diatom Rich in Eicosapentaenoic Acid and Fucoxanthin, Isolated from Osan Harbor, Korea

Third-generation biomass production utilizing microalgae exhibits sustainable and environmentally friendly attributes, along with significant potential as a source of physiologically active compounds. However, the process of screening and localizing strains that are capable of producing high-value-added substances necessitates a significant amount of effort. In the present study, we have successfully isolated the indigenous marine diatom Odontella aurita OAOSH22 from the east coast of Korea. Afterwards, comprehensive analysis was conducted on its morphological, molecular, and biochemical characteristics. In addition, a series of experiments was conducted to analyze the effects of various environmental factors that should be considered during cultivation, such as water temperature, salinity, irradiance, and nutrients (particularly nitrate, silicate, phosphate, and iron). The morphological characteristics of the isolate were observed using optical and electron microscopes, and it exhibited features typical of O. aurita. Additionally, the molecular phylogenetic inference derived from the sequence of the small-subunit 18S rDNA confirmed the classification of the microalgal strain as O. aurita. This isolate has been confirmed to contain 7.1 mg g-1 dry cell weight (DCW) of fucoxanthin, a powerful antioxidant substance. In addition, this isolate contains 11.1 mg g-1 DCW of eicosapentaenoic acid (EPA), which is one of the nutritionally essential polyunsaturated fatty acids. Therefore, this indigenous isolate exhibits significant potential as a valuable source of bioactive substances for various bio-industrial applications.

Valorization of Phaeodactylum tricornutum for integrated preparation of diadinoxanthin and fucoxanthin

Integrated preparation of high-purity carotenoids from marine microalgae using green and efficient methods still faces enormous challenges. In this study, valorization of the economic Phaeodactylum tricornutum using integrated preparation of diadinoxanthin (Ddx) and fucoxanthin (Fx) was explored containing four steps including algae cultivation, solvent extraction, ODS open-column chromatography, and ethanol precipitation for the first time. Several essential key factors were optimized for simultaneously extracting Ddx and Fx from P. tricornutum. ODS open-column chromatography was used to isolate Ddx and Fx. Purification of Ddx and Fx was accomplished using ethanol precipitation. After optimization, the purity of Ddx and Fx was more than 95%, and the total recovery rates of Ddx and Fx were approximately 55% and 85%, respectively. The purified Ddx and Fx were identified as all-trans-diadinoxanthin and all-trans-fucoxanthin, respectively. The antioxidant capacity of the purified Ddx and Fx was assessed using two tests in vitro: DPPH and ABTS radical assays.

Manipulation in Culture Conditions of Nanofrustulum shiloi for Enhanced Fucoxanthin Production and Isolation by Preparative Chromatography

Microalgae produce a variety of high-value chemicals including carotenoids. Fucoxanthin is also a carotenoid that has many physiological functions and biological properties. For this reason, the cost-effective production of fucoxanthin at an industrial scale has gained significant attention. In the proposed study, fucoxanthin production was aimed to be increased by altering the culture conditions of N. shiloi. The effect of light intensity aeration rate, different nitrogen sources, and oxidative stress on the biomass and fucoxanthin productivity have been discussed. Based on these results, the fucoxanthin increased to 97.45 ± 2.64 mg/g by adjusting the light intensity to 50 µmol/m²s, and aeration rate at 5 L/min using oxidative stress through the addition of 0.1 mM H₂O₂ and 0.1 mM NaOCl to the culture medium. Fucoxanthin was then purified with preparative HPLC using C₃₀ carotenoid column (10 mm × 250 mm, 5 μm). After the purification procedure, Liquid chromatography tandem mass spectrometry (LC-MS/MS) and UV-vis spectroscopy were employed for the confirmation of fucoxanthin. This study presented a protocol for obtaining and purifying considerable amounts of biomass and fucoxanthin from diatom by manipulating culture conditions. With the developed methodology, N. shiloi could be evaluated as a promising source of fucoxanthin at the industrial scale for food, feed, cosmetic, and pharmaceutical industries.

Fucoxanthin Production of Microalgae under Different Culture Factors: A Systematic Review

Fucoxanthin is one of the light-harvesting pigments in brown microalgae, which is increasingly gaining attention due to its numerous health-promoting properties. Currently, the production of microalgal fucoxanthin is not yet feasible from an economic perspective. However, the cultivation of microalgae at favourable conditions holds great potential to increase the viability of this fucoxanthin source. Hence, this study aimed to review the fucoxanthin production of microalgae under different conditions systematically. A literature search was performed using the Web of Science, Scopus and PubMed databases. A total of 188 articles were downloaded and 28 articles were selected for the current review by two independent authors. Microalgae appeared to be a more reliable fucoxanthin source compared to macroalgae. Overall, a consensus fucoxanthin production condition was obtained and proposed: light intensity ranging from 10 to 100 µmol/m²/s could achieve a higher fucoxanthin content. However, the optimal light condition in producing fucoxanthin is species-specific. The current review serves as an antecedent by offering insights into the fucoxanthin-producing microalgae response to different culture factors via a systematic analysis. With the current findings and recommendations, the feasibility of producing fucoxanthin commercially could be enhanced and possibly achieve practical and sustainable fucoxanthin production.

New Insights into Xanthophylls and Lipidomic Profile Changes Induced by Glucose Supplementation in the Marine Diatom Nitzschia laevis

Nitzschia laevis is a candidate microorganism for bioactive compounds (fucoxanthin and eicosapentaenoic acid (EPA)) production. In this study, the impacts of glucose-induced trophic transition on biomass, photosynthesis, pigments, and lipid profiles were examined. The specific growth rate was increased under glucose addition, achieved at 0.47 day−1 (0.26 ± 0.01 day−1 for the group without glucose in medium). However, the photosynthetic parameters and pigments including chlorophylls, fucoxanthin, and diatoxanthin were reduced. The net yield of EPA doubled under glucose addition, reaching 20.36 ± 1.22 mg/L in 4 days. In addition, the alteration in detailed lipid molecular species was demonstrated with a focus on EPA-enriched lipids. The effects of 2-deoxyglucose (2DG) indicated that glucose phosphorylation was involved in glucose-induced regulation. These findings provide novel data for guiding the application of this diatom strain in the functional food industries.

Fucoxanthin’s Optimization from Undaria pinnatifida Using Conventional Heat Extraction, Bioactivity Assays and In Silico Studies

Brown macroalgae are a potential source of natural pigments. Among them, Undaria pinnatifida is recognized for its high concentration of fucoxanthin (Fx), which is a pigment with a wide range of bioactivities. In this study, three independent parameters were optimized for conventional heat extraction (CHE) to maximize the recovery of Fx from Undaria pinnatifida. Optimal conditions (temperature = 45 °C, solvent = 70%, and time = 61 min) extracted 5.1 mg Fx/g dw. Later, the bioactivities of the Fx-rich extracts (antioxidant, antimicrobial, and neuroprotective) were assessed using in vitro and in silico approaches. In vitro assays indicated that Fx has a strong antioxidant capacity and even stronger antimicrobial activity against gram-positive bacteria. This data was supported in silico where Fx established a high binding affinity to DR, a Staphylococcus aureus protein, through aa ALA-8, LEU-21, and other alkane interactions. Finally, the in vitro enzymatic inhibition of AChE using Fx, was further supported using docking models that displayed Fx as having a high affinity for aa TYR72 and THR 75; therefore, the Fx extraction behavior explored in this work may reduce the costs associated with energy and solvent consumption. Moreover, this paper demonstrates the efficiency of CHE when recovering high amounts of Fx from Undaria pinnatifida. Furthermore, these findings can be applied in different industries.

Rapid Purification of Fucoxanthin from Phaeodactylum tricornutum

Fucoxanthin is a natural marine xanthophyll and exhibits a broad range of biological activities. In the present study, a simple and efficient two-step method was used to purify fucoxanthin from the diatom, Phaeodactylum tricornutum. The crude pigment extract of fucoxanthin was separated by silica gel column chromatography (SGCC). Then, the fucoxanthin-rich fraction was purified using a hydrophile-lipophile balance (HLB) solid-phase extraction column. The identification and quantification of fucoxanthin were determined by high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS). This two-step method can obtain 92.03% pure fucoxanthin and a 76.67% recovery rate. In addition, ¹H and ¹³C NMR spectrums were adopted to confirm the identity of fucoxanthin. Finally, the purified fucoxanthin exhibited strong antioxidant properties in vitro with the effective concentration for 50% of maximal scavenging (EC50) of 1,1-Dihpenyl-2-picrylhydrazyl (DPPH) and 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radicals being 0.14 mg·mL^-1 and 0.05 mg·mL^-1, respectively.

Nutrient acclimation in benthic diatoms with adaptive laboratory evolution

The growth of marine diatom algaeChaetoceros gracilisandThalassiosira weissflogiiin agricultural fertilizers and additional carbon sources were evaluated. The main objective behind the study was to increase the growth and productivity of the diatom acclimatized under adaptive laboratory culture conditions. In optimized conditions,C.gracilisshowed the highest cell density in NPK (202.5 ± 2.6 × 10⁵ cells mL^-1), maximum carbohydrate (212.8 ± 4.0 mg g^-1) and protein (133.9 ± 1.5 mg g^-1) in urea. In contrast,T.weissflogiishowed the highest cell density in glycerol (148.2 ± 2.5x10⁵ cells mL^-1), maximum carbohydrate in glycerol (273.7 ± 3.3 mg g^-1), and protein in sucrose (126.2 ± 0.7 mg g^-1). Lipid content was maximum in glycerol (73.4 ± 0.6%) and glucose (39.7 ± 0.2%) in C. gracilisand T. weissflogii respectively. Increased pigment production and chrysolaminarin concentration were obtained in both marine species. The study highlights the importance of adaptive laboratory evolution as an promising tool in enhancing productivity in diatom algae.

Mass cultivation of marine diatoms using local salts and its impact on growth and productivity

Diatoms are of great interest for many biotechnological applications. The present study highlights the comparative analysis for mass cultivation under the effect of seawater made from table salt (TS), rock salt (RS), and synthetic seawater in the presence of normal silica and induction coupled plasma (ICP) nanosilica (Nano Si) for inducing diatom growth. Out of all the test formulations, RS-f/2 Nano Si showed the best results with maximum cell density (3.16x107±0.04 and 3.24x107±0.05 cells mL^-1), carbohydrate (403.0±3.4 and 398.0±8.1 mg g^-1), and chrysolaminarin yield (66.2±5.5 and 49.3±5.1 mg g^-1) in both Chaetoceros gracilis and Thalassiosira weissflogii respectively. The presence of a rich pigment profile and lipids further highlights the importance of TS and RS for cost-effective mass culturing. Results reveal that mass cultivation of marine diatoms with TS and RS in the presence of nanosilica not only reduces costs but also enhances metabolite production.

Exploring the Biotechnological Value of Marine Invertebrates: A Closer Look at the Biochemical and Antioxidant Properties of Sabella spallanzanii and Microcosmus squamiger

Sabella spallanzanii and Microcosmus squamiger were profiled for proximate composition, minerals, amino acids, fatty acids (FA), carotenoids, radical scavenging activity on the 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical, oxygen radical absorbance capacity (ORAC) and iron and copper chelating properties. Microcosmus squamiger had the highest level of moisture and crude protein, S. spallanzanii was enriched in crude fat and ash. Both species had similar levels of carbohydrates and energy. There was a prevalence of arginine and glycine in S. spallanzanii, and of taurine in M. squamiger. The most abundant minerals in both species were Na, Ca, and K. The methanol extract of S. spallanzanii had metal chelating properties towards copper and iron, while the methanol extract of M. squamiger was able to chelate copper. M. squamiger extracts had similar ORAC values. Fucoxanthinol and fucoxanthin were the major carotenoids in the M. squamiger dichloromethane extract. Saturated FA were more abundant than unsaturated ones in methanol extracts, and unsaturated FA prevailed in the dichloromethane extracts. Palmitic acid was the predominant FA in methanol extracts, whereas eicosapentaenoic (EPA) and dihomo-γ-linolenic acids were the major compounds in dichloromethane extracts. Low n-6/n-3 ratios were obtained. Our results suggests that both species could be explored as sources of bioactive ingredients with multiple applications.

Production of Fucoxanthin from Phaeodactylum tricornutum Using High Performance Countercurrent Chromatography Retaining Its FOXO3 Nuclear Translocation-Inducing Effect

Phaeodactylum tricornutum is a rich source of fucoxanthin, a carotenoid with several health benefits. In the present study, high performance countercurrent chromatography (HPCCC) was used to isolate fucoxanthin from an extract of P. tricornutum. A multiple sequential injection HPCCC method was developed combining two elution modes (reverse phase and extrusion). The lower phase of a biphasic solvent system (n-heptane, ethyl acetate, ethanol and water, ratio 5/5/6/3, v/v/v/v) was used as the mobile phase, while the upper phase was the stationary phase. Ten consecutive sample injections (240 mg of extract each) were performed leading to the separation of 38 mg fucoxanthin with purity of 97% and a recovery of 98%. The process throughput was 0.189 g/h, while the efficiency per gram of fucoxanthin was 0.003 g/h. Environmental risk and general process evaluation factors were used for assessment of the developed separation method and compared with existing fucoxanthin liquid-liquid isolation methods. The isolated fucoxanthin retained its well-described ability to induce nuclear translocation of transcription factor FOXO3. Overall, the developed isolation method may represent a useful model to produce biologically active fucoxanthin from diatom biomass.

Indoor mass cultivation of marine diatoms for biodiesel production using induction plasma synthesized nanosilica

In this work, two benthic marine diatoms Chaetoceros sp. and Thalassiosira sp. were grown in modified f/2 medium in which normal silica was replaced with inductively coupled plasma (ICP) nanosilica for indoor mass cultivation and its impact on growth, lipid content, lipid quality and metabolite production were monitored. Results indicate thatunder mass cultivation using ICP nano silica medium, Thalassiosirasp. reached 3.6 and Chaetoceros sp. reached 3.2-fold higher cell density compared to normal Si medium. The primary metabolite production and total lipid content was higher in Chaetoceros sp. (44.33 ± 2.51% DCW) compared to Thalassiosira sp. (29.66 ± 1.52% DCW). In mass cultivation, ICP synthesized nanosilica powder was effective in enhancing the cell density, production of metabolites, pigments, and lipids in the marine diatoms studied. This is the first report on the use of ICP nanosilica in carrying out indoor mass cultivation of marine diatom isolates as potential biodiesel and biomolecule feedstocks.

Isolation and Purification of Fucoxanthin from Brown Seaweed Sargassum horneri Using Open ODS Column Chromatography and Ethanol Precipitation

As an abundant marine xanthophyll, fucoxanthin (FX) exhibits a broad range of biological activities. The preparation of high-purity FX is in great demand, however, most of the available methods require organic solvents which cannot meet the green chemistry standard. In the present study, a simple and efficient purification approach for the purification of FX from the brown seaweed Sargassum horneri was carried out. The FX-rich ethanol extract was isolated by octadecylsilyl (ODS) column chromatography using ethanol-water solvent as a gradient eluent. The overwhelming majority of FX was successfully eluted by the ethanol-water mixture (9:1, v/v), with a recovery rate of 95.36%. A parametric study was performed to optimize the aqueous ethanol precipitation process by investigating the effects on the purity and recovery of FX. Under the optimal conditions, the purity of FX was 91.07%, and the recovery rate was 74.98%. Collectively, the eco-friendly method was cost-efficient for the purification of FX. The developed method provides a potential approach for the large-scale production of fucoxanthin from the brown seaweed Sargassum horneri.

A Biorefinery Approach to the Biomass of the Seaweed Undaria pinnatifida (Harvey Suringar, 1873): Obtaining Phlorotannins-Enriched Extracts for Wound Healing

Brown seaweeds are recognized sources of compounds with a wide range of properties and applications. Within these compounds, phlorotannins are known to possess several bioactivities (e.g., antioxidant, anti-inflammatory, and antimicrobial) with potential to improve wound healing. To obtain phlorotannins enriched extracts from Undaria pinnatifida, a biorefinery was set using low-cost industry-friendly methodologies, such as sequential solid-liquid extraction and liquid-liquid extraction. The obtained extracts were screened for their antioxidant and antimicrobial activity against five common wound pathogens and for their anti-inflammatory potential. The ethanolic wash fraction (wE100) had the highest antioxidant activity (114.61 ± 10.04 mmol·mg-1 extract by Diphenyl-1-picrylhydrazyl (DPPH) and 6.56 ± 1.13 mM eq. Fe II·mg-1 extract by and Ferric Reducing Antioxidant Power (FRAP)), acting efficiently against Gram-negative (Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria, and showing a nitric oxide production inhibition over 47% when used at 0.01 µg·mL-1. NMR and FTIR chemical characterization suggested that phlorotannins are present. Obtained fraction wE100 proved to be a promising candidate for further inclusion as wound healing agents, while the remaining fractions analyzed are potential sources for other biotechnological applications, giving emphasis to a biorefinery and circular economy framework to add value to this seaweed and the industry.

Medicinal Prospects of Antioxidants From Algal Sources in Cancer Therapy

Though cancer therapeutics can successfully eradicate cancerous cells, the effectiveness of these medications is mostly restricted to several deleterious side effects. Therefore, to alleviate these side effects, antioxidant supplementation is often warranted, reducing reactive species levels and mitigating persistent oxidative damage. Thus, it can impede the growth of cancer cells while protecting the normal cells simultaneously. Moreover, antioxidant supplementation alone or in combination with chemotherapeutics hinders further tumor development, prevents chemoresistance by improving the response to chemotherapy drugs, and enhances cancer patients' quality of life by alleviating side effects. Preclinical and clinical studies have been revealed the efficacy of using phytochemical and dietary antioxidants from different sources in treating chemo and radiation therapy-induced toxicities and enhancing treatment effectiveness. In this context, algae, both micro and macro, can be considered as alternative natural sources of antioxidants. Algae possess antioxidants from diverse groups, which can be exploited in the pharmaceutical industry. Despite having nutritional benefits, investigation and utilization of algal antioxidants are still in their infancy. This review article summarizes the prospective anticancer effect of twenty-three antioxidants from microalgae and their potential mechanism of action in cancer cells, as well as usage in cancer therapy. In addition, antioxidants from seaweeds, especially from edible species, are outlined, as well.

Microalgae Biomolecules: Extraction, Separation and Purification Methods

Several microalgae species have been exploited due to their great biotechnological potential for the production of a range of biomolecules that can be applied in a large variety of industrial sectors. However, the major challenge of biotechnological processes is to make them economically viable, through the production of commercially valuable compounds. Most of these compounds are accumulated inside the cells, requiring efficient technologies for their extraction, recovery and purification. Recent improvements approaching physicochemical treatments (e.g., supercritical fluid extraction, ultrasound-assisted extraction, pulsed electric fields, among others) and processes without solvents are seeking to establish sustainable and scalable technologies to obtain target products from microalgae with high efficiency and purity. This article reviews the currently available approaches reported in literature, highlighting some examples covering recent granted patents for the microalgae’s components extraction, recovery and purification, at small and large scales, in accordance with the worldwide trend of transition to bio-based products.

Fucoxanthin activities motivate its nano/micro-encapsulation for food or nutraceutical application: a review

Fucoxanthin is a xanthophyll carotenoid abundant in marine brown algae. The potential therapeutic effects of fucoxanthin on tumor intervention have been well documented, which have aroused great interests in utilizing fucoxanthin in functional foods and nutraceuticals. However, the utilization of fucoxanthin as a nutraceutical in food and nutrient supplements is currently limited due to its low water solubility, poor stability, and limited bioaccessibility. Nano/micro-encapsulation is a technology that can overcome these challenges. A systematic review on the recent progresses in nano/micro-delivery systems to encapsulate fucoxanthin in foods or nutraceuticals is warranted. This article starts with a brief introduction of fucoxanthin and the challenges of oral delivery of fucoxanthin. Nano/micro-encapsulation technology is then covered, including materials and strategies for constructing the delivery system. Finally, future prospective has been discussed on properly designed oral delivery systems of fucoxanthin for managing cancer. Natural edible materials such as whey protein, casein, zein, gelatin, and starch have been successfully utilized to fabricate lipid-based, gel-based, or emulsion-based delivery systems, molecular nanocomplexes, and biopolymer nanoparticles with the aid of advanced processing techniques, such as freeze-drying, high pressure homogenization, sonication, anti-solvent precipitation, coacervation, ion crosslinking, ionic gelation, emulsification, and enzymatic conjugation. These formulated nano/micro-capsules have proven to be effective in stabilizing and enhancing the bioaccessibility of fucoxanthin. This review will inspire a surge of multidisciplinary research in a broader community of foods and motivate material scientists and researchers to focus on nano/micro-encapsulated fucoxanthin in order to facilitate the commercialization of orally-deliverable tumor intervention products.

Inductively coupled plasma nanosilica based growth method for enhanced biomass production in marine diatom algae

This work reports a novel solution-based method to trigger the growth of diatoms for enhanced biomass production, which can efficiently stimulate their applications in nutraceuticals, aquaculture and wastewater remediation. The optimization for the growth of three marine diatoms species was performed using inductively coupled plasma (ICP) synthesized nanosilica which can be a cost-effective and productive method for biomass production. The exponential growth phase was achieved in 14 days with high biomass productivity compared to F/2-Si Media [Chaetoceros sp. (125 ± 3 & 750 ± 3 mgL^-1day^-1); Skeletonema sp., (185.3 ± 2.63 & 562.5 ± 3.96 mgL^-1day^-1) and Thalassiosira sp. (312.5 ± 2.51 & 433.5 ± 1.80 mgL^-1day^-1)] along with a sharp rise of 50-100 fold increment in pigmentation. This work opens up an avenue with novel insights to trigger the growth of diatoms on large scale leading to their better exploitation towards biotechnological applications.

Scientific Approaches on Extraction, Purification and Stability for the Commercialization of Fucoxanthin Recovered from Brown Algae

The scientific community has corroborated the numerous beneficial activities of fucoxanthin, such as its antioxidant, anti-inflammatory, anticancer or neuroprotective effects, among others. These properties have attracted the attention of nutraceutical, cosmetic and pharmacological industries, giving rise to various possible applications. Fucoxanthin may be chemically produced, but the extraction from natural sources is considered more cost-effective, efficient and eco-friendly. Thus, identifying suitable sources of this compound and giving a general overview of efficient extraction, quantification, purification and stabilization studies is of great importance for the future production and commercialization of fucoxanthin. The scientific research showed that most of the studies are performed using conventional techniques, but non-conventional techniques begin to gain popularity in the recovery of this compound. High Performance Liquid Chromatography (HPLC), Nuclear Magnetic Resonance (NMR) and spectroscopy techniques have been employed in the quantification and identification of fucoxanthin. The further purification of extracts has been mainly accomplished using purification columns. Finally, the stability of fucoxanthin has been assessed as a free molecule, in an emulsion, or encapsulated to identify the variables that might affect its further industrial application.

Wealth from waste: Diatoms as tools for phycoremediation of wastewater and for obtaining value from the biomass

Diatoms are a type of microalgae with diverse capabilities which make them useful for multiple applications. The abundance of diatoms in water bodies facilitates the removal of pollutants from wastewater originating from different industries, such as agriculture and other anthropogenic sources. The unique photosynthetic, cellular and metabolic characteristics of diatoms allows them to utilize pollutants like nitrate, iron, phosphate, molybdenum, silica, and heavy metals, such as copper, cadmium, chromium, lead, etc., which make diatoms a good option for wastewater treatment. In addition, the biomass produced by diatoms growth on wastewaters has diverse applications and can, therefore, be valuable. This review focusses on the unique capabilities of diatoms for wastewater remediation and the capture of carbon dioxide, concomitant with the generation of valuable products. Diatom biorefinery can be a sustainable solution to wastewater management, and the biomass obtained from treatment can be turned into biofuels, biofertilizers, nutritional supplements for animal production, and used for pharmaceutical applications containing bioactive compounds like EPA, DHA and pigments such as fucoxanthin.

Purification of fucoxanthin from Sargassum wightii Greville and understanding the inhibition of angiotensin 1-converting enzyme: An in vitro and in silico studies

The isolation and purification of active components from the brown algae Sargassum.wightii is highly limited. In the present study, fucoxanthin was purified from S. wightii using simple methods. Ethyl acetate fraction obtained by Soxhlet extraction contained high concentration of fucoxanthin. Fucoxanthin-rich fraction was further subjected to open silica column chromatography and thin layer chromatography to obtain purified fucoxanthin. Purified fucoxanthin showed in vitro antioxidant activity. Fucoxanthin showed inhibition of angiotensin I-converting enzyme (ACE) with half maximal inhibitory value of 822.64 ± 17.69 μM. Kinetic analysis revealed mixed non-competitive inhibition with inhibitory constant of 600 μM for fucoxanthin against ACE. Molecular docking analysis showed the interaction of fucoxanthin with amino acids and zinc ion present in the active site of the human ACE. Molecular dynamics analysis demonstrated the stability of the fucoxanthin and ACE complex in in silico. These results show that S. wightii may be used as food ingredient to overcome hypertension.

Fucoxanthinol from the Diatom Nitzschia Laevis Ameliorates Neuroinflammatory Responses in Lipopolysaccharide-Stimulated BV-2 Microglia

In recent years, microalgae have drawn increasing attention as a valuable source of functional food ingredients. Intriguingly, Nitzschia laevis is rich in fucoxanthinol that is seldom found in natural sources. Fucoxanthinol, a marine xanthophyll carotenoid, possesses various beneficial bioactivities. Nevertheless, it's not clear whether fucoxanthinol could exert anti-neuroinflammatory function. In light of these premises, the aim of the present study was to investigate the anti-inflammatory role of fucoxanthinol purified from Nitzschia laevis in Lipopolysaccharide (LPS)-stimulated microglia. The results showed that pre-treatment of fucoxanthinol remarkably attenuated the expression of LPS-induced nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the production of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE-2), nitric oxide (NO) and reactive oxygen species (ROS) induction. Modulation mechanism studies revealed that fucoxanthinol hampered nuclear factor-kappa B (NF-κB), Akt, and mitogen-activated protein kinase (MAPK) pathways. Meanwhile, fucoxanthinol led to the enhancement of nuclear translocation of NF-E2-related factor 2 (Nrf2), and the upregulation of heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO-1). Taken together, the results indicated that fucoxanthinol obtained from Nitzschia laevis had great potential as a neuroprotective agent in neuroinflammation and neurodegenerative disorders.