Simultaneous removal of 5-hydroxy methyl furfural (5-HMF) and hydrogen production from acid (H2SO4) pretreated red-algal hydrolysate via hybrid immobilized cells

This study dealt with a new approach for the removal of 5-hydroxy methyl furfural (5-HMF) from dilute acid pretreated red algal hydrolysate using hybrid immobilized cells along with the generation of H2 as energy carrier. Under batch conditions, the peak 5-HMF removal of 1.6 g/L (100% removal) and hydrogen production rate of 1.48 L/L-d were obtained at 50% (v/v) algal hydrolysate content which is equivalent to 16.6 g sugar/L. Beyond the content, only the 5-HMF removal has been taken place, but the hydrogen production has been inhibited significantly. Further, an anaerobic sequencing batch operation performed using the optimal 50% AH concentration showed a stable hydrogen production rate and yield of 4.8 L/L-d and 2.40 mol/mol hexoseutilized respectively.