2. Each individual curve shows the same growth characteristics.

Independent from the inoculum dilutions they reached nearly the same maximum cell concentration. Obviously, the lag time and the maximum growth rate differ from dilutions (DL) in a dependent way. This effect was also described by Baranyi et al. [4] and [6] with a mathematical background. Furthermore, the data lead to the assumption that there exists a minimum lag time with an optimal cell concentration. That means that the lag time cannot be reduced by a further increase of the cell concentration (Fig. 2A). A slight decrease of the cell density within the first hours of the experiments can be noticed (Fig. 2B). This is possible due to a lysis process during the adaptation period of the MOs to the new environment. Also a reduction of the cell density can be detected at the end of the IDH tumor final cell concentration. If the inocula concentration is about ln(N0) = 25 ln(cfu/ml), no increase of OD

is detected (1:2 DL in Fig. 2A and 1:2, 1:4, and 1:8 DL in Fig. 2B). The other DL leads to the same final concentration of strain-1 of about ln(Nmax) = 28.913 ± 0.049 ln(cfu/ml) without lignin and ln(Nmax) = 26.103 ± 0.396 ln(cfu/ml) with 0.4 g/l of lignin. Consequently, a threshold exists for the highest achievable concentration Small molecule library chemical structure depending on the lignin concentration. The parameters of growth characteristics, μm and λ are estimated and the average values are taken. In Fig. 3 an exemplary survey of the parameters for the different inocula dilutions of strain-2 and strain-3 is shown. All parameters show direct dependence

Amoxicillin on the initial inoculum. With increasing inoculum concentration μm, λ, and the differences in the maximum of the achieved cell concentration, Δy shows a decreasing behaviour, as can be expected. In Fig. 3A, a general lower μm of strain-2 compared to strain-3 ( Fig. 3B) is visible. Likewise, strain-2 does not vary much in the value of μm and λ about 0.6 g/l of lignin. Also Δy ( Fig. 3C) is very low and does not indicate any growth. The high cell density only leads to little growth of the microorganisms and might be the reason for the growth impulse at the point of higher inocula. Unexpectedly, strain-2 shows a slightly higher value of μm and also a decrease in lag time concerning 0.2 and 0.4 g/l of lignin. The growth is detected only with higher inoculum concentrations. Strain-3 shows growth on all indicated lignin concentrations, with a steady decrease of μm ( Fig. 3D). The parameter λ of strain-3 ( Fig. 3E) also shows a little variance, just like Δy ( Fig. 3F). As a result of the aspect, it gets clear that the estimated parameter cannot be used directly to distinguish between the capabilities of the MOs to withstand higher concentrations of lignin. A dimensionless parameter α = exp(I − μmλ) is described by by Baranyi [4] and [6] to to quantify the physiological state of an initial population.