A holistic approach toward development of plant-based meat alternatives through incorporation of novel microalgae-based ingredients

This study explored the changes in the physiochemical, textural, sensory, and functional characteristics of plant-based meat (PBM) after incorporating novel plant-based ingredients including spirulina (SPI), duck Weed (DW), and yellow Chlorella (YC). In the chromaticity evaluation, the YC group (YCI YC2, and YC3%) displayed significant differences (p < 0.05) in lightness (L*) indices as compared to the control. Whereas, based on concertation gradient of SPI microalgae (SP0.5, SP0.7, and SP1%) incorporated into PBM patties demonstrated that SPI 1 had the lowest values (p < 0.05) in redness (a*) and yellowness (b*) followed by SPI 0.7 and SPI 0.5% concentration, respectively. The concentration gradient of the YC group indicated that YC3 was intended to be the highest crude fat value followed by YC2 and YCI. The ash content in PBM patties increased considerably (p < 0.05) as the concentration level of microalgae advanced in all treated groups. Based on the concentration level of YC incorporated microalgae into PBM patties indicated that YC 3 had the highest (p < 0.05) gumminess and chewiness while YC 1 had the lowest reported values in terms of gumminess and chewiness. Moreover, springiness and cohesiveness showed considerable differences between SPI and YC groups. In the sensory evaluation, SPI 1 showed the lowest value only in color and appearance (p < 0.05), conversely, the other sensory parameters were non-significant among all treatment groups (p > 0.05). The micronutrient in PBM presented an irregular pattern after incorporating various ingredients. However, levels were higher (p < 0.05) in the DW group (DW 0.5 DW 0.7, and DW% 1) than those in the other groups. Moreover, the SPI and YC groups showed detectable levels of diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity with, SP 1 showing the highest level of antioxidant activity. Acknowledging the limited research on PBM production, extraction technologies, and selecting various novel suitable ingredients in meat substitutes. Hence, to fill this knowledge gap an attempt has been made to incorporate various concentrations of microalgae including SPI, YC, and DW to enhance the quality and functionality of meat alternatives. To the best of our knowledge, this is the first report that describes the physiochemical, textural, sensory, and nutritional attributes of PBM incorporated with novel microalgae. Collectively these results indicate that the incorporation of SPI, DW, and YC may improve the quality of PBM without showing deleterious outcomes on the quality and functionality of the ultimate PBM products.

Cyanobacteria and Algal-Based Biological Life Support System (BLSS) and Planetary Surface Atmospheric Revitalizing Bioreactor Brief Concept Review

Exploring austere environments required a reimagining of resource acquisition and utilization. Cyanobacterial in situ resources utilization (ISRU) and biological life support system (BLSS) bioreactors have been proposed to allow crewed space missions to extend beyond the temporal boundaries that current vehicle mass capacities allow. Many cyanobacteria and other microscopic organisms evolved during a period of Earth’s history that was marked by very harsh conditions, requiring robust biochemical systems to ensure survival. Some species work wonderfully in a bioweathering capacity (siderophilic), and others are widely used for their nutritional power (non-siderophilic). Playing to each of their strengths and having them grow and feed off of each other is the basis for the proposed idea for a series of three bioreactors, starting from regolith processing and proceeding to nutritional products, gaseous liberation, and biofuel production. In this paper, we discuss what that three reactor system will look like, with the main emphasis on the nutritional stage.

Biological active metabolites from microalgae for healthcare and pharmaceutical industries: A comprehensive review

Microalgae are photoautotrophic microorganisms which comprise of species from several phyla. Microalgae are promising in producing a varieties of products, including food, feed supplements, chemicals, and biofuels. Medicinal supplements derived from microalgae are of a significant market in which compounds such as -carotene, astaxanthin, polyunsaturated fatty acids (PUFA) such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and polysaccharides such as -glucan, are prominent. Microalgae species which are commonly applied for commercial productions include Isochrysis sp., Chaetoceros (Chlorella sp.), Arthrospira sp. (Spirulina Bioactive) and many more. In this present review, microalgae species which are feasible in metabolites production are being summarized. Metabolites produced by microalgae as well as their prospective applications in the healthcare and pharmaceutical industries, are comprehensively discussed. This evaluation is greatly assisting industrial stakeholders, investors, and researchers in making business decisions, investing in ventures, and moving the production of microalgae-based metabolites forward.

Tendencies Affecting the Growth and Cultivation of Genus Spirulina: An Investigative Review on Current Trends

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 Spirulina 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.

Microalgae/cyanobacteria: the potential green future of vitamin B12 production

This review summarizes the available information about potential sources of vitamin B12, especially for people who follow a vegan or vegetarian diet and inhabitants of poor countries in the developing world. Cyanobacteria and microalgae approved for food purposes can play a critical role as promising and innovative sources of this vitamin. This work involves a discussion of whether the form of vitamin B12 extracted from microalgae/cyanobacteria is biologically available to humans, specifically focusing on the genera Arthrospira and Chlorella. It describes analyses of their biomass composition, cultivation requirements, and genetic properties in B12 production. Furthermore, this review discusses the function of cobalamin in microalgae and cyanobacteria themselves and the possibility of modification and cocultivation to increase the content of B12 in their biomass.

Current Status and Future Trends in Removal, Control, and Mitigation of Algae Food Safety Risks for Human Consumption

With the rapid development of the economy and productivity, an increasing number of citizens are not only concerned about the nutritional value of algae as a potential new food resource but are also, in particular, paying more attention to the safety of its consumption. Many studies and reports pointed out that analyzing and solving seaweed food safety issues requires holistic and systematic consideration. The three main factors that have been found to affect the food safety of algal are physical, chemical, and microbiological hazards. At the same time, although food safety awareness among food producers and consumers has increased, foodborne diseases caused by algal food safety incidents occur frequently. It threatens the health and lives of consumers and may cause irreversible harm if treatment is not done promptly. A series of studies have also proved the idea that microbial contamination of algae is the main cause of this problem. Therefore, the rapid and efficient detection of toxic and pathogenic microbial contamination in algal products is an urgent issue that needs to be addressed. At the same time, two other factors, such as physical and chemical hazards, cannot be ignored. Nowadays, the detection techniques are mainly focused on three major hazards in traditional methods. However, especially for food microorganisms, the use of traditional microbiological control techniques is time-consuming and has limitations in terms of accuracy. In recent years, these two evaluations of microbial foodborne pathogens monitoring in the farm-to-table chain have shown more importance, especially during the COVID-19 pandemic. Meanwhile, there are also many new developments in the monitoring of heavy metals, algal toxins, and other pollutants. In the future, algal food safety risk assessment will not only focus on convenient, rapid, low-cost and high-accuracy detection but also be connected with some novel technologies, such as the Internet of Things (artificial intelligence, machine learning), biosensor, and molecular biology, to reach the purpose of simultaneous detection.

Trends and Technological Advancements in the Possible Food Applications of Spirulina and Their Health Benefits: A Review

Spirulina is a kind of blue-green algae (BGA) that is multicellular, filamentous, and prokaryotic. It is also known as a cyanobacterium. It is classified within the phylum known as blue-green algae. Despite the fact that it includes a high concentration of nutrients, such as proteins, vitamins, minerals, and fatty acids—in particular, the necessary omega-3 fatty acids and omega-6 fatty acids—the percentage of total fat and cholesterol that can be found in these algae is substantially lower when compared to other food sources. This is the case even if the percentage of total fat that can be found in these algae is also significantly lower. In addition to this, spirulina has a high concentration of bioactive compounds, such as phenols, phycocyanin pigment, and polysaccharides, which all take part in a number of biological activities, such as antioxidant and anti-inflammatory activity. As a result of this, spirulina has found its way into the formulation of a great number of medicinal foods, functional foods, and nutritional supplements. Therefore, this article makes an effort to shed light on spirulina, its nutritional value as a result of its chemical composition, and its applications to some food product formulations, such as dairy products, snacks, cookies, and pasta, that are necessary at an industrial level in the food industry all over the world. In addition, this article supports the idea of incorporating it into the food sector, both from a nutritional and health perspective, as it offers numerous advantages.

Microalgae fortification of low-fat oil-in-water food emulsions: an evaluation of the physicochemical and rheological properties

Reducing the fat content in emulsions can give additional nutritional health benefits. Hence, developing low-fat oil-in-water emulsions, fortified with healthy microalgae providing advantageous properties, is an interesting topic. In this study, the addition of Arthrospira platensis (Spirulina), Chlorella vulgaris (Chlorella), and Dunaliella salina (Dunaliella) microalgae biomass on the physicochemical properties of low-fat oil-in-water emulsion formulations were evaluated. The rheological properties of food emulsions were measured in terms of the viscoelastic, flow behaviour, and textural properties, with all properties studied during 60 days. pH values of all the emulsions ranged between 3.0 and 3.7 and agreed to the Codex Alimentarius Commission. Moreover, their rheological behaviour may be classified as weak gel-like, a distinguishing characteristic of low-fat emulsion products. Substantial differences in rheological properties were observed between the fortified microalgae emulsions over the storage time (60 days). However, incorporating Spirulina or Dunaliella gave emulsions with stable texture, viscoelastic, and rheological properties. The prepared emulsions displayed good colour stability for Chlorella and Dunaliella. Overall, the fortified microalgae low-fat emulsions are expected to provide a blueprint for the design of low-fat mayonnaise-like food emulsions.

Biologically-Based and Physiochemical Life Support and In Situ Resource Utilization for Exploration of the Solar System-Reviewing the Current State and Defining Future Development Needs

The future of long-duration spaceflight missions will place our vehicles and crew outside of the comfort of low-Earth orbit. Luxuries of quick resupply and frequent crew changes will not be available. Future missions will have to be adapted to low resource environments and be suited to use resources at their destinations to complete the latter parts of the mission. This includes the production of food, oxygen, and return fuel for human flight. In this chapter, we performed a review of the current literature, and offer a vision for the implementation of cyanobacteria-based bio-regenerative life support systems and in situ resource utilization during long duration expeditions, using the Moon and Mars for examples. Much work has been done to understand the nutritional benefits of cyanobacteria and their ability to survive in extreme environments like what is expected on other celestial objects. Fuel production is still in its infancy, but cyanobacterial production of methane is a promising front. In this chapter, we put forth a vision of a three-stage reactor system for regolith processing, nutritional and atmospheric production, and biofuel production as well as diving into what that system will look like during flight and a discussion on containment considerations.

Mass transfer and flow characterization of novel algae-based nutrient removal system

BACKGROUND

Recirculating aquaculture systems (RAS) are an essential component of sustainable inland seafood production. Still, nutrient removal from these systems can result in substantial environmental problems, or present a major cost factor with few added value options. In this study, an innovative and energy-efficient algae based nutrient removal system (NRS) was developed that has the potential to generate revenue through algal commercialization. We optimized mass transfer in our NRS design using novel aeration and mixing technology, using air lift pumps and developed an original membrane cartridge for the continuous operation of nutrient removal and algae production. Specifically, we designed, manufactured and tested a 60-L NRS prototype. Based on specific airlift mixing conditions as well as concentration gradients, we assessed NRS nutrient removal capacity. We then examined the effects of different internal bioreactor geometries and radial orientations on the mixing efficiency.

RESULTS

Using the start-up dynamic method, the overall mass transfer coefficient was found to be in the range of 0.00164-0.0074 [Formula: see text], depending on flow parameters and we confirmed a scaling relationship of mass transfer across concentration gradients. We found the optimal Reynolds number to be 500 for optimal mass transfer, as higher Reynolds numbers resulted in a relatively reduced increase of mass transfer. This relationship between mass transfer and Reynolds number is critical to assess scalability of our system. Our results demonstrate an even distribution of dissolved oxygen levels across the reactor core, demonstrating adequate mixing by the airlift pump, a critical consideration for optimal algal growth. Distribution of dissolved gases in the reactor was further assessed using flow visualization in order to relate the bubble distribution to the mass transfer capabilities of the reactor. We run a successful proof of principle trial using the green alga Dunaliella tertiolecta to assess mass transfer of nutrients across the membrane and biomass production.

CONCLUSIONS

Manipulation of the concentration gradient across the membrane demonstrates a more prominent role of airlift mixing at higher concentration gradients. Specifically, the mass transfer rate increased threefold when the concentration gradient was increased 2.5-fold. We found that we can grow algae in the reactor chamber at rates comparable to those of other production systems and that the membrane scaffolds effectively remove nutrients form the wastewater. Our findings provide support for scalability of the design and support the use of this novel NRS for nutrient removal in aquaculture and potentially other applications.

Algae biopolymer towards sustainable circular economy

The accumulation of conventional petroleum-based polymers has increased exponentially over the years. Therefore, algae-based biopolymer has gained interest among researchers as one of the alternative approaches in achieving a sustainable circular economy around the world. The benefits of microalgae biopolymer over other feedstock is its autotrophic complex to reduce the greenhouse gases emission, rapid growing ability with flexibility in diverse environments and its ability to compost that gives greenhouse gas credits. In contrast, this review provides a comprehensive understanding of algae-based biopolymer in the evaluation of microalgae strains, bioplastic characterization and bioplastic blending technologies. The future prospects and challenges on the algae circular bioeconomy which includes the challenges faced in circular economy, issues regard to the scale-up and operating cost of microalgae cultivation and the life cycle assessment on algal-based biopolymer were highlighted. The aim of this review is to provide insights of algae-based biopolymer towards a sustainable circular bioeconomy.

In vitro bioaccessibility of macular xanthophylls from commercial microalgal powders of Arthrospira platensis and Chlorella pyrenoidosa

The bioaccessibility of the major carotenoids present in two commercial microalgal supplements in powder form was investigated through a standardized in vitro digestion method. The dried biomass of Arthrospira platensis contained β-carotene (36.8 mg/100 g) and zeaxanthin (20.8 mg/100 g) as the main carotenoids as well as a high content of saturated fatty acids (61% of total fatty acids), whereas that of Chlorella pyrenoidosa was rich in lutein (37.8 mg/100 g) and had a high level of unsaturated fatty acids (65% of total fatty acids). In the case of the latter, lutein bioaccessibility was not statistically enhanced after the replacement of porcine bile extract with bovine bile extract in the in vitro digestion protocol and after the addition of coconut oil (17.8% as against to 19.2% and 19.2% vs. 18.5%, respectively). In contrast, the use of bovine bile extract along with co-digestion with coconut oil significantly enhanced the bioaccessibility of zeaxanthin from A. platensis, reaching the highest bioaccessibility of 42.8%.

Functional and sensorial properties of cookies enriched with SPIRULINA and DUNALIELLA biomass

The effects of Spirulina platensis and Dunaliella salina biomass (1% and 2%) on formulated cookies were studied. Colour, hardness, moisture content, ash content, protein content, lipid content, total phenolic content and total antioxidant activity by CUPRAC were assessed, and a sensory evaluation of the cookies was performed. The results show that the cookies baked with added Spirulina were significantly harder and darker than the controls, and the Dunaliella addition did not affect the protein content as much as the Spirulina addition, but the effect on moisture content was significantly positive. Additionally, higher total phenolic content and CUPRAC values were found for the Dunaliella-enriched cookies. After the sensory evaluation, the Dunaliella-enriched cookies were more acceptable to consumers.

The Usefulness of Microalgae Compounds for Preventing Biofilm Infections

Biofilms play an important role in infectious diseases. It has been estimated that most medical infections are due to bacterial biofilms, and about 60-70% of nosocomial infections are also caused by the formation of a biofilm. Historically, microalgae are an important source of bioactive compounds, having novel structures and potential biological functions that make them attractive for different industries such as food, animal feed, aquaculture, cosmetics, and pharmaceutical. Several studies have described compounds produced by microalgae and cyanobacteria species with antimicrobial activity. However, studies on the antibiofilm activity of extracts and/or molecules produced by these microorganisms are scarce. Quorum-sensing inhibitor and anti-adherent agents have, among others, been isolated from microalgae and cyanobacteria species. The use of tools such as nanotechnology increase their power of action and can be used for preventing and treating biofilm-related infections.

Microalgal assimilation of vitamin B12 toward the production of a superfood

A network of components from different metabolic pathways is the building scaffold of an indispensable compound in the human organism-vitamin B₁₂ . The biosynthesis of this compound is restricted to a limited number of representatives of bacteria and archaea, while vitamin B₁₂ -dependent enzymes are spread through several domains of life. Different attempts have been performed to increase vitamin B₁₂ levels in dietary products, particularly in vegetarian and vegan dietary regimes. The integration of vitamin B₁₂ in microalgae through symbiosis with microorganisms generally recognized as safe, for example the probiotic Lactobacillus reuteri, can even increase the nutritional value of the microalgal biomass. This study reviews the microbial production of vitamin B₁₂ based on genetic analyses and chemical studies. Recent genetic approaches are focused, particularly potential metabolic engineering targets to increase vitamin B₁₂ production. The bioincorporation of vitamin B₁₂ in microalgae as an attempt to provide a superfood is also reviewed. PRACTICAL APPLICATIONS: Novel food habits (i.e., vegan lifestyle) may lack relevant nutrients, including vitamin B₁₂ . Therefore, there is an increased demand for dietary products rich in vitamin B₁₂ . Of potential interest is the provision of microbial-based superfood rich in numerous nutrients, including this vitamin. This manuscript provides an in-depth and timely overview on vitamin B₁₂ biosynthesis and the major advances on metabolic engineering for improved vitamin B₁₂ production by probiotic bacteria and other microorganisms generally recognized as safe. A relevant advance would result from the bioincorporation of vitamin B₁₂ in alternative microorganisms (non-vitamin B₁₂ producers) increasingly recognized as superfood, that is microalgae.

Microalgae for High-Value Products Towards Human Health and Nutrition

Microalgae represent a potential source of renewable nutrition and there is growing interest in algae-based dietary supplements in the form of whole biomass, e.g., Chlorella and Arthrospira, or purified extracts containing omega-3 fatty acids and carotenoids. The commercial production of bioactive compounds from microalgae is currently challenged by the biorefinery process. This review focuses on the biochemical composition of microalgae, the complexities of mass cultivation, as well as potential therapeutic applications. The advantages of open and closed growth systems are discussed, including common problems encountered with large-scale growth systems. Several methods are used for the purification and isolation of bioactive compounds, and many products from microalgae have shown potential as antioxidants and treatments for hypertension, among other health conditions. However, there are many unknown algal metabolites and potential impurities that could cause harm, so more research is needed to characterize strains of interest, improve overall operation, and generate safe, functional products.

Evaluation of the alleviative role of Chlorella vulgaris and Spirulina platensis extract against ovarian dysfunctions induced by monosodium glutamate in mice

Microalgae provide a wealthy natural resource of bioactive compounds, which have many biological activities. Monosodium glutamate is a food additive that acts either as food preservatives or as tastiness enhancer. It was confirmed that monosodium glutamate poses a serious responsibility in the pathogenesis of anovulatory infertility. Therefore, the idea of this research was directed to reveal efficiency of Chlorella vulgaris and Spirulina platensis extracts against the ovarian dysfunction resulted due to monosodium glutamate consumption. Adult female albino mice were gavages orally monosodium glutamate alone or with either Chlorella vulgaris or Spirulina platensis aqueous extracts for 28 days. Female mice were subjected to superovulation to study the oocytes nuclear maturation stages. Histological and quantitative investigation was carried on ovaries. Biochemical assessment to measure the sex hormones level and ovarian enzymatic antioxidants was done. In addition, ovarian antioxidant mRNA genes were determined using quantitative PCR and Glyceraldehyde-3-phosphate dehydrogenase was used as an internal control. The result revealed that monosodium glutamate reduced the oocytes quality and maturation rate, while, both algae improve the oocyte quality and maturation rate than in monosodium glutamate group. Chlorella vulgaris and Spirulina platensis improved the monosodium glutamate ovarian tissue histological alteration, sex hormones content and raised the ovarian enzymatic antioxidants level. In addition, monosodium glutamate markedly diminished the Glutathione peroxidase, superoxide dismutase and catalase mRNA expressions, However, Chlorella vulgaris or Spirulina platensis upregulated the expression of genes close to control. In conclusion, Chlorella vulgaris and Spirulina platensis showed potential alleviative role against the monosodium glutamate ovarian dysfunction.

Trends in Microalgae Incorporation Into Innovative Food Products With Potential Health Benefits

Microalgae have demonstrated potential to meet the population's need for a more sustainable food supply, specifically with respect to protein demand. These promising protein sources present several advantages over other currently used raw materials from an environmental point of view. Additionally, one of the main characteristics of microalgae is the production of bioactive compounds with potential benefits for human health. Microalgae exploitation as a source of protein (bulk protein) and other valuable products within the food industry still presents some drawbacks, mainly because of the underdeveloped technologies and processes currently available for microalgae processing. The systematic improvement of the technology readiness level (TRL) could help change the current situation if applied to microalgae cultivation and processing. High maturity in microalgae cultivation and processing technologies also requires improvement of the economy of scale and investment of resources in new facilities and research. Antioxidative, antihypertensive, immunomodulatory, anticancerogenic, hepato-protective, and anticoagulant activities have been attributed to some microalgae-derived compounds such as peptides. Nevertheless, research on this topic is scarce and the evidence on potential health benefits is not strong. In the last years, the possibility of using microalgae-derived compounds for innovative functional food products has become of great interest, but the literature available mainly focuses more on the addition of the whole cells or some compound already available on the market. This review describes the status of utilising microalgae as an ingredient in innovative food products with potential health benefits.

Bio-Based Products from Microalgae Cultivated in Digestates

In recent years the increasing demand for food, energy, and valuable chemicals has necessitated research and development on renewable, novel, and sustainable sources. Microalgae represent a promising option to produce various products with environmentally friendly applications. However, several challenges must be overcome to reduce production cost. To this end, using effluents from biogas production units, called digestates, in cultivation systems can help to optimize bioprocesses, and several bioproducts including biofuels, biofertilizers, proteins and valuable chemicals can be obtained. Nevertheless, several parameters, including the productivity and quality of biomass and specific target products, downstream processes, and cost-effectiveness, must be improved. Further investigations will be necessary to take full advantage of the produced biomass and effectively upscale the process.

Industrial potential of carotenoid pigments from microalgae: Current trends and future prospects

Microalgae are rich source of various bioactive molecules such as carotenoids, lipids, fatty acids, hydrocarbons, proteins, carbohydrates, amino acids, etc. and in recent Years carotenoids from algae gained commercial recognition in the global market for food and cosmeceutical applications. However, the production of carotenoids from algae is not yet fully cost effective to compete with synthetic ones. In this context the present review examines the technologies/methods in relation to mass production of algae, cell harvesting for extraction of carotenoids, optimizing extraction methods etc. Research studies from different microalgal species such as Spirulina platensis, Haematococcus pluvialis, Dunaliella salina, Chlorella sps., Nannochloropsis sps., Scenedesmus sps., Chlorococcum sps., Botryococcus braunii and Diatoms in relation to carotenoid content, chemical structure, extraction and processing of carotenoids are discussed. Further these carotenoid pigments, are useful in various health applications and their use in food, feed, nutraceutical, pharmaceutical and cosmeceutical industries was briefly touched upon. The commercial value of algal carotenoids has also been discussed in this review. Possible recommendations for future research studies are proposed.

Chemical composition of microalgae Heterochlorella luteoviridis and Dunaliella tertiolecta with emphasis on carotenoids

BACKGROUND

Microalgae have been used as food supplements owing to their high protein, polyunsaturated fatty acid and carotenoid contents. As different carotenoids have distinct properties and the carotenoid composition of microalgae has been poorly explored in the literature, this study determined the complete carotenoid composition of two microalgae species, Heterochlorella luteoviridis and Dunaliella tertiolecta, using high-performance liquid chromatography coupled with diode array detection and tandem mass spectrometry (HPLC-DAD/MS² ). Additionally, the proximate composition and major minerals were evaluated.

RESULTS

The carotenoid composition of the two microalgae was similar, with 13 carotenoids being found in H. luteoviridis and 12 in D. tertiolecta. The major carotenoids were all-trans-lutein (1.18 mg g^-1 in H. luteoviridis and 1.59 mg g^-1 in D. tertiolecta), all-trans-violaxanthin (0.52 mg g^-1 in H. luteoviridis and 0.45 mg g^-1 in D. tertiolecta) and all-trans-β-carotene (0.50 mg g^-1 in H. luteoviridis and 0.62 mg g^-1 in D. tertiolecta). All-trans-lutein was the predominant carotenoid in both microalgae, representing around 40% (mass fraction) of the total carotenoids. The lutein content found in these microalgae was significantly higher (2-40 times) than that in other important food sources of lutein (e.g. parsley, carrot, red pepper and broccoli).

CONCLUSION

The microalgae H. luteoviridis and D. tertiolecta are excellent sources of lutein that could be commercially exploited by the food and pharmaceutical industries. Moreover, it was confirmed that both microalgae are good sources of protein, lipids and calcium. © 2016 Society of Chemical Industry.

C-phycocyanin suppresses transforming growth factor-β1-induced epithelial mesenchymal transition in human epithelial cells

BACKGROUND

Epithelial mesenchymal transition (EMT) is a process through which epithelial cells undergo multiple biochemical changes, causing them to differentiate into a mesenchymal-cell phenotype. This process has been shown to contribute to the development of fibrotic diseases. C-phycocyanin (C-PC) is a phycobiliprotein extracted from Spirulina platensis. This study was done to investigate the effect of C-PC on transforming growth factor-β1 (TGF-β1)-induced EMT and an EMT associated proliferation in human epithelial cell lines.

METHODS

Human adenocarcinoma cell line, A549 and breast cancer cell line, MCF-7 were treated with TGF-β1, and EMT-related genes expression, cell proliferation and cell cycle arrest were examined.

RESULTS

C-PC suppressed the EMT as assessed by reduced expression of vimentin, type-1-collagen and fibronectin, and increased E-cadherin expression in TGF-β1 treated cells. Further, TGF-β1 treatment induced cell cycle arrest in S and G2/M phase in A549 cells. However, TGF-β1-mediated cell cycle arrest was significantly reversed by combined treatment with C-PC.

CONCLUSIONS

The overall data suggested that C-PC suppresses TGF- β1-induced EMT and warrants further in vivo studies for future evaluation of C-PC as a potential antifibrotic agent.

Antioxidant Potential of Spirulina platensis Mitigates Oxidative Stress and Reprotoxicity Induced by Sodium Arsenite in Male Rats

The present study aimed to examine the protective role of Spirulina platensis (S. platensis) against arsenic-induced testicular oxidative damage in rats. Arsenic (in the form of NaAsO₂ at a dose of 6.3 mg/kg body weight for 8 weeks) caused a significant accumulation of arsenic in testicular tissues as well as a decrease in the levels of testicular superoxide dismutase (SOD), catalase (CAT), reduced glutathione, and zinc. Moreover, it significantly decreased plasma testosterone, luteinizing hormone (LH), triiodothyronine (T₃), and thyroxine (T₄) levels and reduced sperm motility and sperm count. Arsenic (AS) led to a significant increase in testicular malondialdehyde (MDA), tumour necrosis factor alpha (TNF-α), nitric oxide (NO), and sperm abnormalities. S. platensis at a dose of 300 mg/kg was found to attenuate As-induced oxidative stress, testicular damage, and sperm abnormalities by its potent antioxidant activity. S. platensis may represent a potential therapeutic option to protect the testicular tissue from arsenic intoxication.

Effects of Temperature and Other Operational Parameters on Chlorella vulgaris Mass Cultivation in a Simple and Low-Cost Column Photobioreactor

Mass production of microalgae worldwide, and even more so in developing countries, is strongly contingent upon the availability of economical and efficient photobioreactors (PBRs) that are amenable for use in resource-limited environments. Such options are limited. This work assesses the effects of temperature, CO2 enrichment, and mixing by air + CO2 bubbling on Chlorella vulgaris biomass production in a simple, low-cost 84-L column PBR. Cultivation at 25, 30, and 35 °C in a batch process showed that biomass production was negatively affected above 30 °C. Specific growth rates at each temperature were 0.75, 0.76, and 0.63 day(-1), respectively, with batch productivities of 70.50, 81.67, and 35.83 mg L(-1) day(-1). While a relatively low CO2/air ratio (1 %) seemed beneficial during the early stages of cultivation, higher concentrations were required to maintain growth rate and achieve higher biomass concentrations around 1000 mg L(-1). Cultivation with air + CO2 bubbling rates of 100, 200, and 400 L h(-1) led to specific growth rates (and batch productivities) of 0.64 day(-1) (59.58 mg L(-1) day(-1)), 0.74 day(-1) (81.67 mg L(-1) day(-1)), and 0.80 day(-1) (86.67 mg L(-1) day(-1)), respectively. The results indicate that high biomass productivities of C. vulgaris can be obtained up to 30 °C with moderate (2 %) to high (10 %) CO2 in a fairly simple PBR.

Advances in Microalgae-Derived Phytosterols for Functional Food and Pharmaceutical Applications

Microalgae contain a variety of bioactive lipids with potential applications in aquaculture feed, biofuel, food and pharmaceutical industries. While microalgae-derived polyunsaturated fatty acid (PUFA) and their roles in promoting human health have been extensively studied, other lipid types from this resource, such as phytosterols, have been poorly explored. Phytosterols have been used as additives in many food products such as spread, dairy products and salad dressing. This review focuses on the recent advances in microalgae-derived phytosterols with functional bioactivities and their potential applications in functional food and pharmaceutical industries. It highlights the importance of microalgae-derived lipids other than PUFA for the development of an advanced microalgae industry.

Nutritional evaluation of Australian microalgae as potential human health supplements

This study investigated the biochemical suitability of Australian native microalgal species Scenedesmus sp., Nannochloropsis sp., Dunaliella sp., and a chlorophytic polyculture as nutritional supplements for human health. The four microalgal cultures were harvested during exponential growth, lyophilized, and analysed for proximate composition (moisture, ash, lipid, carbohydrates, and protein), pigments, and amino acid and fatty acid profiles. The resulting nutritional value, based on biochemical composition, was compared to commercial Spirulina and Chlorella products. The Australian native microalgae exhibited similar, and in several cases superior, organic nutritional properties relative to the assessed commercial products, with biochemical profiles rich in high-quality protein, nutritious polyunsaturated fats (such as α-linolenic acid, arachidonic acid, and eicosapentaenoic acid), and antioxidant pigments. These findings indicate that the microalgae assessed have great potential as multi-nutrient human health supplements.

Probiotics in fish and shellfish culture: immunomodulatory and ecophysiological responses

Aquaculture is emerging as one of the most viable and promising enterprises for keeping pace with the surging need for animal protein, providing nutritional and food security to humans, particularly those residing in regions where livestock is relatively scarce. With every step toward intensification of aquaculture practices, there is an increase in the stress level in the animal as well as the environment. Hence, disease outbreak is being increasingly recognized as one of the most important constraints to aquaculture production in many countries, including India. Conventionally, the disease control in aquaculture has relied on the use of chemical compounds and antibiotics. The development of non-antibiotic and environmentally friendly agents is one of the key factors for health management in aquaculture. Consequently, with the emerging need for environmentally friendly aquaculture, the use of alternatives to antibiotic growth promoters in fish nutrition is now widely accepted. In recent years, probiotics have taken center stage and are being used as an unconventional approach that has numerous beneficial effects in fish and shellfish culture: improved activity of gastrointestinal microbiota and enhanced immune status, disease resistance, survival, feed utilization and growth performance. As natural products, probiotics have much potential to increase the efficiency and sustainability of aquaculture production. Therefore, comprehensive research to fully characterize the intestinal microbiota of prominent fish species, mechanisms of action of probiotics and their effects on the intestinal ecosystem, immunity, fish health and performance is reasonable. This review highlights the classifications and applications of probiotics in aquaculture. The review also summarizes the advancement and research highlights of the probiotic status and mode of action, which are of great significance from an ecofriendly, sustainable, intensive aquaculture point of view.