Sulphur oxidation by fluorescent pseudomonads isolated from ground nut rhizospheric soil and their variability in sulphate production

This study was conducted to identify sulphur oxidizing ability of fluorescent pseudomonads isolated from groundnut rhizosphere of Rayalaseema districs of Andhra Pradesh and evaluate their sulphur oxidation ability. Out of the 55 (JS1 …. JS55) isolates obtained, 14 were screened based on their efficacy to reduce the pH of the growth medium from 8.0 to ≤ 5.0. The selected isolates were characterized and related to the genus pseudomonas. Their sulphate ion production abilities were in the range of 5mg/ml – 60 mg/ml. JS7, JS16, JS24, JS40, JS49 and JS54 gave the lowest pH and the highest total sulphate in liquid medium after one week. These isolates were checked for optimum growth conditions for efficient sulphur oxidation and their ability to produce sulphate ion. In glucose amended medium broth, bacterial strains JS7 and JS16 produced maximum sulphates i.e. 55.22 mg/ml and 53.14 mg/ml compared to other sugars.