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The use of plastics in a wide range of applications has grown substantially over recent decades, resulting in enormous growth in production volumes to meet demand. Though a wide range of biomass-derived chemicals and materials are available on the market, the production volumes of such renewable alternatives are currently not sufficient to replace their fossil-based analogues due to various factors, in particular cost-effectiveness. Hence, the majority of plastics are still industrially produced from fossil-based feedstocks. Moreover, various reports have clearly raised concern about the plastics that are not recycled at their end-of-life and instead end up in landfills or the oceans. To avoid further pollution of our planet, it is highly desirable to develop recycling processes that use plastic waste as feedstock. Chemical recycling processes could potentially offer a solution, since they afford monomers from which new polymers can be produced, with the same performance as virgin plastics. In this manuscript, the opportunities for using either chemical or biochemical (i.e., enzymatic) approaches in the depolymerization of polycondensation polymers for recycling purposes are reviewed. Our aim is to highlight the strategies that have been developed so far to break down plastic waste into monomers, providing the first step in the development of chemical recycling processes for plastic waste, and to create a renewed awareness of the need to valorize plastic waste by efficiently transforming it into virgin plastics.

Bacterial biomass from existing industrial fermentation and dedicated side-stream fermentation is a relatively unexplored source of sustainable protein with potential consumer appeal. More efficient processing methods and ‘total use’ business cases are expected to emerge in the coming years that will change the bacterial protein landscape dramatically.

Water reuse is one of the possible solutions to prevent depletion of freshwater resources; however, it is often limited by the accumulation of specific ions in the recirculating water. Ion selective desalination technologies can increase the potential for water reuse. Electrodialysis is a water treatment technology that is able to selectively remove ions from water. In order to enhance and further develop the selectivity of the process, a fundamental understanding of the various mechanisms governing multi-ion transport in electrodialysis is essential. In the present study, a theoretical model for multi-ionic (Na+ and K+) mass transport in electrodialysis was developed including ion-water and ion-membrane frictions, and water transport. General properties and the selectivity of ion exchange membranes towards K+ over Na+ ions were experimentally determined and included in the model. The theory was successfully validated for ion flux through the membranes, ion concentrations in the solutions, and water transport by comparing theory with batch-mode electrodialysis experiments. Contributions of different ion transport mechanisms to the selective transport of Na+ and K+ ions were evaluated by model calculations. It was found that electromigration has the largest contribution to ion transport followed by convection, and that diffusion controls the selectivity of ion transport in electrodialysis under constant voltage operation.

Bacterial biomass from existing industrial fermentation and dedicated side-stream fermentation is a relatively unexplored source of sustainable protein with potential consumer appeal. More efficient processing methods and ‘total use’ business cases are expected to emerge in the coming years that will change the bacterial protein landscape dramatically.

Biobutanol, produced by solventogenic bacteria like Clostridium beijerinckii through acetone, butanol, and ethanol (ABE) fermentation, is a promising green alternative to fossil fuels. However, this ABE fermentation suffers drawbacks, such as a relatively low productivity that limits its industrial deployment. Electro-fermentation (EF) can modify the intracellular ratio of oxidized nicotinamide adenine dinucleotide to reduced nicotinamide (NAD+/NADH), a critical factor for butanol synthesis by C. beijerinckii, thus allowing higher product titers (or productivity) to be reached. RESULTS: The present study focuses on glucose-based ABE-EF at laboratory-scale. Three replicate EF reactors (300 mL) were constructed and used to grow C. beijerinckii. Different cathode materials were electrochemically characterized and tested. The effect of voltage application on process productivity was assessed by performing chronoamperometry tests at constant cathode potential (Ecat), ranging from −0,7 to −1,0 V vs Ag/AgCl. These trials were compared with a benchmark ABE fermentation that was performed without voltage application. Poising Ecat at −0,8 V vs Ag/AgCl resulted in the optimal EF scenario. In these conditions, the specific growth rate of bacteria was 73% higher than the benchmark ABE fermentation, with a productivity of 125,6 mg-butanol/L/h, a process yield of 0,15 g-butanol/g-glucose, and a selectivity for butanol of 87% (34%, 25%, and 11% higher than the benchmark fermentation, respectively). The addition of 0,5 mM neutral red as redox mediator in the broth led to a further improvement of butanol productivity (152,9 mg L h−1), requiring a very low energy consumption of 0,02 kWh/kg-butanol to run the EF process. CONCLUSION: Applying EF enhances the ABE fermentation in terms of butanol production, selectivity, and energy consumption.

Seaweeds (macroalgae) are gaining attention as potential sustainable feedstock for the production of fuels and chemicals. This comparative study focuses on the characterization of the microbial production of alcohols from fermentable carbohydrates in the hydrolysate of the macroalgae Laminaria digitata as raw material. The potential of a hydrolysate as a carbon source for the production of selected alcohols was tested, using three physiologically different fermentative microbes, in two main types of processes. For the production of ethanol, Saccharomyces cerevisiae was used as a benchmark microorganism and compared with the strictly anaerobic thermophile Thermoanaerobacterium strain AK17. For mixed production of acetone/isopropanol, butanol, and ethanol (A/IBE), three strictly anaerobic Clostridium strains were compared. All strains grew well on the hydrolysate, and toxicity constraints were not observed, but fermentation performance and product profiles were shown to be both condition- and strain-specific. S. cerevisiae utilized only glucose for ethanol formation, while strain AK17 utilized glucose, mannitol, and parts of the glucan oligosaccharides. The clostridia strains tested showed different nutrient requirements, and were able to utilize glucan, mannitol, and organic acids in the hydrolysate. The novelty of this study embodies the application of different inoculates for fermenting a common brown seaweed found in the northern Atlantic Ocean. It provides important information on the fermentation properties of different microorganisms and pinpoints the value of carbon source utilization when selecting microbes for efficient bioconversion into biofuel and chemical products of interest.

This report contains the main findings of studies carried out by different partners in the context of the TKI project: Valorization of Biomass (Biovalor). The studies were focused on evaluating and testing state-of-the-art technologies for ammonium (NH4+) removal and recovery from different streams: organic residual flows and industrial wastewater. These streams consisted of digester supernatants, i.e., the liquid fraction of digestates, with and without pretreatment, produced at Attero, Loonwerkersbedrijf, van Amstel, Groot Zevert, and Cosun Beet Company. One of the evaluated technologies was transmembrane chemisorption (TMCS), which is used for the recovery of NH4+ in the form of high-purity ammonium salts, e.g., (NH4)2SO4. During TMCS ammonia (NH3) is stripped from the feed stream and recovered in an acid solution as fertilizer. The complexity of the digestates’ matrix—the presence of organic compounds and dissolved salts, among other compounds—in which NH3 is dissolved greatly influences the recovery efficiency of the TMCS process. Therefore, often pretreatment processes are required to efficiently recover NH4+. The application of pressure and electrically driven technologies as pretreatment for TMCS were evaluated. Electrocoagulation was evaluated to improve the quality of digester supernatants by removing COD before membrane filtration processes. Additionally, microfiltration, high-pressure nanofiltration, conventional electrodialysis, and electrodialysis with bipolar membranes were evaluated for the removal of NH4+.

One-carbon (C1) compounds are promising feedstocks for the sustainable production of commodity chemicals. CO2 is a particularly advantageous C1-feedstock since it is an unwanted industrial off-gas that can be converted into valuable products while reducing its atmospheric levels. Acetogens are microorganisms that can grow on CO2/H2 gas mixtures and syngas converting these substrates into ethanol and acetate. Co-cultivation of acetogens with other microbial species that can further process such products, can expand the variety of products to, for example, medium chain fatty acids (MCFA) and longer chain alcohols. Solventogens are microorganisms known to produce MCFA and alcohols via the acetone-butanol-ethanol (ABE) fermentation in which acetate is a key metabolite. Thus, co-cultivation of an acetogen and a solventogen in a consortium provides a potential platform to produce valuable chemicals from CO2. In this study, metabolic modeling was implemented to design a new co-culture of an acetogen and a solventogen to produce butyrate from CO2/H2 mixtures. The model-driven approach suggested the ability of the studied solventogenic species to grow on lactate/glycerol with acetate as co-substrate. This ability was confirmed experimentally by cultivation of Clostridium beijerinckii on these substrates in batch serum bottles and subsequently in pH-controlled bioreactors. Community modeling also suggested that a novel microbial consortium consisting of the acetogen Clostridium autoethanogenum, and the solventogen C. beijerinckii would be feasible and stable. On the basis of this prediction, a co-culture was experimentally established. C. autoethanogenum grew on CO2/H2 producing acetate and traces of ethanol. Acetate was in turn, consumed by C. beijerinckii together with lactate, producing butyrate. These results show that community modeling of metabolism is a valuable tool to guide the design of microbial consortia for the tailored production of chemicals from renewable resources.

The demand for clean label products reveals the vital role fermentation plays in bringing these products to fruition.

Pesticides are used in agriculture to prevent pests. Chlorpyrifos (CHLP) is an insecticide with potentially detrimental effects on humans, bees, and the aquatic environment. Its effects have led to a total ban by the European Union (EU), but outside the EU, CHLP is still produced and used. An indirect lateral flow immunoassay (LFIA) for the detection of CHLP was developed and integrated into a cassette to create a lateral flow device (LFD). Species-specific reporter antibodies were coupled to carbon nanoparticles to create a detector conjugate. Water samples were mixed with a specific CHLP monoclonal antibody and detector conjugate and applied to the LFD. Dose-response curves elicited the detection of low concentrations of CHLP (

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has once more emphasized the urgent need for accurate and fast point-of-care (POC) diagnostics for outbreak control and prevention. The main challenge in the development of POC in vitro diagnostics (IVD) is to combine a short time to result with a high sensitivity, and to keep the testing cost-effective. In this respect, sensors based on photonic integrated circuits (PICs) may offer advantages as they have features such as a high analytical sensitivity, capability for multiplexing, ease of miniaturization, and the potential for high-volume manufacturing. One special type of PIC sensor is the asymmetric Mach–Zehnder Interferometer (aMZI), which is characterized by a high and tunable analytical sensitivity. The current work describes the application of an aMZI-based biosensor platform for sensitive and multiplex detection of anti-SARS-CoV-2 antibodies in human plasma samples using the spike protein (SP), the receptor-binding domain (RBD), and the nucleocapsid protein (NP) as target antigens. The results are in good agreement with several CE-IVD marked reference methods and demonstrate the potential of the aMZI biosensor technology for further development into a photonic IVD platform.

Production of medium chain length polyhydroxyalkanoate (mcl-PHA) up to about 6 g.L−1 was obtained by feeding ethanol to Pseudomonas putida growing in liquid obtained from acidogenic digestion of organic municipal solid waste. Washing the wet, heat-inactivated Pseudomonas cells at the end of the fermentation with ethanol obviated the need of drying the biomass and enabled the removal of contaminating lipids before solvent-mediated extraction of PHA. Using ‘green’ solvents, 90 to near 100% of the mcl-PHA was extracted and purities of 71–78% mcl-PHA were reached already by centrifugation and decantation without further filtration for biomass removal. The mcl-PHA produced in this way consists of 10–18% C8, 72–78% C10 and 8–12% C12 chains (entirely medium chain length), has a crystallinity and melting temperature of ∼13% and ∼49 °C, respectively, and is a stiff rubberlike, colourless material at room temperature.

This paper is the output of a project of the Knowledge-based Programme of the Wageningen University called ‘Nature-Based Solutions for Climate Resilient and Circular Food Systems’. The authors would like to acknowledge funding from the Wageningen University & Research ‘Food Secu- rity and Valuing Water programme’ (KB-35-007-002) and Circular and Climate Neutral’ programme’ (KB-34-007-010), which is supported by the Dutch Ministry of Agriculture, Nature and Food Security., Food systems—encompassing food production, transportation, processing and consump- tion, including food losses and waste—are currently not delivering what is expected or needed to ensure their full contribution to societal well-being and ecological sustainability. In this paper, we hypothesize that nature-based solutions (NBS; solutions that are inspired by, supported by, or copied from nature) can overcome system challenges related to the functioning of the biosphere, society, or economy (including governance arrangements), and support a transition to sustainable climate-resilient food systems. We develop a conceptual framework to assess NBS contributions to such transitions. Three types of NBS are evaluated: intrinsic NBS which make use of existing ecosystems; hybrid NBS which manage and adapt ecosystems; and inspired NBS which consist of newly constructed ecosystems. We show that inspired NBS in particular will increase opportunities to achieve sustainable development in food systems. NBS can facilitate the much-needed transi- tion to a different way of using our natural resources to reach the SDGs by 2030. We identify the knowledge gaps that impede the development of NBS to support a transition towards sustainable, climate-resilient food systems., Wageningen University & Research 'Food Security and Valuing Water programme' KB-35-007-002, Wageningen University & Research Circular and Climate Neutral' programme' - Dutch Ministry of Agriculture, Nature and Food Security KB-34-007-010

Due to low bioavailability of dietary phenolic compounds in small intestine, their metabolism by gut microbiota is gaining increasing attention. The microbial metabolism of theasinensin A (TSA), a bioactive catechin dimer found in black tea, has not been studied yet. Here, TSA was extracted and purified for in vitro fermentation by human fecal microbiota, and epigallocatechin gallate (EGCG) and procyanidin B2 (PCB2) were used for comparison. Despite the similarity in their flavan-3-ol skeletons, metabolic fate of TSA was distinctively different. After degalloylation, its core biphenyl-2,2',3,3',4,4'-hexaol structure remained intact during fermentation. Conversely, EGCG and PCB2 were promptly degraded into a series of hydroxylated phenylcarboxylic acids. Computational analyses comparing TSA and PCB2 revealed that TSA's stronger interflavanic bond and more compact stereo-configuration might underlie its lower fermentability. These insights in the recalcitrance of theasinensins to degradation by human gut microbiota are of key importance for a comprehensive understanding of its health benefits.

PurposeLeafy vegetables may get contaminated with pathogens through the use of irrigation water during open field cultivation. The main control option to prevent this contamination is the use of disinfection technologies that will reduce the pathogenic load of the irrigation water. Several technologies, either chemical or physical, are available for disinfection, which were gathered from the literature and European Union (EU) projects. The purpose of this paper is to prioritise these technologies.Design/methodology/approachA feasibility study was performed to identify the most promising disinfection technology considering 12 different criteria. A two-tier approach was used in which the technologies were first evaluated based on three criteria: legal status, effectiveness and technology readiness level (TRL). Only the technologies that reached pre-set thresholds for these three criteria were then evaluated in the second tier.FindingsThe evaluation showed that the most promising technologies after the tier-2 evaluation were ultrasound, microfiltration, ultraviolet and ozone. The study showed that the followed approach enabled prioritising disinfection technologies allowing for selecting the most promising technologies that can be tested further on a possible application during primary production to prevent possible food safety issues in leafy vegetables.Research limitations/implicationsThe overview is not an exhaustive list of disinfection technologies available rather only those technologies that seemed promising for application in horticulture were addressed. Some technologies may, thus, have been missed. Nevertheless, a total of 12 single and seven combined technologies were evaluated.Originality/valueThis is the first study that uses a structured approach to prioritise a broad range of possible water disinfection technologies for use at primary production.

Theaflavin-3,3'-digallate (TFDG), a bioactive black tea phenolic, is poorly absorbed in the small intestine, and it has been suggested that gut microbiota metabolism plays a crucial role in its bioactivities. However, information on its metabolic fate and impact on gut microbiota is limited. Here, TFDG was anaerobically fermented in vitro by human fecal microbiota, and epigallocatechin gallate (EGCG) was used for comparison. Despite the similar flavan-3-ol skeletons, TFDG was more slowly degraded and yielded a distinctively different metabolic profile. The formation of theanaphthoquinone as the main metabolites was unique to TFDG. Additionally, a number of hydroxylated phenylcarboxylic acids were formed with low concentrations, when comparing to EGCG metabolism. Microbiome profiling demonstrated several similarities in gut microbiota modulatory effects, including growth-promoting effects on Bacteroides, Faecalibacterium, Parabacteroides, and Bifidobacterium, and inhibitory effects on Prevotella and Fusobacterium. In conclusion, TFDG and EGCG underwent significantly different microbial metabolic fates, yet their gut microbiota modulatory effects were similar.

The Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.

Virus-like particles are of special interest as functional delivery vehicles in a variety of fields ranging from nanomedicine to materials science. Controlled formation of virus-like particles relies on manipulating the assembly of the viral coat proteins. Herein, we report a new assembly system based on a triblock polypolypeptide C4-S10-BK12 and -COONa terminated PAMAM dendrimers. The polypolypeptide has a cationic BK12 block with 12 lysines; its binding with anionic PAMAM triggers the folding of the peptide's middle silk-like block and leads to formation of virus-like nanorods, stabilized against aggregation by the long hydrophilic "C" block of the polypeptide. Varying the dendrimer/polypeptide mixing ratio hardly influences the structure and size of the nanorod. However, increasing the dendrimer generation, that is, increasing the dendrimer size results in increased particle length and height, without affecting the width of the nanorod. The branched structure and well-defined size of the dendrimers allows delicate control of the particle size; it is impossible to achieve similar control over assembly of the polypeptide with linear polyelectrolyte as template. In conclusion, we report a novel protein assembling system with properties resembling a viral coat; the findings may therefore be helpful for designing functional virus-like particles like vaccines.

Lactococcus cremoris and L. lactis are well-known for their occurrence and applications in dairy fermentations, but their niche extends to a range of natural and food production environments. L. cremoris and L. lactis produce MKs (vitamin K2), mainly as the long-chain forms represented by MK-9 and MK-8, and a detectable amount of short-chain forms represented by MK-3. The physiological significance of the different MK forms in the lifestyle of these bacterial species has not been investigated extensively. In this study, we used L. cremoris MG1363 to construct mutants producing different MK profiles by deletion of genes encoding (i) a menaquinone-specific isochorismate synthase, (ii) a geranyltranstransferase and (iii) a prenyl diphosphate synthase. These gene deletions resulted in (i) a non-MK producer (ΔmenF), (ii) a presumed MK-1 producer (ΔispA) and (iii) a MK-3 producer (Δllmg_0196), respectively. By examining the phenotypes of the MG1363 wildtype strain and respective mutants, including biomass accumulation, stationary phase survival, oxygen consumption, primary metabolites, azo dye/copper reduction, and proteomes, under aerobic, anaerobic and respiration-permissive conditions, we could infer that short-chain MKs like MK-1 and MK-3 are preferred to mediate extracellular electron transfer and reaction with extracellular oxygen, while the long-chain MKs like MK-9 and MK-8 are more efficient in aerobic respiratory electron transport chain. The different electron transfer routes mediated by short-chain and long-chain MKs likely support growth and survival of L. cremoris in a range of (transiently) anaerobic and aerobic niches including food fermentations, highlighting the physiological significance of diverse MKs in L. cremoris.

Dit rapport kwantificeert mogelijkheden om de afhankelijkheid van soja-producten import voor veevoer (momenteel ongeveer 1800 kton/j sojaproducten per jaar, met daarin ongeveer 720kton eiwit) te verlagen, op basis van binnenlandse productie, met behoud van het huidige volume voedseleiwit productie. Veel ‘nieuwe bronnen’ worden als veelbelovend beschouwd voor verbetering van eiwitproductie. Met ‘verbeteren’ worden echter verschillende vormen bedoeld, zoals verhoging van voedingswaarde voor mens of dier, verbeteren van inzetbaarheid voor voeding of veevoer, ontwikkeling van een aantrekkelijk ‘niche’ product of verhoging van het bulk productiepotentieel. Voor de meeste opties is niet evident hoe groot de daadwerkelijke volume-potentie is, op welke termijn de ontwikkelingen opgeschaald kunnen zijn en welke technische ontwikkelstap en investeringen nog nodig zijn. Dit rapport geeft inzicht in die kwesties waardoor een realistisch perspectief op de mogelijkheden voor bulk productie ontstaat. In deze studie is naast de effecten van inzet van ‘nieuwe bronnen’ voor veevoer ook gekeken naar effecten op eiwitbehoefte als de (voornamelijk plantaardige) nieuwe eiwitbronnen direct worden ingezet voor voeding. Daarvoor hebben we gebruik gemaakt voor een omrekening van voedereiwitten naar voedseleiwitten: we schatten dat 1kg plantaardig voedseleiwit 5 kg veevoeder eiwit verdringt. De resultaten beschrijven primair de volume-potentie om afhankelijkheid van eiwitimport te beperken met instandhouding van totale productie voedingseiwit in Nederland. Hier en daar worden ook duurzaamheidseffecten genoemd en mogelijkheden en belemmeringen van 'nieuwe' eiwitbronnen en circulaire benutting van reststromen, maar die opsomming is niet compleet. De auteurs zijn zich ook bewust dat verschillende opties ook maatschappelijke aanpassingen vragen, maar ook die kwesties vallen buiten de scope van deze kwantitatieve studie. De potenties zijn kwantitatief ingeschat op basis van typische rendement-schattingen (volgens recente literatuur) en beschikbaarheid van biomassabronnen en productiemiddelen in Nederland (afgeleid van literatuur en percentages van landbouwarealen in Nederland). Dit onderzoek is uitgevoerd in opdracht van en gefinancierd door het Ministerie van Landbouw, Natuur en Voedselkwaliteit. De resultaten worden samengevat in onderstaande tabel en de daaropvolgende constateringen en aanbevelingen.

Due to the global need for sustainably produced protein, optimal usage of animal by-product proteins and novel protein sources like insects are being explored. Dry fractionation, an emerging technology, offers significantly lower energy consumptions and no use of chemicals compared to conventional fractionation technologies. This review evaluates the current state and potential of dry fractionation for animal by-products and insects, with respect to characteristics of raw materials, pre-processing methods, milling, and product-oriented process optimisation. The reviewed studies focussed on compound enrichment or fractions with distinct functionalities, rather than in depth product and process optimisation linked to composition and functionality. For animal by-products, optimisation should focus on milling and separation, whereas for insects optimisation should concern the entire process chain. A product portfolio and insight in compositional and functional properties after dry fractionation would allow more efficient use of animal by-product and insect fractions, thereby supporting the protein transition.

The demand for clean label products reveals the vital role fermentation plays in bringing these products to fruition.

Advanced biofuels are produced from renewable resources that comply with stringent sustainability criteria, and lower GHG emissions than fossil fuels. In the BECOOL/BioValue EU-Brazil cooperation project, novel value chains for advanced bioethanol are developed. Second generation (2G) bio-ethanol represents the most important advanced biofuel from sugar streams, but its production costs are higher than those of other fuels, and innovations are needed to improve efficiency and economics of the process. In this work, beech wood pellets were treated using the FABIOLATM technology, an acetone-based low-temperature organosolv fractionation process. This fractionation results in three main product streams: lignin, a high-purity cellulosic pulp and hemicellulose sugars in solution. The cellulosic pulp was enzymatically hydrolysed producing a glucose-rich (C6) stream and the hemicellulose sugar solution (C5) is conditioned for further biological conversion. The C6 and C5 streams obtained were used for fermentation by the yeasts Saccharomyces cerevisiae and Spathaspora passalidarum, respectively. While the C6 stream was readily fermentable, the C5 stream was only fermentable after dilution. Therefore the C5 stream was subjected to detoxification by activated carbon. Detoxified C5 streams showed higher fermentability and the production of bio-ethanol reached approximately 0.3 g bio-ethanol/gram xylose consumed. Fermentation experiments at 10-L scale confirmed the results obtained at laboratory scale. Combining FABIOLATM and detoxification resulted in efficient C6 and C5 utilization for bio-ethanol production., Proceedings of the 30th European Biomass Conference and Exhibition, 9-12 May 2022, Online, pp. 849-850

The aim of the project “More Fuels from Organic Residues” (MOTOR) is to produce advanced biofuels for the transport sectors where electrification or gaseous biofuels will not generate the reduction of their carbon footprint in the short term. In MOTOR, wet lignocellulosic waste streams that do not compete with the food/feed market are used as a feedstock for a smart fermentation process. In the present study, the utilization of paper sludge as substrate for fermentation for production of fuel precursors and subsequent catalytic conversion to fuels at laboratory scale is described. The steps of the process were assessed experimentally, and based on the data generated, a conceptual process is being developed to explore the economic and sustainability aspects of the new value chain for biofuel.. Results show that solubilization of sugars from paper sludge using existing enzyme cocktails is very limited and needs improvement. On the other hand, the catalytic production of fuel from the fermentation products shows promising results in terms of type of products., Proceedings of the 30th European Biomass Conference and Exhibition, 9-12 May 2022, Online, pp. 24-27

This short note was initially prepared as an outline for the project team of the research project ‘Deltas under Pressure’ (DuP) to structure activities and increase impact in the search for possible transition pathways for food systems in a delta environment. The overall aim is to present an overarching framework that clarifies the linkages between the different disciplines in analysing such pathways. This work was supported by the ‘Transition Pathways’ project that is part of the same research programme ‘Food and Water Security’. By placing research in context, the framework helps to increase the impact of research activities as the connections between the different research activities and critical intervention points become evident. The framework might also be helpful for other stakeholders, like policymakers, private sector parties, NGOs, farmers groups, and individuals involved.

Background The use of palm oil for our current needs is unsustainable. Replacing palm oil with oils produced by microbes through the conversion of sustainable feedstocks is a promising alternative. However, there are major technical challenges that must be overcome to enable this transition. Foremost among these challenges is the stark increase in lipid accumulation and production of higher content of specific fatty acids. Therefore, there is a need for more in-depth knowledge and systematic exploration of the oil productivity of the oleaginous yeasts. In this study, we cultivated Cutaneotrichosporon oleaginosus and Yarrowia lipolytica at various C/N ratios and temperatures in a defined medium with glycerol as carbon source and urea as nitrogen source. We ascertained the synergistic effect between various C/N ratios of a defined medium at different temperatures with Response Surface Methodology (RSM) and explored the variation in fatty acid composition through Principal Component Analysis. Results By applying RSM, we determined a temperature of 30 °C and a C/N ratio of 175 g/g to enable maximal oil production by C. oleaginosus and a temperature of 21 °C and a C/N ratio of 140 g/g for Y. lipolytica. We increased production by 71% and 66% respectively for each yeast compared to the average lipid accumulation in all tested conditions. Modulating temperature enabled us to steer the fatty acid compositions. Accordingly, switching from higher temperature to lower cultivation temperature shifted the production of oils from more saturated to unsaturated by 14% in C. oleaginosus and 31% in Y. lipolytica. Higher cultivation temperatures resulted in production of even longer saturated fatty acids, 3% in C. oleaginosus and 1.5% in Y. lipolytica. Conclusions In this study, we provided the optimum C/N ratio and temperature for C. oleaginosus and Y. lipolytica by RSM. Additionally, we demonstrated that lipid accumulation of both oleaginous yeasts was significantly affected by the C/N ratio and temperature. Furthermore, we systematically analyzed the variation in fatty acids composition and proved that changing the C/N ratio and temperature steer the composition. We have further established these oleaginous yeasts as platforms for production of tailored fatty acids.

Boedijn, A.T., Kals, J. en Appelman, W. Peer Reviewers: Van Os, E., Raaphorst, M. en Kuipers, N., november 2022, In deze whitepaper wordt ingegaan op de ontwikkeling van cross-overs: verbindingen tussen ketens waarin uitgaande reststromen van het ene systeem verwaard worden tot grondstoffen voor een ander systeem. Specifiek wordt hier gekeken naar de potentie van een cross-over tussen de glastuinbouw en aquacultuur sectoren. Het onderzoeken van cross-overs tussen teeltsystemen en/of industriële processen is een van de verkenningsroutes in de transitie naar kringlooplandbouw; een essentiële bouwsteen voor een circulaire economie.

The production of biodegradable polymers as coproducts of other commercially relevant plant components can be a sustainable strategy to decrease the carbon footprint and increase the commercial value of a plant. The biodegradable polymer cyanophycin granular polypeptide (CGP) was expressed in the leaves of a commercial tobacco variety, whose seeds can serve as a source for biofuel and feed. In T0 generation in the greenhouse, up to 11% of the leaf dry weight corresponded to the CGP. In T1 generation, the maximum content decreased to approximately 4% dw, both in the greenhouse and first field trial. In the field, a maximum harvest of 4 g CGP/plant could be obtained. Independent of the CGP content, most transgenic plants exhibited a slight yield penalty in the leaf biomass, especially under stress conditions in greenhouse and field trials. After the harvest, the leaves were either Sun dried or ensiled. The resulting material was used to evaluate the extraction of CGP compared to that in the laboratory protocol. The farm-level analysis indicates that the extraction of CGP from tobacco plants can provide alternative income opportunities for tobacco farmers. The CGP yield/ha indicates that the CGP production in plants can be economically feasible depending on the cultivation and extraction costs. Moreover, we analyzed the consumer acceptance of potential applications associated with GM tobacco in four European countries (Germany, Finland, Italy and the Netherlands) and found unexpectedly high acceptance. The production of biodegradable polymers as coproducts of other commercially relevantplant components can be a sustainable strategy to decrease the carbon footprint andincrease the commercial value of a plant. The biodegradable polymer cyanophycingranular polypeptide (CGP) was expressed in the leaves of a commercial tobaccovariety, whose seeds can serve as a source for biofuel and feed. In T0 generation inthe greenhouse, up to 11% of the leaf dry weight corresponded to the CGP. In T1generation, the maximum content decreased to approximately 4% dw, both in thegreenhouse and first field trial. In the field, a maximum harvest of 4 g CGP/plant couldbe obtained. Independent of the CGP content, most transgenic plants exhibited a slightyield penalty in the leaf biomass, especially under stress conditions in greenhouse and fieldtrials. After the harvest, the leaves were either Sun dried or ensiled. The resulting materialwas used to evaluate the extraction of CGP compared to that in the laboratory protocol.The farm-level analysis indicates that the extraction of CGP from tobacco plants canprovide alternative income opportunities for tobacco farmers. The CGP yield/ha indicatesthat the CGP production in plants can be economically feasible depending on thecultivation and extraction costs. Moreover, we analyzed the consumer acceptance ofpotential applications associated with GM tobacco in four European countries (Germany,Finland, Italy and the Netherlands) and found unexpectedly high acceptance.

Seaweed (or macroalgae) produced sustainably at large scale opens opportunities as source of fuels, chemicals and food. The production does not directly compete with terrestrial food production and may make use of anthropogenic sources of carbon dioxide and nitrogen. Seaweed biomass can be transformed into a suitable substrate for fermentation using a biorefinery approach. In this study the entire process of biofuel production from seaweed is described: starting with cultivation and harvest, the seaweed is dried and cut, enzymatically hydrolysed, demineralized, detoxified, and finally fermented into acetone, butanol, and ethanol (ABE). Juvenile Saccharina latissima was directly seeded on AlgaeTex® nets and cultivated in the North East Atlantic off the west coast of Scotland for 6 months. Sun dried seaweed was hydrolysed with different enzymes, looking for optimal glucose release, solid/liquid ratio, and enzyme load. Using Cellic® CTec2 in combination with alginate lyases, approximately 80% of available glucose was released. The hydrolysis was scaled up to 100 L, using only Cellic® CTec2. Part of the hydrolysate was demineralized using ion-exclusion chromatography, removing over 90% of minerals while recovering 92% of glucose and mannitol. A fraction of the demineralized hydrolysate was additionally detoxified using a hydrophobic resin to remove hydrophobic components to a concentration below detection limit. The three hydrolysates (untreated, demineralized, and demineralized followed by detoxification) were used as substrate for ABE production by a newly developed strain of Clostridium acetobutylicum adapted to grow on S. latissima hydrolysate. Demineralization reduced the lag phase of fermentation from 72 h (untreated) to 24–48 h. Further detoxification of the hydrolysate led to immediate fermentation, resulting in a yield of 0.23 ± 0.02 gABE/gsugar similar to control fermentation in control medium (0.19 gABE/gsugar).

To mitigate the climate change impact of aviation, jet fuels from bio-based by-products are considered a promising alternative to conventional jet fuels. Life cycle assessment (LCA) is a commonly applied tool to determine the environmental impacts of bio-jet fuels. This article presents both attributional and consequential LCA models to assess an innovative bio-jet fuel produced from potato by-products in the Netherlands. The two models led to opposite conclusions regarding the overall environmental performance of this bio-jet fuel. The attributional LCA showed that this bio-jet fuel could offer about a 60% GHG emissions reduction compared to conventional jet fuel. In comparison, the consequential LCA estimated either a much lower climate change benefit (5-40%) if the potato by-products taken from the animal feed market are replaced with European animal feed or a 70% increase in GHG emissions if also imported soybean meals are used to replace the feed. Contrasting conclusions were also obtained for photochemical ozone formation. Conversely, the attributional and consequential LCAs agree on acidification, terrestrial eutrophication and depletion of fossil fuels. Although the consequential LCA was affected by higher uncertainties related to the determination of the actual product displaced, it allowed understanding the consequence of additional animal feed production. This process was not included in the system boundaries of the attributional LCA.

A lateral flow test device and method for using same are provided. The device includes epitope test regions having a fragment of an antigenic protein and a full length antigenic protein, and a receptor test region having a receptor for the antigenic protein. Test samples are added to a conjugate pad including free labelled antigenic protein fragments. Neutralising antibodies in the test sample bind to the free labelled antigenic protein, and are detected by the test regions. Binding kinetics and other characteristics of the antibodies can be investigated by monitoring development of label at the test regions, and comparing the same at different test regions. Embodiments describe use for determining antibodies to SARS-CoV-2, using RBD fragments, spike proteins, and human ACE2 receptors, at the respective test regions.

In the published article, an author name was incorrectly written as “Aantoniya Hauerwaas”. The correct spelling is “Antoniya Hauerwaas”. In addition, there was an error in the Funding statement. The correct Funding statement appears below: Funding This publication is part of the project Sustainable Co-Production [053.80.738] of the research programme [ERA-Net Cofund Action under the research and innovation programme Horizon 2020] “Tobacco as sustainable production platform of the natural biopolymer cyanophycin as co-product to oil and protein,” which is partly financed by the Dutch Research Council (NWO), the German Federal Ministry for education and research (BMBF) and by the Argentine government. Finally, the reference for Weisenfeld, U. et al., 2022 was incorrectly written as Weisenfeld, U., Hauerwaas, A., Elshiewy, O., Halder, P., Wesseler, J., Cingiz, K., Broer, I. (2022). Beyond Plastic – a turning point for green biotechnology? Research Policy. It should appear as Weisenfeld, U., Hauerwaas, A., Elshiewy, O., Halder, P., Wesseler, J., Cingiz, K., et al. (2022). Beyond Plastic – a Turning Point for Green Biotechnology? Research paper, under Review. The authors apologize for these errors and state that this does not change the scientific conclusions of the article in any way. The original article has been updated.

Purpose Oral processing behaviour may contribute to individual differences in glycaemic response to foods, especially in plant tissue where chewing behaviour can modulate release of starch from the cellular matrix. The aim of this study was to assess the impact of chewing time of two starch based foods (brown rice and chickpeas) on bolus properties, in vitro starch digestion and postprandial glycaemic excursion in healthy subjects. Methods In a cross-over trial participants (n = 26) consumed two carbohydrates-identical test meals (brown rice: 233 g; chickpeas: 323 g) with either long (brown rice: 41 s/bite; chickpeas: 37 s/bite) or short (brown rice: 23 s/bite; chickpeas: 20 s/bite) chewing time in duplicate while glycaemic responses were monitored using a continuous glucose monitoring device. Expectorated boli were collected, then bolus properties (number, mean area, saliva amylase activity) and in vitro starch digestion were determined. Results Longer chewing resulted in significantly (p chewing time%) than shorter chewing for both foods (brown rice: DH_S%23 s = 84 ± 4% and DH_%S41s = 90 ± 6%; chickpeas: DH_S%20 s = 27 ± 3% and DH_%S37s = 34 ± 5%, p p > 0.05) was found for both meals. Brown rice showed significantly and considerably higher in vitro degree of intestinal starch hydrolysis and glycaemic response (iAUC) than chickpeas regardless of chewing time. No significant correlations were observed between bolus properties and in vitro starch hydrolysis or glycaemic response (p > 0.05). Conclusion Differences in the innate structure of starch based foods (brown rice compared to chickpeas) have a larger effect on postprandial glucose response than differences in mastication behaviour although oral processing behaviour showed consistent effects on bolus properties and in vitro starch digestion. Trial registration ClinicalTrials.gov identifier: NCT04648397 (First posted: December 1, 2020).

Chemicals and materials produced from non-renewable, petrochemical feedstocks contribute greatly to the quality of life we currently enjoy. To ensure that quality of life is maintained in the future, it is imperative that we move towards a circular economy, where care is taken to reuse or recycle materials at their end-of-life and new chemicals and materials are sourced from renewable carbon feedstocks such as biomass. To achieve this transition, efficient conversion methods by which biomass-derived feedstocks can be converted to chemicals are required. The high degree of functionalisation (i.e. high content of oxygen atoms) of biomass-derived feedstocks, makes their conversion by microbial fermentation an interesting option. This article provides an overview of currently available fermentation technologies that have the potential to play a role in the production of biobased bulk chemicals in a circular economy in the period up to 2050. Our focus is primarily on technologies that are sufficiently mature to have been implemented on (at least) industrial pilot scale. In addition to an overview of available technologies, we provide a critical assessment of their potential relevance for use in the production of bulk chemicals in a future circular economy. We conclude that seven fermentation processes for the production of (potential) bulk chemicals have already reached a stage of technological maturity where they are ready to be applied in a circular economy. A number of other processes may reach this stage of maturity in the coming years.

Boedijn, A.T., Kals, J. en Appelman, W. Peer Reviewers: Van Os, E., Raaphorst, M. en Kuipers, N., november 2022

Protein alternatives are crucial for a sustainable food production in future. Cultured meat is presented as a good alternative for consumers who want to be more sustainable but do not wish to change their diet. To validate this sustainability claim, this report evaluates four LCA studies on cultured meat. When comparing overall environmental impact of cultured meat with conventional meat products and other meat substitutes, cultured meat was seen to perform significantly better than beef, favourable to pork, similar to chicken, and worse than plant-based alternatives considering current global average production impacts. It is important to realize that currently no commercial-scale cultured meat facility is operational. All LCA studies modelled a future facility, extrapolating scientific and small-scale facilities. Differences in system boundaries lead to high variability of environmental impact results for cultured meat among reviewed studies. The LCA system boundaries mostly include the cultivation-related processes, while product formulation and distribution are not taken into account. An important technical bottleneck that is not addressed are the large volumes of the fermenters and the extended cultivation times, which will need extraordinary sterility measures. The LCA overview shows that cultured meat production is energy intensive and that energy consumption have the highest contribution in the overall impact. Next, growth medium production showed significant contribution to impact, especially the amino acid production and recombinant protein production for growth factors. Sensitivity analysis of model parameters showed that parameter choices on cell density and medium use impacted the results most. Technically, the cultured meat industry is still very much in development. Obvious improvements that are needed are the reduction in energy, development of scaffolds, and lower medium cost, specifically in developing cheaper plant-based growth factors that are non GMO. Also product development is in its infancy. Cultured meat is part of a movement towards more sustainable meat alternatives that also includes plant-based alternatives, insects and microbial protein. These sources should not be regarded as competition but as complementary products that target different types of consumers. In combination with other meat alternatives, cultured meat can lead to reduced production and consumption of conventional meat.

We analyze selective removal of anions in electrodialysis (ED) from a multicomponent ion mixture where all ions are monovalent, both experimentally, and by a modified theory. The theory makes use of the Nernst-Planck equation to describe transport of ions across ion-exchange membranes in combination with the ion affinity, which is a parameter that accounts for the preference of membrane materials to adsorb one ion more than another. For a mixture of NO3- and Cl- anions, ion affinity was measured in an adsorption experiment, and it was found that NO3- adsorbs more in anion-exchange membranes (AEMs) than Cl-. Faster transport of NO3- relative to Cl- in batch-mode ED experiments is well described by the transport theory, for three types of AEMs that we tested. From analysis of the model, we can derive that membrane selectivity in ED between different anions can be increased further by: i) an increase in the difference in ion affinity of the anions, ii) an increase in the AEM thickness, and iii) a decrease in the charge density of the AEM. The last two strategies go against the general understanding that thin highly charged membranes are in general better for ED. Our proposed strategies follow rigorously from our combined theoretical–experimental study.

Dit rapport kwantificeert mogelijkheden om de afhankelijkheid van soja-producten import voor veevoer (momenteel ongeveer 1800 kton/j sojaproducten per jaar, met daarin ongeveer 720kton eiwit) te verlagen, op basis van binnenlandse productie, met behoud van het huidige volume voedseleiwit productie. Veel ‘nieuwe bronnen’ worden als veelbelovend beschouwd voor verbetering van eiwitproductie. Met ‘verbeteren’ worden echter verschillende vormen bedoeld, zoals verhoging van voedingswaarde voor mens of dier, verbeteren van inzetbaarheid voor voeding of veevoer, ontwikkeling van een aantrekkelijk ‘niche’ product of verhoging van het bulk productiepotentieel. Voor de meeste opties is niet evident hoe groot de daadwerkelijke volume-potentie is, op welke termijn de ontwikkelingen opgeschaald kunnen zijn en welke technische ontwikkelstap en investeringen nog nodig zijn. Dit rapport geeft inzicht in die kwesties waardoor een realistisch perspectief op de mogelijkheden voor bulk productie ontstaat. In deze studie is naast de effecten van inzet van ‘nieuwe bronnen’ voor veevoer ook gekeken naar effecten op eiwitbehoefte als de (voornamelijk plantaardige) nieuwe eiwitbronnen direct worden ingezet voor voeding. Daarvoor hebben we gebruik gemaakt voor een omrekening van voedereiwitten naar voedseleiwitten: we schatten dat 1kg plantaardig voedseleiwit 5 kg veevoeder eiwit verdringt. De resultaten beschrijven primair de volume-potentie om afhankelijkheid van eiwitimport te beperken met instandhouding van totale productie voedingseiwit in Nederland. Hier en daar worden ook duurzaamheidseffecten genoemd en mogelijkheden en belemmeringen van 'nieuwe' eiwitbronnen en circulaire benutting van reststromen, maar die opsomming is niet compleet. De auteurs zijn zich ook bewust dat verschillende opties ook maatschappelijke aanpassingen vragen, maar ook die kwesties vallen buiten de scope van deze kwantitatieve studie. De potenties zijn kwantitatief ingeschat op basis van typische rendement-schattingen (volgens recente literatuur) en beschikbaarheid van biomassabronnen en productiemiddelen in Nederland (afgeleid van literatuur en percentages van landbouwarealen in Nederland). Dit onderzoek is uitgevoerd in opdracht van en gefinancierd door het Ministerie van Landbouw, Natuur en Voedselkwaliteit. De resultaten worden samengevat in onderstaande tabel en de daaropvolgende constateringen en aanbevelingen.

The fatty acid content of microalgae, especially the high content of omega-3 fatty acids such as eicosapentaenoic acid (EPA, C20:5) and docosahexaenoic acid (DHA, C22:6), could enrich eggs when fed to laying hens. Moreover, the properties and bioactive components of omega-3 fatty acids could positively influence the health and production performance of laying hens. In this study, the effects of dried Nannochloropsis limnetica inclusions in diets on yolk omega-3 fatty acid content, laying hen performance, nutrient retention, intestinal morphometry and systemic inflammatory markers were measured. A total of 240 twenty-five-wk-old laying hens were randomly assigned to 5 treatments distributed among 30 pens. Treatment A received the reference diet, while diets in treatments B, C, and D contained the control diet with 1, 2, and 3% microalgae added, respectively. In treatment E, a portion of ingredients of the control diet was replaced with rapeseed meal to induce a mild nutritional challenge, along with an inclusion of 3% microalgae. Compared to the control group the rate of lay increased by approximately 5% (P = 0.039) when birds were fed 2 or 3% microalgae. Furthermore, inclusion of 2 and 3% microalgae resulted in higher feed intake compared to the control group (126, 125, and 119 g/hen/d respectively; P = 0.001). Other performance parameters such as nutrient retention and egg characteristics were not affected by the dietary treatments. The EPA and DHA content of the yolk increased with increasing microalgae inclusion level (P < 0.001). A 2% algal inclusion resulted in 58.3 (EPA) and 603 (DHA) mg per 100 g dry yolk, respectively. Plasma haptoglobin levels of laying hens in both treatments receiving 3% microalgae were almost 3 times lower compared to the control group (1.25 and 1.62 vs. 5.60; P < 0.001), regardless of the inclusion of rapeseed in the diet. Based on these results, it can be concluded that the inclusion of N. limnetica enriches the egg yolk without negatively affecting the performance of laying hens and egg characteristics. Due to the positive effect on feed intake, microalgae in the diet provide nutritional benefits for laying hens. However, the positive effects of microalgae, especially on the health of laying hens, warrants further research.

This research assesses the well-to-tank (WTT) greenhouse gas (GHG) emissions and economic performance of an innovative bio-jet fuel via acetone-butanol-ethanol (ABE) fermentation. Dutch potato by-products from the food processing industry and sugar beets are explored as potential feedstocks. Four product systems differentiated by feedstocks, logistics and centralized/decentralized fermenters are investigated. For both feedstocks, it is found that a centralized large-scale fermentation is preferable to decentralized small-scale fermentation (25–30% less expensive and 5% lower WTT emissions). Once commercialization is reached, the cost and carbon performance of this novel bio-jet fuel could be similar to that of other alcohol-to-jet fuels. Depending on the feedstock and configuration considered, the GHG emission mitigation potential of this novel jet-fuel was estimated between 41% and 52%. To meet the EU RED II 65% GHG reduction criterion, possible options could be using low carbon-intensive processing energy and hydrogen or storing permanently biogenic carbon dioxide from fermentation.