The cost-effective biotechnological production of bulk and platform chemicals as an alternative to petrochemical approaches can only be achieved if previously unused lignocellulose-containing residual biomasses are used as substrates. However, biotechnological use of lignocellulosic substrates requires pretreatment to make them accessible to microorganisms. There are a number of possible methods for digesting biomass and then using it completely or fractionated for biotechnological or chemical processes. However, a disadvantage of all digestion methods is that in addition to the main components that are particularly suitable as microbial substrates, there are often a number of other substances in the digestion that have a toxic or at least negative effect on microbial growth or production. Possible strategies to deal with this problem would be e.g. screening for or generating particularly robust microbial producers that are not negatively affected by the minor components, e.g. by evolution, mutagenesis or genetic engineering methods, or by suitable process control, e.g. continuous, in which the substrate is continuously offered to the microorganisms in diluted form so that growth and production can take place but minor components do not have a negative effect. These strategies are to be tested in the project for their suitability for biotechnological utilization of a very complex side stream using the example of low-temperature carbonization water.