Prospective Life Cycle Assessment of Microbial Sophorolipid Fermentation

Funding Information: This research has been supported by the European Regional Development Fund within the project No. 1.1.1.1/19/A/047 “Sustainable Microbial Valorisation of Waste Lipids into Biosurfactants”. Publisher Copyright: © 2023 by the authors.The biorefinery industry is witnessing a transition from fossil and chemical-based processes to more sustainable practices, with a growing emphasis on using renewable resources. Sophorolipids, a promising group of biosurfactants, present a viable substitute for conventionally produced surfactants. This study focuses on microbial fermentation using yeast and lipid substrate for sophorolipid production. The life cycle assessment (LCA) methodology was employed to identify environmental hotspots of the process and to assess the environmental benefits resulting from the replacement of raw rapeseed cooking oil (base scenario) with waste cooking oil, reduction of process electricity consumption, and increased sophorolipid yield. By compiling scenarios with the lowest environmental impact, a best-case scenario was created. The results revealed that the environmental impact of sophorolipid production could be reduced by 50% in the best-case scenario compared to the base scenario. This research provides valuable insights into the environmental optimization of the fermentation process and through the application of LCA highlights the potential for the reduction of negative environmental impact of sophorolipid production, contributing to the ongoing transition from petroleum oil and petrochemical refineries to sustainable biorefineries.Peer reviewe

Catalyst materials based on plasma-processed alumina nanopowder

A platinum catalyst for glycerol oxidation by molecular oxygen has been developed applying the extractive-pyrolytic method and using, as a support, a fine alumina powder with an average particle size of 30-60 nm processed by plasma technology. The extractive-pyrolytic method (EPM) allows affixing small amounts of catalytic metals (1-5%) with the particle size ranging from several nanometers to several tens of nanometers onto the surface of the support. The prepared material - 4.8 wt. % platinum on nano-sized alumina - can be used as a catalyst for glycerol oxidation by oxygen with conversion up to 84%, in order to produce some organic acids (glyceric and lactic acid) with a selectivity of about 60%

Selective liquid phase oxidation of glycerol to glyceric acid over novel supported Pt catalysts

Several supported platinum catalysts were prepared by extractive-pyrolytic method for the selective glyceric acid production from glycerol. Al2O3, Y2O3, Lu2O3, ZrO2-Y2O3 TiO2, SG, Fe2O3, γ-AlO(OH) and C were used as catalyst supports, glycerol oxidation was carried out in the alkaline solutions and oxygen was used as oxidant. The optimal catalyst preparation parameters and glycerol oxidation conditions to obtain glyceric acid were determined. The best result (selectivity to glyceric acid 57% with glycerol conversion 92%) was achieved in the presence of 4.8%Pt/Al2O3 catalyst

Crypthecodinium cohnii Growth and Omega Fatty Acid Production in Mediums Supplemented with Extract from Recycled Biomass

Crypthecodinium cohnii is a marine heterotrophic dinoflagellate that can accumulate high amounts of omega-3 polyunsaturated fatty acids (PUFAs), and thus has the potential to replace conventional PUFAs production with eco-friendlier technology. So far, C. cohnii cultivation has been mainly carried out with the use of yeast extract (YE) as a nitrogen source. In the present study, alternative carbon and nitrogen sources were studied: the extraction ethanol (EE), remaining after lipid extraction, as a carbon source, and dinoflagellate extract (DE) from recycled algae biomass C. cohnii as a source of carbon, nitrogen, and vitamins. In mediums with glucose and DE, the highest specific biomass growth rate reached a maximum of 1.012 h−1, while the biomass yield from substrate reached 0.601 g·g−1. EE as the carbon source, in comparison to pure ethanol, showed good results in terms of stimulating the biomass growth rate (an 18.5% increase in specific biomass growth rate was observed). DE supplement to the EE-based mediums promoted both the biomass growth (the specific growth rate reached 0.701 h−1) and yield from the substrate (0.234 g·g−1). The FTIR spectroscopy data showed that mediums supplemented with EE or DE promoted the accumulation of PUFAs/docosahexaenoic acid (DHA), when compared to mediums containing glucose and commercial YE

Optimization of Synthetic Media Composition for Kluyveromyces marxianus Fed-Batch Cultivation

The Kluyveromyces marxianus yeast recently has gained considerable attention due to its applicability in high-value-added product manufacturing. In order to intensify the biosynthesis rate of a target product, reaching high biomass concentrations in the reaction medium is mandatory. Fed-batch processes are an attractive and efficient way how to achieve high cell densities. However, depending on the physiology of the particular microbial strain, an optimal media composition should be used to avoid by-product synthesis and, subsequently, a decrease in overall process effi-ciency. Thus, the aim of the present study was to optimise the synthetic growth medium and feeding solution compositions (in terms of carbon, nitrogen, phosphorous, magnesium, and calcium concentrations) for high cell density K. marxianus fed‑batch cultivations. Additionally, the biomass yields from the vitamin mixture and other macro/microelements were identified. A model predictive control algorithm was successfully applied for a fed-batch cultivation control. Biomass growth and substrate consumption kinetics were compared with the mathematical model predictions. Finally, 2‑phenylethanol biosynthesis was induced and its productivity was estimated. The determined optimal macronutrient ratio for K. marxianus biomass growth was identified as C:N:P = 1:0.07:0.011. The maximal attained yeast biomass concentration was close to 70 g·L-1 and the 2-PE biosynthesis rate was 0.372 g·L−1·h−1, with a yield of 74% from 2-phenylalanine

Pichia pastoris growth—coupled heme biosynthesis analysis using metabolic modelling

Abstract Soy leghemoglobin is one of the most important and key ingredients in plant-based meat substitutes that can imitate the colour and flavour of the meat. To improve the high-yield production of leghemoglobin protein and its main component—heme in the yeast Pichia pastoris, glycerol and methanol cultivation conditions were studied. Additionally, in-silico metabolic modelling analysis of growth-coupled enzyme quantity, suggests metabolic gene up/down-regulation strategies for heme production. First, cultivations and metabolic modelling analysis of P. pastoris were performed on glycerol and methanol in different growth media. Glycerol cultivation uptake and production rates can be increased by 50% according to metabolic modelling results, but methanol cultivation—is near the theoretical maximum. Growth-coupled metabolic optimisation results revealed the best feasible upregulation (33 reactions) (1.47% of total reactions) and 66 downregulation/deletion (2.98% of total) reaction suggestions. Finally, we describe reaction regulation suggestions with the highest potential to increase heme production yields