Sucrose-to-ethanol microalgae-based platform using seawater

Microalgal biomass is increasingly considered a promising feedstock for the production of bioethanol because it has simpler biochemical composition and structural features than plant feedstocks. However, it still requires hazardous and/or expensive acid or enzymatic saccharification processes before its conversion into ethanol by fermentation. To bypass this limitation, we identified microalgal strains that accumulate up to 10% (w/w) of sucrose, a readily fermentable sugar. Conditions were optimized to produce sucrose in half-strength seawater, as well as efficient extraction by very mild procedures, and conversion into ethanol. We present a model based on cultivation in environmental photobioreactors that predicted a productivity of 4,200 L ethanol · ha-1 · year-1 in raceway ponds in Brazil, approaching the average sucrose and ethanol productivity from sugarcane.Fil: Sanz Smachetti, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Coronel, Camila Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Salerno, Graciela Lidia. Fundación para Investigaciones Biológicas Aplicadas; ArgentinaFil: Curatti, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; Argentin

Ethanol and protein production from minimally processed biomass of a genetically-modified cyanobacterium over-accumulating sucrose

One of the main bottlenecks of a microalgal or cyanobacterial biomass biorefinery is the separation of differentuseful fractions using simple, low energy-consuming, cost-effective, and scalable separation processes. Althoughthe carbohydrates-rich biomass of these microorganisms presents clear advantages over conventional terrestrialcrops as feedstocks for ethanol, it still requires acid and/or enzymatic hydrolysis for efficient fermentation. Here,we show the genetic modification of carbohydrates partitioning in afilamentous cyanobacterium towards theaccumulation of sucrose up to 10% (w/w) as a readily fermentable feedstock. We optimized two methods for thepreparation of concentrated sucrose syrups, which were efficiently converted into ethanol by yeasts, without theneed of additional pretreatments. Biomass drying and milling, followed by aqueous extraction of sugars andproteins, and the recovery of proteins by short pulses of heat, kept the value of sugars as a feedstock for ethanoland protein for feed supplements within a cost-effective biomass biorefinery.Fil: Sanz Smachetti, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Perez Cenci, Macarena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Salerno, Graciela Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; Argentina. Fundación para Investigaciones Biológicas Aplicadas; ArgentinaFil: Curatti, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; Argentin

A semi-closed loop microalgal biomass production-platform for ethanol from renewable sources of nitrogen and phosphorous

Production of microalgal biomass for feed and fuels demands unsustainable large amounts of fertilizers. The most broadly considered alternative sources of nutrients/fertilizer for microalgae are wastewater and internal recycling in closed-loop production platforms. However, these strategies largely disable co-production of feed and fuel in biomass biorefineries for an increased economic and environmental feasibility. In this study, we aimed at providing proof-of-concept for a semi-closed loop microalgal production-platform and biomass biorefinery for ethanol and feed from renewable resources of N and P. Atmospheric N 2 was assimilated into a N 2 -fixing cyanobacterial biomass, which sustained growth of a microalga that accumulated high levels of carbohydrates (up to 60% (w/w)) as a sole source of fertilizer. The microalgal biomass was efficiently saccharified with H 2 SO 4 , which was recycled to release soluble PO 4 3- from bone meal as a renewable source of P. Fermenting these P-enriched preparations with yeasts quantitatively produced ethanol at theoretical yields, a concentration of up to 50 g ethanol. L −1 and a yield of 0.25 g ethanol. g biomass −1 . Calculations suggested a potential yield from 7600 to 10,800 L ethanol. ha −1 . year −1 , under Buenos Aires environmental conditions, which would be higher than that currently obtained from maize feedstocks. The residual fermentation vinasse, supplemented with P and containing other downstream-process reagents, was recycled as a sole source of macronutrients for the cultivation of the N 2 -fixing cyanobacterium to close the production cycle. Water recycling and co-production of residual biomass enriched in fat and protein as potential feed are also shown. This semi-closed loop biomass production-platform reconciles the concepts of microalgal biomass biorefineries for the co-production of feedstocks for biofuels and feed and nutrients recycling in closed-loop systems that largely minimizes production of waste.Fil: Sánchez Rizza, Lara. Fundación para Investigaciones Biológicas Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Coronel, Camila Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Sanz Smachetti, María Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; ArgentinaFil: Do Nascimento, Mauro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; Argentina. Fundación para Investigaciones Biológicas Aplicadas; ArgentinaFil: Curatti, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología; Argentin

Towards an ideotype for food-fuel dual-purpose wheat in Argentina with focus on biogas production

Wheat straw, one of the most abundant agricultural residues worldwide, can be used to produce biogas, which is considered one of the most efficiently produced renewable energies. Wheat grown with the dual-purpose of producing food and biogas should display simultaneously high grain and straw yields, low lodging susceptibility and high conversion efficiency of straw into biogas. The aims of this study were to determine the best food-fuel dual-purpose wheat candidates among 36 wheat genotypes—including French, CIMMYT and local (Criollo) germplasm—used in breeding programs in Argentina and to gain some insights into the relationships between key traits relevant for dual-purpose wheat genotypes. Results High variability in individual key traits for dual-purpose wheat ideotype has been found. Genotypes of French origin displayed the highest grain yield, and those of CIMMYT origin, the lowest straw yield. Genotypes of Criollo origin showed the highest lodging susceptibility, and French ones, the lowest. Straw yield was positively correlated with grain yield in all genotypes, and negatively correlated with plant height in genotypes of Criollo origin. Straw conversion into biogas was measured in terms of the biogas potential production and kinetic parameters Bmax (maximum specific biogas production) and k (first-order kinetic constant) were analyzed. All key traits were analyzed together by a principal component analysis. Baguette 31 and SNR Nogal, two genotypes of French origin, showed high grain yield, high-to-very high straw yield, low lodging susceptibility, and moderate-to-high Bmax and k. Buck Guapo and Buck Baqueano, two genotypes of Criollo origin, displayed good values for grain yield, straw yield and Bmax and k. However, their high lodging susceptibility precludes their production in shallow soils or high-input systems. Lastly, some old genotypes (e.g. Klein Atlas) harbored a good combination of all key traits and could prove valuable to be included in future breeding programs for dual-purpose wheat. Conclusions While none of the genotypes excelled in every key trait, a few candidates showed potential for dual-purpose ideotype, particularly Baguette 31 and SNR Nogal. The challenge lays in gathering all attributes for food and 2G fuel in the same genotype.EEA BalcarceFil: Gabbanelli, Nadia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Gabbanelli, Nadia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Erbetta, Elisa. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Erbetta, Elisa. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Sanz Smachetti, Maria Eugenia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Sanz Smachetti, Maria Eugenia. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Lorenzo, Máximo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Lorenzo, Máximo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Talia, Paola Mónica. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Agrobiotecnología y Biología Molecular; Argentina.Fil: Ramírez, Ignacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Ramírez, Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Vera, Magdalena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina.Fil: Vera, Magdalena. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Durruty, Ignacio. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentina.Fil: Pontaroli, Ana Clara. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Pontaroli, Ana Clara. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina.Fil: Echarte, María Mercedes. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible; Argentina.Fil: Echarte, María Mercedes. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina

Bioprospecting for native microalgae as an alternative source of sugars for the production of bioethanol

While the production of biofuels holds potential to contribute to energy security, concerns on food prices, land use, and carbon emissions have arisen from increased production of first-generation bioethanol. While second-generation bioethanol from lignocellulosic agricultural waste faces difficult-to-overcome technological barriers, renewed promise is held in microalgae biomass as an alternative feedstock. In this work we show the results of bioprospecting for microalgae native of South America for accumulation of carbohydrates under conditions of nitrogen deficiency, and constant light and temperature. After a preliminary analysis of seventeen strains, we selected strain SP2-3, because its biomass could be enriched in carbohydrates over 70% (w/w) on a dry biomass basis, and Desmodesmus sp. strain FG for its fermentable sugars productivity. After optimization of microalgae culture conditions, biomass hydrolysis and fermentation with baker´s yeast Saccharomyces cerevisiae, we demonstrated ethanol yields of up to 0.24 g ethanol·g of biomass− 1, and an ethanol concentration in the fermentation broth of 24 g ethanol·L of fermentation broth− 1, for up to 87.4% of the maximum theoretical value. These results contribute to support the potential of microalgae biomass as an alternative feedstock for bioethanol and the value of bioprospecting programs to identified candidate strains among natural biodiversity.Fil: Sánchez Rizza, Lara. Fundación para Investigaciones Biológicas Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Biodiversidad y Biotecnología; ArgentinaFil: Sanz Smachetti, María Eugenia. Fundación para Investigaciones Biológicas Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Biodiversidad y Biotecnología; ArgentinaFil: Do Nascimento, Mauro. Fundación para Investigaciones Biológicas Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Biodiversidad y Biotecnología; ArgentinaFil: Salerno, Graciela Lidia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Biodiversidad y Biotecnología; Argentina. Fundación para Investigaciones Biológicas Aplicadas; ArgentinaFil: Curatti, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones En Biodiversidad y Biotecnología; Argentina. Fundación para Investigaciones Biológicas Aplicadas; Argentin