JOURNAL OF
CULTURE COLLECTIONS
Volume 4, 2004-2005,
pp. 61-67
Characteristics of bacterial strain,
superoxidE dismutase producer, isolated from Bulgarian thermal spring
Ivanka Bojadzhieva and Elka Emanuilova*
Institute of Microbiology, Bulgarian Academy of
Sciences
Acad. G. Bonchev str., bl. 26, 1113 Sofia,
Bulgaria
Summary
Twenty one bacterial strains with superoxide dismutase activity were
isolated from samples (flowing spring water, water with soil particles, alga
bacterial mad and mud) collected near different thermal Bulgarian springs. The
strains were Gram positive, rod shaped, spore forming and moderate
thermophiles. Isolate M 20 showed the highest specific total superoxide
dismutase activity of 530 U/mg in shaken flasks cultivation at 55 oC
for 4 hours. An activity of 1300 U/mg was achieved after
selection and optimization of cultivation procedures in fermentor. The optimal
enzyme activity of cell free extract was at 55 oC and pH 8.0,
and the half-life was 30 min at 90 oC. The strain was catalase
positive, it produced peroxidase and proteinase. As a result of morpho-logical,
cultural, physiological and biochemical characteristics the isolate M 20 was
determined as a moderate thermophile belonging to the genus Bacillus.