Open AccessTemperature profile of oxygen activation and defense against oxygen toxicity in a psychrophilic member of the Bacteroidaceae
Author(s) -
Bentzen Greta,
Veldkamp Joost,
Larsen Helge
Publication year - 1991
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.1574-6968.1991.tb04725.x
Subject(s) - psychrophile , bacteroidaceae , anaerobic exercise , oxygen , biochemistry , oxidase test , biology , bacteria , oxygen toxicity , catalase , strain (injury) , methanogen , chemistry , microbiology and biotechnology , enzyme , genetics , physiology , organic chemistry , anatomy
The temperature profiles have been determined for O 2 reduction by activating substrates for whole cells and cell extracts of the psychrophilic, obligately anaerobic bacterium, strain B6, belonging to the Bacteroidaceae. The profiles were similar whether the cells were grown at 15 or 1°C, and also for cells harvested in the exponential or stationary phase. The H 2 O producing pyruvate oxidase displayed in cell‐free extracts a considerably higher activity than the H 2 O 2 producing NADH and NADPH oxidases at all temperatures in the range 30–1°C, and characteristically makes up a larger proportion of the total O 2 reduction capacity the lower the temperature. It thus seems that the O 2 scavenging property of the pyruvate oxidase, postulated to be utilized in a defense mechanism against the detrimental effects of the H 2 O 2 producing pyridine nucleotide oxidases, is particularly well adapted to function at the low temperatures of the Barents Sea, from which this obligately anaerobic organism originates.