S-layer gene as a molecular marker for identification of Lactobacillus helveticus

The paper describes two methods that allow rapid and accurate identificatio n of Lactobacillus helveticus strains based on the nucleotide sequence of t he gene coding for the surface layer (S-layer) protein. The first method is based on a polymerase chain reaction amplification using primers targeting a specific fragment of the S-layer gene. The second method involved a port ion of the S-layer gene of L. helveticus as a probe in a hybridisation lest . The specificity of these protocols was checked for DNA samples isolated f rom various Lactobacillus strains. (C) 2000 Published by Elsevier Science B .V. on behalf of the Federation of European Microbiological Societies.