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Abstract(s)
Atualmente é fundamental encontrar novos cenários e soluções mais sustentáveis, ideias mais limpas e inovadoras, de forma a privilegiar o que é natural, suprindo assim as nossas necessidades como espécie humana, permitindo obter produtos de alto valor comercial com o menor impacto possível para o meio ambiente. Para satisfazer algumas destas necessidades, surgem as microalgas, seres que através das suas características surgem como um bom potencial de investimento e uma boa forma de “limpar” os ecossistemas. A Chlorella zofingiensis é uma microalga que tem uma taxa de crescimento rápida e uniforme, tornando assim possível o encurtamento da duração de cada ensaio. O estudo realizado teve como objetivo otimizar a produção de astaxantina através da alteração dos parâmetros ambientais no cultivo da Chlorella zofingiensis em meio BBM. Os parâmetros estudados incluíram o fotoperíodo (8 ou 12 ou 16 horas), o stress nutritivo (0 dias ou 10 dias ou 20 dias) e a suplementação de luz laranja (0 ou 12 ou 24 horas). As culturas realizadas que apresentaram maiores concentrações de carotenoides foram as submetidas a um fotoperíodo de 16 horas de iluminação, com suplementação de luz laranja e efeito de stress nutritivo ao longo de todo o ensaio. A concentração de carotenoides totais, CAR, mais elevada que foi obtida foi de 11,97±0,06 mg/L e a de astaxantina foi de 9,97±0,04 mg/L (obtida no ensaio 16F20N24L). A astaxantina representa 83,21% dos carotenoides totais, ficando a sobrar cerca de 16,79% para os restantes, como por exemplo, a luteína. Uma vez identificadas as condições que permitiram obter a máxima concentração de carotenoides totais em escala de bancada, procedeu-se ao scale-up para cultivo em fotobiorreatores de 15 L. O ensaio de scale-up veio demonstrar que o escalamento realizado originou os resultados esperados, visto que o crescimento celular e a produção de carotenoides tiveram comportamento idêntico ao observado no ensaio à escala de bancada em que foram alcançados os melhores resultados (16F20N24L). A concentração de biomassa obtida no ensaio escalado ao fim de 20 dias de cultivo foi de 5,80 g/L e a concentração de carotenoides foi de 10,34 mg/L, dos quais cerca de 82% correspondem a astaxantina (8,47 mg/L). Assim, conclui-se que o cultivo de Chlorella zofingiensis em meio sem nutrientes com fotoperíodo 16L:8D (horas de luz: horas no escuro), com suplementação de luz laranja permite otimizar a acumulação de pigmentos acessórios que podem vir a ser distribuídos industrialmente.
Currently, it is essential to find new scenarios and more sustainable solutions, cleaner and innovative ideas that favour what is natural, thus meeting our needs as a human species, in order to obtains products of high commercial value with the least impact on the environment. To fulfil these needs, microalgae arise. These microscopic beings through their characteristics appear as a good potential investment while being a good way to clean up ecosystems. Chlorella zofingiensis is a microalga that has a rapid and uniform growth rate, thus making it possible to shorten the period of each experimental run. This study aimed to optimize the production of astaxanthin by changing the environmental parameters applied in Chlorella zofingiensis cultivation using BBM medium. Thus, the parameters studied included photoperiod, nutritional stress and orange light supplementation. The cultures produced under these conditions that showed higher concentration of carotenoids were subjected to a 16 hour photoperiod, orange light supplementation and nutritional stress effect throughout the experiment. The highest concentration of total carotenoids obtained was 11,97±0,06 mg/L and that of astaxanthin was 9,97±0,04 mg/L (16F20N24L). This represents 83,21% of the total carotenoids, leaving about 16,79% for the remaining, such as lutein. Once the conditions that promoted the maximum concentration of total carotenoids were obtained on a bench scale, the cultivation was scaled-up to 15 L photobioreactors. The scale-up assay showed that the expected results were achieved, since cell growth and carotenoid production had the similar behaviour as in the bench scale assay that yielded the best results (16F20N24L). The biomass concentration was 5.80 g/L and the carotenoid concentration was 10,34 mg/L, where about 82% is astanxanthin (8,47 mg/L). Thus, it is concluded that the cultivation of Chlorella zofigiensis in nutrient-free medium with 16L:8D photopriod (hours of light: hours in the dark), with supplementation of orange light allows to optimize the accumulation of accessory pigments tha may be industrialy distributed.
Currently, it is essential to find new scenarios and more sustainable solutions, cleaner and innovative ideas that favour what is natural, thus meeting our needs as a human species, in order to obtains products of high commercial value with the least impact on the environment. To fulfil these needs, microalgae arise. These microscopic beings through their characteristics appear as a good potential investment while being a good way to clean up ecosystems. Chlorella zofingiensis is a microalga that has a rapid and uniform growth rate, thus making it possible to shorten the period of each experimental run. This study aimed to optimize the production of astaxanthin by changing the environmental parameters applied in Chlorella zofingiensis cultivation using BBM medium. Thus, the parameters studied included photoperiod, nutritional stress and orange light supplementation. The cultures produced under these conditions that showed higher concentration of carotenoids were subjected to a 16 hour photoperiod, orange light supplementation and nutritional stress effect throughout the experiment. The highest concentration of total carotenoids obtained was 11,97±0,06 mg/L and that of astaxanthin was 9,97±0,04 mg/L (16F20N24L). This represents 83,21% of the total carotenoids, leaving about 16,79% for the remaining, such as lutein. Once the conditions that promoted the maximum concentration of total carotenoids were obtained on a bench scale, the cultivation was scaled-up to 15 L photobioreactors. The scale-up assay showed that the expected results were achieved, since cell growth and carotenoid production had the similar behaviour as in the bench scale assay that yielded the best results (16F20N24L). The biomass concentration was 5.80 g/L and the carotenoid concentration was 10,34 mg/L, where about 82% is astanxanthin (8,47 mg/L). Thus, it is concluded that the cultivation of Chlorella zofigiensis in nutrient-free medium with 16L:8D photopriod (hours of light: hours in the dark), with supplementation of orange light allows to optimize the accumulation of accessory pigments tha may be industrialy distributed.
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Keywords
Pigmentos Stress nutricional Chlorella zofingiensis Astaxantina Pigments Nutritional stress Astaxanthin