Blue bioluminescence generated from luminol steps in as a sunlight substitute

Chinese chemists report that, in the absence of sunlight, bioluminescence can drive photosynthesis.

Photosynthesis uses energy from light to convert carbon dioxide and water into oxygen and carbohydrates. Although light emitting diodes (LEDs) and fluorescent lamps have been tested as alternative light sources to natural sunlight, bioluminescence has received much less attention. Advantages of bioluminescence include no heat radiation, high energy conversion efficiencies and no electrical requirements.

When luminol is oxidised to its dianion form, by hydrogen peroxide and the enzyme horseradish peroxidase, it produces blue luminescence. In general, plants grown under blue light photosynthesise faster than plants grown under red or green light. Armed with this knowledge, Shu Wang and his team at the Chinese Academy of Sciences in Beijing have shown that blue luminescence generated from luminol can initiate photosynthesis in geranium leaves. They found that carbohydrate production was related to the intensity of the bioluminescence, which was altered by varying the concentration of luminol in the experiment.

Blue luminescence, emitted when luminol is oxidised by hydrogen peroxide and horseradish peroxidase, can drive photosynthesis

‘Photosynthesis is one of the most important processes for life on Earth. However, photosynthesis is strongly dependent on the light source and extreme conditions will limit photosynthetic activity,’ says Hiroshi Imahori, an expert in biomimetic systems for artificial photosynthesis at Kyoto University in Japan, ‘This study has successfully demonstrated the potential utility of bioluminescence as a light source for photosynthesis.’

Wang suggests that bioluminescence driven photosynthesis could be used in extreme situations like polar nights and the deep sea. The team’s findings may also be applicable to emerging ideas on the photosynthesis-mediated life processes of some marine creatures and bacteria with bioluminescence characteristics.