EVALUATION OFBIOGENIC AMINES FORMATION BY PROTEOLYTIC ENTEROCOCCI STRAINS ISOLATED FROM RAW DROMEDARY MILKS FROM SOUTHERN ALGERIA OMAR HASSAÏNE 1 , HALIMA ZADI-KARAM and NOUR-EDDINE KARAM Laboratoire de Biologie des Microorganismes et de Biotechnologie Department of Biotechnology, Faculty of Sciences Oran University (Es-sénia), Oran 31000, Algeria Accepted for Publication February 20, 2008 ABSTRACT Twenty-three strains of lactic acid enterococci isolated from dromedary raw milks in Southern Algeria were investigated for their proteolytic activity and ability to produce biogenic amines by decarboxylating amino acids: histidine, tyrosine and ornithine. All strains tested displayed proteolytic activi- ties, but none of them were able to produce detectable biogenic amines in the usual adequate laboratory media, namely, Joosten and Northolt medium and Leuschner medium. Polymerase chain reaction experiments indicate a positive correlation between the absence of the hdc and odc genes and the lack of histamine and putrescine production for all tested strains. By contrast, all strains appeared to possess tdc gene, but no correlation was found with a negative expression of tyrosine decarboxylase. PRACTICAL APPLICATIONS In foods, biogenic amines are mainly generated by decarboxylation of the corresponding amino acids through substrate-specific enzymes of the micro- organisms present in this environment, particularly histidine, tyrosine, lysine, ornithine and arginine, and the capability of enterococci and some other lactic acid bacteria to produce biogenic amines has been described. For this purpose, several qualitative and quantitative methods to determine biogenic amines production by these microorganisms have been developed. There is great interest to identify and to characterize the bacteria strains intended for an industrial use and to verify if they are potentially able to produce biogenic amines in order to prevent it’s synthesis and limit the poisoning risk. 1 Corresponding author. TEL/FAX: +213-41-51-43-91; EMAIL: omar.hassaine@hotmail.com DOI: 10.1111/j.1745-4565.2009.00163.x Journal of Food Safety 29 (2009) 381–393. © 2009, The Author(s) Journal compilation © 2009, Wiley Periodicals, Inc. 381