Characterization and purification of acidocin CH5, a bacteriocin produced by Lactobacillus acidophilus CH5

To characterize and to purify a bacteriocin produced by Lactobacillus acidophilus strain with its activity restricted to Gram-positive bacteria.

Native acidocin CH5, a bacteriocin produced by L. acidophilus CH5 an isolate from a dairy starter culture forms in MRS (Oxoid, Basingstoke, UK) broth high-molecular weight aggregates which can dissociate into smaller units (retained by 5 kDa membrane) with higher activity. Acidocin CH5 was purified using combinations of chromatographic methods based on hydrophobic and cation exchange principles and the N-terminal region was sequenced.

Based on our results it is evident that acidocin CH5 belongs, according to bacteriocin classification, to the class II bacteriocins with identical N-terminal amino acid sequence described in the literature previously.

The study has provided further data on bacteriocin acidocin CH5 from class II with wide spectrum of antimicrobial activity atypical for bacteriocins produced by L. acidophilus sharing the same homology.