Title Patterns of Survival and Volatile Metabolites of Selected Lactobacillus Strains During Long-Term Incubation in Milk
Author Łucja Łaniewska-Trokenheim, Magdalena Olszewska*, Marta Mikš-Krajnik, and Anna Zadernowska
Address Chair of Industrial and Food Microbiology, Faculty of Food Science, University of Warmia and Mazury, Pl. Cieszyński 1, PL-10-726 Olsztyn, Poland
Bibliography Journal of Microbiology, 48(4),445-451, 2010,
DOI
Key Words Direct Epifluorescent Filter Technique, CFDA staining, gas-chromatography, L. acidophilus, L. crispatus
Abstract The focus of this study was to monitor the survival of populations and the volatile compound profiles of selected Lactobacillus strains during long-term incubation in milk. The enumeration of cells was determined by both the Direct Epifluorescent Filter Technique using carboxyfluorescein diacetate (CFDA) staining and the plate method. Volatile compounds were analysed by the gas-chromatography technique. All strains exhibited good survival in cultured milks, but Lactobacillus crispatus L800 was the only strain with comparable growth and viability in milk, assessed by plate and epifluorescence methods. The significant differences in cell numbers between plate and microscopic counts were obtained for L. acidophilus strains. The investigated strains exhibited different metabolic profiles. Depending on the strain used, 3 to 8 compounds were produced. The strains produced significantly higher concentrations of acetic acid, compared to other volatiles. Lactobacillus strains differed from one another in number and contents of the volatile compounds.