A new approach for cultivating the cyanobacterium Nostoc calcicola (MACC-612) to produce biomass and bioactive compounds using a thin-layer raceway pond

The culture of microalgae and cyanobacteria in open systems has been improved through the novel approach of thin-layer raceway ponds. The importance of studying mass cultivation of the cyanobacterium Nostoc calcicola (further as Nostoc) lies in its biotechnological potential as a source of bioactive compounds for food and non-food applications. These compounds include polysaccharides, mycosporine-like amino acids and phycocyanin. Nostoc was cultured outdoors in a thin-layer raceway pond where the biomass production, physiological status, photosynthetic activity, and biochemical composition were monitored through the experimental period of 5 days. The biomass, as did the maximal quantum yield of PSII, maximal electron transport rate (ETRmax) and photosynthetic efficiency (αETR) increased throughout the experimental period showing the optimal operation of the thin-layer raceway ponds, due to the light penetrates deeper into the thin culture layer and thus more light is available to the cells. Oxygen levels in the culture increased over time, but no photoinhibition was evident indicating optimal action of non-photochemical mechanisms. Nostoc increased the total internal carbon content over the experimental period. Chlorophyll increased, whereas the N compounds such as the biliprotein phycocyanin decreased. Among the UV-absorbing compounds, polyphenols, mycosporine-like amino acids, such as shinorine and other unknown UV-A absorbing compounds were detected. There components showed a positive correlation to antioxidant activity. Thus, the optimal accumulation of biomass and the accumulation of bio-active compounds having antioxidant capacity show the possible biotechnological applications of Nostoc.Fil: Celis Plá, Paula S. M.. Universidad de Playa Ancha; ChileFil: Rearte, Tomás Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Química Analítica; ArgentinaFil: Neori, Amir. University Of Haifa; Israel. The Interuniversity Institute for Marine Sciences; IsraelFil: Masojídek, Jiří. Czech Academy of Sciences; República Checa. University of South Bohemia; República ChecaFil: Bonomi Barufi, José. Universidade Federal de Santa Catarina; BrasilFil: Álvarez Gómez, Félix. Universidad de Malaga. Facultad de Ciencias. Departamento de Ecología y Geología; EspañaFil: Ranglová, Karolína. Czech Academy of Sciences; República ChecaFil: Carmo da Silva, Jaqueline. Universidade Federal do São Carlos; BrasilFil: Abdala, Roberto. Universidad de Malaga. Facultad de Ciencias. Departamento de Ecología y Geología; EspañaFil: Gómez, Cintia. Universidad de Almería.; EspañaFil: Caporgno, Martín. Czech Academy of Sciences; República ChecaFil: Torzillo, Giuseppe. Consiglio Nazionale delle Ricerche; Italia. Universidad de Costa Rica; Costa RicaFil: Silva Benavides, Ana Margarita. Universidad de Costa Rica; Costa RicaFil: Ralph, Peter J.. University of Sydney; AustraliaFil: Massocato, Thaís Fávero. Universidade Federal de Santa Catarina; BrasilFil: Atzmüller, Richard. Czech Academy of Sciences; República ChecaFil: Vega, Julia. Universidad de Malaga. Facultad de Ciencias. Departamento de Ecología y Geología; EspañaFil: Chávez, Patricia. Universidad de Malaga. Facultad de Ciencias. Departamento de Ecología y Geología; EspañaFil: López Figueroa, Félix. Universidad de Malaga. Facultad de Ciencias. Departamento de Ecología y Geología; Españ