요석증은 비뇨기과에서 흔히 관찰되는 질환으로서 30∼50대에 많이 발생하고, 남자가 여자보다 발생빈도가 높고, 좌측보다는 우측이 많으며, 문화가 발달한 나라에서는 상부요로 결석이 많으나 후진국에서는 하부요로 결석이 많다. 결석성분은 수산칼슘, 인산칼슘, 인산마그네슘암모늄, 요산, 시스틴 결석과 그들이 혼합결석으로 분류된다. 병태생리학에 따르면, 결석의 발생원인은 요중의 무기질 농도가 과포화 상태가 되면 결정체핵이 생성된다는 과포화/결정체설, 기질관여설, 억제물질의 결핍설, 에피택시설 등이 있고, 상피소체기능항진중, 과칼슘뇨증, 과요산뇨증, 과수산뇨증, 시스틴뇨증외에도 원위세뇨관 산증, 과비타민 D증, 소화기계 질환이 통계적으로 유의성있게 관여된다는 것이다. 본 연구에서는 미란성 위염 환자 K43에서 화학분석법, 적외선 흡수 분석, image analysis법을 사용하여 재발성 상부요로 결석성분을 분석한 결과 제 2 수산칼슘과 인산칼슘의 혼합결석으로 확인되어고, 혈액화학 검사와 요 검사등 임상검사 성적은 정상치를 유지하고 있었다. 따라서 K43의 재발성 요로결석은 보고된 생성원인이나 인자들에 대한 통계수치와는 연관성이 없었으며 미란성 위염으로부터 영향을 받았다는 증거도 없었다.

Thiobacillus neopolitanus R-10, which produces a active thiosulfate oxidase, was isolated from nightsoil. The optimal culture conditions of Thiobacillus neopolitanus R-10 for the production of enzyme was determined as followed: 0.8% Na2S203, 0.2% KH2P04, 0.2% K2HP04, 0.04% Na2C03, 0.02% MgSO4·7H2O, 2ml trace elements solution, and pH 6.5 at 30℃ and 72hr cultivation. The oxidase was successively purified 83 folds yield by (NH2)2S04 fractionation, DEAE-Cellulose, Sephadex A-50 column chromatogrophy and gel Sephadex G-150 gel filteration with yield of 5.9%. The molecular weight of purified enzyme was estimated to be 43.000 dalton by SDS-polyacrylamide gel electrophoresis and gel filteration column chromatography. The enzyme activity was highest at 40℃ and pH 7.0 The enzyme activity was relatively high by β-mercaptoethanol but strongly inhibited by cysteine.

Continuous deodorization of malodorous sulfur compounds by Thiobacillus neapolitanus R-10 immobilized onto a polypropylene pellet was studied using a column reactor at 30℃. The maximum amounts of immobilized cells was 5.3 g/ℓ polypropylene with 5 × 7.5㎜ in pellet size, and the amounts of immobilized cells in the higher part of the column was as twice as in the lower part. The optimum pH and temperature for removal of dimethyl sulfide were 6.0 and 30℃, respectively. When 5-20 ㎕/ℓ of hydrogen sulfide and methylmercaptan were employed 98% of removal efficiency were achieved. In contrast, lower concentrations of dimethyl sulfide and dimethyldisulfide should be supplied to meet satisfactory deodorization efficiency. The immobilized cell column was successfully operated for the deodorization of mixture of sulfur compounds over 15 days without significant loss of initial activity achieving high efficiency.

Thiobacillus neapolitanus R-10 isolated from sludge of night soil, showed an oxidizing activity on several malodorous sulfur compounds. The microbe successfully utilized hydrogen sulfide(H_2S), methy mercaptan(MM), dimethyl sulfide(DMS) and dimethyldisulfide(DMDS) during the batch culture reaction, of which H_2S was rather rapidly oxidized. To examine the ability for removal of malodorous sulfur compounds, various concentrations of sulfide substrates were supplemented separately to basal medium and their responses were investigated. As the concentration of sulfide was increased, growth was accelerated within three days of cultivation. 2.5mM was the most favorable substrate concentration of sulfide added for all cases tested. However, when the concentration of sulfur compounds were raised over 4mM, they behaved as a growth inhibitor.