The Production of Polythionates from Thiosulfate by Microörganisms

Abstract

2 strictly autotrophic sulphur bacteria (Thiobacillus thiooxidans and T. thioparus) and a facultative sp. (T. novellus) formed no polythionates during oxidation of thiosulphate in solution media, nor were they produced by T. thiooxidans from elemental S. Cultures of T. trautweinii, a similar form isolated by the author (B), Pseudomonas fluorescens, P. aeruginosa and Achromobacter hartlebii formed polythionates from thiosulphate. Greater amts. of polythionates were produced in media containing organic materials supporting extensive growth of the bacteria. Numerous other bacteria (including actinomycetes) and fungi tested failed to attack thiosulphate, either in mineral media or in media containing organic substances. Thiosulphate exerted no inhibitive effect on growth of heterotrophic organisms at 1% conc. It is concluded that: The capacity to oxidize thiosulphate to polythionates is common to several heterotrophs; T. trautweinii, which has been called an autotroph, is a strict heterotroph; the appearance of polythionates in media or natural environments, where incompletely oxidized inorganic S materials are undergoing oxidation, probably results from the activity of certain heterotrophic microorganisms which can form polythionates from thiosulphate.