Microalgal Metabolites Research Articles

In silico validation of microalgal metabolites against Diabetes mellitus

Aim. Present study aimed to evaluate the efficiency of microalgal metabolites as ligands for anti-diabetic target proteins viz., glucokinase, fructose-1, 6-bisphosphatase, glycogen synthase kinase, cytochrome P450, multi drug resistant protein, and peroxisome proliferator-activated receptor-(PPAR) via computational approach.
 Matherials and methods. Three-dimensional structures of microalgal metabolites were retrieved from PubChem database and were energy minimized. The active site of target protein was predicted through PDB sum. Molecular docking was performed with microalgae metabolites by using Hex 8.0 and DockThor server.
 Results. Hex docking revealed that the binding interaction of fucoxanthin was higher with fructose 1.6 bis-phosphatase (-298.31), human multidrug resistant protein 1 (-369.67), and PPAR(-404.18). DockThor docking indicated that zeaxanthin with glucokinase produced higher total energy (111.23 kcal/mol) and interaction energy (-2.99 kcal/mol). Lutein with fructose 1.6 bis phosphatase, human multidrug resistant protein, glycogen synthase kinase, PPARand cytochrome p450 produced higher total energy and interaction energy.
 Conclusion. Further studies will assess the anti-diabetic effect of carotenoids of microalgae especially lutein, zeaxanthin and fucoxanthin.

PHARMACEUTICALLY VALUABLE BIOACTIVE COMPOUNDS OF ALGAE

ABSTRACT Pharmaceutically valuable products from micro algae and its industrial commercialization today is still in its infancy and can be seen as a gateway to a multibillion dollar industry. Microalgae generally grow autotrophically and are ubiquitous in nature.They represent a major untapped resource of genetic potential for valuable bioactive agents and fine biochemical. This proven ability of microalgae to produce these compounds places these microorganisms in the biotechnological spotlight for applications and commercialization as in the Pharmaceutical industry. The production of microalgal metabolites, which stimulate defense mechanisms in the human body, has spurred intense study of the application of micro algal biomass and products thereof in various food preparations, pharmacological and medical products. There is therefore a huge scope for further study of the identified algal compounds and their activities in the treatment and prevention of various diseases, in addition to an ongoing search for other, as yet undetected, metabolites. Key words:Algae,Pharmaceuticals, Bioactive compounds.

An enclosed rotating floating photobioreactor (RFP) powered by flowing water for mass cultivation of photosynthetic microalgae.

BackgroundThe design of photobioreactor (PBR) for outdoor mass cultivation of microalgae determines the distribution of solar irradiance among cells in the culture, mode of agitation, mass transfer efficacy, and energy consumption, thus determines the productivity of the system and the cost of production. In this study, the concept of a floating photobioreactor with rotation function is proposed. Dunaliella tertiolecta, a model microalga, cultured in the attached vessels was evaluated.ResultsThe rotation of the photobioreactor was powered by flowing water, in this case waves generated through a paddle wheel in an outdoor raceway pond for proof of concept. The rotating floating PBR (RFP) could be powered by natural flowing stream, river, and tidal waves, thus there could be no energy cost for agitation of the cultures in maintaining the cells in suspension. This RFP is characterized by its energy-saving and temperature control properties as well as more homogenous light distribution in the culture as compared to conventional culture systems, such as raceway pond. Maximal cell concentration of 8.38 × 106 cells mL−1, biomass productivity of 3.10 g m−2 day−1, and photosynthetic efficiency of 4.61 % (PAR) were achieved. In addition, satisfactory productivities of D. tertiolecta metabolites including carotenoids, mycosporine-like amino acids and lipids were also obtained.ConclusionsThe RFP, powered by flowing water, creates an innovative culture technology for economical cultivation of microalgal cells and production of microalgal metabolites.

A fast and direct liquid chromatography‐mass spectrometry method to detect and quantify polyunsaturated aldehydes and polar oxylipins in diatoms

AbstractPolyunsaturated aldehydes (PUAs) are a group of microalgal metabolites that have attracted a lot of attention due to their biological activity. Determination of PUAs has become an important routine procedure in plankton and biofilm investigations, especially those that deal with chemically mediated interactions. Here we introduce a fast and direct derivatization free method that allows quantifying PUAs in the nanomolar range, sufficient to undertake the analysis from cultures and field samples. The sample preparation requires one simple filtration step and the initiation of PUA formation by cell disruption. After centrifugation the samples are ready for measurement without any further handling. Within one chromatographic run this method additionally allows us to monitor the formation of the polar oxylipins arising from the cleavage of precursor fatty acids. The robust method is based on analyte separation and detection using ultra high performance liquid chromatography‐atmospheric pressure chemical ionization mass spectrometry (UHPLC‐APCI MS) and enables high throughput investigations by employing an analysis time of only 5 min. Our protocol thus provides an alternative and extension to existing PUA determinations based on gas chromatography‐mass spectrometry (GC‐MS) with shorter run times and without any chemical derivatization. It also enables researchers with widely available LC‐MS analytical platforms to monitor PUAs. Additionally, non‐volatile oxylipins such as ω‐oxo‐acids and related compounds can be elucidated and monitored.

Flow cytometry enables dynamic tracking of algal stress response: A case study using carotenogenesis in Dunaliella salina

The cultivation under adverse growth conditions is a commonly used strategy to trigger carotenoid accumulation in microalgae. In order to characterize important factors affecting the biotechnological productivity of microalgal species, systematic and accurate analysis of cellular properties and the physiological response to abiotic stress is required. Therefore, we have investigated the influence of various stress types on a broad spectrum of cellular properties during carotenogenesis in Dunaliella salina in a dynamic manner. Cellular properties were monitored in stained samples for cell vitality and neutral lipid fluorescence together with intrinsic parameters. The results revealed that nitrogen limitation and oversaturating light induced distinct adaptational responses in the cells. In the presence of nitrogen stress, the homogeneous population distribution split into two heterogeneous sub-populations for the cell vitality and neutral lipid fluorescence. Furthermore, we have demonstrated that flow cytometry is able to rapidly detect changes in the cell population upon exposure to abiotic stress. On the basis of this finding, it is possible to determine optimal harvesting time points based on the product content and culture vitality. This enables new perspectives for flow cytometry in the analysis of the metabolic stress response for robust production strategies of microalgal metabolites.

Biological activity of microalgae can be enhanced by manipulating the cultivation temperature and irradiance

Abstract The escalating levels of antibiotic resistance among pathogenic bacteria and the side effects of chemotherapeutic drugs in use forced the efforts of scientists to search for natural antimicrobial and anticancer substances with novel structures and unique mechanism of action. Focusing on bioproducts, recent trends in drug research have shown that microalgae (including the cyanobacteria) are promising organisms to furnish novel and safer biologically active compounds. Many microalgal metabolites have been found to possess potent antibacterial, antifungal, antiviral, anticancer and antiinflammatory activities, as well as antioxidant, enzyme inhibiting and immunostimulating properties. In this paper, the studies on the biological activity of microalgae associated with potential medical and pharmaceutical applications are briefly presented. Attention is focused on the impact of cultivation temperature, irradiance and growth stage on the biomass accumulation, activity and pathways of cell metabolism and the possibilities of using these variable factors to increase the diversity and quantity of biologically active substances synthesized by microalgae.

Respuesta morfológica y comparación multiparámetro de alternativas de extracción de aceite de microalgas para la obtención de biodiesel y co-productos.

Microalgae biomass emerges as an energy crop of great interest worldwide owing to its potential for obtaining biofuels and high value products and for the development of biorefinery processes owing to their varied composition and high biomass productivities per area unit. Several alternatives of microalgal metabolites extraction and transformation are being studied for the development of novel technologies for biomass using. Microalgae oil extraction is particularly important because is a key stage in microalgal biodiesel production chains and their efficiency contributes significantly to global process efficiency. In this study, a comparison of five oil extraction methods in lab-scale, taking into account extraction efficiency, energy consumption, costs of extraction and toxicity was made using five national bioprospecting microalgae strains. Methods evaluated were Solvent extraction with high speed homogenization (SHE), Continuous efflux solvent extraction (SCE), Hexane based extraction (HBE), Cyclohexane based extraction (CBE) and Ethanol-hexane extraction (EHE), microalgae strains used were Closterium sp., Amphiprora sp., Navicula sp., Nannochloropsis sp., and Guinardia sp., morphologycal response of strains to oil extraction methods was also evaluated using optic microscopy. Results shows that although there is not an unique oil extraction method with the best performance in all evaluated criteria, SCE, SHE and HBE methods presents high oil yields, while HBE method is the more convenient in global terms for use in lab scale and appears as an emerging technology for microalgae oil extraction in large scale.

Disposable Flat Panel Airlift Photobioreactors

AbstractSingle‐use technology based on disposable bioreactors is gaining more and more importance in biotechnology due its high flexibility, easy handling and ready‐to‐use character when supplied. A disposable, low‐cost, transparent flat panel airlift photobioreactor with optimized flow regime for the efficient cultivation of microalgae and production of microalgal metabolites is presented and possible applications are discussed.

Development and optimization of a metabolite extraction process for the high throughput screening of microalgal chimiodiversity

Since a decade, using microalgae for biofuel has become a major challenge worldwide. Several studies have evidenced that potent bioactive molecules can be purified from microalgae for cosmetic or health applications (e.g. antioxidants, immunostimulants, anticancer and antiviral compounds) in order to upgrade biomass. In some species, extraction of bioactive metabolites is tricky for the presence of highly resistant cell walls (Phaeodactylum tricornutum) or exopolysaccharidic barriers surrounding the cell membrane (Porphyridium purpureum). It was therefore essential to develop a process that preserves sensitive molecules. We optimized an extraction grinding process, the Mix Mill process, based on the use of vibrating microbeads. The process efficiency was assessed in pigments extraction experiments. It gave excellent extraction yields, and combined fidelity (no modification of analytes), compatibility with HPLC and LC-MS analysis, accuracy, simplicity, rapidity and safety. Moreover, it allowed to simultaneously extract all pigments, whatever their polarity or the strength that linked them to the cell structures. As a conclusion, the Mix Mill process is a general process for the total extraction of microalgal metabolites thought for high throughput screening of the microalgal chimiodiversity.

Recovery of microalgal biomass and metabolites: process options and economics

Commercial production of intracellular microalgal metabolites requires the following: (1) large-scale monoseptic production of the appropriate microalgal biomass; (2) recovery of the biomass from a relatively dilute broth; (3) extraction of the metabolite from the biomass; and (4) purification of the crude extract. This review examines the options available for recovery of the biomass and the intracellular metabolites from the biomass. Economics of monoseptic production of microalgae in photobioreactors and the downstream recovery of metabolites are discussed using eicosapentaenoic acid (EPA) recovery as a representative case study.

Biosynthesis of marine natural products: microorganisms and macroalgae.

This review covers the literature published on the biosynthesis of marine microbial and macroalgal natural products over a 10-year period from 1989 through 1998. A companion review covering the same time period on the biosynthesis of natural products from marine macroorganisms will appear at a later date in this journal. An earlier report by Garson published in this journal surveyed the whole field of marine natural product biosynthesis through mid 1988.1 The field through mid 1992 was reviewed elsewhere in an updated report,2 and several reviews covering specific aspects of marine microbial and macroalgal natural product biosynthesis have been published during this period. Reviewed biosynthetic topics include dinoflagellate and algal sterol side chains,3,4 algal oxylipins,5–8 and microalgal metabolites.9,10 Some of the microorganisms discussed in this report are not strictly marine. Bacteria isolated from coastal waters may have originated from terrestrial habitats and washed into the ocean. Many of these bacteria found at the interface of terrestrial and marine environments, especially the actinobacteria, tolerate wide ranges of salinities. The biosynthesis of natural products from freshwater cyanobacteria and microalgae are described for compounds that are structurally related to marine products. The biosynthetic origins of many marine invertebrate-derived natural products are not clear and have been proposed to involve associated microorganisms. A section on symbiotic microorganisms highlights our current knowledge on the involvement of invertebrate-hosted microorganisms in natural product biosynthesis through cellular localization studies. The review is organized on the basis of a similar taxonomic system used in previous marine natural product biosynthesis1, 2 and structure11 reviews. General labeling patterns consistently used throughout this report are outlined in Fig. 1. 2 Marine microorganisms

Recent advances in microalgal bioscience in Japan, with special reference to utilization of biomass and metabolites: a review

Japan is one of leading countries in the utilization of and research on microalgae, and various findings have been obtained. Many papers, however, have been published in Japanese, which prevents the information spreading far and wide. The purpose of this review is to introduce recent advances in the utilization of microalgae as well as their basic research in Japan. The discussion covers practical applications ofChlorella andSpirulina biomass to health foods, food additives and feed supplements. The current use of microalgae as live feeds for larvae in aquaculture is also summarized. With respect to microalgal metabolites the present status of research is described with a greater emphasis on bioactive compounds, pigments and oils as potential drugs, coloring matters and biofuels, respectively.