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Updated: Aug 5, 2025

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Published on: October 28, 2021
The effect of light emission spectrum on biohydrogen production by Rhodopseudomonas palustris
Catharine Elizabeth Bosman1, Robert William McClelland Pott2, Steven Martin Bradshaw1
1Department of Process Engineering, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
Abstract:
Photofermentative hydrogen production has gained increasing attention as a source of green energy. To make such photofermentation processes economically competitive, operating costs need to be reduced, possibly through outdoor operation. Because photofermentation processes are light dependent, the emission spectrum and intensity of light both have a significant influence on the hydrogen production and merit investigation. This study investigates the effect of light sources on the hydrogen production and growth of Rhodopseudomonas palustris, comparing the organism's productivity under longer-wavelength light and light mimicking sunlight. Hydrogen production is enhanced under longer-wavelength light, producing 26.8% (± 7.3%) more hydrogen as compared to under light mimicking that of sunlight; however, R. palustris is still able to produce a considerable volume of hydrogen under light with a spectrum mimicking that of sunlight, providing a promising avenue for future research.
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