Improvements in biological hydrogen production by microbial fermentations

摘要

Hydrogen is being touted as an ideal future green fuel. Various biological means for the renewable production of hydrogen are being investigated. Biohydrogen production by microbial fermentation is a process that could use readily available wastes, as well as presently unutilized bioresources. In order to make this process practical, yields must be increased. Recent results show that conversion efficiencies can be improved through nutrient limitation, and genetic modification to increase hydrogenase expression and eliminate competing pathways. Results show that dilution rate is an important factor controlling the overall efficiency of an hydrogen fermentation, with a trade-off between increased production and increased substrate conversion. Biodiesel-derived glycerol is currently produced in large amounts, and its production will dramatically increase in the future. Here we show that photofermentation can be used to stoichiometrically convert glycerol to hydrogen.