Original paper

Optimization of molecular techniques applied to the taxonomy of epilithic Leptolyngbya strains

Bruno, Laura; Billi, Daniela; Albertano, Patrizia B.


Leptolyngbya strains VRUC135 and CSC7-1, isolated from biofilms present in Roman hypogea, were employed as experimental strains to optimize molecular techniques to approach the taxonomy of different epilithic strains of Leptolyngbya, maintained in our laboratory. High quality genomic DNAs were obtained according to the CTAB method, while low quality DNAs were obtained with the hot phenol method. High quality DNAs were used in gradient PCRs to optimize annealing temperatures for 16S-23S rRNA operon amplification and genomic PCR fingerprinting, with primers derived from HIP1, STRR, and LTRR sequences. At the optimized conditions, no significant differences in PCR products were observed using as template low quality DNAs. The employment of both molecular approaches suggested that Leptolyngbya VRUC135 and CSC7-1 are different species: the partial sequence of 16S rRNA gene from Leptolyngbya CSC7-1 showed 91.6% nucleotide identity with the 16S rRNA gene of Leptolyngbya VRUC135, and both strains exhibited a high genetic diversity when typed with HIP1, STRR, and LTRR PCR fingerprinting.


leptolyngbyadna extraction16s-23s rrna operongenomic pcr-fingerprinting