A key aspect of the industrial development of microalgal production processes is the excessive cost of biomass production. A solution is a combination of biodiesel production and wastewater treatment. The microalga Scenedesmus has a high lipid content and a potential extracellular phenoloxidase activity, which could improve the phycoremediation of phenolic pollutants. In this work, the most suitable growth conditions to obtain this twofold aim were analyzed. First, different strains of Scenedesmus vacuolatus microalga were tested at different pH, salinity and CO2 concentration in the gas phase. The two most promising strains were then cultivated in autotrophic and heterotrophic conditions, and were investigated in terms of efficient nitrogen removal, fatty acid profile and maximized extracellular phenoloxidase activity in the medium. The results showed two extreme conditions: (1) biomass productivity doubled when photobioreactors were sparged with 5% CO2 supplemented air with respect to cultures sparged with air (the steady state values of strain 53 were 0.138 g L−1 day−1 in the presence of air, and 0.243 in the presence of CO2 addition), and N-starvation under 5% CO2enhanced the transesterified fraction of lipids (strain 53 FAME fraction in the presence of N-starvation was 33%, in the presence of nitrogen FAME fraction was 22%); (2) phenoloxidase activity was completely suppressed by presence of 5% CO2 in the gas phase (strain 53 0.21 U mL−1), indicating clear catabolite repression for the induction of this enzyme in the algal metabolism.
Scenedesmus vacuolatus cultures for possible combined laccase-like phenoloxidase activity and biodiesel production / Carbone, DORA ALLEGRA; Gargano, Immacolata; Chiaiese, Pasquale; Pollio, Antonino; Marotta, Raffaele; Olivieri, Giuseppe; Pinto, Gabriele. - In: ANNALS OF MICROBIOLOGY. - ISSN 1590-4261. - (2017), pp. 1-7. [10.1007/s13213-017-1309-8]
Scenedesmus vacuolatus cultures for possible combined laccase-like phenoloxidase activity and biodiesel production
CARBONE, DORA ALLEGRA
Writing – Original Draft Preparation
;Gargano, ImmacolataData Curation
;Chiaiese, PasqualeMembro del Collaboration Group
;Pollio, AntoninoWriting – Original Draft Preparation
;Marotta, RaffaeleMembro del Collaboration Group
;Olivieri, GiuseppeWriting – Review & Editing
;Pinto, GabrieleMembro del Collaboration Group
2017
Abstract
A key aspect of the industrial development of microalgal production processes is the excessive cost of biomass production. A solution is a combination of biodiesel production and wastewater treatment. The microalga Scenedesmus has a high lipid content and a potential extracellular phenoloxidase activity, which could improve the phycoremediation of phenolic pollutants. In this work, the most suitable growth conditions to obtain this twofold aim were analyzed. First, different strains of Scenedesmus vacuolatus microalga were tested at different pH, salinity and CO2 concentration in the gas phase. The two most promising strains were then cultivated in autotrophic and heterotrophic conditions, and were investigated in terms of efficient nitrogen removal, fatty acid profile and maximized extracellular phenoloxidase activity in the medium. The results showed two extreme conditions: (1) biomass productivity doubled when photobioreactors were sparged with 5% CO2 supplemented air with respect to cultures sparged with air (the steady state values of strain 53 were 0.138 g L−1 day−1 in the presence of air, and 0.243 in the presence of CO2 addition), and N-starvation under 5% CO2enhanced the transesterified fraction of lipids (strain 53 FAME fraction in the presence of N-starvation was 33%, in the presence of nitrogen FAME fraction was 22%); (2) phenoloxidase activity was completely suppressed by presence of 5% CO2 in the gas phase (strain 53 0.21 U mL−1), indicating clear catabolite repression for the induction of this enzyme in the algal metabolism.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.