ABSTRACT. This study aimed to assess the impact of microalgal concentrations in diets on the settlement and metamorphosis stages of pediveliger larvae and spat of Crassostrea gigas oysters. Diets containing microalgal concentrations of 8, 12, and 16×104 cells mL-1 were administered for seven days during the larval settlement phase of pediveliger larvae. In the metamorphosis and postlarval cultivation phases, diets with microalgal concentrations of 8, 16, 24, and 32×104 cells mL-1 and a control group without food were tested for 14 and 21 days, respectively. Growth, yield, and survival were assessed every seven days. The diet comprised 30% Isochrysis galbana and 70% Chaetoceros muelleri microalgae. In the metamorphosis phase, the results revealed no significant differences in larval metamorphosis rate and survival across the tested diets. The concentrations exhibited similar survival in the spat with an initial average shell height of 0.657 ± 0.05 mm, with a significant difference only in growth. In the spat with an initial average shell height of 0.830 ± 0.12 mm, no differences in survival were observed among the tested concentrations. We concluded that diets of 12 and 16×104 cells mL-1 provide high rates of larval metamorphosis and spat yield during the larval settlement and metamorphosis phases. During the spat cultivation phases, diets of 32 and 24×104 cells mL-1 could optimize the cultivation time and yield of C. gigas spat in the laboratory. However, when considering survival alone, no advantage was found in providing a diet with a microalgal concentration above 8×104 cells mL-1 across all C. gigas oyster cultivation phases.

Abstract The exploration of the biodiversity of cyanobacteria and microalgae holds great promise for obtaining pigments of industrial interest. This study focused on the bioprospecting of these organisms to obtain pigments of industrial interest together with enriched biomass. We investigated the impact of photoperiod and concentration of C/N/P nutrient sources in heterotrophic cultures, controlling specific variables such as light intensity, volume, pH, temperature, air flow and time to produce phycobiliproteins in Arthrospira platensis UTEX1926 and total carotenoids in Scenedesmus sp. using a nonfactorial Plackett‒Burman design in STATISTICA 7.0 software. The biomass concentration was determined by dry weight, while the concentrations of phycocyanin and carotenoids were determined spectrophotometrically at specific wavelengths. Heterotrophic cultures demonstrated superior productivity, with phycocyanin and carotenoids achieving percentages of 7% and 0.4% (w/w), respectively, and an R2 value of 0.99. Among the influential parameters, potassium diphosphate and sodium bicarbonate played pivotal roles in the final deposition of carotenoids and phycocyanin, respectively, yielding concentrations of 96.5 mg/L phycocyanin and 6.5 mg/L carotenoids.

Resumen La exploración de la biodiversidad de cianobacterias y microalgas es muy prometedora para la obtención de pigmentos de interés industrial. Este estudio se centra en la bioprospección de estos organismos para obtener pigmentos de interés industrial junto con biomasa enriquecida. Investigamos el impacto del fotoperiodo y la concentración de fuentes de nutrientes C/N/P en cultivos heterótrofos, controlando variables específicas como la intensidad luminosa, volumen, pH, temperatura, flujo de aire y tiempo para la producción de ficobiliproteínas en Arthrospira platensis UTEX1926 y carotenoides totales en Scenedesmus sp. Empleando un diseño Plackett‒Burman no factorial en el software STATISTICA 7.0. La concentración de biomasa fue determinada por peso seco, mientras que la concentración de ficocianinas y carotenoides fueron determinadas espectrofotométricamente a longitudes de onda específicas. Los cultivos heterótrofos demostraron una productividad superior, alcanzando las ficocianinas y los carotenoides porcentajes del 7% y el 0,4% (% p/p) respectivamente, y un notable valor R2 de 0,99. Entre los parámetros influyentes, el difosfato potásico y el bicarbonato sódico desempeñaron papeles fundamentales en la deposición final de carotenoides y ficocianinas, respectivamente, alcanzando concentraciones de 96,5 mg/L de ficocianinas y 6,5 mg/L de carotenoides.

ABSTRACT Marine diatoms are important part of the diet of mollusks, crustaceans and fish because of their nutritional profile. The objective of this study was to evaluate the nutritional profile of eight strains of microalgae of the genera Chaetoceros and Skeletonema, dominant in the central coast of Peru, in order to rate their potential as an ingredient for aquaculture. For this, 7 L cultures were carried out at a pH of 7.5-8.5, at 17 °C, illumination of 35 µmol.s-1.m-2 and a photoperiod of 12:12 hours. After 15 days of culture, the dry biomass was obtained by lyophilization and the nutritional profile analyzes were performed. The results show values of moisture from 5 to 14 %, ash from 19 to 57 %, carbohydrates from 2 to 23 %, lipids from 3 to 9 %, and proteins from 12 to 30 %. The strain with the highest percentage of the last two compounds was that corresponding to S. costatum (IMP-BG-466). Likewise, all the strains presented high relative percentages of the essential fatty acid, eicopentaenoic acid (EPA), from 13 to 30 % and the essential amino acid leucine from 1 to 3 % (% w/w). However, as this strain presents low concentrations of docosahexaenoic acid (DHA), arginine, histidine and lysine, it is necessary to supplement it with other sources for the formulation of balanced diets.

RESUMEN Las diatomeas marinas forman parte importante de la dieta de moluscos, crustáceos y peces debido a su perfil nutricional. El objetivo de esta investigación fue evaluar el perfil nutricional de ocho cepas de microalgas de los géneros Chaetoceros y Skeletonema, dominantes en la costa central del Perú, y valorar su potencial como ingrediente para acuicultura. Se realizaron cultivos de 7 L a pH de 7.5-8.5, a 17 °C, iluminación de 35 µmol.s-1.m-2 y fotoperiodo 12:12 horas. Luego de 15 días de cultivo, se obtuvo la biomasa seca mediante liofilización y se realizaron los análisis de perfil nutricional. Los resultados indican valores de humedad de 5 a 14 %, cenizas de 19 a 57 %, carbohidratos de 2 a 23 %, lípidos de 3 a 9 % y proteínas de 12 a 30 %. La cepa con mayor porcentaje de estos dos últimos compuestos fue la correspondiente a la especie S. costatum (IMP-BG-466). Así mismo, todas las cepas presentaron altos porcentajes relativos del ácido graso esencial, ácido eicopentaenoico (EPA), de 13 a 30 % y el aminoácido esencial leucina de 1 a 3 % (% p/p). Sin embargo, al presentar bajas concentraciones del ácido docosahexaenoico (DHA), arginina, histidina y lisina, es necesario complementar su utilización con otras fuentes para la formulación de dietas equilibradas.

RESUMEN Las cianobacterias y las microalgas representan fuentes prometedoras para la producción sostenible de biofertilizantes y bioestimulantes, que pueden mejorar el rendimiento, la calidad de los cultivos y contribuir a la seguridad alimentaria. Sin embargo, a pesar de su potencial, su exploración sigue siendo incompleta, obstaculizada por los desafíos técnicos y económicos que surgen cuando se intenta escalar la producción. El objetivo principal de esta revisión es profundizar en los compuestos químicos activos responsables de las funciones de biofertilización y bioestimulación de las cianobacterias y las microalgas. También, explora las operaciones unitarias esenciales involucradas en la transformación de su biomasa en potenciales bioproductos. Además, esta revisión destaca estudios que han empleado cianobacterias y microalgas como fuentes de biofertilizante en diversos cultivos, describiendo su modo de acción y aplicación. Mediante la integración del procesamiento de cianobacterias y microalgas con otras herramientas biotecnológicas avanzadas, se puede mejorar significativamente la viabilidad de estos productos para la agricultura sostenible.

ABSTRACT Cyanobacteria and microalgae represent promising sources for sustainable production of biofertilizers and biostimulants, which can improve crop yield and quality and contribute to food security. However, despite their potential, their exploration remains incomplete, hindered by technical and economic challenges that arise when attempting to scale up production. The primary focus of this review is to delve into the active chemical compounds responsible for the biofertilizing and biostimulating roles of cyanobacteria and microalgae. In addition, it explores the essential unit operations involved in transforming their biomass into potential bioproducts. Moreover, this review highlights studies that have employed cyanobacteria and microalgae as sources of biofertilizer in various crops, describing their mode of action and application. By integrating cyanobacteria and microalgae processing with other advanced biotechnological, the viability of these products for sustainable agriculture can be significantly enhanced.

ABSTRACT This study aimed to evaluate the use of microalgae meal (Aurantiochytrium sp. and Nannochloropsis spp.) as a substitute for fish oil in the diet of shrimp Penaeus vannamei reared in a clear water system. In the diet of these animals, the concentration of fish oil decreased as microalgae meal was inserted, and these were used in five different substitutions: 0, 25, 50, 75, and 100%. The treatments were carried out in triplicate, and after 49 days of cultivation, the zootechnical parameters and the composition of fatty acids in the animals’ muscles were analyzed. In zootechnical performance, the shrimp obtained an average final weight of 16.59 ± 0.3 g, and the growth was approximately 1.89 ± 0.30 g week−1. In addition, feed conversion was, on average, 1.47 ± 0.28, and survival was greater than 97%. However, no significant difference was observed in these parameters. Regardless of the levels of fish oil replacement by microalgae meal, the composition of fatty acids in the shrimp muscle was ensured, as well as their quantity within groups, such as n-3 and n-6 polyunsaturated fatty acids. Thus, with the results obtained in the present study, it is suggested that it is possible to formulate a high-performance diet without any ingredients of marine origin (fish oil or fish meal), contributing to aquaculture's sustainability.

ABSTRACT Haematococcus pluvialis synthesizes and accumulates astaxanthins, while Spirulina (Arthrospira) platensis produces phycocyanins. The ornamental shrimp Neocaridina davidi is commercially important for its variety and intensity of coloration. We evaluate the effect on the coloration of N. davidi by consuming H. pluvialis and S. platensis as a food supplement to preserve their nutritional quality. H. pluvialis was subjected to stress to obtain aplanospores with astaxanthin. Live microalgae were included in gelled spheres to provide them as a supplement to three-day-old N. davidi juveniles with different phenotypes: wild (NdW), red (NdR), and blue (NdB). The experiment involved the commercial food supply and spheres with or without microalgae for 31 days. Chromatophores present in the uropod of each phenotype were examined, their number and expansion estimated, and the area covered by optical density (OD). Results show that H. pluvialis reached a greater astaxanthin accumulation on day 30. The coloration of the NdR and NdB phenotypes improved by consuming microalgae, increasing the OD in the uropod. NdB phenotype showed better coloration when consuming S. platensis (56.2%), while the NdR phenotype was more favored when consuming H. pluvialis (74.2%). The chromatophores expanded their area by doubling in the NdR and NdB phenotypes, where H. pluvialis increased its intensity four times in NdR. The number of chromatophores was significant only in NdR with S. platensis. In conclusion, gelling is a viable method to preserve the nutritional quality of live microalgae and transfer bioactive compounds that improve the coloration of N. davidi.

Abstract This study aimed to characterize seasonal changes in microphytoplankton composition and abundance on Bahia continental shelf, a region with upwelling events. Semi-annual sampling was conducted during summer and winter from 2017 to 2021 at nine points. Microphytoplankton was sampled using a conical plankton net through horizontal subsurface drags, using a flowmeter coupled to the net, to measure the total volume of filtered water. Temperature and salinity were measured in situ, presenting typical values of tropical waters. In addition, dissolved inorganic nutrient concentration corroborated a tropical marine oligotrophic pattern. A total of 144 taxa were identified in the region, with the phyla Heterokontophyta and Dinoflagellata being the most representative, as is typically recorded in tropical coastal regions. The density ranged from 6.08 × 104 to 3.38 × 108 cells L-1, with higher average values in summer. Although cyanobacteria accounted for only 3.2% of species richness in the region, due to summer blooms of Trichodesmium erythraeum (2018, 2019, and 2021), it was the most abundant group throughout the study. It was observed that upwelling events do not seem to establish favorable conditions for marked seasonal changes in microphytoplankton composition and abundance. Trichodesmium erythraeum blooms are closely related to physiology and ecological capacity of this species. Except for bloom periods, the study area presented a high species richness and diversity throughout the analyzed time series.

Resumen El objetivo del presente estudio fue caracterizar los cambios estacionales en la composición y abundancia del microfitoplancton en la plataforma continental de Bahía, una región con presencia de eventos de surgencia. Se realizaron muestreos semestrales durante los veranos e inviernos de 2017 a 2021 en nueve puntos. El microfitoplancton se muestreó utilizando una red cónica de plancton en arrastres horizontales debajo de la superficie, utilizando un medidor de corriente acoplado a la red, para medir el volumen total de agua filtrada. La temperatura y la salinidad fueron medidas in situ, presentando valores típicos de aguas tropicales. Además, las concentraciones de nutrientes inorgánicos disueltos corroboraron el patrón oligotrófico marino tropical. Se identificaron un total de 144 taxones en la región, siendo los phyla Heterokontophyta y Dinoflagellata los más representativos, como se registra típicamente en las regiones costeras tropicales. La densidad varió de 6,08 × 104 a 3,38 × 108 células L-1, con valores promedio más altos en verano. Aunque las cianobacterias representaron solo el 3,2% de la riqueza de especies en la región, debido a las floraciones de verano de Trichodesmium erythraeum (2018, 2019 y 2021), fue el grupo más abundante a lo largo del estudio. Se observó que los eventos de surgencia no parecen establecer condiciones favorables para cambios estacionales marcados en la composición y abundancia del microfitoplancton. Las floraciones de Trichodesmium erythraeum están estrechamente relacionadas con la fisiología y la capacidad ecológica de esta especie. Con excepción de los períodos de floración, el área de estudio presentó patrones de alta riqueza y diversidad de especies a lo largo de la serie temporal analizada.

Abstract Introduction: The aquaculture industry is constantly growing, registering a global production of almost 88 million tonnes by 2020. This industry brings environmental problems if its effluents are not properly treated. In 2020, the first technology-based company of CONICET was established in Argentine Patagonia whose purpose is the aquaculture production of the green sea urchin, Arbacia dufresnii to develop a range of nutraceutical products. Its cultivation system entails a commitment to sustainability since its creation, and yet it generates effluents with high levels of nitrates and phosphates. Objective: Given this scenario, and valuing bioremediation as a water treatment tool, the use of marine microalgae as phytoremediating agents of aquaculture effluent is proposed in this work. Methods: The microalgae Chaetoceros gracilis, Navicula sp., Tetraselmis suecica, Rhodomona salina, Nanochloropsis galvana and Cylindrotheca closterium were use; which are used as food for sea urchins larvae in the production process. An experiment was designed that compares the microalgal growth and the removal capacity of nutrients in the effluent in contrast to the artificial culture medium currently used in the production cycle. Results: It is possible to remedy the aquaculture industry’s effluent by employing the selected microalgae, with a percentage of removal efficiency of 100 % of the nitrate and an average removal efficiency percentage of 50 % for all the microalgae tested. Likewise, significantly higher microalgal biomass values were obtained when the culture was carried out in the effluent the culture in the artificial environment. Conclusions: The advances in research provided in this work show that it is possible to take advantage of a discard to cultivate microalgae, even improving microalgal productivity for use as food, reducing the costs involved in the microalgal production sector by changing the use of the type of current culture medium (F/2) for that from a current discard. These advances, if scaled and validated, can improve industry sustainability standards within the framework of a circular economy.

Resumen Introducción: La industria acuícola está en constante crecimiento, registrando una producción mundial de casi 88 millones de toneladas para el año 2020. Esta industria trae consigo problemas ambientales si sus efluentes no son debidamente tratados. En el 2020, se constituyó la primera empresa de base tecnológica del CONICET en la Patagonia Argentina cuyo propósito es la producción acuícola del erizo verde de mar, Arbacia dufresnii con la finalidad de elaborar una gama de productos nutracéuticos. Su sistema de cultivo conlleva un compromiso de sustentabilidad desde su creación, y sin embargo genera efluentes con niveles altos de nitratos y fosfatos. Objetivo: Ante este escenario, y valorizando la biorremediación como herramienta de tratamiento de aguas, se propone en este trabajo la utilización de las microalgas marinas como agentes fitorremediadores del efluente acuícola. Métodos: Se utilizaron las microalgas Chaetoceros gracilis, Navicula sp., Tetraselmis suecica., Rhodomona salina., Nanochloropsis galvana y Cylindrotheca closterium, las cuales son usadas como alimento de las larvas del erizo en el proceso productivo. Se diseñó un experimento que compara el crecimiento microalgal y la capacidad de remoción de los nutrientes en el efluente en contraste con el medio de cultivo artificial actualmente usado en el ciclo productivo. Resultados: Es posible remediar el efluente de la industria acuícola mediante las microalgas seleccionadas, con porcentaje de eficacia de remoción del 100 % del nitrato y un porcentaje de eficacia de remoción promedio de 50 % para todas las microalgas testeadas. Asimismo, se obtuvieron valores de biomasa microalgal significativamente mayores cuando el cultivo fue realizado en el efluente respecto del cultivo en el medio artificial. Conclusiones: Los avances en investigación proporcionados en este trabajo ponen de manifiesto que es posible el aprovechamiento de un descarte para cultivar las microalgas, incluso mejorando la productividad microalgal para su uso como alimento, disminuyendo los costos involucrados en el sector de producción microalgal cambiando el uso del tipo de medio de cultivo actual (F/2) por el proveniente de un descarte. Estos avances si son escalados y validados, pueden mejorar los estándares de sustentabilidad de la industria en el marco de una economía circular.

ABSTRACT Introduction: The fish processing industry generates large volumes of wastewater, which are generally treated in lagoons, generating bad odors and emitting polluting gases into the atmosphere. According to their organic matter content, these can be treated in anaerobic reactors with a microalgae coupling for the bioremediation of the effluent, due to their high N, P and CO2 removal capacity. Objective: To determine the potential of fish processing wastewater from the fishing industry in Sancti Spíritus for biogas and microalgae production. Materials and Methods: The physicochemical characteristics of the wastewater are taken as a starting point and mass balances are performed using indexes from the literature to determine the volumes of biogas and the amount of biomass harvested from the microalgae Chlorella vulgaris. Results and Discussion: The analyzed waters represent a potential for obtaining biogas and for the development of microalgae cultures as a promising alternative to improve process performance, which allows obtaining energy and high value-added products. Conclusions: The wastewater from the Pescaspir fishing company produces 21.8 m3 of biogas per day and 0.58 kg/d of dry microalgal biomass, so the proposed treatment system allows the generation of renewable energy, the production of biomass, obtaining a purified effluent and reducing the environmental impact on natural aquatic systems, in addition to other possible technological applications.

RESUMEN Introducción: La industria de procesamiento del pescado genera grandes volúmenes de aguas residuales, que generalmente son tratadas en lagunas, generando malos olores y emitiendo gases contaminantes a la atmósfera. De acuerdo a su contenido de materia orgánica estas pueden ser tratadas en reactores anaerobios con un acople de microalgas para la biorremediación del efluente, debido a su alta capacidad de remoción de N, P y CO2. Objetivo: Determinar el potencial de las aguas residuales del procesamiento de pescado de la industria pesquera en Sancti Spíritus para la producción de biogás y microalgas. Materiales y Métodos: Se toma como punto de partida las características fisicoquímicas de las aguas residuales y se realizan balances de masa empleando índices de la literatura, para determinar los volúmenes de biogás y la cantidad de biomasa cosechada de la microalga Chlorella vulgaris. Resultados y Discusión: Las aguas analizadas, representan un potencial para la obtención de biogás y para el desarrollo de cultivos de microalgas como alternativa prometedora para mejorar el rendimiento de los procesos, lo que permite obtener energía y productos de alto valor añadido. Conclusiones: Las aguas residuales de la empresa pesquera Pescaspir, permiten obtener 21,8 m3 de biogás al día y 0,58 kg/d de biomasa microalgal seca, por lo que el sistema de tratamiento propuesto permite la generación de energía renovable, la producción de biomasa, la obtención de un efluente depurado y la reducción del impacto ambiental que causan en los sistemas acuáticos naturales, además de otras posibles aplicaciones tecnológicas.

Abstract The present study evaluated the hematological, antiparasitic and growth responses in tambaqui (Colossoma macropomum) fed with diets supplemented with the microalgae Arthrospira platensis and Chlorella vulgaris (0%; 10% A. platensis; 10% C. vulgaris; and 5% A. platensis+5% C. vulgaris). Tambaqui (n=60, 62.57 ± 8.76 g) were fed for 20 days with experimental diets. Blood samples collection was done to determine hematological parameters, and gills were removed to identify and count monogenetic parasites. Supplementation with A. platensis 10% reduced red blood cells count, in consequence mean corpuscular volume and mean hemoglobin concentration increased. Total leukocyte, monocyte, eosinophil, and basophil counts reduced with the use of A. platensis. Higher monocytes, eosinophil, and basophil numbers in tambaqui fed with diet supplemented with 10% C. vulgaris were observed and may have been due to the presence of immunostimulants in this microalga composition. Reduction on total cholesterol in tambaqui that received both microalgae (A. platensis 5%+C. vulgaris 5%) may indicate that combined supplementation presented greater benefits to the health for C. macropomum than separately. Both microalgae were efficient against monogenetic parasites of tambaqui. Thus, the dietary use of the microalgae A. platensis and C. vulgaris provided immunostimulant and antiparasitic efficacy in C. macropomum. Colossoma 0% 0 (0% 10 A C 5 platensis5 platensis+5 vulgaris. . vulgaris) n=60, n60 n 60 (n=60 6257 62 57 62.5 876 8 76 8.7 g 2 parameters increased leukocyte monocyte eosinophil monocytes composition (A 5C 5%+C separately Thus (0 1 platensis+ n=60 n6 6 (n=6 625 62. 87 7 8. ( n=6 (n= n= (n

Resumo O presente estudo avaliou as respostas hematológicas, antiparasitária e de crescimento de tambaqui (Colossoma macropomum) após alimentação com dietas suplementadas com microalgas Arthospira platensis e Chlorella vulgaris (0%; 10% A. platensis; 10% C. vulgaris; e 5% A. platensis+5% C. vulgaris). Exemplares de tambaqui (n=60, 62,57±8,76 g) foram alimentados por 20 dias com as dietas experimentais. Amostras de sangue foram coletadas para determinação dos parâmetros hematológicos e brânquias foram retiradas para contagem de parasitos monogenéticos. A suplementação com A. platensis 10% reduziu o RBC, consequentemente aumentando os valores de VCM e HCM. As contagens de leucócitos (total) e de monócitos, eosinófilos e basófilos reduziram com o uso de A. platensis. Números altos de monócitos, eosinófilos e basófilos em tambaqui alimentado com dietas com 10% C. vulgaris foram observados e podem ter ocorrido devido à presença de imunoestimulantes na composição da microalga utilizada. Redução dos níveis plasmáticos de colesterol total em tambaqui indicou que a inclusão das duas microalgas (A. platensis 5%+C. vulgaris 5%) pode indicar que maiores benefícios à saúde do peixe do que quando separadamente suplementada. Ambas mostraram eficácia contra parasitos monogenéticos das brânquias de tambaqui. Assim, conclui-se que o uso das microalgas C. vulgaris e A. platensis promovem ação imunoestimulante com eficácia antiparasitária em C. macropomum. hematológicas Colossoma macropomum 0% 0 (0% 10 C 5 platensis5 platensis+5 vulgaris. . vulgaris) n=60, n60 n 60 (n=60 6257876 62 57 8 76 62,57±8,7 g 2 experimentais RBC HCM (total monócitos utilizada (A 5C 5%+C suplementada Assim concluise conclui se (0 1 platensis+ n=60 n6 6 (n=6 625787 7 62,57±8, ( n=6 (n= 62578 62,57±8 n= (n 6257 62,57± 625 62,57 62,5 62,

Resumo A tendência de produção de biocombustíveis a partir de triacilgliceróis de microalgas está aumentando, porque esse substrato é uma boa alternativa sustentável e vantajosa ao combustível de petróleo e gás. No presente estudo, isolados de microalgas indígenas foram selecionados de amostras de água (n = 30) e solo (n = 30) coletadas em três distritos de Punjab, Paquistão, para avaliar seu potencial de produção de biocombustíveis. As amostras foram inoculadas em placas de meio BG – 11 agar por incubação em temperatura ambiente de 25°C proporcionando 1000 lux por 16h de ciclo claro seguido de 8h de escuro por 15 dias. As amostras de água foram ricas em microalgas e 65.33% de microalgas (49 isolados) foram isolados do distrito de Faisalabad. Com base na morfologia microscópica, isolados de microalgas (n = 180) foram selecionados e submetidos à detecção de lipídios por ensaio de coloração com vermelho do Nilo. Isolados positivos para vermelho do Nilo (n = 23) foram processados para caracterização bioquímica (lipídica, proteica e de carboidratos). O isolado AIN63 apresentou maior teor de lipídios (17.4%) conforme detectado pelo ensaio de microvanilina. O isolado de alga AIN128 apresentou os melhores teores de proteína (42.91%) detectados pelo ensaio de Bradford, e o isolado AIN172 apresentou maiores teores de carboidratos (73.83%), conforme detectado pelo ensaio de anthrone. Os isolados de algas selecionados também foram analisados por espectroscopia de infravermelho com transformada de Fourier (FTIR) para confirmação da análise de carboidratos, proteínas e lipídios. Essas algas nativas têm potencial para a produção de biocombustíveis in vitro a partir de resíduos agrícolas.

Abstract Trend of biofuel production from microalgal triacylglycerols is enhancing, because this substrate is a good sustainable and advantageous alternative to oil and gas fuel. In the present study, indigenous micro algal isolates were screened from water (n=30) and soil (n=30) samples collected from three districts of Punjab, Pakistan to evaluate their biofuel production potential. The samples were inoculated on BG – 11 agar medium plates by incubating at room temperature of 25°C providing 1000 lux for 16h light cycle followed by 8h of dark cycle for 15 d. Water samples were found to be rich in microalgae and 65.33% microalgae (49 isolates) were isolated from Faisalabad district. On the basis of microscopic morphology microalgal isolates (n=180) were selected and subjected to lipid detection by Nile red staining assay. Nile red positive isolates (n=23) were processed for biochemical (lipid, protein and carbohydrates) characterization. AIN63 isolate showed higher lipids (17.4%) content as detected by micro vanillin assay. Algal isolate AIN128 showed best protein contents (42.91%) detected by Bradford assay and AIN172 isolate showed higher carbohydrate contents (73.83%) as detected by anthrone assay. The selected algal isolates were also analyzed by Fourier transform infrared (FTIR) spectroscopy for confirmation of carbohydrate, protein and lipid analysis. These indigenous algae have the potential for in-vitro biofuel production from agricultural waste.

Abstract The papaya (Carica papaya L.) is among the mainly fruit species produced in tropical and subtropical climate. The salinity of water in agricultural areas is considered a limiting factor for the expansion of papaya. This study aimed to evaluate calcium-enriched microalgae extract (EMa-Ca) as an attenuator of saline stress in irrigation water on the growth and physiology of Formosa papaya seedlings, hybrid Tainung. The experiment was conducted in a protected environment, with treatments distributed in a 5 × 2 factorial scheme, comprising five electrical conductivities of irrigation water (0.50; 1.10; 2.50; 3.90 and 4.50 dSm-1) with the presence and absence of EMa-Ca in the substrate. Evaluated characteristics were: plant height, number of leaves, stem diameter, leaf area, dry masses weight of roots, aboveground parts and total. Gas exchanges and chlorophyll indices (a, b and total) were also evaluated. The application of EMa-Ca resulted in an increase of 6.05% in height and 6.33% in trunk diameter. The number of leaves decreased with an increase in electrical conductivity, and the leaf area was reduced by 33%. All seedling dry masses showed greater declines in the absence of EM-Ca. The EMa-Ca increased net photosynthesis, CO2 concentration, transpiration and stomatal conductance by 39.13%, 30.43%, 38.88% and 42.85%, respectively. For chlorophyll without the use of EMa-Ca, a decrease rate of 1.21%, 0.41% and 1.62% was observed for Chla, Chlb and Chlt, respectively. Therefore, the EMa-Ca application (1.0 ml/L) significantly enhance the vegetative development, gas exchanges, and chlorophyll indices of papaya seedlings under saline stress conditions. Carica L. L climate calciumenriched calcium enriched EMaCa EMa Ca (EMa-Ca Tainung environment scheme 0.50 050 0 50 (0.50 1.10 110 1 10 2.50 250 390 3 90 3.9 450 4 4.5 dSm1 dSm dSm-1 substrate diameter roots total a, (a evaluated 605 6 05 6.05 633 33 6.33 conductivity 33% EMCa. EMCa EM Ca. EM-Ca photosynthesis CO concentration 3913 39 13 39.13% 3043 30 43 30.43% 3888 38 88 38.88 4285 42 85 42.85% respectively EMaCa, Ca, 121 21 1.21% 041 41 0.41 162 62 1.62 Chla Chlt Therefore 1.0 (1. ml/L mlL ml development conditions 0.5 (0.5 1.1 11 2.5 25 9 3. 45 4. dSm- 60 6.0 63 6.3 391 39.13 304 30.43 388 8 38.8 428 42.85 12 1.21 04 0.4 16 1.6 1. (1 0. (0. 2. 6. 39.1 30.4 38. 42.8 1.2 ( (0 39. 30. 42.

Resumo O mamão (Carica papaya L.) está entre as principais espécies frutíferas produzidas em clima tropical e subtropical. A condição de salinidade da água nas áreas agrícolas pode ser considerada um fator limitante para a expansão do mamão. Este estudo teve como objetivo avaliar o extrato de microalga enriquecido com cálcio (EMa-Ca) como atenuador do estresse salino em água de irrigação no crescimento e na fisiologia de mudas de mamão Formosa, híbrido Tainung. O experimento foi conduzido em ambiente protegido, com tratamentos distribuídos em esquema fatorial 5 × 2, compreendendo cinco condutividades elétricas da água de irrigação (0,50; 1,10; 2,50; 3,90 e 4,50 dSm-1) com a presença e ausência no substrato de EMa-Ca. As características avaliadas foram: altura da planta, número de folhas, diâmetro do caule, área foliar, peso de massa seca das raízes, partes aérea e total. Também foram avaliadas as trocas gasosas e os índices de clorofila (a, b e total). A aplicação de EMa-Ca resultou em aumento de 6,05% na altura e 6,33% no diâmetro do tronco. O número de folhas diminuiu com aumento da condutividade elétrica e a área foliar reduziu 33%. Todas as massas secas das mudas apresentaram maiores declínios na ausência do EM-Ca. O EMa-Ca aumentou a fotossíntese líquida, concentração de CO2, transpiração e condutância estomática em 39,13%, 30,43%, 38,88% e 42,85%, respectivamente. Para a clorofila sem a utilização do EMa-Ca observa-se uma taxa de diminuição de 1,21%, 0,41% e 1,62% para Chla, Chlb e Chlt, respectivamente. Portanto, a aplicação de EMa-Ca (1,0 ml/L) melhora significativamente o desenvolvimento vegetativo, as trocas gasosas e os índices de clorofila de mudas de mamoeiro sob condições de estresse salino. Carica L. L subtropical EMaCa EMa Ca (EMa-Ca Formosa Tainung protegido 2 0,50 050 0 50 (0,50 1,10 110 1 10 2,50 250 390 3 90 3,9 450 4 4,5 dSm1 dSm dSm-1 EMaCa. Ca. planta caule raízes total a, (a . total) 605 6 05 6,05 633 33 6,33 tronco 33% EMCa. EMCa EM EM-Ca líquida CO2 CO 3913 39 13 39,13% 3043 30 43 30,43% 3888 38 88 38,88 4285 42 85 42,85% respectivamente observase observa se 121 21 1,21% 041 41 0,41 162 62 1,62 Chla Chlt Portanto 1,0 (1, ml/L mlL ml vegetativo 0,5 (0,5 1,1 11 2,5 25 9 3, 45 4, dSm- 60 6,0 63 6,3 391 39,13 304 30,43 388 8 38,8 428 42,85 12 1,21 04 0,4 16 1,6 1, (1 0, (0, 6, 39,1 30,4 38, 42,8 1,2 ( (0 39, 30, 42,

RESUMO: As microalgas são organismos cuja biomassa possui biomoléculas abundantes como carboidratos, lipídeos, proteínas, pigmentos, vitaminas, minerais e compostos antioxidantes, com inúmeras aplicações industriais com destaque para os segmentos de alimentos, nutricional, farmacológico, cosmético e de energia, na produção de biocombustíveis. Entretanto, o acesso de forma integra a essas biomoléculas pode ser dificultado pela rigidez estrutural de sua parede celular, sendo necessário a aplicação de um pré-tratamento que promova a lise celular. As diferentes técnicas de ruptura celular aplicáveis à biomassa microalgal descritas na literatura podem ser de natureza mecânica, com destaque para as técnicas de moagem em moinho de bolas e homogeneização à alta pressão (HAP) ou não mecânica (química, térmica e enzimática), cada uma com vantagens e desvantagens. Assim, o objetivo da presente revisão narrativa é descrever o uso de diferentes métodos para o rompimento de células de microalgas, com suas vantagens, desvantagens e seus desafios. RESUMO carboidratos lipídeos proteínas pigmentos vitaminas antioxidantes alimentos nutricional farmacológico energia biocombustíveis Entretanto prétratamento pré tratamento HAP (HAP química, química (química enzimática, enzimática , enzimática) Assim desafios

ABSTRACT: Microalgae are organisms whose biomass contains different biomolecules, such as carbohydrates, lipids, proteins, pigments, vitamins, minerals, and antioxidant compounds, with numerous industrial applications, highlighting the food, nutritional, cosmetic, pharmacological, and biofuel segments. However, access to these biomolecules in an integrated manner is often hampered due to the structural rigidity of their cell wall, requiring the application of a pre-treatment that promotes cell lysis. Various cell rupture techniques applied to microalgae biomass have been reported. These methods can be mechanical, especially ball milling techniques and high-pressure homogenization (HPH), or non-mechanical, such as chemical, thermal, and enzymatic procedures, each with advantages and disadvantages. Thus, this review addressed the different methods of cell disruption, listing their advantages and disadvantages, applications in cell biomass, and challenges. ABSTRACT carbohydrates lipids proteins pigments vitamins minerals compounds food nutritional cosmetic pharmacological segments However wall pretreatment pre treatment lysis reported mechanical highpressure high pressure HPH, HPH , (HPH) nonmechanical, nonmechanical non non-mechanical chemical thermal procedures disadvantages Thus disruption challenges (HPH

Photosynthetic microorganisms have been widely studied as an alternative technology for CO2 capture. Aiming to overcome some operational challenges in the application of these microorganisms for gas treatment on a large scale, the immobilization of microalgae in solid matrices emerges as an alternative to facilitate effective management of microalgae culture during harvesting process. In this work, different matrices for microalgae immobilization composed of silica/alginate were obtained varying silica precursors. The synthesized materials were characterized in terms of their specific surface area, cell viability, transparency and physical-chemical properties. Additionally, a new methodology was developed to evaluate the CO2 capture by microalgae using a pressurized system with natural gas mixture. Tests were carried out exploring the influence of some variables, such as headspace volume, cell concentration, stirring and pressure. Once the optimized parameters were established, the amount of CO2 captured by immobilized microalgae was investigated for 7 days by determining the CO2 relative concentrations using gas chromatography. The results of immobilized microalgae showed levels of CO2 removal of 41.4%. This work proved the potential application of the studied biomaterial for natural gas processing, making even more feasible the adoption of this technology for selective capture of CO2 on an industrial scale. CO scale process silicaalginate alginate precursors area viability physicalchemical physical chemical properties Additionally mixture variables volume concentration pressure established chromatography 414 41 4 41.4% processing 41.4 41.

The present review presents the biotechnological potential of microalgae, highlighting its applications in biofuels, bioremediation, production of bioactive compounds, biocatalysts, and biofertilizers. Microalgae are photosynthetic microorganisms that combine characteristics of plants and heterotrophic microorganisms, such as yeasts, bacteria, and fungi. They can be considered biotechnological agents of extreme versatility and metabolic adaptability. Its photosynthetic efficiency can absorb large volumes of anthropogenic CO2 and convert it into biomass rich in compounds of high biological and energetic value, enabling the development of sustainable bioremediation processes and the production of third-generation biofuels and biofertilizers. In addition, its biomass has aroused interest in obtaining compounds with biological action, such as carotenoids, mycosporine-like amino acids, polyunsaturated fatty acids, sterols, phycocolloids, carbohydrates, and proteins. The biotechnological potential of microalgae does not end with the production and extraction of its biomass. Its dynamic and adaptive metabolism allows its use in the biotransformation of xenobiotic substrates and the production of compounds of chemical and pharmaceutical interest. In this perspective, microalgae have application qualities as a biotechnological platform in developing synergistic processes between the environment, society, and industry, thus contributing to the expansion and use of Green Chemistry and strengthening the circular economy. biocatalysts biofertilizers yeasts bacteria fungi adaptability CO value thirdgeneration third generation addition action carotenoids mycosporinelike mycosporine like acids sterols phycocolloids carbohydrates proteins perspective environment society industry economy