Hydrogen metabolism of mutant forms of Anabaena variabilis in continuous cultures and under nutritional stress

Abstract

Nitrogenase activity and H2 evolution were studied in two mutants of the cyanobacterium Anabaena variabilis ATCC 29413 which are impaired in molecular H2-related metabolism. Evidence was obtained that mutants deficient in uptake and reversible hydrogenases were suitable for biotechnological research on H2 production. H2 production by the mutant PK84 in continuous cultures was 4.3 times higher compared to the wild-type. Enhancement in H2 evolution by all the cultures under N2 (1.8–1.9 times) and CO2 starvation (1.4–1.5 times) was observed.