Partial Purification and Characterisation of Sulphur Oxidase from Micrococcus sp. and Klebsiella sp. Isolated from Mangrove Soils of Mahanadi River Delta, Odisha, India

摘要

As knowledge of sulphur oxidising bacterial communities in mangrove sediments is very sparse and sulphur oxidizers have wide application such as in treatment of wastewater containing high sulphate levels which causes unwanted H_(2)S production by sulfate reducing bacteria (SRB), oxidation of elemental sulphur to plant available sulphate for plant growth promotion, bio leaching, biocontroling agent etc. Hence, in the present study an attempt has been made to explore the diversity of sulphur oxidizing bacteria from mangroves of Mahanadi delta, Odisha to evaluate their biotechnological potential. Two sulphur oxidising bacteria (SOB-7and SOB-8) were isolated from mangrove soils of Mahanadi river delta, based on the change of colour of the thiosulphate broth medium from purple to colour less by reducing the pH. Based on morphological, biochemical and 16S rRNA gene sequencing the two strains (SOB-7) and (SOB-8) were identified as Klebsiella sp., and Micrococcus sp. respectively. The gene bank accession number of the strains are KR632644 (SOB-7) and KR632643 (SOB-8). The strain Klebsiella sp. and Micrococcus sp showed sulphate ion production ability of 243 mg/ml and 240 mg/ml respectively with decrease in pH from 7.0 to 4.0. Among these two isolates, SOB-8 showed higher sulphide oxidase production ability (126.83 U/ml) than the isolate, SOB-7 (126.0 U/ml). Maximum sulphide oxidase by both the strains were obtained at temperature 45℃, peptone as nitrogen source, thiosulphate concentration of 10 mg/ml. pH 9.0 for the isolate SOB-8 whereas pH 7.0 for the isolate, SOB-7. Partially purified enzyme of both the isolate showed higher activity at same substrate concentration of 1.5mg/ml, but varies with pH and temperature.