Fagos de Streptococcus thermophilus en derivados de suero de quesería: ¿nueva problemática para la industria láctea? POSTER

BRIGGILER MARCÓ, M.; MACHADO, N.; QUIBERONI, A.; SUÁREZ, V.

Córdoba

Congreso; VIII Congreso Internacional de Ciencia y Tecnología de Alimentos; 2022

Ministerio de Ciencia y Tecnología (Córdoba)

Fifteen samples of whey protein concentrate (WPC) were tested against thirty-seven commercial Streptococcus thermophilus strains to detect infective bacteriophages. Seventy-three diverse phages were isolated from twelve samples, characterized by using DNA restriction patterns and host range analyses. Sixty-two of them were classified as cos, two as pac and nine as 5093, according to PCR multiplex assays. Phage concentration was greater than 10exp4 PFU/g for 25.3 % of isolated phages. Seven phages showed an unusual wide host range, being able to infect to a high number of the tested strains. Regarding thermal resistance, pac phages were the most sensitive, followed by cos phages, being the most resistant those classified as 5093. All phages survived to pasteurization treatments commonly applied in dairy industry being necessary, at least, 85 °C for 5 min to inactivate them. Results demonstrated that the use, without control, of these whey derivatives as additives in dairy fermentations could be a threat because of the potential phage infection of starter’s strains. In this sense, these phages constitute a pool of new isolates used toimprove the phage resistance of starter cultures applied today in the fermentative industry.