Sequential multi-stage extraction of biocompounds from Spirulina platensis: Combined effect of ohmic heating and enzymatic treatment

A sequential multi-stage procedure was applied on the extraction of biocompounds from Spirulina platensis. The process consisted in three steps: 1) aqueous extraction, using conventional thermal extraction (CE), ohmic heating (OH, 7V/cm), enzymatic treatment (EAE, 0.8 mgLysozyme/mL), or both OH and EAE combined; 2) ethanolic extraction; 3) CHCl3/MeOH extraction. The results evidenced that the combined OH-EAE extraction allowed selective recovery of phycobiliproteins in the 1st step, with increments of more than 100% in yield in comparison with CE. Pigments and lipids were selectively extracted in the 2nd step. The combination of OH and EAE in the 1st step resulted in higher amounts of extracted compounds in the following phases compared to processes using non-combined technologies. Results demonstrate that the intensification of extraction steps facilitates the use of environmentally friendly technologies in a multi-stage process capable of recovering and isolating different fractions with bio-functional properties, targeting waste reduction and circular economy. Industrial relevance Spirulina plantensis represents a potential biomass feedstock due to its potential as a source of compounds of great economic value (including antioxidants, proteins, lipids and natural pigments, in particular blue colorants). The combined use of ohmic heating and enzymes in the aqueous extraction step fosters the use of environmentally friendly technologies to implement sequential high yield and high purity extraction of the different valuable fractions with bio-functional properties, targeting waste reduction and contributing to the implementation of circular economy strategies. This can be integrated with a design of Industry 4.0 driving the development of new products.This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, by program Marie Skłodowska-Curie grant (MSCA-RISE; FODIAC; 778388) and by project OH2O - POCI-01-0145-FEDER-029145 (funded by FCT, COMPETE2020 – Competitiveness and Internationalization Operational Program and European Fund for Regional Development - FEDER). Pedro Santos is recipient of a PhD fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte (NORTE-08-5369-FSE-000036). Sílvia Miranda acknowledges the financial support provided by FCT through the Doctoral grant SFRH/BD/144188/2019. Spirulina platensis was kindly supplied by EVRA S.r.l. (Potenza, Italy).info:eu-repo/semantics/publishedVersio

Le respect de la forme urbaine à San Francisco

Die Berücksichtigung der gewachsenen Urbanen Form in San Francisco Die Bauverordnungen in San Francisco bemühen sich, die Kontinuität von Vergangenheit und Gegenwart durch eine Festschreibung formaler Charakteristika zu organisieren : gemäßigte Bebauungsdichte, Regelungen für die Bebauungsfläche, die Hausfronten, die Höhe der Gebäude usw... Die Rettung des Altbestandes übernimmt die Aufgabe, neuen Wohnraum anzubieten, und erschließt ihn im bestehenden Gefüge der Stadt.The respect of city shapes in San Francisco Town planning regulations in San Francisco try to preserve a certain continuity between the past and the present by laying down a building code, regulating density, ground holding, appearance and height, etc. The supply of new accomodation is provided by restoration and so, is integrated into an existing network. However this urban policy is not without certain troublesome side effects and isolated failures.Le règlement d'urbanisme de San Francisco s'efforce d'organiser la continuité entre le passé et l'actuel par un codage des caractéristiques formelles du bâti : densification modérée, emprises au sol, prospects et hauteurs réglés, etc. La réhabilitation relaie l'offre de logements neufs et cette dernière s'inscrit dans le tissu existant. Cependant cette volonté urbanistique ne va pas sans effets pervers, ou échecs ponctuels.El respecto de la forma urbana en San Francisco El reglamento de urbanismo de San Francisco se esfuerza por organizar la continuidad entre el pasado y el présente a través de una codificación de las características formales de lo edificado : densificación moderada, superficie ocupada, perspectivas y alturas reguladas, etc... La rehabilitación toma el relevo de la oferta de viviendas nuevas y esta última se integra al tejido existente.Vernès-Moudon Anne. Le respect de la forme urbaine à San Francisco. In: Les Annales de la recherche urbaine, N°37, 1988. Plans et projets. pp. 9-19