Virucidal activity of microalgae extracts harvested during phycoremediation of swine wastewater

Phycoremediation of swine wastewater is a promising treatment since it efficiently removes nutrients and contaminants and, simultaneously, its biomass can be harvested and used to obtain a wide range of valuable compounds and metabolites. In this context, biomass microalgae were investigated for the phycoremediation of swine wastewater, and biomass extracts for its virucidal effect against enveloped and non-enveloped viruses. Microalgae were cultivated in a pilot scale bioreactor fed with swine wastewater as the growth substrate. Hexane, dichloromethane, and methanol were used to obtain the microalgae extracts. Extracts were tested for virucidal potential against HSV-1 and HAdV-5. Virucidal assays were conducted at temperatures that emulate environmental conditions (21 °C) and body temperature (37 °C). The maximum production of microalgae biomass reached a concentration of 318.5 ± 23.6 mgDW L−1. The results showed that phycoremediation removed 100% of ammonia-N and phosphate-P, with rates (k1) of 0.218 ± 0.013 and 0.501 ± 0.038 (day−1), respectively. All microalgae extract reduced 100% of the infectious capacity of HSV-1. The microalgae extracts with dichloromethane and methanol showed inhibition activities at the lowest concentration (3.125 µg mL−1). Virucidal assays against HAdV-5 using microalgae extract of hexane and methanol inhibited the infectious capacity of the virus by 70% at all concentrations tested at 37 °C. At a concentration of 12.5 µg mL−1, the dichloromethane microalgae extract reduced 50?80% of the infectious capacity of HAdV-5, also at 37 °C. Overall, the results suggest that the microalgae can be an attractive source of feedstock biomass for the exploration of alternative virucidal compounds. Resumo: A ficorremediação de águas residuais de suinocultura é um tratamento promissor, pois remove eficientemente nutrientes e contaminantes e, simultaneamente, sua biomassa pode ser colhida e utilizada para obter uma ampla gama de compostos e metabólitos valiosos. Neste contexto, microalgas de biomassa foram investigadas para a fitomediação de águas residuais de suínos, e extratos de biomassa por seu efeito virucida contra vírus envelopados e não envelopados. As microalgas foram cultivadas em um biorreator de escala piloto alimentado com água residuária de suínos como substrato de crescimento. Hexano, diclorometano e metanol foram usados ​​para obter os extratos de microalgas. Os extratos foram testados quanto ao potencial virucida contra HSV-1 e HAdV-5. Os ensaios virucidas foram conduzidos em temperaturas que simulam as condições ambientais (21°C) e a temperatura corporal (37°C).DW L −1 . Os resultados mostraram que a ficorremediação removeu 100% de amônia-N e fosfato-P, com taxas ( k 1 ) de 0,218 ± 0,013 e 0,501 ± 0,038 (dia −1 ), respectivamente. Todos os extratos de microalgas reduziram em 100% a capacidade infecciosa do HSV-1. Os extratos de microalgas com diclorometano e metanol apresentaram atividades de inibição na concentração mais baixa (3,125 µg mL −1 ). Ensaios virucidas contra HAdV-5 usando extrato de microalgas de hexano e metanol inibiram a capacidade infecciosa do vírus em 70% em todas as concentrações testadas a 37 °C. Em uma concentração de 12,5 µg mL -1, o extrato de microalgas diclorometano reduziu 50-80% da capacidade infecciosa do HAdV-5, também a 37 °C. No geral, os resultados sugerem que as microalgas podem ser uma fonte atrativa de biomassa de matéria-prima para a exploração de compostos viricidas alternativos. Made available in DSpace on 2022-04-11T14:01:08Z (GMT). No. of bitstreams: 1 final9878.pdf: 4339051 bytes, checksum: 95cbce0603f5f7c9f945420adecc1925 (MD5) Previous issue date: 2022