Importance of Sulfide, Polysulfides, and Elemental Sulfur for Abiotic and Biotic Redox Processes in Sulfur-Metal(loid)Systems
type: CreativeWork
description: Sulfur, an ubiquitous element in the environment, occurs in different oxidation states from +6 to -2. Between the thermodynamically stable end members sulfate and sulfide, a variety of intermediate sulfur species exist, examples of which are sulfite, polythionates, thiosulfate, elemental sulfur, and polysulfides. Polysulfides are highly reducing and nucleophilic sulfur chains of the general structure Sn2-(n ≥ 2). Due to their high reactivity and instability, inorganic polysulfide analysis is challenging. Currently, the most reliable analytical approach is derivatization of inorganic polysulfides to form more stable organic polysulfanes, which can be analyzed chromatographically. Intermediate sulfur species in general and polysulfides in particular are assumed to be decisive for a variety of redox transformation processes of metal(loid)s but are only rarely analyzed. The aim of the present study was to investigate the role of sulfide, elemental sulfur, and especially polysulfides for abiotic and biotic redox processes in sulfur-metal(loid) systems. Open questions resulting from previous investigations concerning the interaction of different sulfur species with iron, arsenic, and molybdenum were addressed with special focus on the sulfur speciation. Elemental sulfur disproportionation is among the oldest metabolic pathways in earth’s history and still raises many questions. Growth of microorganisms by elemental sulfur disproportionation was found to depend on the presence of a sulfide scavenger such as ferric iron. In the present study, growth of haloalkaliphilic bacteria by elemental sulfur disproportionation was shown for the first time and was observed both, in the presence of iron, which is in accordance to previous studies, but also in the absence of iron. This was possible due to substantial formation of polysulfides under anoxic and alkaline conditions, which decreased free sulfide concentrations in solution and consequently rendered elemental sulfur disproport…
abstract: Sulfur, an ubiquitous element in the environment, occurs in different oxidation states from +6 to -2. Between the thermodynamically stable end members sulfate and sulfide, a variety of intermediate sulfur species exist, examples of which are sulfite, polythionates, thiosulfate, elemental sulfur, and polysulfides. Polysulfides are highly reducing and nucleophilic sulfur chains of the general structure Sn2-(n ≥ 2). Due to their high reactivity and instability, inorganic polysulfide analysis is challenging. Currently, the most reliable analytical approach is derivatization of inorganic polysulfides to form more stable organic polysulfanes, which can be analyzed chromatographically. Intermediate sulfur species in general and polysulfides in particular are assumed to be decisive for a variety of redox transformation processes of metal(loid)s but are only rarely analyzed. The aim of the present study was to investigate the role of sulfide, elemental sulfur, and especially polysulfides for abiotic and biotic redox processes in sulfur-metal(loid) systems. Open questions resulting from previous investigations concerning the interaction of different sulfur species with iron, arsenic, and molybdenum were addressed with special focus on the sulfur speciation. Elemental sulfur disproportionation is among the oldest metabolic pathways in earth’s history and still raises many questions. Growth of microorganisms by elemental sulfur disproportionation was found to depend on the presence of a sulfide scavenger such as ferric iron. In the present study, growth of haloalkaliphilic bacteria by elemental sulfur disproportionation was shown for the first time and was observed both, in the presence of iron, which is in accordance to previous studies, but also in the absence of iron. This was possible due to substantial formation of polysulfides under anoxic and alkaline conditions, which decreased free sulfide concentrations in solution and consequently rendered elemental sulfur disproport…
author: Lohmayer, Regina
date published: 2015-10-30
date modified: 2026-07-27T18:49:49Z
provider: Universität Bayreuth
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Universität Bayreuth