Effect of organic forms of phosphorus and variable concentrations of sulfide on the metabolic generation of soluble-reactive phosphate by sulfur chemolithoautotrophs: A laboratory study

Abstract

In aquatic systems, recycling of phosphorus (P) is strongly influenced by microbial metabolic responses. This study was designed to look at the generation of P (as soluble-reactive phosphate (SRP)) from organic P-enriched sediments by benthic sulfur chemolithoautotrophs. The study revealed that microbial density was greater in organic P-enriched sediments when compared to sediments without added organic P and the presence of organic P significantly influenced mobilization of SRP from sediment. Generation of SRP by sediment microbes was cumulative, dependent on time. The results indicated dissolved sulfide (S 2) to be necessary for initiation of the metabolism-related mobilization of P: there was no statistically significant effect of variations in ambient concentrations of sulfide (S2). The results elucidate possible outcomes of addition of organic P in aquatic ecosystems. © 2007 International Society for Microbial Ecology All rights reserved.