In many cases in industrial biotechnology, substrate costs make up a major part of the overall production costs. One strategy to achieve more cost-efficient processes in general is to exploit cheaper sources of substrate. Small organic acids derived from fast pyrolysis of lignocellulosic biomass represent a significant proportion of microbially accessible carbon in bio-oil. However, using bio-oil for microbial cultivation is a highly challenging task due to its strong adverse effects on microbial growth as well as its complex composition. In this study, the suitability of bio-oil as a substrate for industrial biotechnology was investigated with special focus on organic acids. For this purpose, using the example of the genetically engineered, non-pathogenic bacterium Pseudomonas putida KT2440 producing mono-rhamnolipids, cultivation on small organic acids derived from fast pyrolysis of lignocellulosic biomass, as well as on bio-oil fractions, was investigated and evaluated. As biosurfactants, rhamnolipids represent a potential bulk product of industrial biotechnology where substitution of traditional carbon sources is of conceivable interest. Results suggest that maximum achievable productivities as well as substrate-to-biomass yields are in a comparable range for glucose, acetate, as well as the mixture of acetate, formate and propionate. Similar yields were obtained for a pretreated bio-oil fraction, which was used as reference real raw material, although with significantly lower titers. As such, the reported process constitutes a proof-of-principle for using bio-oil as a potential cost-effective alternative carbon source in a future bio-based economy.

The upscaling of pea protein extraction from laboratory scale with a centrifuge to pilot scale with a decanter centrifuge was investigated, and the pea protein extraction efficiency from dry milled and pre-treated peas was compared. Upscaling from laboratory to pilot scale is possible since starch was under the limit of detection (< 0.5%). The protein banding pattern of a sodium-dodecyl-sulfate polyacrylamide gel electrophoresis confirmed that albumins and globulins were extracted by alkali extraction. Protein yield increased from 59.5% to 67.1% for dry milled peas due to constant and quick discharge of dry matter in the decanter centrifuge. For pre-treated peas, the protein yield increased from 60.3% to 94.3%, which is explained by an improved cutting and improved separation in pilot scale compared to laboratory scale. The impact of acceleration, mass flow, differential speed and their respective interactions in the decanting process was determined with a design of experiments. For dry milled peas, only the mass flow exceeded the significance level. However, a mass flow of 5 kg h−1, an acceleration of 1000 g$$\times$$ × and a differential speed of 50 min−1 led to the highest protein yield of 75.6%. The obtained protein yields for the pre-treated peas were in the range of 83 to 96% and therefore did not show significant differences in protein yield.