Thiosulphate broth (composition given below) was used for enrichment of Sulphur oxidizing media. After incubation (30 degree centigrade temp.) of 15 days the pH and color of the medium changes showing growth of Sulphur oxidizing bacteria (SOB). But I was unable to get the isolated colonies present in the broth on all the media I have tried (Nutrient agar,Thiosulphate agar medium with indicator and Starkely agar medium)

thiosulphate broth ;contained 5.0 g Na2S2O3,

0.1 g K2HPO4, 0.2 g NaHCO3, 0.1 g NH4Cl in

1000 ml distilled water, with pH 8.0. Bromo

cresol purple was the indicator used