Active CO sub 2 transport by the green alga Chlamydomonas reinhardtii

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.89.4.1213· OSTI ID:6638820

Sueltemeyer, D F; Miller, A G; Espie, G S; Fock, H P; Canvin, D T ^[1]

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1. Queen's Univ., Kingston, Ontario (Canada) Univ. of Kaiserslautern (West Germany)

Mass spectrometric measurements of dissolved free {sup 13}CO{sub 2} were used to monitor CO{sub 2} uptake by air grown (low CO{sub 2}) cells and protoplasts from the green alga Chlamydomonas reinhardtii. In the presence of 50 micromolar dissolved inorganic carbon and light, protoplasts which had been washed free of external carbonic anhydrase reduced the {sup 13}CO{sub 2} concentration in the medium to close to zero. Similar results were obtained with low CO{sub 2} cells treated with 50 micromolar acetazolamide. Addition of carbonic anhydrase to protoplasts after the period of rapid CO{sub 2} uptake revealed that the removal of CO{sub 2} from the medium in the light was due to selective and active CO{sub 2} transport rather than uptake of total dissolved inorganic carbon. In the light, low CO{sub 2} cells and protoplasts incubated with carbonic anhydrase took up CO{sub 2} at an apparently low rate which reflected the uptake of total dissolved inorganic carbon. No net CO{sub 2} uptake occurred in the dark. Measurement of chlorophyll a fluorescence yield with low CO{sub 2} cells and washed protoplasts showed that variable fluorescence was mainly influenced by energy quenching which was reciprocally related to photosynthetic activity with its highest value at the CO{sub 2} compensation point. During the linear uptake of CO{sub 2}, low CO{sub 2} cells and protoplasts incubated with carbonic anhydrase showed similar rates of net O{sub 2} evolution.

• OSTI ID: 6638820
• Journal Information: Plant Physiology; (USA), Vol. 89:4; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
CARBON DIOXIDE
MEMBRANE TRANSPORT
CHLAMYDOMONAS
PHOTOSYNTHESIS
CARBON 13
CARBONIC ANHYDRASE
CHLOROPHYLL
FLUORESCENCE
TRACER TECHNIQUES
VISIBLE RADIATION
ALGAE
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON OXIDES
CARBON-OXYGEN LYASES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CHLOROPHYCOTA
ELECTROMAGNETIC RADIATION
ENZYMES
EVEN-ODD NUCLEI
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDRO-LYASES
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
LUMINESCENCE
LYASES
MICROORGANISMS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
PROTEINS
RADIATIONS
STABLE ISOTOPES
SYNTHESIS
UNICELLULAR ALGAE
560300* - Chemicals Metabolism & Toxicology