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

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.