title: Chlorophyll f-driven photosynthesis in a cavernous cyanobacterium.
abstract: Chlorophyll (Chl) f is the most recently discovered chlorophyll and has only been found in cyanobacteria from wet environments. Although its structure and biophysical properties are resolved, the importance of Chl f as an accessory pigment in photosynthesis remains unresolved. We found Chl f in a cyanobacterium enriched from a cavernous environment and report the first example of Chl f-supported oxygenic photosynthesis in cyanobacteria from such habitats. Pigment extraction, hyperspectral microscopy and transmission electron microscopy demonstrated the presence of Chl a and f in unicellular cyanobacteria found in enrichment cultures. Amplicon sequencing indicated that all oxygenic phototrophs were related to KC1, a Chl f-containing cyanobacterium previously isolated from an aquatic environment. Microsensor measurements on aggregates demonstrated oxygenic photosynthesis at 742 nm and less efficient photosynthesis under 768- and 777-nm light probably because of diminished overlap with the absorption spectrum of Chl f and other far-red absorbing pigments. Our findings suggest the importance of Chl f-containing cyanobacteria in terrestrial habitats.
authors: 1] Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark [2] Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark [3] Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen N, Denmark.
authors: Lars
authors: L
authors: Behrendt
authors: Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors: Asker
authors: A
authors: Brejnrod
authors: Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales, Australia.
authors: Martin
authors: M
authors: Schliep
authors: Section of Microbiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
authors: Søren J
authors: SJ
authors: Sørensen
authors: Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales, Australia.
authors: Anthony W D
authors: AW
authors: Larkum
authors: 1] Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark [2] Plant Functional Biology and Climate Change Cluster, University of Technology Sydney, Sydney, New South Wales, Australia.
authors: Michael
authors: M
authors: Kühl
mesh_terms: D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics; D000077194:Chlorophyll A; D002965:Classification; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D017753:Ecosystem; D008027:Light; D046529:Microscopy, Electron, Transmission; D010100:Oxygen / Q000737:chemistry; D010788:Photosynthesis; D010858:Pigmentation; D019265:Spectroscopy, Near-Infrared; D014871:Water Microbiology
chemical_list: C583352:chlorophyll f; D002734:Chlorophyll; D010100:Oxygen; D000077194:Chlorophyll A