DYNAMICS AND CHARACTERIZATION OF A YEAST POPULATION FROM AN ITALIAN FERMENTED SAUSAGE

Yeast populations of twenty-one samples of an Italian fermented sausage were investigated during ripening in a pilot-scale chamber. Samples were analyzed in three manufacturing steps: fresh product (0 days), sausage after 15 days of maturation and finished product (60 days). In addition, 100 yeast strains were isolated and identified to the species level using a morphological and biochemical characterization procedure. With regard to the yeast population dynamics, the counts increased 1.15 log CFU/g (2.75 to 3.90) during the ripening process. Pichia carsonii (33%) was the most frequently isolated species, followed by Candida lipolytica (anamorph of Yarrowia lipolytica) (13%), Candida japonica (anamorph of Filobasidium capsuligenum) (9%), Debaryomyces hansenii (8%), Geotrichum candidum (anamorph of Galactomyces geotrichum) (7%), Pichia etchellsii (6%) and Lodderomyces elongisporus (5%). D. hansenii was the only yeast species found in all the stages of the manufacturing process.