Figure 4

Assessment of minimal media for Arxula adeninivorans LS3 by measuring respiration rates in shake flask cultures (for operating conditions and media formulation see [25]). Original YMM (black circles), containing poor concentrations of calcium (0.338 mg/L) and iron (0.041 mg/L), led to poor culture respiration rates below 10 mmol/(L*h). Modified YMM* (grey circles) is pH-buffered with MES and contains higher concentrations of calcium (272.8 mg/L) and iron (2.1 mg/L), thus leading to a more vital cultivation as shown by the higher respiration rate of up to 25 mmol/(L*h) and a condensed cultivation time of 24 hours (see drop of respiration, signalling the depletion of the carbon source glucose). SYN6-MES (open circles), containing exceeding nutrient quantities, provided non-limited growth of the culture as shown by the distinct exponential increase of respiration to 45 mmol/(L*h) and an early cease of respiration after only 15 hours, again signalling the depletion of carbon source.