16S rRNA gene high-throughput sequencing data revealed lactic acid bacteria diversity during quinoa and amaranth sourdough fermentation

Abstract

Quinoa (Chenopodium quinoa) and amaranth (Amaranthus caudatus) are ancestral Andean grain having high nutritional value (balanced composition of essential amino acids, minerals and vitamins) and gluten-free (GF) characteristic. Thus, there is an emergent market for new bakery products manufactured using GF grains, in particular for celiac people. In this work, two Quinoa flours, commercial Yin Yang (Dietética Científica, Buenos Aires, Argentina; QY) and natural Real Hornillos (CAUQUEVA, Jujuy, Argentina; QR), and commercial amaranth flour (Sturla, Buenos Aires, Argentina) were used in the preparation of spontaneous laboratory sourdoughs. Samples taken at each backslopping stage: 0 (dough), 2, 3, 6, 8 and 10 (sourdough) days of fermentation were subject to High Throughput Sequencing (HTS) analysis using the Illumina HTS technology. The taxonomical assignment showed that the 99.4% of sequences were correctly classified at genus level and 94.4% at the species level. The OTU data were filtered with a cut-off of 99.9%. Results showed that a succession of LAB species occurred during continuous backslopping. Bioinformatics analysis revealed the differential presence of LAB species during two quinoa flour fermentation; at the early stages of QR fermentation, Enterococcus, Lactococcus, Leuconostocs and Lactobacillus species were detected, being Lactobacillus plantarum and Lactobacillus brevis the main species identified at the end of the sampling time. Lactobacillus plantarum dominated largely the QY and Amaranth flour fermentation process; Lactobacillus zeae, Enterococcus casseliflavus and Lactococcus garvie being also identified. Results on the dynamics of autochthonous LAB during laboratory spontaneous Andean grains sourdoughs fermentation will contribute to overcome challenges for GF-fermented products development.