Many carbon sources with the stock concentration of 20% were added to the culture to obtain the final concentration of 0.1% before starting the hydrogen production (Figure 3.11A). Glycerol was used as C-3 sources. Glucose, fructose, galactose, and sorbitol were used as C-6 source. Maltose, sucrose, and lactose were used as C-12 sources. The hydrogen production was compared with the rate of culture without any carbon source addition (control)