title: Acclimation strategy of Rhodopseudomonas palustris to high light irradiance.
abstract: The ability of Rhodopseudomonas palustris cells to rapidly acclimate to high light irradiance is an essential issue when cells are grown under sunlight. The aim of this study was to investigate the photo-acclimation process in Rhodopseudomonas palustris 42OL under different culturing conditions: (i) anaerobic (AnG), (ii) aerobic (AG), and (iii) under H2-producing (HP) conditions both at low (LL) and high light (HL) irradiances. The results obtained clearly showed that the photosynthetic unit was significantly affected by the light irradiance at which Rp. palustris 42OL was grown. The synthesis of carotenoids was affected by both illumination and culturing conditions. At LL, lycopene was the main carotenoid synthetized under all conditions tested, while at HL under HP conditions, it resulted the predominant carotenoid. Oppositely, under AnG and AG at HL, rhodovibrin was the major carotenoid detected. The increase in light intensity produced a deeper variation in light-harvesting complexes (LHC) ratio. These findings are important for understanding the ecological distribution of PNSB in natural environments, mostly characterized by high light intensities, and for its growth outdoors.
authors.affiliation: Department of Agrifood Production and Environmental Sciences, University of Florence, via Maragliano 77, 50144, Florence, Italy. Electronic address: dayanaisabel.muzziottigil@unifi.it.
authors.forename: Dayana
authors.initials: D
authors.lastname: Muzziotti
authors.affiliation: Department of Agrifood Production and Environmental Sciences, University of Florence, via Maragliano 77, 50144, Florence, Italy; Institute of Chemistry of Organometallic Compounds (ICCOM), CNR, Via Madonna del Piano, 10-50019 Sesto Fiorentino, Florence, Italy. Electronic address: alessandra.adessi@unifi.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Adessi
authors.affiliation: Institute of Ecosystem Study (ISE), CNR, Via Madonna del Piano, 10-50019 Sesto Fiorentino, Florence, Italy. Electronic address: faraloni@ise.cnr.it.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Faraloni
authors.affiliation: Institute of Ecosystem Study (ISE), CNR, Via Madonna del Piano, 10-50019 Sesto Fiorentino, Florence, Italy. Electronic address: torzillo@ise.cnr.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Torzillo
authors.affiliation: Department of Agrifood Production and Environmental Sciences, University of Florence, via Maragliano 77, 50144, Florence, Italy; Institute of Chemistry of Organometallic Compounds (ICCOM), CNR, Via Madonna del Piano, 10-50019 Sesto Fiorentino, Florence, Italy. Electronic address: roberto.dephilippis@unifi.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: De Philippis
mesh_terms: D000064:Acclimatization / Q000502:physiology* / Q000528:radiation effects; D018533:Biomass; D002338:Carotenoids / Q000096:biosynthesis; D006859:Hydrogen / Q000378:metabolism; D008027:Light; D000077276:Lycopene; D018462:Photobiology / Q000379:methods; D017785:Photons; D012241:Rhodopseudomonas / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects*; D013472:Sunlight
chemical_list: C522079:rhodovibrin; D002338:Carotenoids; D006859:Hydrogen; D000077276:Lycopene
keywords: Aerobic growing conditions; Anaerobic growing conditions; H(2)-producing conditions; Photo-acclimation; Photo-protection