Biofilm Formation and Extracellular Polymeric Substances (EPS) Analysis by New Isolates of <i>Leptospirillum</i>, <i>Acidithiobacillus</i> and <i>Sulfobacillus</i> from Armenia

Abstract

Biofilm formation by new isolates, Leptospirillum sp. strain ZC, Acidithiobacillus sp. strain 61 and Sulfobacillus sp. strain 6 isolated from different biotopes of sulfide ores in Armenia on pyrite was studied by atomic force microscopy (AFM) combined with epifluorescence microscopy (EFM). It was revealed that all the tested species formed monolayer biofilms The results showed that in contrast to Acidithiobacillus sp. strain 61 and Sulfobacillus sp. strain 6, cells of Leptospirillum sp. strain ZC were often observed by clusters and aggregates.The composition of capsular and colloidal EPS formed by isolated Leptospirillum sp. strain ZC, Acidithiobacillus sp. strain 61 and Sulfobacillus sp. strain 6 was studied. It was revealed that the EPS of all three species grown on iron (II) mainly consisted of carbohydrates, proteins as well as uronic acids.

Extracellular Polymeric Substances from Geobacter sulfurreducens Biofilms in Microbial Fuel Cells

“…The named studies indicate the importance of EPSs in BESs and the EET of electroactive microorganisms. However, approaches pointing toward a comprehensive identification and quantification of the EPS and their constituents from cells grown on the electrode in the BES have not been published so far as it has exemplarily been for leaching bacteria. − …”

Bioleaching of Chalcopyrite by a New Strain Leptospirillum ferrodiazotrophum Ksh-L Isolated from a Dump-Bioleaching System of Kashen Copper-Molybdenum Mine

“…EPSs play an essential role in the formation of a biofilm, which mediates the adhesion of cells to the mineral surface and forms a cohesive three-dimensional polymer, interconnecting and immobilizing cells in the process of bioleaching by iron-and sulfur-oxidizing bacteria [74][75][76]. An important role of capsular polysaccharides as a fundamental structural element of the EPS, determining the mechanical stability of biofilm was disclosed.…”

Peculiarities of a Colloidal Polysaccharide of Newly Isolated Iron Oxidizing Bacteria in Armenia

“…The value of α less than 0.06 means that the investigated object is rod-shaped. Previously, we have studied the peculiarities of bioleaching of sulfide minerals by the above-mentioned bacteria, the adhesion on the surface of the mineral, the capsular EPS and the properties of immobilized cells on natural carriers [11,[18][19][20][21]. In continuation of these studies, we set out to study the characteristics of the colloidal polysaccharide produced by L. ferriphilum.…”

“…EPS play an essential role for the formation of a biofilm, which mediates adhesion of cells to the minerals surface and form a cohesive three-dimensional polymer interconnecting and immobilizing cells in the process of bioleaching by iron and sulfur-oxidizing bacteria. An important role of capsular polysaccharides as a fundamental structural element of the EPS, determining the mechanical stability of biofilm was disclosed [8][9][10][11][12].…”