Microbial diversity and acidification kinetics of intermediate wheatgrass sourdough as compared to whole wheat

Intermediate wheatgrass (IWG, Thinopyrum intermedium), a perennial wheat, presents environmental benefits as compared to annual wheat. The aim of the present study was to investigate metabolite kinetics, microbial counts and dynamics, and characterization of the microbial diversity over time of spontaneously fermented IWG (two cultivars) and whole wheat (WW) sourdoughs. Vmax was achieved between 32 and 40h of fermentation for all substrates, with significant differences between the two IWG cultivars. IWG fermentations achieved a higher final total titratable acidity compared to whole wheat. The fermentation quotient and lactic acid production were also found to be higher for IWG, in agreement with initial higher microbial population enumeration. Microbial community compositions changed over time and based on the initial substrate used for sourdough, with an increasing abundance of LAB by the end of the fermentation. The principal coordinate analysis (PCoA) indicated microbial composition differences between WW and IWG samples, with greater diversity and abundance observed in IWG. Resistance genes analysis revealed the presence of qacG and tetM only on day 7 in IWG (cultivar K7) samples. This study highlights the potential application of IWG as a novel substrate in sourdough fermentation.