Comparative Genomics on A. ferrooxidans recently isolated form Theisen sludge

摘要

Recently we isolated an Acidithiobacillus ferrooxidans Hel18 from Theisen sludge, a bituminous flue dust deposited in slag heaps for decades. Theisen sludge contains heavy metals (zinc, lead, copper, cadmium), metalloids (arsenic) and (toxic) organic compounds. The genome of Hel 18 was sequenced and compared with closely related A. ferrooxidans strains (ATCC 23270~T and 53993~T) and A. ferrivorans SS3. The aim was the investigation of genetic adaptions towards greater heavy metal or toxic organic resistance. Genes for cobalt-zinc-cadmium and copper resistance were present in greater copy numbers. Furthermore, the A. ferrooxidans Hel18 genome contained 11 sections, potentially acquired by gene transfer and including mercury resistance genes. Genes for increased resistance towards toxic organics, however, could not be identified.By BLAST analysis we identified 9 resistance genes being unique for A. ferrooxidans. We performed modified multilocus sequencing analysis (MLSA), which is a viable tool for differentiation of phylogenetic groups within the genus Acidithiobacillus. We could show, that differentiation between A. ferrooxidans and A. ferrivorans is possible with resistance genes as marker for MLSA.