Inorganic carbon limitation and chemical composition of two freshwater green microalgae

Journal Article · Thu Jan 01 00:00:00 EST 1981 · Appl. Environ. Microbiol.; (United States)

OSTI ID:6603231

Goldman, J C ^[1]; Graham, S J

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1. Woods Hole Oceanographic Inst., MA

Two freshwater Chlorophytes, Chlorella vulgaris and Scenedesmus obliquus, were grown in inorganic carbon-limited continuous cultures in which HCO/sub 3//sup -/ was the sole source of inorganic carbon. The response of the steady-state growth rate to the external total inorganic carbon concentration was reasonably well described by the Monod equation; however, the response to the internal nutrient concentration was only moderately well represented by the Droop equation when the internal carbon concentration was defined on a cellular basis. The Droop equation was totally inapplicable when total biomass (dry weight) was used to define internal carbon because the ratio of carbon to dry weight did not vary over the entire growth rate spectrum. In batch cultures, maximum growth rates were achieved at the CO/sub 2/ levels present in atmospheric air and at HCO/sub 3//sup -/ concentrations of 3 mM. No growth was observed at 100% CO/sub 2/. Both nitrogen uptake and chlorophyll synthesis were tightly coupled to carbon assimilation, as indicated by the constant C/N and C/chlorophyll ratios found at all growth rates. The main influence of inorganic carbon limitation appears to be not on the chemical structure of the biomass, but rather on cell size; higher steady-state growth rates lead to bigger cells.

• DOE Contract Number: AC02-78ET20604
• OSTI ID: 6603231
• Journal Information: Appl. Environ. Microbiol.; (United States), Vol. 41:1
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ALGAE
CHEMICAL COMPOSITION
GROWTH
CARBON
METABOLISM
BIOMASS
CARBON DIOXIDE
CHLOROPHYLL
MATHEMATICS
NITROGEN
NUTRIENTS
PHOTOSYNTHESIS
PRODUCTIVITY
QUANTITY RATIO
SENSITIVITY
UPTAKE
CARBON COMPOUNDS
CARBON OXIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
ENERGY SOURCES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHYTOCHROMES
PIGMENTS
PLANTS
PORPHYRINS
RENEWABLE ENERGY SOURCES
SYNTHESIS
550700* - Microbiology
550500 - Metabolism