Sustained photobiological hydrogen production by Chlorella vulgaris without nutrient starvation

This article describes the ability of the Chlorella vulgaris BEIJ strain G-120 to produce hydrogen (H-2) via both direct and indirect pathways without the use of nutrient starvation. Photobiological H-2 production reached a maximum rate of 12 mL H-2 L(-1 )h(-1), corresponding to a light conversion efficiency (light to H-2) of 7.7% (average 3.2%, over the 8-day period) of PAR, (photosynthetically active irradiance). Cells presented a maximum in vivo hydrogenase activity of 25.5 +/- 0.2 nmoles H-2 mu gChl(-1) h(-1) and the calculated in vitro hydrogenase activity was 830 +/- 61 nmoles H-2 mu gChl(-1) h(-1). The strain is able to grow either heterotrophically or photo autotrophically. The total output of 896 mL of H-2 was attained for illuminated culture and 405 mL for dark cultures. The average H-2 production rate was 4.98 mL L-1 h(-1) for the illuminated culture and 2.08 mL L-1 h(-)(1) for the one maintained in the dark. (C) 2020 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.

Automated summary

This article discusses the ability of Chlorella vulgaris BEIJ strain G-120 to produce hydrogen through direct and indirect pathways without nutrient starvation. The strain showed high hydrogen production efficiency and can grow heterotrophically or photo autotrophically.