Fig 4.

LC-MS chromatograms of R. rubrum lipid extracts. Extracted ion chromatograms are shown for [RQ₁₀ + H]⁺ (m/z 848.7) (left column) and [Q₁₀ + H]⁺ (m/z 863.7) (right column) in five R. rubrum samples (A to E). The retention times of RQ₁₀ and Q₁₀ were approximately 7 and 7.5 min, respectively, under LC conditions outlined in Materials and Methods. (A) ATCC 11170 (WT R. rubrum, grown aerobically); (B) F11 (RQ-deficient R. rubrum mutant, grown aerobically); (C) ATCC 11170 (WT R. rubrum, grown anaerobically); (D) F11::pJRQ1 (pJRQ1-complemented F11, grown anaerobically); (E) ATCC 11170::ΔrquA mutant (knockout mutant, grown aerobically). No RQ₁₀ was found in either F11 or the ATCC 11170::ΔrquA strain.