Open AccessMetabolic role and properties of nitrite reductase of nitrate‐ammonifying marine Vibrio species
Author(s) -
Rehr Bert,
Klemme JobstHeinrich
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01551.x
Subject(s) - nitrite , nitrate , nitrate reductase , chemistry , nitrite reductase , chlorate , biochemistry , ammonia , gluconic acid , food science , inorganic chemistry , nuclear chemistry , organic chemistry
Nitrate reduction to ammonia by marine Vibrio species was studied in batch and continuous culture. In pH‐controlled batch cultures (pH 7.4; 50 mM glucose, 20 mM KNO 3 ), the nitrate consumed accumulated to more than 90% as nitrite. Under these conditions, the nitrite reductase (NO − 2 → NH 3 ) was severely repressed. In pH‐controlled continuous cultures of V. alginolyticus with glucose or glycerol as substrates ( D = 0.045 h −1 ) and limiting N‐source (nitrate or nitrite), nitrite reductase was significantly derepressed with cellular activities in the range of 0.7–1.2 μmol min −1 (mg protein) −1 . The enzyme was purified close to electrophoretic homogeneity with catalytic activity concentrations of about 1800 nkat/mg protein. It catalyzed the reduction of nitrite to ammonia with dithionite‐reduced viologen dyes or flavins as electron donors, had an M r of about 50 000 (determined by gel filtration) and contained c‐type heme groups (probably 4–6 per molecule).