Biofilm formation analysis and molecular identification of copper-resistant bacteria isolated from PT Freeport Indonesia’s tailings

Abstract

Copper is an essen al macronutrient for living organisms. Nevertheless, at high concentra ons, it is toxic to most forms of life, including microorganisms. In this research, we examined the biofilm forma on ability and iden fied the molecular characteris cs of copper-resistant bacteria isolated from PT Freeport Indonesia's tailings. Four bacteria isolates from PT Freeport Indonesia's tailings were used in this study. Qualita ve analysis of biofilm forma on by copper-resistant bacteria was performed using the Scanning Electron Microscopy (SEM) method and Micro ter Plate Biofilm Assay. The results showed that the C53 isolate could be categorized as a strong biofilm former, and three other isolates (C38, C40, and C43) as medium biofilm formers. The iden ty of the selected isolates was based on 16S rRNA gene sequence analysis: C38 isolate had a 99% similarity to Bacillus cereus strain HM85, C43 isolate had a 99% similarity to Bacillus sub lis strain EN16, C40 isolate had a 99% similarity to Lycinibacillus fusiformis strain MB52, and C53 isolate had a 98% similarity to Pseudomonas aeuruginosa strain GGRJ21. The capability of the C53 isolate to form strong biofilm can be exploited in bioremedia on processes aiming to remove copper from tailings.