Figure 5.

Pronounced isotope fractionation indicated rapid glyphosate exchange across the bacterial cell envelope. The carbon isotope fractionation factor (ε¹³C = −4.5 (±0.5)‰) was determined according to the Rayleigh equation (eq 1). The corresponding AKIE_carbon = 1.014 ± 0.003 (see eq 8) was in the range of typical carbon isotope effects. This indicated that the enzymatic isotope fractionation was not masked by mass transfer limitations and that exchange of glyphosate across the cell envelope was comparatively rapid during bacterial degradation by Ochrobactrum sp. FrEM.