Screening and characterization of Geobacillus strains for bioremediation

Geobacillus are a genus of thermophilic bacteria isolated from various geothermal areas often under harsh environmental conditions and attract industrial interest as sources for thermostable enzymes that can be potentially used for bioremediation and other industrial processes. Some Geobacillus species have been found to be able to degrade or tolerate a variety of pollutants in wastewater and oil contaminated soil, such as heavy metals, arsenate, azo dyes, phenols, and aliphatic hydrocarbons. Previous studies focused on evaluation of one or several Geobacillus species for the ability to remediate a single type of pollutants. No systematic characterization has been done and the mechanisms at the molecular level are not clear. In this work, different assays are developed to screen and characterize a collection of 150 Geobacillus strains obtained from Bacillus Genetic Stock Center for their ability to degrade various hydrocarbons and polysaccharide and their tolerance to different heavy metals. The ones with excellent remediation ability are being sequenced to identify the genes responsible for these features and elucidate the underlying pathways and mechanisms, which will provide the basis for engineering and improving these strains for better bioremediation.