Consumption of MTBE and gaseous n-alkanes during cell growth on n-pentane. A series of cultures of P. mendocina KR-1 were grown in sealed glass serum vials (125 ml) containing mineral salt medium (25 ml) with either n-pentane alone (87 μmol) or with n-pentane (87 μmol) and either MTBE (16.8 μmol), methane, ethane, propane, or n-butane (44.6 μmol of each gas). Each of the cultures was conducted in duplicate. Gas phase samples (25 μl) were removed at the indicated times and were analyzed by GC as described in Materials and Methods. The figure shows the time course of n-pentane consumption (open symbols) and supplementary substrate consumption (solid symbols) for the cultures grown with n-pentane plus MTBE (□, ▪); n-pentane plus methane (▵, ▴); n-pentane plus ethane (▿, ▾); n-pentane plus propane (⋄, ♦); n-pentane plus n-butane (○, •); and n-pentane alone (*). The symbols represent the mean value of each data set for the duplicate cultures, while the error bars show the range of values for the data for the duplicate cultures.