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National Laboratory of Energy and Geology Scientific Repository
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Phenological Development, Productivity, and Oil Profiles of Different Safflower Cultivars for Biofuel Production
Publication . Silva, Raimunda Adlany Dias; Gouveia, Luisa; Rocha, Thomaz Gabriel Barros; Gondim, Amanda Duarte; Lichston, Juliana Espada; Santos, Nataly Albuquerque
ABSTRACT: The production of oilseed biomass to meet the demand of the energy sector is constrained by several factors, including regional soil and climate conditions, phenological and production issues, such as yield and oil profile, and the compatibility of these factors with the requirements of the energy sector. Safflower is a small oilseed, and its brief phenological cycle and high productivity, concentration, and oil profile distinguish it as a notable candidate for research on energy applications. The objective of this study was to analyze the germination, seed vigor, yield, and oil profile parameters of safflower cultivars (IMAmt 1470, IMAmt 894, and IMAmt S525) with a view to determining their potential as biomass for the biofuel production chain, especially biodiesel and renewable aviation hydrocarbons. Safflower cultivars displayed high germination rates and germination vigor after 12 months of storage. They also met the production standards of 6797.7 kg ha-1 in 2021. The cultivar IMAmt-S525 exhibited a high oil content of 35%. The oil compositions of the safflower cultivars included in this study were found to be 9.7% palmitic acid (IMAmt1470), 71.82% linoleic acid (IMAmt 894), and 41% oleic acid (IMAmt 894 harvest 2022). It is recommended that the following cultivars be selected for production: IMAmt 894, IMAmt-S525, and IMAmt 1470, taking into consideration the physiological, production, and oil composition parameters. Since all three cultivars have high standards of physiological quality, productivity, and oil yield, they have the potential to be used as biomass to diversify oilseed matrices for biofuels.
A solar panel-origin microalga, Coelastrella thermophila D14, with high potential for wastewater biotechnology
Publication . Baldanta, Sara; Ferreira, Alice; Vinuesa, Arantxa Marco; García-García, Isabel; Gouveia, Luisa; Llorens, Juana Maria Navarro; Guevara, Govinda
ABSTRACT: Extremophilic environments are rich reservoirs for discovering microorganisms with vast biotechnological potential. Among these, microalgae stand out for their pivotal role in sustainable wastewater treatment and nutrient recycling. This study introduces Coelastrella thermophile D14, a microalga isolated from a solar panel, identified through morphological studies and genomic sequencing. The genus Coelastrella has been characterized and classified as highly productive strains valuable for biofuel and bioproduct generation as well as for their ability to produce significant amounts of carotenoids. Experiments revealed the extraordinary resilience of this strain to prolonged desiccation and high-strength piggery wastewater. Notably, D14 cultivated in 10% pig effluent exhibited biostimulant properties, achieving a germination index 23% higher than the control on Lepidium sativum. In a groundbreaking development, we have successfully established an Agrobacterium-mediated transformation protocol for C. thermophila D14, optimizing key parameters for effective T-DNA transfer. This marks a pioneering achievement within the genus Coelastrella. These findings highlight the significant potential of D14 as a robust platform for future biotechnological applications, opening new opportunities for innovative solutions, especially in environmental protection and sustainable agriculture.Key points center dot First microalga from solar panel biofilm: Coelastrella sp. D14 isolated and characterized.center dot Strain D14 tolerates prolonged desiccation and grows well in piggery wastewater.center dot Stable Agrobacterium-mediated transformation enables future metabolic engineering.Key points center dot First microalga from solar panel biofilm: Coelastrella sp. D14 isolated and characterized.center dot Strain D14 tolerates prolonged desiccation and grows well in piggery wastewater.center dot Stable Agrobacterium-mediated transformation enables future metabolic engineering.Key points center dot First microalga from solar panel biofilm: Coelastrella sp. D14 isolated and characterized.center dot Strain D14 tolerates prolonged desiccation and grows well in piggery wastewater.center dot Stable Agrobacterium-mediated transformation enables future metabolic engineering.
Shining a light on outdoor algal systems for wastewater treatment: How artificial light enhancement impacts biomass costs and life cycle
Publication . Magalhães, Iara; Jesus Junior, Maurino Magno; França, Bruna Thomazinho; Silva, Thiago; Saleme Aona de Paula Pereira, Alexia; Souza, Lucas Cescon de Almeida; Rodrigues, Fábio de Ávila; Reis, Alberto; Peixoto Assemany, Paula; Calijuri, Maria Lucia
ABSTRACT: Microalgae-based wastewater treatment is increasingly viewed as a cleaner production strategy, combining nutrient removal and biomass generation for high-value applications. However, productivity constraints remain a critical barrier to broader implementation. This study examines the viability of integrating light-emitting diodes (LEDs) into outdoor bubble column reactors for domestic wastewater treatment and biomass production, focusing on environmental impacts and techno-economic performance. Three lighting regimes—natural light only (control), 12-h LED cycles, and 24-h LED cycles—were experimentally evaluated and scaled up using Aspen Plus® simulation. Life cycle assessments (LCA) were conducted to quantify environmental impacts (ReCiPe, 2016 method), and a detailed techno-economic analysis determined minimum biomass selling prices. Compared to the control, LED-assisted systems increased biomass yields by 24–34 %, yet capital and operational costs offset productivity gains. Under grid electricity, minimum selling prices considering capital and operational costs ranged from 80.76 to 91.37 USD/kg for LED systems versus 68.85 USD/kg for the control. Photovoltaic (PV) integration reduced operational costs by up to 16.89 %, but LED scenarios remained more expensive. LCA findings highlighted substantially higher environmental impacts (78–149 times) for LED systems, partly alleviated by PV-powered operations. Sensitivity analysis identified nutrient availability, process scale, and reactor costs as pivotal factors influencing the feasibility of LED-enhanced wastewater treatment. Overall, while LED technology offers notable productivity benefits, its economic and environmental trade-offs underscore the need for integrated approaches—ranging from material innovations to policy incentives—to achieve truly sustainable wastewater-based microalgal production.
Modulating microalgal metabolism and its integration into dark fermentation: Challenges and opportunities with wastewater-grown biomass
Publication . Ferreira, Jessica; Silva, Thiago; Saleme Aona de Paula Pereira, Alexia; Reis, Alberto; Zaiat, Marcelo; ; Calijuri, Maria Lucia
ABSTRACT: Microalgae represent a promising feedstock for the sustainable production of bioproducts and bioenergy, due to their versatile biochemical composition and environmental adaptability. Given the wide range of bioproducts that can be derived from their biomass, its biochemical composition suggests more favorable conversion routes and can be enhanced through cultivation conditions focused on the synthesis of one (or more) metabolites of interest to the biotechnology market. Accordingly, this review focuses on approaches for modulating microalgal metabolism, such as nutrient depletion and reactor configuration characteristics, among others, as well as on key outcomes obtained through two-stage cultivation, which combine phases of high biomass and metabolite productivity. From a resource recovery perspective, emphasis was placed on approaches that are more readily applicable to wastewater treatment plants. Furthermore, as energy-oriented routes are more suitable for valorizing of biomass grown in wastewater and considering that biohydrogen has been shown to be an emerging product of scientific relevance, this review also analyzes the limitations and strategies for integrating its production via dark fermentation. Pretreatment techniques and co-fermentation approaches were discussed as strategies to overcome the challenges associated with the anaerobic fermentation/digestion of microalgae due to their characteristics and biochemical composition. Finally, biorefinery configurations that integrate these processes were discussed from a scale-up perspective.
Pilot-Scale cultivation of microalgae in blended effluents: C/N ratio management to boost biomass and biofuel precursors
Publication . Saleme Aona de Paula Pereira, Alexia; Silva, Thiago; Magalhães, Iara; Santos, Weller Gabriel da Silva; Oliveira, Mateus Soares de; Reis, Alberto; Couto, Eduardo de Aguiar; Calijuri, Maria Lucia
ABSTRACT: Algal biotechnology offers a sustainable pathway for wastewater treatment and resource recovery. However, the low carbon-to-nitrogen (C/N) ratio in domestic wastewater often limits microalgal productivity, which may compromise process viability and, consequently, limit its application in bioproduct valorization routes. This study evaluated the effects of blending municipal wastewater (MW) with industrial wastewater from juice processing (IWJ) at different ratios on biomass production, biochemical composition, and pollutant removal. Pilot-scale experiments in outdoor high-rate algal ponds, operated without external carbon dioxide (CO2) supply (relying on inorganic carbon present in the wastewater and passive diffusion from air). These experiments tested three blends: T1 (60 % MW + 40 % IWJ, C/N 9.25), T2 (40 % MW + 60 % IWJ, C/N 25.31), and T3 (20 % MW + 80 % IWJ, C/N 52.71). T1 achieved the highest biomass productivity and lipid content (14.44 %, p < 0.05), while T3 presented the highest levels of saturated fatty acids C16:0 (40.39 %) and C18:0 (10.08 %), supporting its biodiesel potential. Carbohydrate accumulation was enhanced in T2 (18.44 %) and T3 (21.09 %) under nitrogen-limited conditions. Microalgal species composition varied significantly with the C/N ratio, indicating selective adaptation. Additionally, dissolved organic carbon removal followed first-order kinetics across treatments, confirming model applicability. These findings underscore the effectiveness of effluent blending and C/N adjustment to enhance biomass quality, pollutant removal, and suitability for biofuel production in integrated algal-based wastewater treatment systems.