[en] The near-UV (NUV, 300-400 nm) sensitivity of logarithmically growing Escherichia coli cells of the fatty acid auxotroph K1060 increases with the number of carbon carbon double bonds in the fatty acid used as supplement. Cultures of K1060 grown to stationary phase on unsaturated fatty acids of the same chain length but differing in the number of carbon double bonds per molecule differed only marginally in their NUV sensitivity. The clear NUV-sensitizing effect of increasing double bonds in the fatty acid supplement used to support logarithmic growth implies that the membrane may be an important NUV target only for logarithmically growing cells. Based on these observations, a previous suggestion that inefficient conversion of fatty acids in the membrane to their cyclopropane analogs as an explanation for the NUV-sensitizing effect of the nur mutation on stationary E. coli cell populations must be wrong. (author)