Influence of artisan bakery- or laboratory-propagated sourdoughs on\ud the diversity of lactic acid bacterium and yeast microbiotas

摘要

Seven mature type I sourdoughs were comparatively back-slopped (80 days) at artisan bakery and laboratory levels under constant\udtechnology parameters. The cell density of presumptive lactic acid bacteria and related biochemical features were not affected\udby the environment of propagation. On the contrary, the number of yeasts markedly decreased from artisan bakery to\udlaboratory propagation. During late laboratory propagation, denaturing gradient gel electrophoresis (DGGE) showed that the\udDNA band corresponding to Saccharomyces cerevisiae was no longer detectable in several sourdoughs. Twelve species of lactic\udacid bacteria were variously identified through a culture-dependent approach. All sourdoughs harbored a certain number of\udspecies and strains, which were dominant throughout time and, in several cases, varied depending on the environment of propagation.\udAs shown by statistical permutation analysis, the lactic acid bacterium populations differed among sourdoughs propagated\udat artisan bakery and laboratory levels. Lactobacillus plantarum, Lactobacillus sakei, and Weissella cibaria dominated in\udonly some sourdoughs back-slopped at artisan bakeries, and Leuconostoc citreum seemed to be more persistent under laboratory\udconditions. Strains of Lactobacillus sanfranciscensis were indifferently found in some sourdoughs. Together with the other stable\udspecies and strains, other lactic acid bacteria temporarily contaminated the sourdoughs and largely differed between artisan\udbakery and laboratory levels. The environment of propagation has an undoubted influence on the composition of sourdough\udyeast and lactic acid bacterium microbiotas.