Amplified rDNA Restriction Analysis and Further Genotypic Characterisation of Metal-Resistant Soil Bacteria and Related Facultative Hydrogenotrophs

The level of genotypic relationship between czc+soil bacteria mainly resistant to zinc (but also to various other metals), and related facultative hydrogenotrophs previously assigned to the genera Alcaligenes, Ralstonia, and Burkholderiawas evaluated using ARDRA (Amplified Ribosomal DNA Restriction Analysis). The analysis included 44 strains isolated from harsh industrial environments in sediments, soils and wastes with high content of heavy metals. These strains were selected by their ability to grow in the presence of high concentrations of multiple heavy metals and to hybridise with czcor nccprobes. The czcoperon confers resistance to cadmium, zinc and cobalt in strain Ralstonia eutrophaCH34. The nccoperon confers resistance to nickel, cobalt and cadmium in strain 31A known as Alcaligenes xylosoxidans.