Estudio sobre el crecimiento y síntesis de metabolitos de importancia comercial en la diatomea Phaeodactylum tricornutum bajo tratamientos fitohormonales.
No Thumbnail Available
Date
2024
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
Phaeodactylum tricornutum es una diatomea marina reconocida por su riqueza en lípidos y en sustancias altamente valiosas, ha sido objeto de extensos estudios debido a sus bioproductos con aplicaciones industriales y biotecnológicos. Entre estos compuestos destaca el ácido graso poliinsaturado acido eicosapentaenoico (EPA), perteneciente al grupo omega3, y el carotenoide fucoxantina, ambos compuestos de gran importancia por sus beneficios farmacológicos y nutracéuticos tanto en salud humana como animal. Actualmente, la fuente de ácidos grasos omega-3 es el aceite de pescado obtenido de la pesca extractiva, industria ampliamente cuestionada por su falta de sustentabilidad ambiental. Dada la alta demanda de estos aceites es de suma importancia disponer de nuevas fuentes de producción renovable y sustentable, donde el cultivo de microalgas como P. tricornutum emergen como una alternativa promisoria. Una estrategia prometedora para mejorar y potenciar la producción de compuestos de interés comercial en microalgas es el empleo de fitohormonas, que han sido originalmente utilizadas en plantas superiores, pero su uso en microalgas está ganando fuerza debido a que han demostrado su capacidad para potenciar la acumulación de diversos metabolitos (primarios y secundarios) y estimular el crecimiento de cultivos en diversas especies. En este estudio se investigó el efecto de la suplementación con fitohormonas en cultivos de una cepa de Phaeodactylum tricornutum originaria del sur de Chile. Se evaluó el efecto de las fitohormonas: ácido giberélico (GA3), acido indol 3-acético (AIA) y Kinetina (KIN) en el crecimiento de la cepa. De dichas hormonas, se seleccionó a kinetina a una concentración de 0.5 ppm, para generar cultivos en volúmenes de 1 L. Además, se evaluó a la fitohormona ácido abscísico (ABA) en una concentración de 2mg/ml. Los resultados mostraron un incremento significativo en la densidad celular máxima alcanzada por los cultivos en presencia de Kinetina, mientras que los cultivos con ácido abscísico no mostraron variaciones en el crecimiento. Se evaluaron los parámetros fotobiológicos durante el tiempo de cultivo, detectándose un incremento en el ETRmax al principio y al final de los cultivos expuestos a ABA, los valores de NPQ no mostraron una tendencia clara; mientras que el valor de Fv/Fm incrementó en todos los tratamientos a partir del día 4 de cultivo. Respecto al análisis bioquímico de la biomasa, se obtuvo que los lípidos totales disminuyeron en presencia de kinetina y ABA y el EPA disminuyó sólo en presencia de ABA. Los tratamientos con las hormonas no afectaron el contenido de proteínas, carotenoides totales ni fucoxantina; mientras que el ABA incrementó el contenido de carbohidratos y disminuyó el contenido de fenoles totales y clorofilas (a y c). Se concluye que los tratamientos con las hormonas kinetina y ABA, en las condiciones evaluadas no afectan significativamente el crecimiento y la acumulación de metabolitos de interés comercial en la cepa de P. tricornutum estudiada.
Phaeodactylum tricornutum is a marine diatom recognized for its richness in lipids and highly valuable substances and has been the subject of extensive studies due to its bioproducts with industrial and biotechnological applications. Among these compounds are the polyunsaturated fatty acid eicosapentaenoic acid (EPA), belonging to the omega-3 group, and the carotenoid fucoxanthin, both compounds of great importance for their pharmacological and nutraceutical benefits in both human and animal health. Currently, the source of omega-3 fatty acids is fish oil obtained from extractive fishing, an industry widely questioned for its lack of environmental sustainability. Given the high demand for these oils, it is of utmost importance to have new sources of renewable and sustainable production, where the cultivation of microalgae such as P. tricornutum emerges as a promising alternative source. A promising strategy to improve and enhance the production of compounds of commercial interest in microalgae is the use of phytohormones, which have been originally used in higher plants, but their use in microalgae is gaining strength because they have demonstrated their ability to enhance the accumulation of various metabolites (primary and secondary) and stimulate crop growth in various species. In this study, the effect of phytohormone supplementation in cultures of a Phaeodactylum tricornutum strain from southern Chile was investigated. The effect of the phytohormones gibberellic acid (GA3), indole 3-acetic acid (IAA) and Kinetin (KIN) on the growth of the strain was evaluated. Of these hormones, kinetin was selected at a concentration of 0.5 ppm, to generate cultures in 1 L volumes. In addition, the phytohormone abscisic acid (ABA) was evaluated at a concentration of 2 mg/ml. The results showed a significant increase in the maximum cell density reached by the cultures in the presence of Kinetin, while the cultures with abscisic acid showed no variation in growth. Photobiological parameters were evaluated during the culture time, detecting an increase in ETRmax at the beginning and at the end of the cultures exposed to ABA, NPQ values did not show a clear trend, while the Fv/Fm value increased in all treatments from day 4 of culture. Regarding the biochemical analysis of biomass, total lipids decreased in the presence of kinetin and ABA and EPA decreased only in the presence of ABA. The hormone treatments did not affect protein, total carotenoids or fucoxanthin content, while ABA increased carbohydrate content and decreased total phenols and chlorophylls (a and c). It is concluded that the treatments with the hormone’s kinetin and ABA, under the conditions evaluated, did not significantly affect the growth and accumulation of metabolites of commercial interest in the strain of P. tricornutum studied.
Phaeodactylum tricornutum is a marine diatom recognized for its richness in lipids and highly valuable substances and has been the subject of extensive studies due to its bioproducts with industrial and biotechnological applications. Among these compounds are the polyunsaturated fatty acid eicosapentaenoic acid (EPA), belonging to the omega-3 group, and the carotenoid fucoxanthin, both compounds of great importance for their pharmacological and nutraceutical benefits in both human and animal health. Currently, the source of omega-3 fatty acids is fish oil obtained from extractive fishing, an industry widely questioned for its lack of environmental sustainability. Given the high demand for these oils, it is of utmost importance to have new sources of renewable and sustainable production, where the cultivation of microalgae such as P. tricornutum emerges as a promising alternative source. A promising strategy to improve and enhance the production of compounds of commercial interest in microalgae is the use of phytohormones, which have been originally used in higher plants, but their use in microalgae is gaining strength because they have demonstrated their ability to enhance the accumulation of various metabolites (primary and secondary) and stimulate crop growth in various species. In this study, the effect of phytohormone supplementation in cultures of a Phaeodactylum tricornutum strain from southern Chile was investigated. The effect of the phytohormones gibberellic acid (GA3), indole 3-acetic acid (IAA) and Kinetin (KIN) on the growth of the strain was evaluated. Of these hormones, kinetin was selected at a concentration of 0.5 ppm, to generate cultures in 1 L volumes. In addition, the phytohormone abscisic acid (ABA) was evaluated at a concentration of 2 mg/ml. The results showed a significant increase in the maximum cell density reached by the cultures in the presence of Kinetin, while the cultures with abscisic acid showed no variation in growth. Photobiological parameters were evaluated during the culture time, detecting an increase in ETRmax at the beginning and at the end of the cultures exposed to ABA, NPQ values did not show a clear trend, while the Fv/Fm value increased in all treatments from day 4 of culture. Regarding the biochemical analysis of biomass, total lipids decreased in the presence of kinetin and ABA and EPA decreased only in the presence of ABA. The hormone treatments did not affect protein, total carotenoids or fucoxanthin content, while ABA increased carbohydrate content and decreased total phenols and chlorophylls (a and c). It is concluded that the treatments with the hormone’s kinetin and ABA, under the conditions evaluated, did not significantly affect the growth and accumulation of metabolites of commercial interest in the strain of P. tricornutum studied.
Description
Tesis presentada para optar al optar al título de Bióloga
Keywords
Metabolitos, Diatomeas, Hormonas vegetales