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: Microalgae have a great potential to change their metabolism pathway under stress condition, and nitrogen deficiency is an effective technique for maximizing lipids synthesis. This study focus on the growth performance, and biochemical composition of Tetradesmus obliquus (Turpin) M.J. Wynne cultured in different nitrogen concentrations (BG 11-Blue-Green Medium, 50% N+, 50% N-, 75% N+, 75% N-). Specific growth rate and protein content of T. obliquus decreased with nitrogen deficiency, but its lipid content was increased. Maximum specific growth rate (0.20-0.21) and protein content (47.82%, 47.62% DW-dried weight) values were obtained in 75% N+, 50% N+ medium. The highest lipid percentage was obtained in 50% N- medium. The biochemical composition of T. obliquus changes based on nitrogen concentration. Polyunsaturated fatty acids (PUFAs) are more abundant (49.69%) in this microalga under deficient nitrogen. To obtain more lipid and PUFAs in T. obliquus, N deficiency is an effective method, but it is not applicable to protein content. T. obliquus can be used as an alternative nutritional supplement with its high PUFAs content. Since different results are obtained from species to others in such studies, culture conditions should be determined for each species and according to the desired item. ABSTRACT condition synthesis performance Turpin (Turpin MJ M J M.J BG 11BlueGreen BlueGreen 11 Blue Green Medium 50 N, , 75 N. . N-) T increased 0.200.21 020021 0.20 0.21 0 20 21 (0.20-0.21 47.82%, 4782 47 82 (47.82% 4762 62 47.62 DWdried DW dried weight medium concentration (PUFAs 49.69% 4969 49 69 (49.69% method studies item 1 5 7 200 0.200.2 02002 020 0.2 021 2 (0.20-0.2 47.82% 478 4 8 (47.82 476 6 47.6 49.69 496 (49.69 0.200. 0200 02 0. (0.20-0. 47.82 (47.8 47. 49.6 (49.6 0.200 (0.20-0 47.8 (47. 49. (49. (0.20- (47 (49 (0.20 (4 (0.2 ( (0. (0

RESUMO: As microalgas têm um grande potencial para alterar sua via metabólica sob condição de estresse, e a deficiência de nitrogênio é uma técnica eficaz para maximizar a síntese de lipídios. Este estudo enfoca o desempenho do crescimento e a composição bioquímica de Tetradesmus obliquus (Turpin) M.J. Wynne cultivado em diferentes concentrações de nitrogênio (BG 11-Blue-Green Medium, 50% N+, 50% N-, 75% N+, 75% N- ). A taxa de crescimento específico e o teor de proteína de T. obliquus diminuíram com a deficiência de nitrogênio, mas seu teor de lipídeos aumentou. Os valores máximos de taxa de crescimento específico (0,20-0,21) e teor de proteína (47,82%, 47,62% DW-peso seco) foram obtidos em meio 75% N+, 50% N+. O maior percentual lipídico foi obtido em meio 50% N-. A composição bioquímica de T. obliquus muda com base na concentração de nitrogênio. Os ácidos graxos poliinsaturados (PUFAs) são mais abundantes (49,69%) nesta microalga sob nitrogênio deficiente. Para obter mais lipídios e PUFAs em T. obliquus, a deficiência de N é um método eficaz, mas não é aplicável ao teor de proteína. T. obliquus pode ser usado como um suplemento nutricional alternativo com seu alto teor de PUFAs. Como são obtidos resultados diferentes de uma espécie para outra nesses estudos, as condições de cultivo devem ser determinadas para cada espécie e de acordo com o item desejado. RESUMO estresse Turpin (Turpin MJ M J M.J BG 11BlueGreen BlueGreen 11 Blue Green Medium 50 N+ N, , 75 . ) T aumentou 0,200,21 020021 0,20 0,21 0 20 21 (0,20-0,21 47,82%, 4782 47 82 (47,82% 4762 62 47,62 DWpeso DW peso seco N. (PUFAs 49,69% 4969 49 69 (49,69% deficiente estudos desejado 1 5 7 200 0,200,2 02002 020 0,2 021 2 (0,20-0,2 47,82% 478 4 8 (47,82 476 6 47,6 49,69 496 (49,69 0,200, 0200 02 0, (0,20-0, 47,82 (47,8 47, 49,6 (49,6 0,200 (0,20-0 47,8 (47, 49, (49, (0,20- (47 (49 (0,20 (4 (0,2 ( (0, (0

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,

ABSTRACT This study evaluated the effect of co-feeding with commercial feed and live food (enriched or not with microalgae) on the growth and survival of Trachelyopterus galeatus larvae. Five treatments were carried out: commercial feed as a control (F); brine shrimp nauplii (BS); brine shrimp nauplii enriched with Chaetoceros sp. Microalgae (BSM); combined feed with brine shrimp nauplii (F+BS) and combined feed with brine shrimp nauplii enriched with microalgae (FBSM). The larvae (5.00±0.02 mg and 5.95±0.33mm) were reared for 30 days. There were no significant differences (P>0.05) in water quality between treatments, but there were significant differences in weight, weight gain and survival. The F+BS and F+BSM treatments, which involved co-feeding, showed the best results in final weight (0.168±0.004g and 0.169±0.007g) and weight gain (0.1278±0.004 g and 0.1294±0.007g), respectively. The treatments with live food, enriched or not, showed high survival rates of over 73%, with no significant differences between them. On the other hand, the exclusive use of feed resulted in low survival (36.7 ± 9.53%), indicating that this may result in low growth and make the production of T. galeatus larvae unfeasible. cofeeding co feeding out F (F) BS (BS) sp BSM (BSM) FBS (F+BS FBSM. FBSM . (FBSM) 5.00±0.02 500002 5 00 0 02 (5.00±0.0 5.95±0.33mm 595033mm mm 95 33mm 3 days P>0.05 P005 P 05 (P>0.05 cofeeding, feeding, 0.168±0.004g 01680004g 168 004g 0.169±0.007g 01690007g 169 007g 0.1278±0.004 012780004 1278 004 (0.1278±0.00 0.1294±0.007g, 012940007g 0.1294±0.007g , 1294 0.1294±0.007g) respectively 73 73% them hand 36.7 367 36 7 (36. 9.53%, 953 9.53% 9 53 9.53%) T unfeasible (F (BS (BSM (FBSM 5.00±0.0 50000 (5.00±0. P>0.0 P00 (P>0.0 16 0.1278±0.00 01278000 127 (0.1278±0.0 129 36. (36 9.53 5.00±0. 5000 (5.00±0 P>0. P0 (P>0. 1 0.1278±0.0 0127800 12 (0.1278±0. (3 9.5 5.00±0 500 (5.00± P>0 (P>0 0.1278±0. 012780 (0.1278±0 ( 9. 5.00± 50 (5.00 P> (P> 0.1278±0 01278 (0.1278± 5.00 (5.0 (P 0.1278± 0127 (0.1278 5.0 (5. 0.1278 012 (0.127 5. (5 0.127 01 (0.12 0.12 (0.1 0.1 (0. 0. (0

RESUMO Este estudo avaliou o efeito da coalimentação com ração comercial e alimentos vivos (enriquecidos ou não com microalgas) no crescimento e na sobrevivência das larvas de Trachelyopterus galeatus. Foram realizados cinco tratamentos: ração comercial como controle (F); náuplios de artêmia (BS); náuplios de artêmia enriquecidos com microalga Chaetoceros sp. (BSM); ração combinada com náuplios de artêmia (F+BS) e ração combinada com náuplios de artêmia enriquecidos com microalga (F+BSM). As larvas (5,00±0,02mg e 5,95±0,33mm) foram criadas por 30 dias. Não houve diferenças significativas (P>0,05) na qualidade da água entre os tratamentos, mas houve diferenças significativas no peso, no ganho de peso e na sobrevivência. Os tratamentos F+BS e F+BSM, que envolveram coalimentação, mostraram os melhores resultados em peso final (0,168±0,004g e 0,169±0,007g) e em ganho de peso (0,1278±0,004g e 0,1294±0,007g), respectivamente. Os tratamentos com alimentos vivos, enriquecidos ou não, mostraram altas taxas de sobrevivência acima de 73%, sem diferenças significativas entre eles. Por outro lado, o uso exclusivo de ração resultou em baixa sobrevivência (36,7±9,53%), indicando que isso pode resultar em baixo crescimento e inviabilizar a produção de larvas de T. galeatus. microalgas galeatus F (F) BS (BS) sp BSM (BSM) FBS (F+BS F+BSM. FBSM F+BSM . (F+BSM) 5,00±0,02mg 500002mg mg 5 00 0 02mg 5,95±0,33mm 595033mm mm 95 33mm 3 dias P>0,05 P005 P 05 (P>0,05 0,168±0,004g 01680004g g 168 004g 0,169±0,007g 01690007g 169 007g 0,1278±0,004g 012780004g 1278 0,1294±0,007g, 012940007g 0,1294±0,007g , 1294 0,1294±0,007g) respectivamente 73 73% eles lado 36,7±9,53%, 367953 36,7±9,53% 36 7 9 53 (36,7±9,53%) T (F (BS (BSM (F+BSM P>0,0 P00 (P>0,0 16 127 129 36795 36,7±9,53 (36,7±9,53% P>0, P0 (P>0, 1 12 3679 36,7±9,5 (36,7±9,53 P>0 (P>0 367 36,7±9, (36,7±9,5 P> (P> 36,7±9 (36,7±9, (P 36,7± (36,7±9 36,7 (36,7± 36, (36,7 (36, (36 (3 (

The use of microalgae cultures to process effluents from industries, leachates, and tanneries, among others, quantified by the reduction of metallic materials in the medium and the reduction of chemical oxygen demand (COD), helps reduce the environmental impact caused by human development. In addition, with the growth of the culture, it is possible to produce a significant amount of chlorophyll, a carotenoid of high value in the cosmetics and food industries that are used as a natural pigment. In this context, this work presents a study conducted to verify the bioremediation and chlorophyll production potential of the cultivation of the microalgae Chlorella minutíssima, using the Taguchi method. The microalgae Chlorella minutissima has given good results in the bioremediation of leachate, as a mean reduction of 33% in COD was obtained, as well as a 92% reduction in the toxic components. In addition, statistical analysis revealed that the four process factors were significant factors for chlorophyll a, chlorophyll b and carotenoid productivity (p < 0.05). Finally, it was observed that the maximum chlorophyll a (111.9 ± 0.8 mg-L-1-d-1), chlorophyll b (66.1 ± 1.7 mg-L-1-d-1), and carotenoid (31.9 ± 0.03 mg-L-1-d-1) values obtained occurred in Experiment 8, which is closer to the ideal conditions identified by statistical analysis, revealing the effectiveness of the use of the Taguchi method for the design of experiments.

Abstract The test was carried out in the month of March 2021 at the Continental Laboratory of Puno - IMARPE, in order to determine the effect of the use of the microalga Chlorella vulgaris as food at the beginning of the ontogeny of Orestias luteus, a test was carried out with 1600 larvae kept in two 45 L aquariums. One aquarium with Chlorella vulgaris (green water), and the other aquarium without Chlorella vulgaris (clear water). It is reflected that during the first 7 days the larvae fed and maintained with microalgae presented higher survival due to the high nutritional level that the microalgae present, such as docosahexaenoic acid (DHA), apparently influenced the development of the Orestias Luteos larvae. Likewise, when added directly to the aquariums, the microalgae exerted a positive influence on the physiological state of Orestias luteus larvae, which translates into the obtaining of high-quality fingerlings. It is concluded that live food such as planktonic organisms constitute the feeding base in the larval stage of Carachi Amarillo and obtaining high survival of seeds allowing better growth and greater survival.

Resumen El ensayo se realizó en el mes de marzo del 2021 en el Laboratorio Continental de Puno - IMARPE, con la finalidad de determinar el efecto del uso de la microalga Chlorella vulgaris como alimento al inicio de la ontogenia de Orestias luteus, se realizó ensayo con 1600 larvas mantenidas en dos acuarios de 45 L. Un acuario con Chlorella vulgaris (agua verde), y el otro acuario sin Chlorella vulgaris (agua clara). Se reflejan que durante los primeros 7 días las larvas alimentadas y mantenidas con microalgas presentaron mayor supervivencia debido a que el alto nivel nutricional que presenta la microalga como el ácido docosahexaenoico (DHA) aparentemente influyó en el desarrollo de las larvas de Orestias luteos. Asimismo al ser añadidas directamente a los acuarios, las microalgas ejercieron una influencia positiva en el estado fisiológico de larvas de Orestias luteus que se traduce en la obtención de alevines de elevada calidad. Se concluye que, el alimento vivo como organismos planctónicos constituyen la base de alimentación en el estadío larvario de Carachi amarillo y la obtención de alta supervivencia de semillas permitiendo mejor crecimiento y mayor supervivencia.

ABSTRACT Microalgae have proven to have multiple applications in the biotechnology industry. Porphyridium cruentum is a microalgae that exhibits a wide content of polysaccharides and proteins with potential pharmacological activity. This work evaluates the antimicrobial activity of the P. cruentum biomass against the parasites Leishmania infantum, Trypanosoma rhodesiense, Trypanosoma cruzi, and Trypanosoma brucei through the microdilution method in plates, as well as the cytotoxicity in leukocyte cell lines, using as a drug reference Tamoxifen. The biomass showed inhibitory activity against the parasites T. brucei, T. rhodesiensis, and T. cruzi. The study also demonstrated that the biomass does not exert cytotoxic activity on THP-1 human monocytes and RAW 264.7 murine macrophages. The results obtained indicate that the active compounds present in Porphyridium cruentum could be considered as possible antimicrobial candidates.

RESUMEN Actualmente, existe una creciente preocupación por el aumento de la resistencia microbiana de numerosos agentes patógenos. Las microalgas han demostrado tener múltiples aplicaciones en la industria biotecnológica. Porphyridium cruentum es una microalga que exhibe un amplio contenido de polisacáridos y proteínas con potencial actividad farmacológica. Este trabajo evalúa la actividad antimicrobiana de la biomasa P. cruentum frente a los parásitos Leishmania infantum, Trypanosoma rhodesiense, Trypanosoma cruzi, y Trypanosoma brucei a través del método de microdilución en placas, así como la citotoxicidad en líneas celulares de leucocitos, utilizando como fármaco de referencia el Tamoxifeno. La biomasa mostró actividad inhibitoria frente a los parásitos T. brucei, T. rhodesiensis, y T. cruzi. El estudio demostró, además, que la biomasa no ejerce actividad citotóxica sobre monocitos humanos THP-1 y macrófagos murinos RAW 264.7. Los resultados obtenidos apuntan que los compuestos activos presentes en Porphyridium cruentum podrían ser considerados como posibles candidatos antimicrobianos.

Abstract A fibrinolytic enzyme from the microalga Dunaliella tertiolecta was produced under mixotrophic conditions using different corn steep liquor (CSL) concentrations ( 0 ≤ CLS ≤ 0.75%), purified using a combination of salting out and ion-exchange chromatography, and then biochemical characterized. Cultivation of this microalga using 0.5% CSL led to the highest maximum cell concentration (1.960±0.010 mg L-1) and cell productivity (0.140g L-1 day-1), besides a high fibrinolytic activity of the extract obtained by the homogenization method (102 ±1 U mL-1). The enzyme extracted from the microalgal biomass was 5-fold purified with a 20% yield and was found to have a specific activity of 670 U mg-1. The enzyme, whose molecular weight determined by fibrin zymography was 10 kDa, was shown to be stable at pH 3.0–9.0 and up to 70°C with optimal pH and temperature values of 8.0 and 50°C, respectively. When compared to other fibrinolytic enzymes, this protease stood out for its high fibrinolytic activity, which was enhanced by Fe2+, inhibited by Zn2+, Cu2+, Mg2+, and Ca2+, and strongly inhibited by phenylmethylsulfonyl fluoride, suggesting that it belongs to the serine metalloprotease family. Moreover, thanks to its thermal stability, the enzyme may be easily preserved and activated under high-temperature conditions. (CSL 0.75%, 075 0.75% , 75 0.75%) ionexchange ion exchange chromatography characterized 05 5 0.5 1.960±0.010 19600010 1 960 010 (1.960±0.01 L1 L 0.140g 0140g g 140g L- day1, day1 day day-1) 102 (10 ± mL1. mL1 mL . mL-1) 5fold fold 20 67 mg1. mg1 1. mg-1 kDa 3090 3 9 3.0–9. 70C C 70 80 8 8. 50C 50 50°C respectively enzymes Fe2 Fe Fe2+ Zn2 Zn Zn2+ Cu2 Cu Cu2+ Mg2 Mg Mg2+ Ca2 Ca Ca2+ fluoride family Moreover stability hightemperature 07 0.75 7 0. 1.960±0.01 1960001 96 01 (1.960±0.0 day-1 (1 mL-1 2 6 mg- 309 3.0–9 0.7 1.960±0.0 196000 (1.960±0. day- mL- 30 3.0– 1.960±0. 19600 (1.960±0 3.0 1.960±0 1960 (1.960± 3. 1.960± 196 (1.960 1.960 19 (1.96 1.96 (1.9 1.9 (1.

ABSTRACT Aquatic ecosystems suffer alterations by the input of several pollutants as potentially toxic elements which interact with the planktonic community with likelihood of bioconcentration, bioaccumulation, and biomagnification through the trophic chains despite the fact of being in low concentrations. The goal of this study involves assessing the toxicity, bioaccumulation, and transfer of the lead under controlled laboratory conditions by estimating the bioconcentration factor (BCF) and bioaccumulation factor (BAF) in organisms usually used in aquaculture, as Nannochloropsis oculata microalgae, Brachionus plicatilis rotifer, and the Malaysian prawn Macrobrachium rosenbergii. We assessed toxicity, bioconcentration, and transfer of the lead from the microalgae to higher trophic levels, the rotifer, and the prawn larvae. We performed three bioassays: (1) lead-exposed microalgae, (2) rotifer fed with lead-exposed microalgae, and (3) prawn larvae fed with either lead-exposed microalgae or rotifers fed with these microalgae. The toxicity endpoints were obtained for microalgae. The concentration of the lead in all organisms was analyzed by atomic absorption spectrophotometry for estimating BCF and BAF values. The endpoints No Observed Effect Concentration (NOEC) and Effective Concentration 50 (EC50) are 1 and 5.42 mg/L, respectively, for N. oculata. The BCF in the microalgae decreases as lead concentration increases. A BAF of 2948 in rotifers, and a BAF of 42.1 in prawns were obtained. In conclusion, lead can concentrate in microalgae, transfer, and accumulate through consumption toward the consecutive trophic levels, but not among invertebrates due to their detoxification mechanisms.

RESUMEN Los ecosistemas acuáticos sufren alteraciones por ingreso de varios contaminantes como elementos potencialmente tóxicos que interactúan con la comunidad planctónica con probabilidad de bioconcentración, bioacumulación y biomagnificación hacia las cadenas tróficas a pesar de estar en bajas concentraciones. El objetivo de este estudio involucra la evaluación de la toxicidad, bioacumulación y transferencia de plomo en condiciones controladas de laboratorio mediante la estimación del factor de bioconcentración (FBC) y el factor de bioacumulación (FBA) en organismos usualmente empleados en acuacultura como la microalga Nannochloropsis oculata, el rotífero Brachionus plicatilis y el langostino malayo Macrobrachium rosenbergii. Nosotros evaluamos la toxicidad, bioconcentración y transferencia de plomo de la microalga hacia los niveles tróficos superiores, el rotífero y la larva de langostino. Realizamos tres bioensayos: 1) microalga expuesta a plomo, 2) rotífero alimentado con microalgas expuestas a plomo y 3) larvas de langostino alimentadas con microalga expuesta a plomo o rotíferos alimentados con microalga contaminada. Se obtuvieron parámetros de toxicidad para microalgas. La concentración de plomo en todos los organismos fue analizada por espectrofotometría de absorción atómica, estimándose los valores de FBC y FBA. Los parámetros concentración donde no se observa efecto (CNOE) y concentración efectiva 50 (CE50) fueron 1 y 5.42 mg/L, respectivamente, para N. oculata. El FBC en la microalga disminuye al aumentar la concentración de plomo. Se obtuvieron valores de FBA de 2948 en rotíferos, y FBA de 42.1 en langostinos. En conclusión, el plomo puede concentrarse en la microalga, transferirse y acumularse a través de su consumo hacia los siguientes niveles tróficos, pero no entre invertebrados debido a su mecanismo de detoxificación.

Abstract Extraction and fractioning of microalgal lipids have been recurrently studied because of the market value of certain lipid families (i.e. carotenoids and xanthophylls) and the opportunity that microalgal oils represent for obtaining biofuels. Most of the methods developed for the total extraction of microalgal lipids require a subsequent separation for the different families (i.e neutral lipids, polar lipids) to be quantified. Moreover, most of them use toxic and expensive solvents. In the present study less toxic solvents that are widely used in the industry, such as hexane, acetone and, ethanol were tested in different orders for the extraction of microalgal biomass of different lipid composition and content (i.e. three different levels of nutritional stress). A comparison of the methods proposed by Bligh and Dyer, Folch and, Hara and Radin is also presented. The new method achieves microalgal total lipid extraction and separation of the lipid families simultaneously.

Resumen La extracción y fraccionamiento de lípidos de microalgas ha sido objeto de estudio recurrente debido al valor de mercado de ciertas familias de lípidos (carotenoides y xantofilas) y la oportunidad que representan los aceites de microalgas para la obtención de biocombustibles. La mayoría de los métodos desarrollados para la extracción total de lípidos de microalgas requieren una posterior separación de las diferentes familias (lípidos neutros, lípidos polares) a cuantificar. Además, la mayoría de ellos utilizan disolventes tóxicos y caros. En el presente estudio, se probaron solventes menos tóxicos que son ampliamente utilizados en la industria, como hexano, acetona y etanol, en diferentes órdenes para la extracción de biomasa de microalgas de distinta composición y contenido de lípidos (es decir, tres niveles diferentes de estrés nutricional). También se presenta una comparación de los métodos propuestos por Bligh y Dyer, Folch y Hara y Radin. El nuevo método logra la extracción de lípidos totales de microalgas y la separación de las familias de lípidos simultáneamente.

RESUMO Spirulina platensis é uma microalga com atividade biológica utilizada para produzir suplementos nutricionais ricos em proteínas, ácidos graxos essenciais, vitaminas e minerais. O estudo atual visa provar o impacto do produto ZooBioR2 (obtido da Spirulina platensis) na saúde e na histologia do duodeno, jejuno, íleo e ceco em galinhas poedeiras. O experimento foi realizado em duplicata em cinco grupos de galinhas (14 aves/grupo), um controle e quatro experimentais, nos quais a ração foi suplementada com ZooBioR2 em diferentes doses (5,0; 10,0; 15,0; 20,0mg de substância ativa/kg de forragem). A inclusão do suplemento na ração determinou uma diminuição significativa da altura das vilosidades intestinais, da profundidade dos crypts e da espessura da camada muscular da mucosa nos grupos experimentais que receberam15,0 e 20,0mg/kg. A diminuição da profundidade das criptas é um indicador de maior taxa de rotação do tecido epitelial. As alterações morfológicas da mucosa intestinal podem estar envolvidas em uma melhor digestibilidade da forragem.

ABSTRACT Spirulina platensis is a microalga with biological activity used to produce nutritional supplements rich in proteins, essential fatty acids, vitamins, and minerals. The current study aims to prove the impact of the product ZooBioR2 (obtained from Spirulina platensis) on health, and on the histology of duodenum, jejunum, ileum, and cecum in laying hens. The experiment was performed in duplicate on 5 groups of hens (14 birds/group), one control and four experimental, in which the feed was supplemented with ZooBioR2 in different doses (5.0; 10.0; 15.0; 20.0mg active substance/kg of fodder). Inclusion of the supplement in the diet have determined a significant decrease of height of intestinal villi, the depth of the crypts and the thickness of muscular layer of mucosa in the experimental groups receiving 15.0 and 20.0mg/kg. The decrease of crypts depth is an indicator of a higher rate of turn-over of epithelial tissue. The morphological changes of intestinal mucosa could be involved in a better digestibility of the fodder.

This work was carried out in Manzanillo municipality, Granma province, with the support of Manzanillo Fishing Industry. The objective of the research was to propose a treatment system capable of reducing the contaminating potential of wastewater from the EPIGRAN Company with the use of the microalgae Chlorella sp. For this, the high-speed lagoons were approached, evaluated in advance by fishing specialists. In this way, the sustainable use of wastewater will be promoted, since high value-added by-products will be obtained for animal feed, the pharmaceutical and cosmetic industries. The clarified water will have a maximum BOD5 of 50 mg/L and 4.5 kg/m3 of wet algal biomass will be obtained (1.0 kg/m3 of dry biomass).

RESUMEN El presente trabajo se realizó en el municipio de Manzanillo, provincia Granma, con el apoyo de la Industria Pesquera de Manzanillo. La investigación tuvo como objetivo proponer un sistema de tratamiento capaz de disminuir el potencial contaminante de las aguas residuales de la Empresa EPIGRAN con el empleo de la microalga Chlorella sp. Para ello se abordaron las lagunas de alta velocidad, evaluadas con antelación por especialistas de la pesca. De esta forma, se potenciará el uso sostenible del agua residual, ya que se alcanzarán subproductos de alto valor agregado para la alimentación animal, la industria farmacéutica y del cosmético. El agua clarificada tendrá una DBO5 de 50 mg/L como máximo y se obtendrán 4,5 kg/m3 de biomasa algal húmeda (1,0 kg/m3 de biomasa seca).

Resumen En el presente estudio se estableció las condiciones para el cultivo autotrófico y mixotrófico de Scenedesmus sp, utilizando efluentes de drenajes ácidos de mina de carbón con el objeto de estudiar la producción de biomasa y de carotenoides tanto en condiciones autótrofas y mixotróficas en relación con el efecto de diferentes fuentes de nitrógeno: nitrato de sodio, la urea y el fosfato de amonio. Se determinó la remoción de contaminantes como DQO, COT, Metales pesados, iones y Sólidos Suspendidos totales. Los cultivos fueron por lote durante nueve días y se comparó la producción de biomasa, carotenoides y remoción de contaminantes en cada condición. La mayor concentración de biomasa alcanzada fue de 1,2 g/L se alcanzó en el cultivo mixotrófico para el medio con urea, seguido por del medio con nitrato de sodio de 0,9 g/L en una relación C/N de 6:1. La mayor concentración específica de carotenoides se alcanzó en el cultivo mixotrófico para el medio con nitrato de sodio y fue de 19.43 mg carotenoides / g biomasa. El medio con fosfato de amonio resultó ser inhibitorio para el crecimiento de la microalga con los resultados más bajos de todos los parámetros con excepción del cultivo autotrófico donde la concentración de carotenoides fue muy similar que las alcanzadas con el medio con nitrato de sodio y urea. Finalmente, el cultivo mixótrófico en el medio con urea presentó los mayores porcentajes de remoción siendo 86,97% para hierro total, 58,29% para cloruros y 92,5% para DQO.

Abstract In the present study, the conditions for an autotrophic and mixotrophic culture of Scenedesmus sp were established. Effluents from acidic coal mine drains were used to study biomass and carotenoid production, both under autotrophic and mixotrophic conditions in relation to the effect of different sources of nitrogen: sodium nitrate, urea and ammonium phosphate. Pollutant removal was determined, such as COD, TOC, heavy metals, ions and total suspended solids. Batch cultures lasted nine days and biomass production, carotenoids and pollutant removal were compared in each condition. The highest biomass concentration reached was 1.2 g/L in the mixotrophic culture with urea, followed by the culture with sodium nitrate of 0.9 g/L in a C/N ratio of 6:1. The highest carotenoid specific concentration was reached in the mixotrophic culture with sodium nitrate, 19.43 mg carotenoids /g biomass. The culture with ammonium phosphate was found to be inhibitory for the growth of the microalgae with the lowest results of all the parameters except for the autotrophic culture where the concentration of carotenoids was very similar to those reached with sodium nitrate and urea. Finally, the mixotrophic culture with urea presented the highest removal percentages, being 86.97% for total iron, 58.29% for chlorides and 92.5% for COD.

ABSTRACT Background: Microalgae are being studied as a source of fatty acids to produce food with high added value. The content of oils can increase or decrease due to changes in abiotic factors such as nitrogen and phosphorus concentration in the culture medium. Goals: To determine the carbon/nitrogen and carbon/phosphorus ratio that favor biomass and fatty acid production in the native microalgae Chlorella sorokiniana. Methods: Microalgae isolated from the Parque Norte Lake in the city of Medellin, Antioquia, Colombia, was cultured in a heterotrophic way using glucose as carbon source at different carbon to nitrogen (C/N) (10/1, 25/1 y 50/1) and carbon to phosphorus (C/P) (200/1, 300/1 y 400/1) ratios. Results: The highest concentration of biomass was 9.70 gL-1 and 9.17 gL-1 at C/N 10/1 and C/P 200/1. The yields were 1.08 gL-1d-1 and 1.02 gL-1d-1. The biomass yield from glucose (were 0.43gg-1 and 0.44gg-1. Total fatty acids are favored by the C/N and C/P ratios of 50/1 and 400/1, yielding 24.27% and 20.48% total fatty acids measured over dried cell weight alongside higher fatty acid yield from biomass of 26.97m gL-1d-1 and 22.76m gL-1d-1, respectively. Conclusions: Lower C/N and C/P ratios favor the production of biomass while lowering the production of total fatty acids; conversely, higher C/N and C/P rations favor the production of total fatty acids and the lipid yield from biomass. Therefore, it is necessary to reach the highest production of biomass with low C/N ratio for enabling the elongation of the polyunsaturated fatty acid chain during the nutrient depletion stage in the culture medium as a response to the stress conditions.

RESUMEN Antecedentes: Las microalgas están siendo estudias como fuente de ácidos grasos para la producción de alimentos con alto valor agregado. El contenido de aceites en estas puede aumentar o disminuir debido a cambios en los factores abióticos como la concentración de nitrógeno y fósforo en el medio de cultivo. Objetivo: Determinar la relación carbono/nitrógeno y carbono/fosforo que favorezcan la producción de biomasa y ácidos grasos en la microalga nativa Chlorella sorokiniana. Métodos: La microalga aislada del lago del parque norte en la ciudad de Medellín, Antioquia, Colombia, fue cultivada de forma heterotrófica con glucosa como fuente de carbono a diferentes relaciones carbono nitrógeno (C/N) (10/1, 25/1 y 50/1) y carbono fósforo (C/P) (200/1, 300/1 y 400/1). Resultado: La máxima concentración de biomasa que se obtuvo fue de 9.70gL-1 y 9.17 gL-1 con las relaciones C/N 10/1 y C/P 200/1, sus productividades fueron de 1.08 gL-1d-1 y 1.02 gL-1d-1 y sus rendimientos de biomasa en glucosa (fueron de 0.43 y 0.44 gg-1. Los ácidos grasos totales se ven favorecidos con las relaciones C/N 50/1 y C/P 400/1 alcanzando un 24.27% y 20.48% de ácidos grasos totales sobre la biomasa seca, además de mayores productividades de ácidos grasos en biomasa seca de 26.97 mgL-1d-1 y 22.76 mgL-1d-1 respectivamente. Conclusiones: Relaciones C/N y C/P bajas favorecen la producción de biomasa y disminuyen la producción de ácidos grasos totales, por el contrario, relaciones C/N y C/P altas, favorecen la producción de ácidos grasos totales y la productividad de lípidos en biomasa. De esta manera se debe alcanzar la máxima producción de biomasa con bajas relaciones C/N para lograr que en la etapa de agotamiento nutricional en el medio de cultivo se induzca la elongación de las cadenas de ácidos grasos poliinsaturados como respuesta a las condiciones de estrés.

• ABSTRACT • The sensitivity analysis of a mathematical model allows to determine how the uncertainty of the model's outputs can be assigned to its input variables. In this work, the Morris or elemental effects method is used to perform the global sensitivity analysis to the PRO-ALGA model, to simulate the growth of the microalgae Chlorella vulgaris. The following steps were followed: specification of objectives, selection of the factors to be analyzed, selection of the probability density functions for each factor, generation of the input sample and evaluation of the model. The results allowed to identify that the input parameters maximum growth rate of microalgae (µa), mean saturation constant for pH (KpH), mean saturation constant for algae concentration (KCA), mass transfer coefficient for oxygen at 25 ºC during the day (KLAD) and mass transfer coefficient for oxygen at 25 ºC at night (KLAN) have the greatest influence on the output parameters of the model. The model is very sensitive to variations in KCA; the input parameters µa, KLAD and KLAN have non-linear or interaction effects on the output parameters of the model. The input parameters kpH and KCA have no significant effect on the output variables.

RESUMEN • El análisis de sensibilidad de un modelo matemático permite determinar cómo la incertidumbre de las salidas del modelo puede ser asignada a sus variables de entrada. En este trabajo se utiliza el método de Morris o de efectos elementales para realizar el análisis de sensibilidad global al modelo PRO-ALGA, para simulación del crecimiento de la microalga Chlorella vulgaris. Se siguieron los pasos siguientes: especificación de objetivos, selección de los factores a analizar, selección de las funciones de densidad de probabilidad para cada factor, generación de la muestra de entrada y evaluación del modelo. Los resultados permitieron identificar que los parámetros de entrada velocidad máxima de crecimiento de las microalgas (µa), constante de saturación media para el pH (KpH), constante de saturación media para la concentración de algas (KCA), coeficiente de transferencia de masa para el oxígeno a 25oC durante el día (KLAD) y coeficiente de transferencia de masa para el oxígeno a 25oC durante la noche (KLAN) son los que mayor influencia tienen sobre los parámetros de salida del modelo. El modelo es muy sensible a las variaciones de KCA; los parámetros de entrada µa, KLAD y KLAN tienen efectos no lineales o de interacción sobre los parámetros de salida del modelo. Los parámetros de entrada KpH y KCA no tienen efectos significativos sobre las variables de salida.