Api 50 chl galleries

The metabolism of several carbohydrates by sourdough LAB strains was determined by using API 50 CHL galleries (BioMérieux, Marcy-l’Etoile, France) according to the manufacturer instructions. Gas production was detected by Durham tube method [37 ] in MRS broth (Biolife, Milan, Italy) for 24 h at 30 °C. The growth performance of strains was monitored at 10, 30, 37 and 45 °C for 24 h in an MRS broth using a Thermo Bioscreen C automatic turbidometer (Labsystems, Helsinki, Finland). The viability of the isolated strains to grow in acidic environments was evaluated in MRS broth acidified to a final pH of 2.5 with HCl (Biolife, Milan, Italy) in tubes, according to Lee et al. [38 (link)]. Total viable counts were determined by using standard plate count techniques [39 ]. The results were expressed as log of colony-forming units (CFU) per milliliter. All phenotype analyses were carried out in triplicate.

Carbohydrate fermentation reactions were recorded using API 50 CHL galleries (BioMe´rieux, Marcy l’Etoile, France), according to the manufacturer’s instructions. Readings (changes in colour from violet) were monitored after 24 and 48 hr at 30°C. Positive results were marked as ˮ+ˮ or ˮ+/-ˮ, where ˮ+ˮ denoted a complete change to yellow and ˮ+/-ˮ partial change (closer to yellow, than to violet). Esculin hydrolysis (revealed by a change to a darker colour or black) was represented by a positive sign (+).