Role of microalgae in achieving sustainable development goals and circular economy

Insights on microalgae-based technologies with potential impact on global methane budget - Perspectives for industrial applications

The European Union's Methane Action Plan outlined policies and targets supporting the Global Methane Pledge to cut CH4 emissions by 30% by 2030, yet urgent implementation is needed to treat medium and diluted CH4 streams. Microalgae-based technologies offer a groundbreaking solution, merging CH4 mitigation with biomass valorization to drive sustainable industrial practices. This review examines three key applications: photosynthetic biogas upgrading, a viable alternative to physical/chemical methods, producing biomethane and valuable algal biomass; microalgae-methanotroph co-cultivation, a promising but underdeveloped method for diluted CH4 streams; and CH4-producing microalgae, unveiling a novel route for biomethane production. Despite their potential, significant research gaps remain, particularly in reactor design, culture conditions, and large-scale viability. By addressing these challenges, microalgae could revamp CH4 management, bridging environmental goals with bioeconomic progress. This review calls for policy updates, intensified research, and industrial engagement to unlock microalgae's full potential in CH4 mitigation and valorization.

Recent advances and challenges in mechanistic modelling of photosynthetic processes for wastewater treatment

Phototrophy-based wastewater treatment has the potential to reduce wastewater bioremediation costs, improving environmental impacts and allowing for enhanced resource recovery. Microbial interactions occurring in phototrophic-chemotrophic consortia treating wastewater are particularly complex, and with varying impact on each microbial clade by different chemical, biological and physical factors, including light-related aspects. For this reason, mechanistic mathematical modelling of these systems is challenging, and the resulting models are especially complex. The present study focuses particularly on the extension of microalgae-focused models to the simulation of phototrophic-chemotrophic systems, especially as for (i) microalgae-bacteria consortia and (ii) purple bacteria-enriched communities. The review identifies model structures and typical modelling choices, as well as the potential applications and limitations of available experimental protocols for model calibration, identifying relevant research needs and requirements. Simplified models have been proposed, which allow assessment of dominant mechanisms, but may not represent more complex behaviour, including nutrient removal and response to light cycling. These models have been largely applied to simple (oxygen and carbon dioxide) exchange between algae and aerobic heterotrophs. More comprehensive models, including all relevant microbial clades, have been recently published, which consider nutrient cycling, competitive uptake, and other features, including temperature, pH, and gas transfer. These models have comparable structures, but a quantitative comparison between these models is often challenging due to different fundamental stoichiometry (e.g., in the assumed algae composition), or in differing approaches to storage compounds. Particularly for models with a high complexity, it is often difficult to properly estimate biokinetic species-specific parameters for the different phototrophic and chemotrophic populations involved. Several methods have been proposed for model calibration, among which photo-respirometry has shown considerable potential. However, photo-respirometric methods do not follow a standardised approach, which has limited their application and comparability between studies. Finally, the validation of models on long-term data sets, demonstrating the impact of seasonality, as well as long-term population adaptation, is rare.

Amphidinium carterae growth in hydroponic wastewater. A sustainable approach to a microalgae-based process promoting a circular bioeconomy

Hydroponic cultivation is being increasingly used worldwide for horticultural production. However, this technique consumes large quantities of freshwater and produces significant amounts of wastewater. Effluent wastewater from hydroponic cultures may contain high nitrogen (N) and phosphorus (P) concentrations, thus contributing to soil, surface, and subsurface water pollution if directly discharged into the environment; it also potentially leads to ecosystem degradation. In the present work, a synthetic hydroponic effluent wastewater was formulated to evaluate the potential of a marine microalga to remove the main nutrients (N and P) and to test its suitability for sustainable, large-scale cultivation. The marine dinoflagellate microalga Amphidinium carterae successfully removed 100 % of the N and P from the hydroponic wastewater. The formulation yielded comparable biomass yields (0.5 g L-1) to those of the same culture grown in a control medium but considerably increased the production of carotenoids (40 %), polyunsaturated fatty acids (17 %), and, significantly, amphidinols (56 %). Hence, the use of A. carterae to treat and valorise hydroponic effluents shows significant promise, supporting further investigation into utilizing hydroponic wastewater from different origins to cultivate marine microalgae that can then be used to produce agricultural bio-based fungicides and other bioproducts in line with the principles of the circular bioeconomy.

Role of nanobionics to improve the photosynthetic productivity in plants and algae: an emerging approach

The domain of nanobionics has gained attention since its inception due to its potential applicability in plant, microalgal treatments, productivity enhancement. This review compares the intake and mobilization of nanoparticles (NPs) in plant and algal cell. In plants, NPs enter from root or other openings, and then carried by apoplastic or symplastic transport and accumulated in various parts, whereas in algae, NPs enter via endocytosis, passive transmission pathways, traverse the algal cell cytoplasm. This study demonstrated the mechanisms of metal-based NPs such as zinc (Zn), silver (Ag), iron (Fe), copper (Cu), titanium (Ti), and silica (Si) for seed priming or plant treatments to improve productivity. These metal NPs are used as nano-fertilizer for plant growths. It has also been observed that these NPs can reduce pathogenic infection and help to cope up with environmental stresses including heavy metals contamination such as arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb). Overall, the photosynthetic productivity increases through NPs as it increases ability to enhance light capture, improve electron transport, and optimize carbon fixation pathways and withstand stresses. These advancements not only elevate biomass production in plant improving agricultural output but also support the sustainable generation of biofuels and bioproducts from algae.

Development of Vegetable Creams Enriched with Different Microalgae Species: A Study on the Physicochemical and Sensory Stability over Time

Vegetable creams are a popular food with sensory characteristics (intense color, smooth texture, rich flavor) suitable for the inclusion of microalgae ingredients. Limited examples of vegetable creams reformulation with microalgae are reported in the literature, and no research has focused on their stability. This study evaluates the quality parameters of heat-treated, high-protein vegetable creams formulated with Spirulina, Tetraselmis chui, and four different Chlorella vulgaris strains over an 8-month period. The investigation examines changes in physicochemical properties (color, moisture, consistency, pH, °Brix, syneresis), microbiological parameters, and sensory profile. Physicochemical results showed enhanced homogenization effects of microalgae, suggesting valuable technological applications. The sensory analysis highlights a general enhancement of umami and salty perception, with differences depending on the species considered. Yellow chlorellas were the least impactful in terms of flavor but require further investigation regarding their pronounced color influence. Tetraselmis chui altered the most the sensory profile with a strong fishy and shellfish flavor. Over time, color variation deserves attention since slight browning phenomena, with possible negative effects on consumer perception, were observed. Regarding sensory aspects, limited and no detrimental effects were detected over time in texture, taste, and smell. No adverse impact on shelf life was observed, suggesting applications in long-term storage foods.

Advancements and challenges in microalgal protein production: A sustainable alternative to conventional protein sources

The increasing global demand for sustainable protein sources necessitates the exploration of alternative solutions beyond traditional livestock and crop-based proteins. Microalgae present a promising alternative due to their high protein content, rapid biomass accumulation, and minimal land and water requirements. Furthermore, their ability to thrive on non-arable land and in wastewater systems enhances their sustainability and resource efficiency. Despite these advantages, scalability and economical feasibility remain major challenges in microalgal protein production. This review explores recent advancements in microalgal protein cultivation and extraction technologies, including pulsed electric field, ultrasound-assisted extraction, enzyme-assisted extraction, and microwave-assisted extraction. These innovative techniques have significantly improved protein extraction efficiency, purity, and sustainability, while addressing cell wall disruption and protein recovery challenges. Additionally, the review examines protein digestibility and bioavailability, particularly in the context of human nutrition and aquafeed applications. A critical analysis of life cycle assessment studies highlights the environmental footprint and economical feasibility of microalgal protein production compared to conventional protein sources. Although microalgal protein production requires significant energy inputs, advancements in biorefinery approaches, carbon dioxide sequestration, and industrial integration can help mitigate these limitations. Finally, this review outlines key challenges and future research directions, emphasizing the need for cost reduction strategies, genetic engineering for enhanced yields, and industrial-scale process optimization. By integrating innovative extraction techniques with biorefinery models, microalgal proteins hold immense potential as a sustainable, high-quality protein source for food, feed, and nutraceutical applications.

Effective bioprocess engineering to enhance omega-6 polyunsaturated fatty acid production from Arthrospira platensis

Contrary to the robustness of microbial ω-3 polyunsaturated fatty acid (PUFA) production, the microbial synthesis of ω-6 PUFAs remains challenging. The rising demand for ω-6 PUFAs, especially for pregnancy and infant formulas, calls for scalable and sustainable production methods. Arthrospira platensis, a rarely explored microalgae, shows promise as a platform for producing gamma linoleic acid (GLA) and linolenic acid (LA), key components of ω-6 PUFAs. This study employs a two-phase cultivation approach to enhance ω-6 PUFA production in A. platensis. The initial growth phase was optimized to maximize biomass, followed by a stress-induced phase to boost lipid and ω-6 PUFA accumulation. Notably, ω-6 producing strains like A. platensis are protein-rich and not a high oleaginous species, achieving over 15% total lipid content particularly is significant. Under optimized conditions, a maximum biomass of 4.9 g/L with a productivity rate of (0.233 g/L/day) was obtained at 8 K Lux light irradiance, with 2X nitrogen concentration and 4 mg/L phytohormones. The subsequent stress phase, involving 20 K Lux light, 10 mg/L FeSO4, and 1% glycerol, resulted in a lipid content of 22.8%. This approach led to a 2.4-fold and 1.5-fold increase in microalgal biomass and lipid content respectively. Moreover, C18:2 and C18:3 PUFAs reaching approx. 17.1 ± 0.06% and 24.1 ± 0.07%, respectively. This research promotes microalgae cultivation to meet rising ω-6 PUFA demand, aligning with sustainable development goal 3: Good health and well-being.

Unleashing the power of microalgae: a pioneering path to sustainability and achieving the sustainable development goals

This study explores the remarkable potential of algae in addressing global sustainability challenges. Microalgae, in particular, emerge as sustainability champions. Their applications span an impressive array of industries and processes, including food and feed production, biofuels, cosmetics, pharmaceuticals, and environmental remediation. This versatility positions algae as key players in achieving over 50% of UN Sustainable Development Goals (SDGs) simultaneously, addressing issues such as climate action, clean water and sanitation, affordable and clean energy, and zero hunger. From sequestering carbon, purifying wastewater, and producing clean energy to combating malnutrition, algae demonstrates unparalleled potential. Their ability to flourish in extreme conditions and their rapid growth rates further enhance their appeal for large-scale cultivation. As research advances, innovative applications continue to emerge, such as algae-based bioplastics and dye-sensitized solar cells, promising novel solutions to pressing global issues. This study illuminates how harnessing the power of algae can drive us towards a more resilient, sustainable world. By leveraging algae's multifaceted capabilities, we can tackle climate change, resource scarcity, and economic development concurrently. The research highlights the critical role of algae in promoting circular economy principles and achieving a harmonious balance between human needs and environmental preservation, paving the way for a greener, more sustainable future.

Mixotrophy in Marine Microalgae to Enhance Their Bioactivity

Photosynthetic microorganisms, such as microalgae, are remarkable for their ability to harness sunlight, fix carbon dioxide, and produce a variety of bioactive compounds. These organisms are pivotal in climate mitigation strategies as they can absorb carbon dioxide while generating valuable biomolecules. Among the diverse cultivation approaches, mixotrophic growth combines light energy with both inorganic and organic carbon sources, offering a unique strategy to enhance biomass production and metabolic diversity in microalgae. Here, microalgal species such as Nannochloropsis granulata, Phaeodactylum tricornutum, and Chlorella sp. were investigated for their potential applications under different cultivation methods, including phototrophy and mixotrophy. Mixotrophic conditions significantly improved biomass production across all tested species. Among these, Phaeodactylum tricornutum, a marine diatom, emerged as a promising candidate for bioactive compound production, exhibiting higher antiproliferative activity against human melanoma cells and antibacterial effects against Staphylococcus aureus. Importantly, Chlorella sp. was also found to possess antibacterial activity against Staphylococcus aureus, broadening its potential applications. Additionally, metabolomics analysis was performed on Chlorella sp. and Phaeodactylum tricornutum to identify the compounds responsible for the observed bioactivity. This study highlights the value of mixotrophic cultivation in enhancing the productivity and bioactivity of microalgae, positioning them as versatile organisms for sustainable biotechnological applications.

Poultry litter extract as solid waste supplement for enhanced microalgal biomass production and wastewater treatment

Wastewater and livestock waste can be used as a cheap source of nutrients for microalgae growth. In this work, a cocktail waste medium (CWM) was developed using 75% Chhalera municipal wastewater (C-MWW), 25% Parag dairy wastewater (P-DWW), and 15 g L-1 of poultry litter extract (PLE-15) for low-cost cultivation of Chlorella sp. BRE4. The highest specific growth rate of 0.57 day-1 and biomass productivity of 315 mg L-1 day-1 was found in CWM. Microalgae grown in the photobioreactor with the strategic supply of PLE (PBR-4) resulted in the highest lipid productivity of 113.5 mg L-1 day-1, which was 1.3 and 5.4 times of PBR-3 (PLE supplemented since day 1) and PBR-1 (no additional PLE), respectively. The carbohydrate content (30.45%) in PBR-4 showed a 1.33-fold increase than PBR-1, confirming the suitability of the strategy for enhancing carbohydrates and lipids simultaneously. The high removal percentage of total nitrogen (92.6%) and phosphorus (97.4%) from CWM under strategic supply conditions demonstrated Chlorella sp. BRE4 is a suitable candidate for waste valorization and biofuel production.

Decarbonizing the Transport of Microalgae-based Products -The Role of E-mobility

BACKGROUND

The decarbonization of road transport is a precondition for achieving carbon neutrality. Battery-electric vehicle technology, driven by several patents, can make this a reality. In this bias, the objective of the article is to shed light on the ongoing debate about the potentially important role of the adoption of electric vehicles in the transport of microalgae-based products to help them advance to a cleaner life cycle.

METHODS

Five routes, including unimodal and multimodal conditions, were defined to assess the carbon emissions of the transport system and, more specifically, of road transport. The headquarters of market-leading microalgae manufacturers were selected as the origin of the routes and, as the destination, regions that sustain them.

RESULTS

The results reveal the supremacy of road transport of microalgae-based products using electric vehicles powered by nuclear, hydroelectric, and wind, followed by biomass and photovoltaic energy. They also show that the positive impact of wind, water, and photovoltaic energy on the climate, added to the lower battery charging costs and the greater opportunity to generate revenue from the sale of carbon credits, make their trade-offs.

CONCLUSION

The exquisite results of this study convey key messages to decision-makers and stakeholders about the role of electromobility in building a zero-carbon delivery route.

Microalgae for bioremediation: advances, challenges, and public perception on genetic engineering

The increase in the global population and industrial activities has led to an extensive use of water, the release of wastewater, and overall contamination of the environment. To address these issues, efficient treatment methods have been developed to decrease wastewater nutrient content and contaminants. Microalgae are a promising tool as a sustainable alternative to traditional wastewater treatment. Furthermore, the biomass obtained from the wastewater treatment can be used in different applications, having a positive economic impact. This review describes the potential of microalgae as a biological wastewater remediation tool, including the use of genetically engineered strains. Their current industrial utilization and their untapped commercial potential in terms of bioremediation are also examined. Finally, this work discusses how microalgal biotechnology is perceived by the public and governments, analyses the potential risks of microalgae to the environment, and examines standard procedures that can be implemented for the safe biocontainment of large-scale microalgae cultures.

Energizing the future: Unleashing the potential of innovative waste-to-energy technologies for energy development and sustainability within Zimbabwe's tourism sector

Zimbabwe's tourism industry, renowned for its natural wonders and cultural heritage, faces a looming energy crisis rooted in the detrimental over-reliance on fossil fuels and the underutilization of substantial waste resources that lie dormant. The article investigates multifaceted relationship between six independent variables: landfill gas recovery and anaerobic digestion, pyrolysis and gasification, incineration, biogas production, biodiesel production, ethanol production and syngas fermentation and one dependent variable: energy development and sustainability. In this study, a quantitative methodology was adopted, involving the gathering of data from 519 stakeholders in the tourism supply chain through a simple random sampling technique, with the sample size determined using the Krejcie and Morgan table. The distribution of questionnaires was facilitated through Google Forms, and the data analysis was conducted using Smart PLS. Statistical findings indicate direct significant relationship between variables, and t-statistic values all hypotheses were all greater than the threshold of 1.96, ranging from a minimum of 2.911 to a maximum of 9.431. These findings underscore the robustness of the relationships between the waste-to-energy technologies and energy development and sustainability within Zimbabwe's tourism sector. This empirical evidence highlights the substantial potential for these innovative technologies to play a pivotal role in mitigating the energy crisis and fostering sustainable energy development.

Resource recovery and contaminants of emerging concern mitigation by microalgae treating wastewater

This study aimed to investigate the recovery of agricultural biostimulants and biogas from microalgae treating wastewater, in the framework of a circular bioeconomy. To this end, municipal wastewater was treated in demonstrative raceway ponds, and microalgal biomass (Scenedesmus sp.) was then harvested and downstream processed to recover biostimulants and biogas in a biorefinery approach. The effect of microalgal biostimulants on plants was evaluated by means of bioassays, while the biogas produced was quantified in biochemical methane potential (BMP) tests. Furthermore, the fate of contaminants of emerging concern (CECs) over the process was also assessed. Bioassays confirmed the biostimulant effect of microalgae, which showed gibberellin-, auxin- and cytokinin-like activity in watercress seed germination, mung bean rooting, and wheat leaf chlorophyll retention. In addition, the downstream process applied to raw biomass acted as a pre-treatment to enhance anaerobic digestion performance. After biostimulant extraction, the residual biomass represented 91% of the methane yield from the raw biomass (276 mLCH4·g-1VS). The kinetic profile of the residual biomass was 43% higher than that of the unprocessed biomass. Co-digestion with primary sludge further increased biogas production by 24%. Finally, the concentration of CECs in wastewater was reduced by more than 80%, and only 6 out of 22 CECs analyzed were present in the biostimulant obtained. Most importantly, the concentration of those contaminants was lower than in biosolids that are commonly used in agriculture, ensuring environmental safety.

Manipulation of ion/electron carrier genes in the model diatom Phaeodactylum tricornutum enables its growth under lethal acidic stress

A major obstacle to exploiting industrial flue gas for microalgae cultivation is the unfavorable acidic environment. We previously identified three upregulated genes in the low-pH-adapted model diatom Phaeodactylum tricornutum: ferredoxin (PtFDX), cation/proton antiporter (PtCPA), and HCO3 - transporter (PtSCL4-2). Here, we individually overexpressed these genes in P. tricornutum to investigate their respective roles in resisting acidic stress (pH 5.0). The genetic modifications enabled positive growths of transgenic strains under acidic stress that completely inhibited the growth of the wild-type strain. Physiological studies indicated improved photosynthesis and reduced oxidative stress in the transgenic strains. Transcriptomes of the PtCPA- and PtSCL4-2-overexpressing transgenics showed widespread upregulation of various transmembrane transporters, which could help counteract excessive external protons. This work highlights ion/electron carrier genes' role in enhancing diatom resistance to acidic stress, providing insights into phytoplankton adaptation to ocean acidification and a strategy for biological carbon capture and industrial flue gas CO2 utilization.

Waves of change: Electrochemical innovations for environmental management and resource recovery from water - A review

Environmental electrochemistry and water resource recovery are covered in this review. The study discusses the growing field's scientific basis, methods, and applications, focusing on innovative remediation tactics. Environmental electrochemistry may solve water pollution and extract resources. Electrochemical methods may effectively destroy or convert pollutants. This method targets heavy metals, organic compounds, and emerging water contaminants such as pharmaceuticals and microplastics, making it versatile. Environmental electrochemistry and resource recovery synergize to boost efficiency and sustainability. Innovative electrochemical methods can extract or synthesise metals, nutrients, and energy from wastewater streams, decreasing treatment costs and environmental effect. The study discusses electrocoagulation, electrooxidation, and electrochemical advanced oxidation processes and their mechanics and performance. Additionally, it discusses current electrode materials, reactor designs, and process optimisation tactics to improve efficiency and scalability. Resource recovery in electrochemical remediation methods is also examined for economic and environmental feasibility. Through critical examination of case studies and techno-economic evaluations, it explains the pros and cons of scaling up these integrated techniques. This study covers environmental electrochemistry and resource recovery's fundamental foundations, technology advances, and sustainable water management consequences.

Threat or prospect? Exploring the impact of digital entrepreneurs' artificial intelligence perception and intention to adopt blockchain technology on the achievement of SDGs

This paper explores how digital entrepreneurs' intention toward blockchain technology adoption, perception of reduced costs, and knowledge of Artificial Intelligence impact achieving UN's Sustainable Development Goals (SDGs), drawing attention from various sectors. Present study applies explanatory sequential mixed method for data collection. Moreover, to work with the dual face patterned data, PLS-SEM is used to perform quantitative analysis of the data collected from 389 digital entrepreneurs who are chosen through purposive sampling and then content analysis is performed for the qualitative data according to the explanatory sequential mixed method's rule of thumb. The study's quantitative phase shows that factors such as perceived ease of use and usefulness of Industry 4.0 technologies, knowledge of artificial intelligence (KAI), and perception of reduced cost positively influence digital entrepreneurs' intention to adopt blockchain technology (BCT). Notably, KAI has the strongest impact. In the qualitative phase, it's found that digital entrepreneurs' KAI and willingness to adopt BCT strongly align with achieving several UN Sustainable Development Goals (SDGs), suggesting BCT adoption's potential for sustainable outcomes. The outcomes of this study set a new benchmark in the domain of SDGs achievement with careful integration to Industry 4.0, AI and BCT. This study results undoubtedly instigate the digital entrepreneurs to adopt BCT in doing their start-up and convince the policymakers to set regulatory landscape with convenient environment for the utilization of BCT which then ultimately accelerates the achievement of SDGs.

Environmental microbial diversity and water pollution characteristics resulted from 150 km coastline in Quanzhou Bay offshore area

As a typical transitional area between the land and sea, the offshore area is subjected to the triple synergistic pressure from the ocean, land, and atmosphere at the same time, and has obvious characteristics such as complex and diverse chemical, physical, and biological processes, coupled and changeable environmental factors, and sensitive and fragile ecological environment. With the deepening of the urbanization process, the offshore area has gradually become the final receptions of pollutants produced by industry, agriculture, and service industries, and plays a key role in the global environmental geochemical cycle of pollutants. In this study, the Quanzhou Bay offshore area was selected as the research object. Sediment and water samples were collected from 8 sampling points within about 150 km of coastline in the Quanzhou Bay offshore area. 16s rDNA high-throughput sequencing method was used to investigate the variation rule of microbial diversity in the offshore area, and multi-parameter water quality analysis was carried out at the same time. The results showed that the distribution characteristics of microbial communities and water quality in the Quanzhou Bay offshore area showed significant differences in different latitudes and longitudes. This difference is closely related to the complexity of offshore area. This study can provide scientific support for protecting and improving the ecological environment of offshore areas.

A Comparative Analysis Assessing Growth Dynamics of Locally Isolated Chlorella sorokiniana and Chlorella vulgaris for Biomass and Lipid Production with Biodiesel Potential

Prior research has emphasized the potential of microalgae in biodiesel production, driven by their ability to replace fossil fuels. However, the significant costs associated with microalgae cultivation present a major obstacle to scaling up production. This study aims to develop an eco-friendly microalgae cultivation system by integrating carbon dioxide from flue gas emissions with an affordable photobioreactor, providing a sustainable biomass production. The research evaluates the growth performance of Chlorella sorokiniana and Chlorella vulgaris across this integrated system for biomass and lipid production. Results indicate substantial biomass yields of 1.97 and 1.84 g/L, with lipid contents of 35 % and 41 % for C. sorokiniana and C. vulgaris, respectively. The macrobubble photobioreactor demonstrates high potential for microalgae biomass and lipid production, yielding quality fatty acid methyl esters such as palmitic, linoleic and stearic. This study presents an environmentally friendly system for efficient microalgae cultivation, generating lipid-rich biomass suitable for biodiesel production.

Dietary spirulina platensis a promising growth promotor and immune stimulant in broiler chickens

Algae, as a biological component of the environment, holds promise for the development of novel cuisines. This study aimed to appreciate the dietary Spirulina platensis (SP) impact on growth patterns and as an immune stimulant in broilers. SP-fed chicks at 0.5, 1, and 2 g/kg doses significantly improved hematological indices. Also, gas chromatography of fatty acid profile in broiler breast muscles exhibited greater elevation. Serum total proteins, albumin, and globulin levels significantly increased. ElISA (enzyme-linked immunosorbent assay) revealed elevated immunoglobin M, G, and leptin levels as mirrors for immunological response coordination. Reverse transcription polymerase chain reaction (RT-PCR) exhibited depressed tumour necrosis factor-alpha gene expression (TNF-α) in ilial tissue. Gut's histopathology showed well-developed villi. In conclusion, Spirulina platensis in doses up to 2 g/kg enhances immunity, fatty acid profile, liver function, anti-inflammatory properties, and intestinal absorption of broilers, while doses up to 4 g/kg cause the opposite effect on previous parameters.

Emerging microalgal feed additives for ruminant production and sustainability

The global demand for animal-derived foods has led to a substantial expansion in ruminant production, which has raised concerns regarding methane emissions. To address these challenges, microalgal species that are nutritionally-rich and contain bioactive compounds in their biomass have been explored as attractive feed additives for ruminant livestock production. In this review, we discuss the different microalgal species used for this purpose in recent studies, and review the effects of microalgal feed supplements on ruminant growth, performance, health, and product quality, as well as their potential contributions in reducing methane emissions. We also examine the potential complexities of adopting microalgae as feed additives in the ruminant industry.

Current challenges of microalgae applications: exploiting the potential of non-conventional microalgae species

The intensified attention to health, the growth of an elderly population, the changing lifestyles, and the medical discoveries have increased demand for natural and nutrient-rich foods, shaping the popularity of microalgae products. Microalgae thanks to their metabolic versatility represent a promising solution for a 'green' economy, exploiting non-arable land, non-potable water, capturing carbon dioxide (CO2) and solar energy. The interest in microalgae is justified by their high content of bioactive molecules, such as amino acids, peptides, proteins, carbohydrates, polysaccharides, polyunsaturated fatty acids (as ω-3 fatty acids), pigments (as β-carotene, astaxanthin, fucoxanthin, phycocyanin, zeaxanthin and lutein), or mineral elements. Such molecules are of interest for human and animal nutrition, cosmetic and biofuel production, for which microalgae are potential renewable sources. Microalgae, also, represent effective biological systems for treating a variety of wastewaters and can be used as a CO2 mitigation approach, helping to combat greenhouse gases and global warming emergencies. Recently a growing interest has focused on extremophilic microalgae species, which are easier to cultivate axenically and represent good candidates for open pond cultivation. In some cases, the cultivation and/or harvesting systems are still immature, but novel techniques appear as promising solutions to overcome such barriers. This review provides an overview on the actual microalgae cultivation systems and the current state of their biotechnological applications to obtain high value compounds or ingredients. Moreover, potential and future research opportunities for environment, human and animal benefits are pointed out. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Valorization of Nannochloropsis oceanica for integrated co-production of violaxanthin cycle carotenoids

The development of integrated co-production of multiple high-purity carotenoids from microalgal cells holds considerable significance for the valorization of microalgae. In this study, the economical microalga Nannochloropsis oceanica was identified as an accumulator of violaxanthin cycle carotenoids, including violaxanthin, antheraxanthin, and zeaxanthin. Notably, a novel and competent approach for the integrated co-production of violaxanthin cycle carotenoids was explored, encompassing four steps: microalgal cultivation, solvent extraction, octadecylsilyl open-column chromatography, and ethanol precipitation. Under optimal co-production conditions, the purities of the obtained violaxanthin, antheraxanthin, and zeaxanthin all exceeded 92%, with total recovery rates of approximately 51%, 40%, and 60%, respectively. Utilizing nuclear magnetic resonance techniques, the purified violaxanthin, antheraxanthin, and zeaxanthin were identified as all-trans-violaxanthin, all-trans-antheraxanthin, and all-trans-zeaxanthin, respectively. This method held significance for the multiproduct biorefinery of the microalga N. oceanica and carried potential future implications for the violaxanthin cycle carotenoids.

The toxic effects of petroleum pollutants to microalgae in marine environment

Marine oil pollution is one of the major global environmental pollution problems. Marine microalgae are the foundation of the marine food chain, providing the main primary productivity of the ocean. They not only maintain the energy flow and material cycle of the entire marine ecosystem, but also play an important role in regulating global climate change. Exploring the impact of petroleum pollutants on marine microalgae is extremely important for studying marine environmental pollution. This review first introduced the sources, compositions, and forms of petroleum pollutants and their migration and transformation processes in the ocean. Then, the toxic effects of petroleum pollutants on marine microalgae were summarized. The growth of marine microalgae showed low-concentration promotion and high-concentration inhibition. The population growth and interspecific relationships of marine microalga was changed and the photosynthesis of marine microalgae was influenced. Finally, potential research directions and suggestions for marine microalgae in the future were proposed.

Cultivation of microalgae in food processing effluent for pollution attenuation and astaxanthin production: a review of technological innovation and downstream application

Valorization of food processing effluent (FPE) by microalgae cultivation for astaxanthin production is regarded as a potential strategy to solve the environmental pollution of food processing industry and promote the development of eco-friendly agriculture. In this review paper, microalgal species which have the potential to be employed for astaxanthin in FPE were identified. Additionally, in terms of CO2 emission, the performances of microalgae cultivation and traditional methods for FPE remediation were compared. Thirdly, an in-depth discussion of some innovative technologies, which may be employed to lower the total cost, improve the nutrient profile of FPE, and enhance the astaxanthin synthesis, was provided. Finally, specific effects of dietary supplementation of algal astaxanthin on the growth rate, immune response, and pigmentation of animals were discussed. Based on the discussion of this work, the cultivation of microalgae in FPE for astaxanthin production is a value-adding process which can bring environmental benefits and ecological benefits to the food processing industry and agriculture. Particularly, technological innovations in recent years are promoting the shift of this new idea from academic research to practical application. In the coming future, with the reduction of the total cost of algal astaxanthin, policy support from the governments, and further improvement of the innovative technologies, the concept of growing microalgae in FPE for astaxanthin will be more applicable in the industry.

Assessment of photosynthetic activity in dense microalgae cultures using oxygen production

Microalgae are photosynthetic microorganisms playing a pivotal role in primary production in aquatic ecosystems, sustaining the entry of carbon in the biosphere. Microalgae have also been recognized as sustainable source of biomass to complement crops. For this objective they are cultivated in photobioreactors or ponds at high cell density to maximize biomass productivity and lower the cost of downstream processes. Photosynthesis depends on light availability, that is often not constant over time. In nature, sunlight fluctuates over diurnal cycles and weather conditions. In high-density microalgae cultures of photobioreactors outdoors, on top of natural variations, microalgae are subjected to further complexity in light exposure. Because of the high-density cells experience self-shading effects that heavily limit light availability in most of the mass culture volume. This limitation strongly affects biomass productivity of industrial microalgae cultivation plants with important implications on economic feasibility. Understanding how photosynthesis responds to cell density is informative to assess functionality in the inhomogeneous light environment of industrial photobioreactors. In this work we exploited a high-sensitivity Clark electrode to measure microalgae photosynthesis and compare cultures with different densities, using Nannochloropsis as model organism. We observed that cell density has a substantial impact on photosynthetic activity, and demonstrated the reduction of the cell's light-absorption capacity by genetic modification is a valuable strategy to increase photosynthetic functionality on a chlorophyll-basis of dense microalgae cultures.

Improving biomass yields of microalgae biofilm by coculturing two microalgae species via forming biofilms with uniform microstructures and small cell-clusters

Microalgae coculture has the potential to promote microalgae biofilm growth. Herein, three two-species cocultured biofilms were studied by determining biomass yields and detailed microstructure parameters, including porosity, average pore length, average cluster length, etc. It was found that biomass yields could reduce by 21-53 % when biofilm porosities decreased from about 35 % to 20 %; while at similar porosities (∼20 %), biomass yields of cocultured biofilms increased by 37 % when they possessed uniform microstructure and small cell-clusters (pores and clusters of 1 ∼ 10 μm accounted for 96 % and 68 %, respectively). By analyzing morphologies and surface properties of cells, it was found that cells with small size, spherical shape, and reduced surface polymers could hinder the cell-clusters formation, thereby promoting biomass yields. The study provides new insights into choosing cocultured microalgae species for improving the biomass yield of biofilm via manipulating biofilm microstructures.

Regulation of microclimate and shading effects of microalgal photobioreactors on rooftops: Microalgae as a promising emergent for green roof technology

Urban areas remarkably affect global public health due to their emissions of greenhouse gases and poor air quality. Although urban areas only cover 2% of the Earth's surface, they are responsible for 80% of greenhouse gas emissions. Dense buildings limit vegetation, leading to increased air pollution and disruption of the local and regional carbon cycle. The substitution of urban gray roofs with microalgal green roofs has the potential to improve the carbon cycle by sequestering CO2 from the atmosphere. Microalgae can fix 15-50 times more CO2 than other types of vegetation. Advanced microalgal-based green roof technology may significantly accelerate the reduction of atmospheric CO2 in a more effective way. Microalgal green roofs also enhance air quality, oxygen production, acoustic isolation, sunlight absorption, and biomass production. This endeavor yields the advantage of simultaneously generating protein, lipids, vitamins, and a spectrum of valuable bioactive compounds, including astaxanthin, carotenoids, polysaccharides, and phycocyanin, thus contributing to a green economy. The primary focus of the current work is on analyzing the ecological advantages and CO2 bio-fixation efficiency attained through microalgal cultivation on urban rooftops. This study also briefly examines the idea of green roofs, clarifies the ecological benefits associated with them, discusses the practice of growing microalgae on rooftops, identifies the difficulties involved, and the positive aspects of this novel strategy.

Bioengineering strategies of microalgae biomass for biofuel production: recent advancement and insight

Algae-based biofuel developed over the past decade has become a viable substitute for petroleum-based energy sources. Due to their high lipid accumulation rates and low carbon dioxide emissions, microalgal species are considered highly valuable feedstock for biofuel generation. This review article presented the importance of biofuel and the flaws that need to be overcome to ensure algae-based biofuels are effective for future-ready bioenergy sources. Besides, several issues related to the optimization and engineering strategies to be implemented for microalgae-based biofuel derivatives and their production were evaluated. In addition, the fundamental studies on the microalgae technology, experimental cultivation, and engineering processes involved in the development are all measures that are commendably used in the pre-treatment processes. The review article also provides a comprehensive overview of the latest findings about various algae species cultivation and biomass production. It concludes with the most recent data on environmental consequences, their relevance to global efforts to create microalgae-based biomass as effective biofuels, and the most significant threats and future possibilities.

Fungus-based bioherbicides on circular economy

This review aimed to show that bioherbicides are possible in organic agriculture as natural compounds from fungi and metabolites produced by them. It is discussed that new formulations must be developed to improve field stability and enable the commercialization of microbial herbicides. Due to these bottlenecks, it is crucial to advance the bioprocesses behind the formulation and fermentation of bio-based herbicides, scaling up, strategies for field application, and the potential of bioherbicides in the global market. In this sense, it proposed insights for modern agriculture based on sustainable development and circular economy, precisely the formulation, scale-up, and field application of microbial bioherbicides.

Commercial paper as a promising carrier for biofilm cultivation of Chlorella sp. for the treatment of anaerobic digestate food effluent (ADFE): Effect on the photosynthetic efficiency

Microalgal technology is still economically unattractive due to the high cost associated with microalgal cultivation and biomass recovery from conventional suspension cultures. Biofilm-based cultivation is a promising alternative for higher biomass yield and cheap/easy biomass harvesting opportunities. Additionally, using anaerobic digestate food effluent (ADFE) as a nutrient source reduces the cultivation cost and achieves ADFE treatment as an added value. However, the search for locally available, inexpensive, and efficient support materials is still open to research. This study evaluates the potential of commercially available, low-cost papers as support material for biofilm cultivation of Chlorella sp. and treatment of ADFE. Among the four papers screened for microalgal attachment, quill board paper performed better in higher biomass yield and stability throughout the study period. The attached growth study was done in a modular food container vessel, using anaerobic digestate food effluent (ADFE) as a nutrient source and a basal medium as a control. The microalgae grew well on the support material with higher biomass yield and productivity of 108.64 g(DW) m-2 and 9.96 g (DW) m-2 d-1, respectively, in the ADFE medium compared with 85.87 g (DW) m-2 and 4.99 g (DW) m-2 d-1, respectively in the basal medium. Chlorophyll, a fluorescence (ChlF) probe, showed that cell density in the biofilm significantly changes the photosynthetic apparatus of the algae, with evidence of stress observed as the culture progressed. Also, efficient nutrient removal from the ADFE medium was achieved in the 100 %, 85 %, and 40.2 % ratios for ammoniacal nitrogen, phosphate, and chemical oxygen demand (COD). Therefore, using quill board paper as carrier material for microalgal cultivation offers promising advantages, including high biomass production, easy biomass harvesting (by scrapping or rolling the biomass with the paper), and efficient effluent treatment.

Microalga Broths Synthesize Antibacterial and Non-Cytotoxic Silver Nanoparticles Showing Synergy with Antibiotics and Bacterial ROS Induction and Can Be Reused for Successive AgNP Batches

The era of increasing bacterial antibiotic resistance requires new approaches to fight infections. With this purpose, silver-based nanomaterials are a reality in some fields and promise new developments. We report the green synthesis of silver nanoparticles (AgNPs) using culture broths from a microalga. Broths from two media, with different compositions and pHs and sampled at two growth phases, produced eight AgNP types. Nanoparticles harvested after several synthesis periods showed differences in antibacterial activity and stability. Moreover, an evaluation of the broths for several consecutive syntheses did not find relevant kinetics or activity differences until the third round. Physicochemical characteristics of the AgNPs (core and hydrodynamic sizes, Z-potential, crystallinity, and corona composition) were determined, observing differences depending on the broths used. AgNPs showed good antibacterial activity at concentrations producing no or low cytotoxicity on cultured eukaryotic cells. All the AgNPs had high levels of synergy against Escherichia coli and Staphylococcus aureus with the classic antibiotics streptomycin and kanamycin, but with ampicillin only against S. aureus and tetracycline against E. coli. Differences in the synergy levels were also dependent on the types of AgNPs. We also found that, for some AgNPs, the killing of bacteria started before the massive accumulation of ROS.

Strategies and challenges to enhance commercial viability of algal biorefineries for biofuel production

The rise in energy consumption would quadruple in the coming century and the, existing energy resources might be insufficient to meet the demand of the growing population. An alternative and sustainable energy resource is therefore needed to address the fossil fuel deficiency. The utility of microalgae strains in the aspect of biorefinery has been in research for quite some time. Algal biorefinery is an alternate way of renewable energy however even after decades of research it still suffers from commercialization bottlenecks. The current manuscript reviews the scenarios where the innovation needs an ignition for its commercialization. This review discusses the prospects of up-scale cultivation, and harvesting algal biomass for biorefineries. It narrates algal biorefinery hurdles that can be solved using integrated technology approach, life cycle assessment and applications of nanotechnology. The review also sheds light upon the ties of algal biorefineries with its economic viability.

Astaxanthin: Past, Present, and Future

Astaxanthin (AX), a lipid-soluble pigment belonging to the xanthophyll carotenoids family, has recently garnered significant attention due to its unique physical properties, biochemical attributes, and physiological effects. Originally recognized primarily for its role in imparting the characteristic red-pink color to various organisms, AX is currently experiencing a surge in interest and research. The growing body of literature in this field predominantly focuses on AXs distinctive bioactivities and properties. However, the potential of algae-derived AX as a solution to various global environmental and societal challenges that threaten life on our planet has not received extensive attention. Furthermore, the historical context and the role of AX in nature, as well as its significance in diverse cultures and traditional health practices, have not been comprehensively explored in previous works. This review article embarks on a comprehensive journey through the history leading up to the present, offering insights into the discovery of AX, its chemical and physical attributes, distribution in organisms, and biosynthesis. Additionally, it delves into the intricate realm of health benefits, biofunctional characteristics, and the current market status of AX. By encompassing these multifaceted aspects, this review aims to provide readers with a more profound understanding and a robust foundation for future scientific endeavors directed at addressing societal needs for sustainable nutritional and medicinal solutions. An updated summary of AXs health benefits, its present market status, and potential future applications are also included for a well-rounded perspective.

Growth of Dunaliella viridis in multiple cycles of reclaimed media after repeated high pH-induced flocculation and harvesting

Minimizing the use of water for growing microalgae is crucial for lowering the energy and costs of animal feed, food, and biofuel production from microalgae. Dunaliella spp., a haloterant species that can accumulate high intracellular levels of lipids, carotenoids, or glycerol can be harvested effectively using low-cost and scalable high pH-induced flocculation. However, the growth of Dunaliella spp. in reclaimed media after flocculation and the impact of recycling on the flocculation efficiency have not been explored. In this study, repeated cycles of growth of Dunaliella viridis in repeatedly reclaimed media from high pH-induced flocculation were studied by evaluating cell concentrations, cellular components, dissolved organic matter (DOM), and bacterial community shifts in the reclaimed media. In reclaimed media, D. viridis grew to the same concentrations of cells and intracellular components as fresh media-107 cells/mL with cellular composition of 3 % lipids, 40 % proteins, and 15 % carbohydrates-even though DOM accumulated and the dominant bacterial populations changed. There was a decrease in the maximum specific growth rate and flocculation efficiency from 0.72 d-1 to 0.45 d-1 and from 60 % to 48 %, respectively. This study shows the potential of repeated (at least five times) flocculation and reuse of media as a possible way of reducing the costs of water and nutrients with some tradeoffs in growth rate and flocculation efficiency.

Sufficient Phosphorus Enhances Resistance and Changes Accumulation of Lead in Chlamydomonas reinhardtii

Phosphorus (P) is critical for algal growth and resistance to environmental stress. However, little is known about the effects of P supply on the lead (Pb) toxicity and accumulation in microalgae. We set up two P concentrations, 315 (PL ) and 3150 μg L-1 (PH ), in algal culture, and the responses of Chlamydomonas reinhardtii to various Pb treatments (0, 200, 500, 1000, 2000, and 5000 μg L-1 ) were investigated. Compared with the PL condition, PH promoted cell growth but reduced cellular respiration by approximately 50%. Moreover, PH alleviated damage to the photosynthetic system in algal cells after Pb stress. After exposure to 200-2000 μg L-1 Pb, higher Pb2+ concentrations and Pb removal were observed in the PL medium. However, under exposure to 5000 μg L-1 Pb, less Pb2+ was present but more Pb was removed by the algal cells in the PH medium. More P supply enhanced the secretion of extracellular fluorescent substances by C. reinhardtii. Transcriptomic analysis showed that genes associated with synthesis of phospholipids, tyrosine-like proteins, ferredoxin, and RuBisCO were up-regulated after Pb exposure. Together the findings of our study demonstrated the critical roles of P in Pb accumulation and resistance in C. reinhardtii. Environ Toxicol Chem 2023;42:1960-1970. © 2023 SETAC.

Epitomizing biohydrogen production from microbes: Critical challenges vs opportunities

Hydrogen is a clean and green biofuel choice for the future because it is carbon-free, non-toxic, and has high energy conversion efficiency. In exploiting hydrogen as the main energy, guidelines for implementing the hydrogen economy and roadmaps for the developments of hydrogen technology have been released by several countries. Besides, this review also unveils various hydrogen storage methods and applications of hydrogen in transportation industry. Biohydrogen productions from microbes, namely, fermentative bacteria, photosynthetic bacteria, cyanobacteria, and green microalgae, via biological metabolisms have received significant interests off late due to its sustainability and environmentally friendly potentials. Accordingly, the review is as well outlining the biohydrogen production processes by various microbes. Furthermore, several factors such as light intensity, pH, temperature and addition of supplementary nutrients to enhance the microbial biohydrogen production are highlighted at their respective optimum conditions. Despite the advantages, the amounts of biohydrogen being produced by microbes are still insufficient to be a competitive energy source in the market. In addition, several major obstacles have also directly hampered the commercialization effors of biohydrogen. Thus, this review uncovers the constraints of biohydrogen production from microbes such as microalgae and offers solutions associated with recent strategies to overcome the setbacks via genetic engineering, pretreatments of biomass, and introduction of nanoparticles as well as oxygen scavengers. The opportunities of exploiting microalgae as a suastainable source of biohydrogen production and the plausibility to produce biohydrogen from biowastes are accentuated. Lastly, this review addresses the future perspectives of biological methods to ensure the sustainability and economy viability of biohydrogen production.

Artificial intelligence and machine learning tools for high-performance microalgal wastewater treatment and algal biorefinery: A critical review

The increased water scarcity, depletion of freshwater resources, and rising environmental awareness are stressing for the development of sustainable wastewater treatment processes. Microalgae-based wastewater treatment has resulted in a paradigm shift in our approach toward nutrient removal and simultaneous resource recovery from wastewater. Wastewater treatment and the generation of biofuels and bioproducts from microalgae can be coupled to promote the circular economy synergistically. A microalgal biorefinery transforms microalgal biomass into biofuels, bioactive chemicals, and biomaterials. The large-scale cultivation of microalgae is essential for the commercialization and industrialization of microalgae biorefinery. However, the inherent complexity of microalgal cultivation parameters regarding physiological and illumination parameters renders it challenging to facilitate a smooth and cost-effective operation. Artificial intelligence (AI)/machine learning algorithms (MLA) offer innovative strategies for assessing, predicting, and regulating uncertainties in algal wastewater treatment and biorefinery. The current study presents a critical review of the most promising AI/MLAs that demonstrate a potential to be applied in microalgal technologies. The most commonly used MLAs include artificial neural networks, support vector machine, genetic algorithms, decision tree, and random forest algorithms. Recent developments in AI have made it possible to combine cutting-edge techniques from AI research fields with microalgae for accurate analysis of large datasets. MLAs have been extensively studied for their potential in microalgae detection and classification. However, the ML application in microalgal industries, such as optimizing microalgae cultivation for increased biomass productivity, is still in its infancy. Incorporating smart AI/ML-enabled Internet of Things (IoT) based technologies can help the microalgal industries to operate effectively with minimum resources. Future research directions are also highlighted, and some of the challenges and perspectives of AI/ML are outlined. As the world is entering the digitalized industrial era, this review provides an insightful discussion about intelligent microalgal wastewater treatment and biorefinery for researchers in the field of microalgae.

Microbial itaconic acid bioproduction towards sustainable development: Insights, challenges, and prospects

Microbial biomanufacturing is a promising approach to produce high-value compounds with low-carbon footprint and significant economic benefits. Among twelve "Top Value-Added Chemicals from Biomass", itaconic acid (IA) stands out as a versatile platform chemical with numerous applications. IA is naturally produced by Aspergillus and Ustilago species through a cascade enzymatic reaction between aconitase (EC 4.2.1.3) and cis-aconitic acid decarboxylase (EC 4.1.1.6). Recently, non-native hosts such as Escherichia coli, Corynebacterium glutamicum, Saccharomyces cerevisiae, and Yarrowia lipolytica have been genetically engineered to produce IA through the introduction of key enzymes. This review provides an up-to-date summary of the progress made in IA bioproduction, from native to engineered hosts, covers in vivo and in vitro approaches, and highlights the prospects of combination tactics. Current challenges and recent endeavors are also addressed to envision comprehensive strategies for renewable IA production in the future towards sustainable development goals (SDGs).

A review on the emerging conversion technology of cellulose, starch, lignin, protein and other organics from vegetable-fruit-based waste

A large amount of vegetable-fruit-based waste (VFBW) belonging to agricultural waste is produced around the world every year, imposing a huge burden on the environment and sustainable development. VFBW contains a lot of water and useful organic compounds (e.g., cellulose, minerals, starch, proteins, organic acids, lipids, and soluble sugars). Taking into account the composition characteristics and circular economy of VFBW, many new emerging conversion technologies for the treatment of VFBW (such as hydrothermal gasification, ultrasound-assisted extraction, and synthesis of bioplastics) have been developed. This review summarizes the current literature discussing the technical parameters, process, mechanism, and characteristics of various emerging conversion methods, as well as analyzing the application, environmental impact, and bio-economy of by-products from the conversion process, to facilitate solutions to the key problems of engineering cases using these methods. The shortcomings of the current study and the direction of future research are also highlighted in the review.

Membrane-based water and wastewater treatment technologies: Issues, current trends, challenges, and role in achieving sustainable development goals, and circular economy

Membrane-based technologies are recently being considered as effective methods for conventional water and wastewater remediation processes to achieve the increasing demands for clean water and minimize the negative environmental effects. Although there are numerous merits of such technologies, some major challenges like high capital and operating costs . This study first focuses on reporting the current membrane-based technologies, i.e., nanofiltration, ultrafiltration, microfiltration, and forward- and reverse-osmosis membranes. The second part of this study deeply discusses the contributions of membrane-based technologies in achieving the sustainable development goals (SDGs) stated by the United Nations (UNs) in 2015 followed by their role in the circular economy. In brief, the membrane based processes directly impact 15 out of 17 SDGs which are SDG1, 2, 3, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16 and 17. However, the merits, challenges, efficiencies, operating conditions, and applications are considered as the basis for evaluating such technologies in sustainable development, circular economy, and future development.