PURIFICATION AND PROPERTIES OF A SULFIDE-OXIDIZING ENZYME FROM STREPTOMYCES SP. STRAIN SH91

A heterotrophic Streptomyces sp. strain SH91 isolated from pig feces c ompost had the ability to oxidize hydrogen sulfide to odorless substan ces. With several purification steps including ion-exchange and hydrop hobic chromatographies, the hydrogen sulfide oxidizing enzyme was puri fied to a homogeneous form. The molecular mass was estimated to be 37 kDa by SDS-PAGE. The optimum reaction pH and temperature were 6.5 and 30 degrees C, respectively. The enzyme was stable between pH 6.0 and 8 .0 and up to 40 degrees C. The enzyme was activated by Ba2+ Mg2+, and Ca2+ and inhibited by Mn2+, and Al3+. The main product was thiosulfate .