Figure 4.

The degradation of arbutin spiked in soybeans fermented with arbutin-producing B. subtilis strains. (a) The total arbutin content (the total amount of arbutin naturally present in soybeans in addition to spiked arbutin); (b) the relative content of spiked arbutin. Arbutin was added in respective soybean samples at a concentration of 100 mg/kg. The relative content of arbutin was represented as the percentage of spiked arbutin content remaining in fermented or non-inoculated soybeans. □: control without an inoculum, ■: positive control inoculated with B. subtilis KCTC 3135, ▨: experimental samples (mean values). The mean values of striped bars were calculated from different experimental samples inoculated with each of the four B. subtilis strains (B. subtilis CJ 151, TF 207, NT 424, and GJ 614). Values of bars in the same color with different letters (A–E) are significantly different (p < 0.05). Error bars indicate standard deviations determined from duplicate experiments (control and positive control) or different experimental samples (experimental samples).