Isolation and Characterization of a Hydrogen Sulfide-Removing Bacterium, Pseudomonas sp. Strain DO-1

Five microbial strains that removed hydrogen sulfide (H2S) or methylmercaptan (CH3SH) gas were newly isolated from soil samples. Strain DO-1, one of the isolates, was identified as a member of Pseudomonas sp., and it’s immobilized cells removed 1 or 10 ppm of H2S gas within 2 hours. When strain DO-1 was cultured aerobically in a flask containing nutrient broth medium, the deodorizing activity increased, depending on the growth of the culture, and the maximum activity was obtained after 48 hours. Even though the immobilized cells were stored at 4 or 25°C in sealed bottles for 6 months, the deodorizing activity remained. Throughout this study, strain DO-1 removed H2 S gas without preliminary feeding or exposure to sulfur com-pounds as growth substrates or inducers. These characteristics are advantageous for the deodorization of the malodorous gases surrounding us in daily life.