Investigation of catalase activities from some thermophilic bacteria

Investigation of Catalase Activities from Some Thermophilic Bacteria In this study, the capacity of some thermophilic species that were isolated by a research group in the Department of Biology of K.T.U. to produce catalase, an industrial enzyme, was investigated, and some kinetic parameters and spectroscopic properties of these catalase enzymes were determined. The catalase-producing ability of these thermophilic species was explored by petri test and native electrophoresis. The catalases were shown to posses considerably high activity. The catalase activity of Bacillus thermosphaericus A3 (A3) was found to be especially high and this species appears to be a good industrial source of this enzyme. The catalases of all the species exhibited the highest activity at pH 7.0. The catalases of A3, Anoxybacillus ayderensis Ay9 (Ay9), Saccharococcus caldoxylolyticus TK4 (TK4), Anoxybacillus gonensis A9 (A9), Anoxybacillus gonensis A5 (A5), and Anoxybacillus gonensis A6 (A6) were found to be stable at a wide pH range. Although its activity was lower than that of other species used in the investigation, the catalase of A2 species was both more thermophilic and more alkalophilic. hi addition, the catalases of Ay9, TK4, Anoxybacillus kestanbolensis Kl (Kl), and A5 preserved their activity up to 50 °C. The affinity of the catalases for H2O2 substrate was in the order A3>TK4>A9>Ay9>A5>A4>K4>A2>Kl>A6. Inhibition studies showed that all the catalases were inhibited almost to 100% by 0.5 mM NaN3, KCN and HgCk, The catalases obtained from ten species having the highest activity were observed to give Soret peak between 408-417 nm showing the heme group, and the reduction of these catalases yielded a-band and P-band peaks around 520-550 nm. In conclusion, the thermophilic species tested in this study were found, because of their high catalase activity, to be a potential source of catalase for the industries utilizing hydrogen peroxide.Key words: Catalase, hydrogen peroxide oxidoreductase, thermophilic bacteria