Figure 2

Alpha-diversity analysis. This figure was produced using R software version 4.1.3 to observe alpha-diversity, representing the diversity of bacterial species within a single spice group such as Curcuma, 7 spice, local spices or thyme. This alpha diversity is observed through its different parameters: the “observed species” (Fig. 2a) gives the number of bacterial species observed in each spice group considered; the chao1 index (Fig. 2b) gives the actual number of bacterial species in the environment based on the previously estimated number; the Shannon index (Fig. 2c), which shows the main differences in the diversity of the spice groups studied, as the higher the index, the greater the diversity; the Simpson index (Fig. 2d), which completes the interpretation of alpha diversity, as it varies between 0 and 1, showing maximum diversity if it tends towards 1 and minimum if it tends towards 0.