Biomass production and studies on Rhodopseudomonas palustris grown in an outdoor, temperature controlled, underwater tubular photobioreactor.
A temperature controlled underwater tubular photobioreactor was studied for 6 months in outdoor conditions to determine biomass production of Rhodopseudomonas palustris 42OL. Biomass output rate was very high during the study period. In July, productivity was about 75.0 g reactor(-1) d(-1) for a short period (5 days). The biomass yield averaged 0.7 g biomass dry weight (d.w.)xg acetic acid(-1). We also obtained a mean photosynthetic efficiency of 7.6% in winter and 7.1% in summer. Biomasses rich in pigments and a biodegradable thermoplastic polymer [poly-beta-hydroxybutyrate (PHB)] were obtained. During the summer, PHB was about 4.0% of the biomass d.w. The bacteriochlorophyll/carotenoid ratio was lower at midday than either in the morning or in the evening. The reduction in this ratio may have been a response of the Rhodopseudomonas cells to high irradiance (about 900 W m(-2)). A reduced rate of protein synthesis continued even in the dark. PHB and carbohydrates, synthesized in excess during the day, were used as substrates for night protein synthesis.
Carlozzi
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Centro di Studio dei Microrganismi Autotrofi del Consiglio Nazionale delle Ricerche, c/o il Dipartimento di Biotecnologie Agrarie, Facoltà di Agraria, Università di Firenze, Piazzale delle Cascine, 27 - 50144, Firenze, Italy. carlozzi@csma.fi.cnr.it
Sacchi
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D018533:Biomass; D019149:Bioreactors; D002940:Circadian Rhythm; D014975:Lutein / Q000096:biosynthesis; D018462:Photobiology; D010788:Photosynthesis; D012241:Rhodopseudomonas / Q000254:growth & development* / Q000378:metabolism; D012621:Seasons; D013696:Temperature; D014871:Water Microbiology
D014975:Lutein