Monitoring structural transformation of hydroxy-sulphate green rust in the presence of sulphate reducing bacteria

Abstract

The activities of bacterial consortia enable organisms to maximize their metabolic capabilities. This article assesses the synergetic relationship between iron reducing bacteria (IRB), Shewanella putrefaciens and sulphate reducing bacteria (SRB) Desulfovibrio alaskensis. Thus, the aim of this study was first to form a biogenic hydroxy-sulpahte green rust GR2(\( {\text{SO}}_{{\text{4}}} ^{{2 - }} \)) through the bioreduction of lepidocrocite by S. putrefaciens and secondly to investigate if sulfate anions intercalated in the biogenic GR2(\( {\text{SO}}_{{\text{4}}} ^{{2 - }} \)) could serve as final electron acceptor for a sulfate reducing bacterium, D. alaskensis. The results indicate that the IRB lead to the formation of GR2(\( {\text{SO}}_{{\text{4}}} ^{{2 - }} \)) and this mineral serve as an electron acceptor for SRB. GR2(\( {\text{SO}}_{{\text{4}}} ^{{2 - }} \)) precipitation and its transformation was demonstrated by using X-ray diffraction (DRX), Mossbauer spectroscopy (TMS) and transmission electron spectroscopy (TEM). These observations point out the possible acceleration of steel corrosion in marine environment in presence of IRB/SRB consortia.