초록
Sunlight represents an important choice for low cost photosynthetic cultures irradiation, especially in up-scaled processes. The aim of this study was the assessment of the hydrogen production performances of Rhodopseudomonas palustris strain 42OL cultivated outdoors, under sunlight, in a 50L tubular photobioreactor. Moreover, bacteriochlorophyll a fluorescence was used for the first time as a tool for monitoring the physiological status of Rp. palustris mass cultures. The maximum H<SUB>2</SUB> production rate of 27.2mlL<SUP>-1</SUP>h<SUP>-1</SUP>, and the mean rate per illuminated surface of 3.54+/-1.53Lm<SUP>-2</SUP>d<SUP>-1</SUP> obtained resulted the highest so far reported for outdoor experiments carried out with purple bacteria in tubular photobioreactors of comparable dimensions. The in-situ measurement of bacteriochlorophyll a fluorescence (F<SUB>v</SUB>/F<SUB>m</SUB>) showed that the photosystem was unaffected by changing light irradiance during the day and remained fully active over the whole period of hydrogen production.