Fig. 3

Growth of Z. mobilis strain S912 in different biogas slurry mediums which are listed in Table 1. a The growth curves of S912 in the biogas slurry medium with different pH values as follows: pH 3.5 (Orange square), pH 4.5 (Blue circle), pH 5.5 (Gray up-triangle), pH 6.5 (Pink cross), pH 7.5 (Yellow diamond), pH 8.5 (Green star), pH 9.5 (Purple down-triangle). b The growth curves of S912 in the biogas slurry medium with different initial glucose concentrations as follows: 50 g/L (Orange square), 75 g/L (Blue circle), 100 g/L (Gray up-triangle), 125 g/L (Pink cross), 150 g/L (Yellow diamond), 175 g/L (Green star). c The growth curves of S912 in the biogas slurry medium with 1.0 g/L KH₂PO₄ (Blue up-triangle), 1.0 g/L H₃PO₄ (Orange circle), or without addition (Gray square). d The growth curves of S912 in the biogas slurry medium with different initial NH⁴⁺-N concentrations as follows: 178 ± 2 mg/L (Yellow square), 647 ± 4 mg/L (Gray circle), 1059 ± 8 mg/L (Orange triangle), 1487 ± 1 mg/L (Green cross), 1911 ± 6 mg/L (Blue diamond). Growth was determined by measuring OD₆₀₀ value. The 10% (v/v) inoculum cells were used for all batch cultivations. The biogas slurry was sterilized using a 0.22 μm filter membrane. All fermentations were conducted in 150-mL flask contains 100-mL biogas slurry medium at 30 °C without shaking. All fermentations were carried out in triplicate. Error bars show standard deviation (n = 3)