A model predictive control (MPC) method was investigated as a route to optimize and control the growth of E. coli BL21 (DE3) and biosynthesis of two different recombinant proteins (nerve growth factor NGF and coat protein of bacteriophage Qβ (Qβ-CP)). To determine the target trajectory for the E. coli cultivation process and estimate the model parameters, the off-line run-to-run optimization method was used. The proven method allowed us to successfully control the growth of microbial biomass, with a deviation of 6–12% from the target trajectory. It was proven that it is possible to obtain a “Golden Batch” profile for the implementation of MPC using datasets from only four to eight fermentation runs. The method showed its robustness when the cultivation of E. coli was carried out with two different titrant supply control systems—volumetric and gravimetric. Furthermore, the MPC method exhibited high adaptability, reliability, and resistance to various types of disturbances. MPC proved to be a reliable and effective method for controlling the cultivation and recombinant protein biosynthesis of fast-growing microorganisms such as E. coli.

There are several ways in which mathematical modeling is used in fermentation control, but mechanistic mathematical genome-scale models of metabolism within the cell have not been applied or implemented so far. As part of the metabolic engineering task setting, we propose that metabolite fluxes and/or biomass growth rate be used to search for a fermentation steady state marker rule. During fermentation, the bioreactor control system can automatically detect the desired steady state using a logical marker rule. The marker rule identification can be also integrated with the production growth coupling approach, as presented in this study. A design of strain with marker rule is demonstrated on genome scale metabolic model iML1515 of Escherichia coli MG1655 proposing two gene deletions enabling a measurable marker rule for succinate production using glucose as a substrate. The marker rule example at glucose consumption 10.0 is: IF (specific growth rate μ is above 0.060 h⁻¹, AND CO₂ production under 1.0, AND ethanol production above 5.5), THEN succinate production is within the range 8.2–10, where all metabolic fluxes units are mmol ∗ gDW⁻¹ ∗ h⁻¹. An objective function for application in metabolic engineering, including productivity features and rule detecting sensor set characterizing parameters, is proposed. Two-phase approach to implementing marker rules in the cultivation control system is presented to avoid the need for a modeler during production.

In this work novel Pd supported on cerium oxide nanocomposites in the liquid phase glycerol oxidation with molecular oxygen was studied. Pd/CeO₂ and Pd-NiO/CeO₂ composites with different Pd loading were prepared using the extractive-pyrolytic method. In the glycerol oxidation processes it was found that Pd/CeO₂ and Pd-NiO/CeO₂ composites are catalytically active. Besides, NiO additives can significantly increase Pd/CeO₂ catalysts’ activity and selectivity to the main product – glyceric acid. Several glycerol oxidation parameters like NaOH initial concentration, glycerol/Pd molar ratio, oxygen pressure and temperature were varied. The best yield of glyceric acid reached 71–75 mol% with full glycerol conversion.

The present research assesses the potential of rapeseed oil soapstock for producing lecithin and its application in the food industry in the context of the circular economy and bioeconomy. The theoretical part summarizes information on the types of lecithin and its production technologies and functional properties, while the empirical part combines semi-structured interviews with 30 experts and company representatives (in Latvia and abroad) and a laboratory experiment with rapeseed soapstock samples. The data provided by the experts were analyzed using descriptive statistics and thematic analysis, while the soapstock samples were tested for dry matter, lipid content, and lecithin and acid oil yield using the techniques of n-hexane Soxhlet extraction and fractionation with cold acetone. The experts’ ratings showed that rapeseed lecithin is technologically competitive with soybean and sunflower lecithin, especially to produce bread, flour confectionery, as well as oil and fat, thereby providing good emulsification capability, texture improvement, and stabilization. The highest potential for the introduction of rapeseed lecithin has been identified in the oil and fat, bread and flour confectionery segments, but wider use is currently hampered by high production costs and lower market visibility. This research demonstrated the practical possibility of isolating lecithin from rapeseed oil soapstock. The laboratory experiment revealed that it is possible to obtain lecithin from rapeseed soapstock in amounts of 1.4–5.2% of the total weight of soapstock (6.2–23.5% of dry matter), which confirmed the usability of rapeseed soapstock as a raw material for lecithin production. The results confirm that the use of rapeseed oil soapstock to produce lecithin can reduce the amount of industrial waste and increase resource efficiency, thus reducing dependence on imported soybean lecithin. Rapeseed lecithin can be found as a sustainable alternative to soybean and sunflower lecithin with potential for oil and fat and bread production.