The Relationship between the Characteristics of some Cations and Anions and Sulfur-Oxidizing Activity by Microorganisms in Aerosol and Rainwater

Abstract

We investigated the relationship between ionic concentrations and the sulfuroxidizing activity of microorganisms in aerosols and rainwater . Aerosol and rainwater samples were collected in Niigata City over a period of one and four years, respectively. Aerosol and rainwater were examined for microbial sulfur -oxidizingactivity in pH 4.0, 6.0 and 3.5 culture medium which contained sodium thiosulfate as anenergy source. The sulfur-oxidizing activity was measured as thiosulfate consumptionand sulfuric acid formation . We found high concentrations of Ca²⁺ and NH₄⁺ and lowconcentrations of Na+ and SO₄^2- in the aerosol component from December to May.Little sulfur-oxidizing activity by microorganis was found in the aerosol .Highly significant correlations were shown between the nss-SO₄^2-- and nss-Ca²⁺concentrations in the autumn and spring rainwater . In rainwater, we suggest 2 typesof sulfur-oxidizing microorganisms one of which oxidizes thiosulfate to sulfate in theculture media of pH 6 and pH 3.5 while the other is able to oxidize thiosulfate but notto sulfate in the same media with pH 6.For rainwater which had the higher sulfur-oxidizing activity in the pH 3.5 and 4.0culture medium, ratio of nss-SO₄^2- to the total-SO₄^2- was high. We investigated the relationship between ionic concentrations and the sulfur oxidizing activity of microorganisms in aerosols and rainwater. Aerosol and rain water samples were collected in Niigata City over a period of one and four years, respectively. Aerosol and rainwater were examined for microbial sulfur -oxidizing activity in pH 4.0, 6.0 and 3.5 culture medium which contained sodium thiosulfate as an energy source. The sulfur-oxidizing activity was measured as thiosulfate consumption and sulfuric acid formation . We found high concentrations of Ca²⁺ and NH₄⁺ and low concentrations of Na⁺ and SO₄^2- in the aerosol component from December to May.Little sulfur-oxidizing activity by microorganis was found in the aerosol. Highly significant correlations were shown between the nss-SO₄^2-- and nss-Ca²⁺ concentrations in the autumn and spring rainwater . In rainwater, we suggest 2 types of sulfur-oxidizing microorganisms one of which oxidizes thiosulfate to sulfate in the culture media of pH 6 and pH 3.5 while the other is able to oxidize thiosulfate but not to sulfate in the same media with pH 6. For rainwater which had the higher sulfur-oxidizing activity in the pH 3.5 and 4.0 culture medium, ratio of nss-SO₄^2- to the total-SO₄^2- was high.