title: Chromatic acclimation and population dynamics of green sulfur bacteria grown with spectrally tailored light.
abstract: Living organisms have to adjust to their surrounding in order to survive in stressful conditions. We study this mechanism in one of most primitive creatures - photosynthetic green sulfur bacteria. These bacteria absorb photons very efficiently using the chlorosome antenna complexes and perform photosynthesis in extreme low-light environments. How the chlorosomes in green sulfur bacteria are acclimated to the stressful light conditions, for instance, if the spectrum of light is not optimal for absorption, is unknown. Studying Chlorobaculum tepidum cultures with far-red to near-infrared light-emitting diodes, we found that these bacteria react to changes in energy flow by regulating the amount of light-absorbing pigments and the size of the chlorosomes. Surprisingly, our results indicate that the bacteria can survive in near-infrared lights capturing low-frequency photons by the intermediate units of the light-harvesting complex. The latter strategy may be used by the species recently found near hydrothermal vents in the Pacific Ocean.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Semion K
authors.initials: SK
authors.lastname: Saikin
authors.affiliation: School of Chemistry and Biochemistry, Clark University, Worcester, MA 01610-1477, USA.
authors.forename: Yadana
authors.initials: Y
authors.lastname: Khin
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Joonsuk
authors.initials: J
authors.lastname: Huh
authors.affiliation: Department of Physics, Clark University, Worcester, MA 01610-1477, USA.
authors.forename: Moataz
authors.initials: M
authors.lastname: Hannout
authors.affiliation: School of Chemistry and Biochemistry, Clark University, Worcester, MA 01610-1477, USA.
authors.forename: Yaya
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Chemistry and Biochemistry, Clark University, Worcester, MA 01610-1477, USA.
authors.forename: Farrokh
authors.initials: F
authors.lastname: Zare
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Alán
authors.initials: A
authors.lastname: Aspuru-Guzik
authors.affiliation: School of Chemistry and Biochemistry, Clark University, Worcester, MA 01610-1477, USA.
authors.forename: Joseph Kuo-Hsiang
authors.initials: JK
authors.lastname: Tang
mesh_terms: D000064:Acclimatization; D001429:Bacteriochlorophylls / Q000235:genetics / Q000378:metabolism*; D019414:Chlorobi / Q000235:genetics / Q000254:growth & development*; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000235:genetics; D015388:Organelles / Q000235:genetics / Q000378:metabolism; D010140:Pacific Ocean; D010788:Photosynthesis / Q000235:genetics; D011157:Population Dynamics
chemical_list: D001429:Bacteriochlorophylls; D045342:Light-Harvesting Protein Complexes