Silvana Cecilia Ledesma, Irina Kristof, Gisselle Raquel Apud, and Pedro Adrián Aredes-Fernández*
*Facultad de Bioquímica, Química y Farmacia – Universidad Nacional de Tucumán – CONICET, Ayacucho 471, San Miguel de Tucumán/Tucumán/4000, Argentina 
(pedro.aredes@fbqf.unt.edu.ar)

Different species of lactic acid bacteria (LAB) produce biogenic amines (BA) in wine, including histamine and tyramine. A selective isolation of LAB was carried out from four samples of Malbec and Cabernet Sauvignon wines at the end of vinification from two wineries located at the rural district of Colalao del Valle, Tucumán, Argentina. Thirty randomly selected isolates were first screened for histidine and tyrosine decarboxylase. Then, 16S rDNA gene sequencing and typing of the isolates by RAPD-PCR were performed. The detection of the hdc and tdc genes was carried out by PCR. Eleven isolates corresponded to Lacticaseibacillus paracasei species and through RAPD-PCR were grouped into four clusters. One representative strain was selected for the further assays: L. paracasei AT38 (group I), L. paracasei RA39 (group II), L. paracasei RA49 (group III), and L. paracasei AT45 (group IV). The evaluation of BA production was carried out in a laboratory wine inoculated with the selected strains of L. paracasei at a cell concentration of 106 cfu/mL for 96 hrs at 28°C. Quantification of amines was performed using colorimetric methods development in our laboratory. The presence of the hdc gene in two strains and the tdc gene in four strains was demonstrated. L. paracasei AT45 was the main producer strain of BA in wine. This study evidences, for the first time, histamine and tyramine-producing strains of L. paracasei isolated from Argentine wine.

Funding Support: Consejo Nacional de Investigaciones Científicas Y Técnicas (CONICET)