Hydrogen photoproduction by immobilized n2-fixing cyanobacteria: understanding the role of the uptake hydrogenase in the long-term process.

ABSTRACT: We have investigated two approaches to enhance and extend H2 photoproduction yields in heterocystous, N2-fixing cyanobacteria entrapped in thin alginate films. In the first approach, periodic CO2 supplementation was provided to alginate-entrapped, N-deprived cells. N deprivation led to the inhibition of photosynthetic activity in vegetative cells and the attenuation of H2 production over time. Our results demonstrated that alginate-entrapped ΔhupL cells were considerably more sensitive to high light intensity, N deficiency, and imbalances in C/N ratios than wild-type cells. In the second approach, Anabaena strain PCC 7120, its ΔhupL mutant, and Calothrix strain 336/3 films were supplemented with N2 by periodic treatments of air, or air plus CO2. These treatments restored the photosynthetic

SUBMITTER: Kosourov S 

PROVIDER: S-EPMC4178605 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature