Biomaterial Database

Nitrogenase activity of immobilized Azotobacter vinelandii. 1979

E Seyhan, and D J Kirwan

As part of a program to investigate the use of biological nitrogen fixation for fertilizer ammonia production, an investigation into the immobilization of the aerobic, nitrogen-fixing bacterium, Azotobacter vinelandii was undertaken. Immobilization was acaccomplished by adsorption onto an anionic exchange cellulose (Cellex E) with loadings as high as 10'' cells/g resin. Immobilized cell preparations were tested under both batch and continuous-flow conditions. Nitrogenase activities as high as 4200 nmol/min g resin were observed as measured by the acetylene reduction assay. Immobilized cells retained their activity for as long as 117 hr in a continuous-flow reactor. Activity loss appeared to be related to the development of a variant strain.

UI	MeSH Term	Description	Entries
D007475	Ion Exchange Resins	High molecular weight, insoluble polymers which contain functional groups that are capable of undergoing exchange reactions (ION EXCHANGE) with either cations or anions.	Ion Exchange Resin,Exchange Resin, Ion,Exchange Resins, Ion,Resin, Ion Exchange,Resins, Ion Exchange
D009591	Nitrogenase	An enzyme system that catalyzes the fixing of nitrogen in soil bacteria and blue-green algae (CYANOBACTERIA). EC 1.18.6.1.	Dinitrogenase,Vanadium Nitrogenase,Nitrogenase, Vanadium
D010084	Oxidation-Reduction	A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).	Redox,Oxidation Reduction
D000114	Acetylene	The simplest two carbon alkyne with the formula HCCH.	Ethyne
D000327	Adsorption	The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.	Adsorptions
D001395	Azotobacter	A genus of gram-negative, aerobic bacteria found in soil and water. Its organisms occur singly, in pairs or irregular clumps, and sometimes in chains of varying lengths.