Enhancing Hydrogen Productivity of Photosynthetic Bacteria from the Formulated Carbon Components of Lignocellulose

Abstract

To develop an efficient photofermentative process capable of higher rate biohydrogen production using carbon components of lignocellulosic hydrolysate, a desired carbon substrate by mixing xylose with glucose was formulated. Effects of crucial process parameters affecting cellular biochemical reaction of hydrogen by photosynthetic bacteria (PSB), i.e variation in initial concentration of total carbon, glucose content in initial carbon substrate, as well as light intensity were experimental investigated using response surface methodology (RSM) with a Box-Benhnken design (BBD). Hydrogen production rate (HPR) in the maximum value of 30.6 mL h− 1 L− 1 was attained under conditions of 39 mM initial concentration of total carbon, 59% (mol/mol) glucose content in initial carbon substrate and 12.6 W m− 2 light intensity at light wavelength of 590 nm. Synergic effects of metabolizing such a well formulated carbon substrate for sustaining the active microbial synthesis to sufficiently accumulate biomass in bioreactor, as well as stimulating enzyme activity of nitrogenase for the higher rate biohydrogen production were attributed to this carbon substrate can enable PSB to maintain the relatively consistent microenvironment in suitable culture pH condition during the optimized photofermentative process.