Bacterial diversity in a soil sample collected from uranium mill-tailings called Gittersee and situated near the city of Dresden, Germany, was analysed by using a culture-independent 16S rDNA approach exploiting PCR ampli�cation primers 7F and 1513R. The results were compared with those obtained earlier analysing the same sample by using another primer pair, namely 43F-1404R [1]. The two 16S rDNA approaches demonstrated that Proteobacteria were the most predominant group in the sample, followed by Cytophaga/Flavobacterium/Bacteroides and by Gram positive
bacteria with low and with high G+C content, too. A large number of 16S rDNA sequences from two libraries were identical or almost identical. However, the ratio between the bacterial groups represented in them signifcantly differed.
7F-1513R primer set retrieved in addition to the above mentioned sequences also 16S rRNA genes, those of green non-sulphur bacteria and representatives of AD1 and OP11 divisions. The latter indicates that 7F-1513R primer set seems to be more reliable in analyses of bacterial diversity