Optimization of hydrogen production by Halobacterium salinarium coupled with E coli using milk plasma as fermentative substrate

Batch experiments were conducted to investigate the fermentative hydrogen production by coupled system of Halobacterium salinarium and E. coli. Increase in the light intensity from 6000 lux to 12000 lux and changing the inoculums level of E coli resulted in 10 fold increase in the rate of hydrogen production using the coupled system. Statistical based design of experiments was applied to optimize the rate of hydrogen production using milk plasma,popularly known as cheese whey, a dairy industry byproduct. An optimal rate of hydrogen production of 56.7 ml/l h was achieved with 14.42 % (by volume) of milk plasma and an initial pH of 6.6. The investigations provided information on achieving higher yields with milk plasma as substrate, its optimal concentration, and importance of media pH for producing higher rate of hydrogen.