“…Fermentative bio-hydrogen, overcomes this issue but suffers from low yields. Reviews regarding research on bio-hydrogen (Singh et al, 2017) and its production technologies are available and interested readers are referred to the following articles for further information detailing the current status of dark-fermentation (Kumar et al, 2018;Lin et al, 2017;Nagarajan et al, 2017;Urbaniec & Bakker, 2015), photo-fermentation (Khetkorn et al, 2017;Lin et al, 2017;Nagarajan et al, 2017;Zhang et al, 2017) and combined dark-photo-fermentation (Ghosh et al, 2017).…”