natural overproduction of catalase by kocuria sp. asb 107: extraction and semi-purification

Background and objectives: because of importance of catalase in various industries, efforts have been made to find more suitable bacterial sources for catalase production. kocuria is one of well-known catalase-producing genus. this is the first report about a new catalase-overproducing bacterial strain, kocuria sp. asb 107. materials and methods: kocuria sp. asb 107 had been isolated from abe-siah spring in ramsar in our previous report. the bacterial biomass freezed, thawed and then lysed by three different operations separately: ultrasound, lysing buffer and enzymatic digestion. the crude extract was subjected to ammonium sulfate precipitation (40 and 60% saturation). quality and quantity of the semi-purification was checked by electrophoresis and measuring specific activity, respectively. results: kocuria sp. asb 107 can be lysed by a freeze-thaw stage followed by lysozyme digestion and not by lysing buffer and not by ultrasound. surprisingly specific activity of catalase in crude extract from kocuria sp. asb 107 was measured to be 195, 370 u/mg protein which is too much higher than other bacterial strains. the bacterium showed a relatively long growth curve about 40 hours. semi-purification using ammonium sulfate precipitation was led in an increased specific activity up to about 7×106 u/mg protein implying more than 3.6-fold purification. conclusion: we have showed natural catalase-overproducing ability of kocuria sp. asb 107. yield and purity of catalase from kocuria sp. asb 107 showed great potential in industrial application suggesting the strain as good source for mass production of catalase for treatment of h2o2-containing wastewater in comparison to other bacterial sources.