By comparing with sequences in the Genbank database , the sequences retrieved from the ARDRA clusters were assigned to12 genera encompassing five classes of bacteria : rhizobium , sphingomonas and Bosea (class Alphaproteobacteria): Achromobacter (class Bataproteobacteria);Panteoa , Serratia , Pseudompnas and xanthonas (class Gammaproteobacteria); Bacillus and Paenibacillus (class bacilli); microbacterium and micrococcus (class actinobacteria.)