Organic Stabilization of Extracellular Elemental Sulfur in a Sulfurovum-Rich Biofilm: A New Role for Extracellular Polymeric Substances?

This work shines light on the role of extracellular polymeric substance (EPS) in formation and preservation elemental sulfur biominerals produced by sulfur-oxidizing bacteria. We characterized particles within a Sulfurovum -rich biofilm Frasassi Cave System (Italy). The adopt spherical bipyramidal morphologies, display both stable (α-S 8 ) metastable (β-S crystal structures. Elemental is embedded dense matrix EPS, are surrounded organic envelopes rich amide carboxylic groups. Organic encapsulation presence structures consistent with organomineralization, i.e., stabilization organics, mechanism that has previously been observed laboratory studies. research provides new evidence for important microbial EPS mineral environment. hypothesize organics used bacteria minerals outside cell wall as store chemical energy. energy sources (in form solid electron acceptor) biofilms potential requires further investigation.