Methylorubrum species are prominent members of the plant phyllosphere, where they are exposed to fluctuating environmental conditions, including intense ultraviolet (UV) radiation. To mitigate such stressors, these bacteria commonly synthesise carotenoids as an oxidative protection. In this study, we investigated the carotenoid production of two closely related methylotrophic strai ns, Methylorubrum extorquens PA1 and AM1 (short PA1 & AM1), with a particular focus on the influence of iron av