Open AccessPurification and characterisation of a possible assimilatory nitrite reductase from the halophile archaeon Haloferax mediterranei
Author(s) -
Martı́nezEspinosa Rosa M,
MarhuendaEgea Frutos C,
Bonete Marı́a José
Publication year - 2001
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.1574-6968.2001.tb10550.x
Subject(s) - halophile , nitrite reductase , ferredoxin , nitrite , nitrate reductase , chemistry , biochemistry , nitrate , reductase , enzyme , bacteria , biology , organic chemistry , genetics
The nitrite reductase from the extreme halophilic archaeon, Haloferax mediterranei , has been purified and characterised. H. mediterranei is capable of growing in a minimal medium (inorganic salts and glucose as a carbon source) with nitrate as the only nitrogen source. The overall purification was 46‐fold with about 4% recovery of activity. The enzyme is a monomeric protein of approximately 66 kDa. A pH of 7.5 and high temperatures up to 60°C are necessary for optimum activity. Reduced methyl viologen has been found to be an electron donor as effective as ferredoxin. NADPH and NADH, which are electron donors in nitrite reductases from different non‐photosynthetic bacteria, were not effective with nitrite reductase from H. mediterranei .