Characterization of a hyperthermophilic sulphur-oxidizing biofilm produced by archaea isolated from a hot spring

Emky Valdebenito-Rolack, Nathaly Ruiz-Tagle, Leslie Abarzúa, Germán Aroca, Homero Urrutia

Laboratorio de Biopelículas y Microbiología Ambiental, Centro de Biotecnología, Universidad de Concepción, Concepción, Chile.

Abstract

Background

Sulphur-oxidizing microorganisms are widely used in the biofiltration of total reduced sulphur compounds (odorous and neurotoxic) produced by industries such as the cellulose and petrochemical industries, which include high-temperature process steps. Some hyperthermophilic microorganisms have the capability to oxidize these compounds at high temperatures (> 60°C), and archaea of this group, for example, Sulfolobus metallicus, are commonly used in biofiltration technology.

Results

In this study, a hyperthermophilic sulphur-oxidizing strain of archaea was isolated from a hot spring (Chillán, Chile) and designated as M1. It was identified as archaea of the genus Sulfolobus (99% homology with S. solfataricus 16S rDNA). Biofilms of this culture grown on polyethylene rings showed an elemental sulphur oxidation rate of 95.15 ± 15.39 mg S l^-1 d^-1, higher than the rate exhibited by the biofilm of the sulphur-oxidizing archaea S. metallicus (56.8 ± 10.91 mg l^-1 d^-1).

Conclusions

The results suggest that the culture M1 is useful for the biofiltration of total reduced sulphur gases at high temperatures and for other biotechnological applications.

Keywords: Biofilms on polyethylene; Biofiltration; Cellulose industries; Denaturing gradient gel electrophoresis extremophile; Hyperthermophile; Industrial gas emissions; Petroleum refinery; Sulfolobus; Sulphide; Sulphur-oxidizing archaea; Sulphur-oxidizing microorganisms.