Even cells can grow in the absence of light as described in section 3.3, the light intensity during culturing was also tested in order to compare the H2 production. Cells were grown in different light intensities ranging from 0 to 90 μE/m2s for 24 hours and further checked for the production rate as shown in Figure 3.8. The highest rate was significantly obtained from cells grown under darkness. Increasing light intensity resulted in lowering down the H2 production rate.