Effect of light on fermentation and development of photosynthetic cells. Progress report, March 1, 1984-July 1, 1985

Technical Report · Mon Jul 01 00:00:00 EDT 1985

OSTI ID:5501369

Gibbs, M

Intact Chlamydomonas cells ferment their starch in the dark to formate, acetate and ethanol in the ratios of 2:1:1 coupled to the evolution of H/sub 2/. Light causes an increase in H/sub 2/ but acetate and ethanol are minor products. On the addition of an uncoupler, acetate is produced while the presence of a plastoquinone antagonist restores ethanol formation. The latter is interpreted in terms of a chloroplastic respiratory pathway. Acetate is photoassimilated by Chlamydomonas cells under N/sub 2/ to CO/sub 2/ and H/sub 2/ with a stoichiometry indicating a light-dependent anaerobic glyoxylate cycle as the primary assimilatory route prior to conversion to lipid and carbohydrate. Isolated Chlamydomonas chloroplasts can fix CO/sub 2/ at rated between 25 to 50 micromole/mg chlorophyll per hour. The aerobically isolated chloroplasts can be adapted to a hydrogen metabolism. They can evolve H/sub 2/ (as compared to the whole cell), photoreduce CO/sub 2/ with H/sub 2/ and reduce methyl viologen at rates between 5 to 6 (15 to 20), 1.5 (4.5), 18 to 50 (35 to 100) micromole/mg chlorophyll per hour. The chloroplasts cannot perform the oxyhydrogen reaction. A Pasteur effect was detected in all algae tested. (DT)

• Research Organization: Brandeis Univ., Waltham, MA (USA)
• DOE Contract Number: AC02-76ER03231
• OSTI ID: 5501369
• Report Number(s): DOE/ER/03231-1; ON: DE85014757
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
PHOTOSYNTHESIS
BIOCHEMISTRY
AMYLASE
ANAEROBIC CONDITIONS
CHLAMYDOMONAS
CHLOROPLASTS
FERMENTATION
PHOSPHOTRANSFERASES
TEMPERATURE DEPENDENCE
ALGAE
BIOCONVERSION
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHEMISTRY
ENZYMES
GLYCOSYL HYDROLASES
HYDROLASES
MICROORGANISMS
O-GLYCOSYL HYDROLASES
PHOSPHORUS-GROUP TRANSFERASES
PHOTOCHEMICAL REACTIONS
PLANTS
SYNTHESIS
TRANSFERASES
UNICELLULAR ALGAE
140505* - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)