Occurrence of glutamate dehydrogenase isoenzymes during growth of oocystis alga

Journal Article · Fri Jul 01 04:00:00 EDT 1983 · Biotechnol. Bioeng.; (United States)

DOI:https://doi.org/10.1002/bit.260250710· OSTI ID:5229403

Lee, B H; Picard, G A

Oocystis species, a unicellular green alga, contained two glutamate dehydrogenase isoenzymes: one was specific for NADH and the other for NADPH. Activity staining after gel electrophoresis indicated that one component in NADH-GDH was not specific for the cofactor and three components in NADPH-GDH. The optimal concentration of substrate, purification procedure and kinetic properties of both glutamate dehydrogenase (GDH) enzymes in vitro are presented. The kinetics of growth, nutrient removal and enzyme activities of Oocystis growing in waste water showed that ammonia was preferentially utilized over nitrate and the medium was depleted before the maximum population was obtained in indoor culture. There was a sharp increase in NADPH-GDH activity following the exhaustion of ammonia from the medium but NADH-GDH activity remained unchanged. The NADPH-GDH activity at the outset increased exponentially with time in greenhouse culture but then decreased sharply accompanied by a rapid increase in biomass and nitrite concentration. The Km values for ammonia in this algal GDH was high, while glutamate synthase activity was not detected; this suggests that Oocystis may adapt to conditions of ammonia limitation by producing large quantities of NADPH-GDH instead of using glutamate synthase pathway. 32 references

• Research Organization: Agriculture Canada Research Station, St-Jean-sur-Richelieu, Quebec, Canada J3B 6Z8; Univ. Laval, Quebec, Canada G1K 7P4, Dept. de Sciences et Technol des Aliments and Centre de Recherche en Nutrition
• OSTI ID: 5229403
• Journal Information: Biotechnol. Bioeng.; (United States), Journal Name: Biotechnol. Bioeng.; (United States) Vol. 25:7; ISSN BIBIA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ALGAE
BIOCHEMICAL REACTION KINETICS
ENZYME ACTIVITY
ENZYMES
GROWTH
HYDROGEN COMPOUNDS
KINETICS
LIQUID WASTES
MANAGEMENT
MICROORGANISMS
NUTRIENTS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PLANTS
REACTION KINETICS
REMOVAL
UNICELLULAR ALGAE
WASTE MANAGEMENT
WASTE WATER
WASTES
WATER