%0 Journal Article 
%A Marcos Sánchez, José Luis
%A Cabrera Revuelta, Gema
%A Hernandez, Daniel  F.
%A Luque, Beatriz
%A Valle Gallardo, Antonio
%A Bolívar Pérez, Jorge
%T Production of hydrogen from crude glycerol via an integrated process of L-malate biosynthesis by Escherichia coli and photofermentation by Rhodobacter capsulatus
%D 2025
%@ 1475-2859
%U http://hdl.handle.net/10498/39326
%X Biorefinery is an innovative concept for resource utilization. To further increase its efficiency, the integration of different biomass conversion technologies (integrated biorefinery) is essential. Biodiesel, a traditional biofuel, generates glycerol as an inevitable byproduct; making it an attractive carbon source for biorefineries due to its abundance, low price, and high degree of reduction. In this work, we propose an integrated two-step process of dark fermentation with Escherichia coli to produce L-malate from glycerol and photofermentation by Rhodobacter capsulatus to convert this L-malate into hydrogen, a clean and sustainable energy carrier. To this end, we optimized an E. coli L-malate-producing strain by overexpressing GlpK in the M4-Δiclr/pBAD-pck strain and scale up the process from shake flask to bioreactor using waste crude glycerol from a biodiesel biorefinery instead of pure glycerol. Under the optimized conditions, E. coli produced up to 11 g/L L-malate in 24 h. The culture medium from this dark fermentation was used to formulate an L-malate enriched medium for Rhodobacter that led to the production of 58.0 ± 6 mM H2 in 90 h.
%K Biorefinery
%K Biodiesel
%K Crude glycerol
%K L-malate
%K Bio-H2
%K Escherichia coli
%K Rhodobacter capsulatus
%~ Universidad de Cádiz