Fig 4. Reversible effect of PABA or PHB on inhibition of CoQ₁₀ production by Bz.

WT PR110 cells were pre-cultivated in 10 mL YES medium for 1 day. Cells at an initial density of ~1×10⁵ cells/mL were cultivated in the presence of 10 or 100 μg/mL Bz, or without Bz, as well as with PABA or PHB, with rotation at 30°C. Gray bars show the CoQ₁₀ content per 50 mL of medium, and white bars show CoQ₁₀ normalized against cell number. Diamonds show cell number. Five micrograms of CoQ₆ was used as an internal standard. Data are represented as the mean ± SD of three measurements. Asterisks on bars denote statistically significant differences (**p<0.01, *p<0.05) relative to the sample in YES with 10 μg/mL Bz (A) or 100 μg/mL Bz (B), calculated by Student’s t-test.