Cyanobacterial biological nitrogen fi xation as a sustainable nitrogen fertilizer for the production of microalgal oil

MAURO DO NASCIMENTO; LARA SANCHEZ RIZZA; ANDRES ARRUEBARRENA DI PALMA; MARIA DE LOS ANGELES DUBLAN; GRACIELA L SALERNO; LUIS RUBIO; LEONARDO CURATTI

Algal Research

ELSEVIER B.V.

Lugar: Amsterdam; Año: 2015 vol. 12 p. 142 - 148

2211-9264

Oleaginousmicroalgae have a great potential as a feedstock for biodiesel and otherbiofuels. However, the current cost of producing biofuels from microalgaebiomass is still high to envision massive and profitable commercialization inthe near future. One of the drawbacks of implementing large-scale cultivationof these organisms is the unsustainablerequirement of N-fertilizers. It is presumed that co-production of higher valueby-products in the frame of a biorefinery would increase the profitability ofproducing oil from microalgae. The aim of this work is to provideproof-of-concept for the complete substitution of chemical N-fertilization by on-sitebiological N2 fixation in a process of microalgal oil production. We show theefficient conversion of bio-mass of a N2-fixing cyanobacterium into oil-richmicroalgae biomass when the eukaryotic alga is fed with a cyanobacteriumextract as a sole source of nutrients. Oil production yields in environmentalphotobioreactor simulations were in the range of current yields obtained at theexpense of synthetic N-fertilizer and up to 20-fold higher than those reportedwhen using plant feedstocks.