Principles, drivers and opportunities of a circular bioeconomy

Co-designing sustainable biochar business models with sub-Saharan African communities for inclusive socio-economic transformation

Smallholder farmers in sub-Saharan Africa (SSA) encounter multiple livelihood challenges. Embracing circular bioeconomy principles, particularly considering agricultural and food processing residues, could enable inclusive, locally led, sustainable development pathways within rural communities. Biochar products are one such example of a bio-based material that can be generated using circular principles and deployed for sustainable community development, including among smallholder farmers. This research leverages empirical evidence from four SSA regions to explore the potential of inclusive and sustainable biochar business models, namely: (i) Northern Region, Ghana, (ii) Yamoussoukro, Côte d'Ivoire, (iii) Casamance, Senegal, and (iv) Western Region, Uganda. Co-creation workshops using the Triple-Layered Business Model Canvas framework were carried out in each region with local stakeholders to evaluate the social, ecological, and economic implications of four locally relevant biochar applications: water filtration, biogas purification, soil amendment, and cooking fuel briquettes. Data was analysed at an aggregate level for all regions and applications. The study describes this consolidated biochar business model and examines the implications for SSA communities. The resulting sustainable bio-based business model can guide value chain actors and policymakers in SSA communities towards rural sustainable development with a better understanding of the needs, opportunities, challenges, and impacts of biochar-based value chain development.

Low-dose ionizing radiation generates a hormetic response to modify lipid metabolism in Chlorella sorokiniana

Algal biomass is a viable source of chemicals and metabolites for various energy, nutritional, medicinal and agricultural uses. While stresses have commonly been used to induce metabolite accumulation in microalgae in attempts to enhance high-value product yields, this is often very detrimental to growth. Therefore, understanding how to modify metabolism without deleterious consequences is highly beneficial. We demonstrate that low-doses (1-5 Gy) of ionizing radiation in the X-ray range induces a non-toxic, hormetic response in microalgae to promote metabolic activation. We identify specific radiation exposure parameters that give reproducible metabolic responses in Chlorella sorokiniana caused by transcriptional changes. This includes up-regulation of >30 lipid metabolism genes, such as genes encoding an acetyl-CoA carboxylase subunit, phosphatidic acid phosphatase, lysophosphatidic acid acyltransferase, and diacylglycerol acyltransferase. The outcome is an increased lipid yield in stationary phase cultures by 25% in just 24 hours, without any negative effects on cell viability or biomass.

A novel approach to identify critical knowledge gaps for food safety in circular food systems

The transition from linear production towards a circular agro-food system is an important step towards increasing Europe's sustainability. This requires re-designing the food production systems, which inevitably comes with challenges as regards controlling the safety of our food, animals and the ecosystem. Where in current food production systems many food safety hazards are understood and well-managed, it is anticipated that with the transition towards circular food production systems, known hazards may re-emerge and new hazards will appear or accumulate, leading to new -and less understood- food safety risks. In this perspective paper, we present a simple, yet effective approach, to identify knowledge gaps with regard to food safety in the transition to a circular food system. An approach with five questions is proposed, derived from current food safety management approaches like HACCP. Applying this to two cases shows that risk assessment and management should emphasize more on the exposure to unexpected (with regards to its nature and its origin) hazards, as hazards might circulate and accumulate in the food production system. Five knowledge gaps became apparent: there's a need for (1) risk assessment and management to focus more on unknown hazards and mixtures of hazards, (2) more data on the occurrence of hazards in by-products, (3) better understanding the fate of hazards in the circular food production system, (4) the development of models to adequately perform risk assessments for a broad range of hazards and (5) new ways of valorization of co-products in which a safe-by-design approach should be adopted.

Piglets performance, nutrient digestibility and gut health in response to feeding Ulva lactuca seaweed supplemented with a recombinant ulvan lyase or a commercial carbohydrase mixture

Ulva lactuca, a green seaweed, may be an alternative source of nutrients and bioactive compounds for weaned piglets. However, it has a recalcitrant cell wall rich in a sulphated polysaccharide - ulvan - that is indigestible to monogastrics. The objective of this study was to evaluate the effect of dietary incorporation of 7% U. lactuca, combined with carbohydrases supplementation (commercial carbohydrase mixture or recombinant ulvan lyase), on growth performance, nutrient digestibility and gut health parameters (morphology and microbiota) of weaned piglets. The experiment was conducted over 14 days using 40 weaned piglets randomly allocated to one of four experimental diets: a control diet based on wheat-maize-soybean meal, a diet with 7% U. lactuca replacing the control diet (UL), a diet with UL supplemented with 0.005% Rovabio® Excel AP, and a diet with UL supplemented with 0.01% of a recombinant ulvan lyase. The dietary treatments had no major effects on growth performance, nitrogen balance and gut content variables, as well as histological measurements. Contrarily, dry matter and organic matter digestibility decreased with dietary seaweed inclusion, while hemicellulose digestibility increased, suggesting a high fermentability of this cell wall fraction independently of carbohydrases supplementation. Some beneficial microbial populations increased as a consequence of enzymatic supplementation (e.g., Prevotella), while seaweed diets as a whole led to an increased abundance of Shuttleworthia, Anaeroplasma and Lachnospiraceae_NK3A20_group, all related with a healthier gut. It also decreased Lactobacillus when compared to controls, which is possibly related to increased bioavailability of seaweed zinc. This study indicates that, under these experimental conditions, up to 7% dietary U. lactuca has no detrimental effect on piglet growth, despite decreasing acid detergent fibre digestibility. Carbohydrases supplementation of Ulva diets is not required at this incorporation level.

Impact of dietary Laminaria digitata with alginate lyase or carbohydrase mixture on nutrient digestibility and gut health of weaned piglets

Laminaria digitata is a brown seaweed rich in prebiotic polysaccharides, mainly laminarin, but its alginate-rich cell wall could compromise nutrient access. Carbohydrase supplementation, such as individual alginate lyase and carbohydrases mixture (Rovabio® Excel AP), could enhance nutrient digestibility and prebiotic potential. This study aimed to evaluate the effect of these enzymes on nutrient digestibility and gut health of weaned piglets fed with 10% L. digitata. Diets did not affect growth performance (P > 0.05). The majority of the feed fractions had similar digestibility across all diets, but the supplementation of alginate lyase increased hemicellulose digestibility by 3.3% compared to the control group (P = 0.047). Additionally, we observed that algal zinc was more readily available compared to the control group, even without enzymatic supplementation (P < 0.001). However, the increased digestibility of some minerals, such as potassium, raises concerns about potential mineral imbalance. Seaweed groups had a higher abundance of beneficial bacteria in colon contents, such as Prevotella, Oscillospira and Catenisphaera. Furthermore, the addition of alginate lyase led to a lower pH in the colon (P < 0.001) and caecum (P < 0.001) of piglets, which is possibly a result of released fermentable laminarin, and is consistent with the higher proportion of butyric acid found in these intestinal compartments. L. digitata is a putative supplement to enhance piglet gut health due to its prebiotic polysaccharides. Alginate lyase supplementation further improves nutrient digestibility and prebiotic potential. These results suggest the potential use of L. digitata and these enzymatic supplements in commercial piglet-feeding practices.

Valorization of non-edible fruit seeds into valuable products: A sustainable approach towards circular bioeconomy

Global imperatives have recently shown a paradigm shift in the prevailing resource utilization model from a linear approach to a circular bioeconomy. The primary goal of the circular bioeconomy model is to minimize waste by effective re-usage of organic waste and efficient nutrient recycling. In essence, circular bioeconomy integrates the fundamental concept of circular economy, which strives to offer sustainable goods and services by leveraging biological resources and processes. Notably, the circular bioeconomy differs from conventional waste recycling by prioritizing the safeguarding and restoration of production ecosystems, focusing on harnessing renewable biological resources and their associated waste streams to produce value-added products like food, animal feed, and bioenergy. Amidst these sustainability efforts, fruit seeds are getting considerable attention, which were previously overlooked and commonly discarded but were known to comprise diverse chemicals with significant industrial applications, not limited to cosmetics and pharmaceutical industries. While, polyphenols in these seeds offer extensive health benefits, the inadequate conversion of fruit waste into valuable products poses substantial environmental challenges and resource wastage. This review aims to comprehend the known information about the application of non-edible fruit seeds for synthesising metallic nanoparticles, carbon dots, biochar, biosorbent, and biodiesel. Further, this review sheds light on the potential use of these seeds as functional foods and feed ingredients; it also comprehends the safety aspects associated with their utilization. Overall, this review aims to provide a roadmap for harnessing the potential of non-edible fruit seeds by adhering to the principles of a sustainable circular bioeconomy.

Carbon reduction and water saving potentials for growing corrugated boxes for express delivery services in China

Corrugated packaging for express grew by 90 times to 16.5 Mt y-1 in China, where 81% of recent global express delivery growth occurred. However, the environmental impacts of production, usage, disposal, and recycling of corrugated boxes under the entire supply chain remain unclear. Here, we estimate the magnitudes, drivers, and mitigation potentials of cradle-to-grave life-cycle carbon footprint (CF) and three colors of water footprints (WFs) for corrugated cardboard packaging in China. Over 2007 to 2021, CF, blue and gray WFs per unit package decreased by 45%, 60%, and 84%, respectively, while green WF increased by 23% with growing imports of virgin pulp and China's waste ban. National total CF and WFs were 21 to 102 folded with the scale effects. Only a combination of the supply chain reconstruction, lighter single-piece packaging, and increased recycling rate can possibly reduce the environmental footprints by 24 to 44% by 2035.

Knowledge gaps on how to adapt crop production under changing saline circumstances in the Netherlands

Salinization, the increase and accumulation of salts in water and soil, impacts productivity of arable crops and is exacerbated by climate change. The Netherlands, like several other deltas and semi-arid regions, faces increasing salinization that negatively impacts agriculture and freshwater availability. Although a lot of salinity expertise exist in the Netherlands, several knowledge gaps on the impact of salinization in the Netherlands, as well as steps to facilitate closing this knowledge gaps to improve saline agriculture in the Netherlands, still exist. This review/opinion article moves beyond existing papers on salinization in bringing together various adaptation measures by thoroughly reviewing the measures through a triple P (People, Planet, Profit) lens. Five main salinity adaptation measures of the crop-soil-water continuum are 1) breeding and selection of salt tolerant varieties, 2) increased cultivation of halophytes, 3) soil management interventions, 4) use of biostimulants, and 5) irrigation techniques. These adaptation measures are described, discussed and analysed for their compliance to the sustainable development elements People, Planet and Profit. All five adaptation measures have potential positive impact on livelihood, contribute to food security and generate revenue but on the other hand, these measures may contribute to unwarranted changes of the ecosystem. The paper ends with a concluding chapter in which the bottlenecks and knowledge gaps that need resolving are identified based on the critical, including triple P, assessment of the discussed adaptation measures. Three key knowledge gaps on breeding, agronomy, environmental sciences and socioeconomics are identified with several approaches that lead to insights elucidated. Thereby informing on future research and action plans to optimize implementation of salinity adaptation measures in the Netherlands.

Interventions to increase circularity and reduce environmental impacts in food systems

Applying specific circularity interventions to the food system may have environmental benefits. Using an iterative linear food system optimisation model (FOODSOM), we assess how changes in human diets, imports and exports, and the utilisation of waste streams impact land use and greenhouse gas emissions (GHG). After including these circularity principles, land use and GHG emissions were on average 40% and 68% lower than in the current food system, primarily driven by a reduction in production volumes and a shift towards feeding the domestic population. Shifting from the current diet to a circular diet decreased land use with 43% and GHG emissions with 52%. Allowing up to half of each nutrient in the human diet to be imported, while balancing imports with equal exports in terms of nitrogen, phosphorus and potassium, also decreased land use (up to 34%) and GHG emissions (up to 26%) compared to no imported food. Our findings show that circularity interventions should not be implemented mutually exclusively; by combining a circular diet with imported food and fully utilising waste streams, the lowest land use and GHG emissions can be realised.

Hybrid Amyloid-Chitin Nanofibrils for Magnetic and Catalytic Aerogels

In the quest for a sustainable and circular economy, it is essential to explore environmentally friendly alternatives to traditional petroleum-based materials. A promising pathway toward this goal lies in the leveraging of biopolymers derived from food waste, such as proteins and polysaccharides, to develop advanced sustainable materials. Here, we design versatile hybrid materials by hybridizing amyloid nanofibrils derived by self-assembly of whey, a dairy byproduct, with chitin nanofibrils exfoliated from the two distinct allomorphs of α-chitin and β-chitin, extracted from seafood waste. Various hydrogels and aerogels were developed via the hybridization and reassembly of these biopolymeric nanobuilding blocks, and they were further magnetized upon biomineralization with iron nanoparticles. The pH-phase diagram highlights the significant role of electrostatic interactions in gel formation, between positively charged amyloid fibrils and negatively charged chitin nanofibrils. Hybrid magnetic aerogels exhibit a ferromagnetic response characterized by a low coercivity (<50 Oe) and a high specific magnetization (>40 emu/g) at all temperatures, making them particularly suitable for superparamagnetic applications. Additionally, these aerogels exhibit a distinct magnetic transition, featuring a higher blocking temperature (200 K) compared to previously reported similar nanoparticles (160 K), indicating enhanced magnetic stability at elevated temperatures. Finally, we demonstrate the practical application of these hybrid magnetic materials as catalysts for carbon monoxide oxidation, showcasing their potential in environmental pollution control and highlighting their versatility as catalyst supports.

Fungal bioremediation approaches for the removal of toxic pollutants: Mechanistic understanding for biorefinery applications

Pollution is a global menace that poses harmful effects on all the living ecosystems and to the Earth. As years pass by, the available and the looming rate of pollutants increases at a faster rate. Although many treatments and processing strategies are waged for treating such pollutants, the by-products and the wastes or drain off generated by these treatments further engages in the emission of hazardous waste. Innovative and long-lasting solutions are required to address the urgent global issue of hazardous pollutant remediation from contaminated environments. Myco-remediation is a top-down green and eco-friendly tool for pollution management. It is a cost-effective and safer practice of converting pernicious substances into non-toxic forms by the use of fungi. But these pollutants can be transformed into useable products along with multiple benefits for the environment such as sequestration of carbon emissions and also to generate high valuable bioactive materials that fits as a sustainable economic model. The current study has examined the possible applications of fungi in biorefineries and their critical role in the transformation and detoxification of pollutants. The paper offers important insights into using fungal bioremediation for both economically and environmentally sound solutions in the domain of biorefinery applications by combining recent research findings.

The Complementarity of Nuclear Magnetic Resonance and Native Mass Spectrometry in Probing Protein-Protein Interactions

Nuclear magnetic resonance (NMR) and native mass spectrometry (MS) are mature physicochemical techniques with long histories and important applications. NMR spectroscopy provides detailed information about the structure, dynamics, interactions, and chemical environment of biomolecules. MS is an effective approach for determining the mass of biomolecules with high accuracy, sensitivity, and speed. The two techniques offer unique advantages and provide solid tools for structural biology. In the present review, we discuss their individual merits in the context of their applications to structural studies in biology with specific focus on protein interactions and evaluate their limitations. We provide specific examples in which these techniques can complement each other, providing new information on the same scientific case. We discuss how the field may develop and what challenges are expected in the future. Overall, the combination of NMR and MS plays an increasingly important role in integrative structural biology, assisting scientists in deciphering the three-dimensional structure of composite macromolecular assemblies.

Determining the transformative potential of circular agriculture initiatives

Policymakers and scientists regard emerging circular initiatives as levers for transformations towards more sustainable food systems. However, it remains unclear how to determine the extent to which circular initiatives have transformative potential. That is, can these initiatives foster a transformation as a result of how they currently bring circularity into practice? In the transformation literature, the characteristics of transformative initiatives are conceptualised in a generic and abstract way. To address this gap, we develop a heuristic of five characteristics for potentially transformative circular agriculture initiatives, which we illustrate with examples of existing initiatives. The heuristic builds on the 'small wins' and circular agriculture literature. Initiatives that hold transformative potential contribute to circular agriculture principles with outcomes that are concrete, in-depth and both technological and social in nature. Additionally, these initiatives faced barriers and overcame them. The heuristic enables policymakers, who call for circular solutions, to identify truly transformative circular initiatives.

Risk to rely on soil carbon sequestration to offset global ruminant emissions

Carbon sequestration in grasslands has been proposed as an important means to offset greenhouse gas emissions from ruminant systems. To understand the potential and limitations of this strategy, we need to acknowledge that soil carbon sequestration is a time-limited benefit, and there are intrinsic differences between short- and long-lived greenhouse gases. Here, our analysis shows that one tonne of carbon sequestrated can offset radiative forcing of a continuous emission of 0.99 kg methane or 0.1 kg nitrous oxide per year over 100 years. About 135 gigatonnes of carbon is required to offset the continuous methane and nitrous oxide emissions from ruminant sector worldwide, nearly twice the current global carbon stock in managed grasslands. For various regions, grassland carbon stocks would need to increase by approximately 25% - 2,000%, indicating that solely relying on carbon sequestration in grasslands to offset warming effect of emissions from current ruminant systems is not feasible.

Recoupling livestock and feed production in the Netherlands to reduce environmental impacts

In many places on earth, livestock and feed production are decoupled, as feed is grown in one region and fed to livestock in another. This disrupts nutrient cycles by depleting resources in feed producing regions and accumulating resources in livestock areas, which leads to environmental degradation. One solution is to recouple livestock and feed production at a more local level, which enhances nutrient circularity. Recoupling livestock and feed production creates a natural ceiling for livestock numbers based on the feed producing capacity of a region. In this study we assess the consequences of recoupling livestock and feed production (i.e., by avoiding the import and export of animal feed) on ammonia and greenhouse gas (GHG) emissions, with and without feed-food competition. To this end, we used FOODSOM, an agro-ecological food system optimisation model representing the Dutch food system in this study. The Netherlands is one example of a region with high livestock densities and resource accumulation. We found that recoupling decreased livestock numbers (beef cattle: -100 %; dairy cattle: -29 %; broiler chickens: -57 %; laying hens: -67 %; pigs: -62 %; sheep -100 %) and animal-sourced food exports (-59 %) while still meeting the current human diet in the Netherlands. Consequently, ammonia emissions and GHG emissions decreased, and the nitrogen use efficiency increased from 31 % to 38 % at the food systems level. Recoupling alone was almost sufficient to meet national emission targets. Fully meeting these targets required further small changes in livestock numbers. Avoiding feed-food competition decreased livestock productivity and GHG emissions but did not improve nitrogen use efficiency. Total meat production could not meet domestic consumption levels while avoiding feed-food competition, and resulted in additional beef cattle. We show that recoupling livestock and feed production is a promising next step to enhance circularity while decreasing agricultures environmental impact.

Sustainable Isolation of Bioactive Compounds and Proteins from Plant-Based Food (and Byproducts)

Plant-based food produces significantly less greenhouse gases, and due to its wealth of bioactive components and/or plant-based protein, it becomes an alternative in a sustainable food system. However, the processing and production of products from plant sources creates byproducts, which can be waste or a source of useful substances that can be reused. The waste produced during the production and processing of food is essentially nutrient- and energy-rich, and it is recognized as an excellent source of secondary raw materials that could be repurposed in the process of manufacturing and preparing food, or as feed for livestock. This review offers an overview of the sources and techniques of the sustainable isolation of bioactive substances and proteins from various sources that might represent waste in the preparation or production of food of plant origin. The aim is to uncover novel approaches to use waste and byproducts from the process of making food to provide this waste food an additional benefit, not forgetting the expectations of the end user, the consumer. For the successful isolation of bioactive ingredients and proteins from food of plant origin, it is crucial to develop more eco-friendly and efficient extraction techniques with a low CO2 footprint while considering the economic aspects.

Low-opportunity-cost feed can reduce land-use-related environmental impacts by about one-third in China

Feeding animals more low-opportunity-cost feed products (LCFs), such as food waste and by-products, may decrease food-feed competition for cropland. Using a feed allocation optimization model that considers the availability of feed sources and animal requirements for protein and energy, we explored the perspectives of feeding more LCFs to animals in China. We found that about one-third of the animal feed consisted of human-edible products, while only 23% of the available LCFs were used as feed during 2009-2013. An increased utilization of LCFs (45-90 Mt) could potentially save 25-32% of feed-producing cropland area without impairing livestock productivity. Parallelly, about one-third of feed-related irrigation water, synthetic fertilizer and greenhouse gas emissions would be saved. Re-allocating the saved cropland could sustain the food energy demand of 30-185 million people. Achieving the potentials of increased LCF use requires improved technology and coordination among stakeholders.

Harnessing the Value of Tripolium pannonicum and Crithmum maritimum Halophyte Biomass through Integrated Green Biorefinery

Bioactive extracts are often the target fractions in bioprospecting, and halophyte plants could provide a potential source of feedstock for high-value applications as a part of integrated biorefineries. Tripolium pannonicum (Jacq.) Dobrocz. (sea aster) and Crithmum maritimum L. (sea fennel) are edible plants suggested for biosaline halophyte-based agriculture. After food production and harvesting of fresh leaves for food, the inedible plant fractions could be utilized to produce extracts rich in bioactive phytochemicals to maximize feedstock application and increase the economic feasibility of biomass processing to bioenergy. This study analyzed fresh juice and extracts from screw-pressed sea aster and sea fennel for their different phenolic compounds and pigment concentrations. Antioxidant and enzyme inhibition activities were also tested in vitro. Extracts from sea aster and sea fennel had phenolic contents up to 45.2 mgGAE/gDM and 64.7 mgGAE/gDM, respectively, and exhibited >70% antioxidant activity in several assays. Ethanol extracts also showed >70% inhibition activity against acetylcholinesterase and >50% inhibition of tyrosinase and α-glucosidase. Therefore, these species can be seen as potential feedstocks for further investigations.

Circular agriculture increases food production and can reduce N fertilizer use of commercial farms for tropical environments

World food production must increase in the coming years with minimal environmental impact for food and nutrition security. Circular Agriculture has emerged as an approach to minimize non-renewable resource depletion and encourage by-product reuse. The goal of this study was to evaluate Circular Agriculture as a tool to increase food production and N recovery. The assessment was conducted for two Brazilian farms (Farm 1; Farm 2) with Oxisols under no-till and a diversified cropping system, including five species of grain, three cover crop species, and sweet potato. Both farms implemented an annual two-crop rotation and an integrated crop-livestock system with beef cattle confined for 2-years. Grain and forage from the fields, leftovers from silos, and crop residues were used as cattle feed. Grain yield was 4.8 and 4.5 t ha^-1 for soybean, 12.5 and 12.1 t ha^-1 for maize, and 2.6 and 2.4 t ha^-1 for common bean, for Farm 1 and Farm 2, respectively, which is higher than the national average. The animals gained 1.2 kg day^-1 of live weight. Farm 1 exported 246 kg ha^-1 year^-1 of N in grains, tubers, and animals, while 216 kg ha^-1 year^-1 was added as fertilizer and N to cattle. Farm 2 exported 224 kg ha^-1 year^-1 in grain and animals, while 215 kg ha^-1 year^-1 was added as fertilizer and N to cattle. Circular practices, i.e., no-till, crop rotation, year-round soil covered, maize intercropped with brachiaria ruziziensis, biological N fixation, and crop-livestock integration, increased crop yield and decreased N application by 14.7 % (Farm 1) and 4.3 % (Farm 2). 85 % of the N consumed by the confined animals was excreted and converted into organic compost. Overall, circular practices associated with adequate crop management allowed recovering high rate of applied N, reducing environmental impacts, and increasing food production with lower production costs.

Optimization of integrated anaerobic digestion and pyrolysis for biogas, biochar and bio-oil production from the perspective of energy flow

Valorization of lignocellulosic biomass via anaerobic digestion (AD) is limited by its reluctant structure, leading to a substantial energy remaining in the solid digestate. To mitigate this effect, the integration of AD and pyrolysis has attracted attention in recent years. However, the energy recovery efficiency of this cascading system is still unclear, especially the time node. Herein, a comprehensive evaluation of this integration, using varied AD periods, was conducted, to produce biogas, bio-oil and biochar, and to enhance the energy recovery, from the perspective of energy flow. The result indicated that the accumulative CH₄ yields increased from 33.23 to 249.20 mL/g VS as the AD time increased from 3 to 15 days. Pyrolysis of the obtained solid digestate obtained biochar from 28.81 to 35.96 %, while the bio-oil and pyrolysis gas slowly decreased. The highest energy efficiency of 71.9 % with a net energy gain of 2.0 MJ/kg wet biomass was achieved by the coupled system optimization at an AD time of 12 days as suggested by the energy flow analysis. This study provides new insight for the maximal conversion of biomass waste into energy products and provides a new way of recycling it.

Effect of Laminaria digitata dietary inclusion and CAZyme supplementation on blood cells, serum metabolites and hepatic lipids and minerals of weaned piglets

Seaweeds, such as Laminaria digitata, are a sustainable alternative to conventional feedstuffs for weaned piglet diets, improving their health and mitigating environmental impacts. L. digitata has a complex cell wall that can be difficult for monogastrics to digest. However, carbohydrate-active enzymes (CAZymes) such as Rovabio® Excel AP and alginate lyase can help break down these polysaccharides and render intracellular nutrients more accessible. This study aimed to evaluate the impact of 10% L. digitata feed inclusion and CAZyme supplementation on piglet blood cells, serum metabolites, liver lipid and mineral profiles. Forty weaned piglets were randomly assigned to one of four diets (n = 10 each): a control diet, 10% L. digitata (LA), 10% L. digitata + 0.005% Rovabio® Excel AP (LAR), and 10% L. digitata + 0.01% alginate lyase (LAL). After two weeks of trial, animals were slaughtered and liver and blood serum samples taken for analysis. The results showed that the LA and LAL diets increased blood lymphocytes, IgG and IgM, and decreased serum lipids, improving both cellular and humoral immune response and cardiovascular health. Dietary CAZymes reversed the anti-inflammatory and hematopoietic effects. Additionally, cortisol levels were reduced with seaweed inclusion compared to the control diet (P < 0.001). In the liver, total n-3 PUFA and n-6/n-3 ratio were increased and decreased, respectively, due to eicosapentaenoic acid and α-linolenic acid accumulation (P < 0.001). However, total liver mineral content was incorporated to a lesser extent with the combined seaweed and enzyme diets (P < 0.001), potentially indicating a negative effect on mineral bioavailability. Overall, results suggest that a 10% L. digitata inclusion can effectively improve piglet health by reducing stress during weaning, without the need for dietary CAZymes.

Circularity in Europe strengthens the sustainability of the global food system

Redesigning the European food system on the basis of circularity principles could bring environmental benefits for Europe and the world. Here we deploy a biophysical optimization model to explore the effects of adopting three circularity scenarios in the European Union (EU)27 + UK. We calculate a potential reduction of 71% in agricultural land use and 29% per capita in agricultural greenhouse gas emissions, while producing enough healthy food within a self-sufficient European food system. Under global food shortages, savings in agricultural land could be used to feed an additional 767 million people outside the EU (+149%), while reducing per capita greenhouse gas emissions by 38% but increasing overall emissions by 55% due to the increased population served. Transitioning the EU's food system towards circularity implies sequential changes among all its components and has great potential to safeguard human and planetary health.

Shifting towards optimized healthy and sustainable Dutch diets: impact on protein quality

PURPOSE

To reduce the environmental impact of Western diets, a reduction of meat consumption and a substitution by plant-based protein sources is needed. This protein transition will affect the quantity and quality of dietary protein. Therefore, the aim of this study was to evaluate the protein adequacy of diets optimized for nutritional health and diet-related greenhouse gas emission (GHGE).

METHODS

Data from 2150 adult participants of the Dutch National Food Consumption Survey were used, with diet assessed using two non-consecutive 24 h dietary recalls. Utilizable protein of current diets per day was based on meal composition and the Protein Digestibility-Corrected Amino Acid Score and was compared to protein requirements. Optimized diets were derived as linear combinations of current diets that minimized GHGE and maximized the Dutch Healthy Diet 2015 score, with/without constraints to keep dietary change within 33% of current consumption. Protein adequacy was evaluated in both current and optimized diets.

RESULTS

In all age and gender strata, the healthiest diets had higher GHGE, the most sustainable diets had the lowest dietary quality, though higher than current diets, and protein adequacy remained sufficient. When limiting dietary change to 33% of current consumption, in the most promising trade-off diet GHGE was reduced by 12-16%. The current diet provided 1.4-2.2 times the required amount of utilizable protein.

CONCLUSION

These results suggest that a realistic aim for the next decade might be to reduce diet-related GHGE to 12-16% of the current levels without compromising protein adequacy and diet quality. To achieve global targets, upstream food system transformations are needed with subsequent dietary changes.

Review: Connecting circularity to animal welfare calls for a 'novel' conceptual framework based on integrity

The current food system is not sustainable. Circular agriculture aims to save the environment and produce food sustainably by closing nutrient cycles, possibly without improving animal welfare. This paper proposes a new conceptual framework, called a circular welfare economy (CWE), to facilitate a transition towards a sustainable agriculture based on integrity. The CWE framework explains how welfare relates to circular agriculture, how potential conflicts can be solved and what future livestock farming could look like. CWE applies the notion of circularity to welfare defined as the quality of life as perceived by the individual itself. CWE also identifies human integrity, defined as being open and honest, as a sine qua non for sustainability. Animal-welfare problems arise when animals are merely used as a means, e.g., for profits. Instead, profits and circular agriculture are means to the end of welfare. In a CWE, welfare is promoted sustainably, without causing undue need frustration in other individuals. This requires informed moral decision-making involving human integrity and the closure of welfare-related feedback loops. Conflicts between circular agriculture and animal welfare are solved by weighing all welfare needs impartially. Three future scenarios are presented: Animal-welfare-exclusive circular agriculture, which resembles modern intensive livestock farming, animal rights agriculture without livestock farming, and a CWE-based agriculture which integrates circular agriculture and animal welfare. In the latter case, we will not use animals merely as a means to close nutrient cycles, but take every effort, openly and honestly, to understand and benefit their points of view as we do our own.

Recent Advances in Health Benefits of Bioactive Compounds from Food Wastes and By-Products: Biochemical Aspects

Bioactive compounds, including terpenoids, polyphenols, alkaloids and other nitrogen-containing constituents, exert various beneficial effects arising from their antioxidant and anti-inflammatory properties. These compounds can be found in vegetables, fruits, grains, spices and their derived foods and beverages such as tea, olive oil, fruit juices, wine, chocolate and beer. Agricultural production and the food supply chain are major sources of food wastes, which can become resources, as they are rich in bioactive compounds. The aim of this review is to highlight recent articles demonstrating the numerous potential uses of products and by-products of the agro-food supply chain, which can have various applications.

Lower pork consumption and technological change in feed production can reduce the pork supply chain environmental footprint in China

Nearly half of global pork production and consumption occurs in China, but the transition towards intensification is associated with worsening environmental impacts. Here we explore scenarios for implementing structural and technological changes across the pork supply chain to improve environmental sustainability and meet future demand. Following the middle-of-the-road socio-economic pathway (SSP2), we estimate that the environmental footprint from the pork supply chain will increase by ~50% from 2017 to 2050. Utilizing technologies that improve feed crop production and manure management could reduce phosphorus and nitrogen losses by three-quarters and one-third, respectively, with modest reductions in greenhouse gas emissions and cropland area. Reducing pork consumption had substantial mitigation potential. Increased feed and pork imports would decrease domestic environmental footprints and meet demand, but increase footprints elsewhere. We conclude that farm-specific technologies and structural adjustments can support the development of rural, small-scale pig farms near cropland and promote circular economy principles.

Base editing for reprogramming cyanobacterium Synechococcus elongatus

Cyanobacteria can directly convert carbon dioxide (CO₂) at the atmospheric level to biofuels, value-added chemicals and food products, making them ideal candidates to alleviate global climate change. Despite decades-long pioneering successes, the development of genome-editing tools, especially the CRISPR-Cas-based approaches, seems to lag behind other microbial chassis, slowing down the innovations of cyanobacteria. Here, we adapted and tailored base editing for cyanobacteria based on the CRISPR-Cas system and deamination. We achieved precise and efficient genome editing at a single-nucleotide resolution and demonstrated multiplex base editing in the model cyanobacterium Synechococcus elongatus. By using the base-editing tool, we successfully manipulated the glycogen metabolic pathway via the introduction of premature STOP codons in the relevant genes, building engineered strains with elevated potentials to produce chemicals and food from CO₂. We present here the first report of base editing in the phylum of cyanobacteria, and a paradigm for applying CRISPR-Cas systems in bacteria. We believe that our work will accelerate the metabolic engineering and synthetic biology of cyanobacteria and drive more innovations to alleviate global climate change.

Combined conversion of lignocellulosic biomass into high-value products with ultrasonic cavitation and photocatalytic produced reactive oxygen species - A review

The production of high-value products from lignocellulosic biomass is carried out through the selective scission of crosslinked CC/CO bonds. Nowadays, several techniques are applied to optimize biomass conversion into desired products with high yields. Photocatalytic technology has been proven to be a valuable tool for valorizing biomass at mild conditions. The photoproduced reactive oxygen species (ROSs) can initiate the scission of crosslinked bonds and form radical intermediates. However, the low mass transfer of the photocatalytic process could limit the production of a high yield of products. The incorporation of ultrasonic cavitation in the photocatalytic system provides an exceptional condition to boost the fragmentation and transformation of biomass into the desired products within a lesser reaction time. This review critically discusses the main factors governing the application of photocatalysis for biomass valorization and tricks to boost the selectivity for enhancing the yield of desired products. Synergistic effects obtained through the combination of sonolysis and photocatalysis were discussed in depth. Under ultrasonic vibration, hot spots could be produced on the surface of the photocatalysts, improving the mass transfer through the jet phenomenon. In addition, shock waves can assist the dissolution and mixing of biomass particles.

Microalgal remediation and valorisation of polluted wastewaters for zero-carbon circular bioeconomy

Overexploitation of natural resources to meet human needs has considerably impacted CO₂ emissions, contributing to global warming and severe climatic change. This review furnishes an understanding of the sources, brutality, and effects of CO₂ emissions and compelling requirements for metamorphosis from a linear to a circular bioeconomy. A detailed emphasis on microalgae, its types, properties, and cultivation are explained with significance in attaining a zero-carbon circular bioeconomy. Microalgal treatment of a variety of wastewaters with the conversion of generated biomass into value-added products such as bio-energy and pharmaceuticals, along with agricultural products is elaborated. Challenges encountered in large-scale implementation of microalgal technologies for low-carbon circular bioeconomy are discussed along with solutions and future perceptions. Emphasis on the suitability of microalgae in wastewater treatment and its conversion into alternate low-carbon footprint bio-energies and value-added products enforcing a zero-carbon circular bioeconomy is the major focus of this review.

Upgrading agrifood co-products via solid fermentation yields environmental benefits under specific conditions only

Transforming residual biomass into edible ingredients is increasingly promoted to alleviate the environmental impacts of food systems. Yet, these approaches mostly rely on emerging technologies and constrained resources, and their environmental benefits remain unclear. By combining process-based consequential life cycle analysis, uncertainty assessment and biomass resource estimation, we quantified the impacts of deploying waste-to-nutrition pathways, here applied to the upgrading of agrifood co-products by solid-state fermentation (SSF). The benefits of reducing the demand for soybean meal by enhancing the protein concentration of feed through SSF do not compensate for the environmental burdens induced by the process on climate change, water depletion and land use. Besides unlocking feed markets to low-feed-quality streams, SSF outperforms energy valorization for most environmental impacts but is less competitive to mitigate climate change. Yet, SSF yields overall environmental benefits when unlocking food markets rather than supplying feed and energy services. Systematic methodological harmonization is required to assess the potential of novel ingredients, as outcomes vary according to the displaced food and feed baskets, and related land use changes.

Advances in Komagataella phaffii Engineering for the Production of Renewable Chemicals and Proteins

The need for a more sustainable society has prompted the development of bio-based processes to produce fuels, chemicals, and materials in substitution for fossil-based ones. In this context, microorganisms have been employed to convert renewable carbon sources into various products. The methylotrophic yeast Komagataella phaffii has been extensively used in the production of heterologous proteins. More recently, it has been explored as a host organism to produce various chemicals through new metabolic engineering and synthetic biology tools. This review first summarizes Komagataella taxonomy and diversity and then highlights the recent approaches in cell engineering to produce renewable chemicals and proteins. Finally, strategies to optimize and develop new fermentative processes using K. phaffii as a cell factory are presented and discussed. The yeast K. phaffii shows an outstanding performance for renewable chemicals and protein production due to its ability to metabolize different carbon sources and the availability of engineering tools. Indeed, it has been employed in producing alcohols, carboxylic acids, proteins, and other compounds using different carbon sources, including glycerol, glucose, xylose, methanol, and even CO2.

Circular bioeconomy in African food systems: What is the status quo? Insights from Rwanda, DRC, and Ethiopia

Increasing global food insecurity amidst a growing population and diminishing production resources renders the currently dominant linear production model insufficient to combat such challenges. Hence, a circular bioeconomy (CBE) model that ensures more conservative use of resources has become essential. Specifically, a CBE model that focuses on recycling and reusing organic waste is essential to close nutrient loops and establish more resilient rural-urban nexus food systems. However, the CBE status quo in many African food systems is not established. Moreover, scientific evidence on CBE in Africa is almost inexistent, thus limiting policy guidance to achieving circular food systems. Using a sample of about 2,100 farmers and consumers from key food value chains (cassava in Rwanda, coffee in DRC, and bananas in Ethiopia), we explored existing CBE practices; awareness, knowledge, and support for CBE practices; consumers’ opinions on eating foods grown on processed organic waste (CBE fertilizers), and determinants of such opinions. We analysed data in Stata, first descriptively, and then econometrically using the ordered logistic regression, whose proportional odds assumption was violated, thus resorting to the generalized ordered logistic regression. Results show that communities practice aspects of CBE, mainly composting, and are broadly aware, knowledgeable, supportive of CBE practices, and would broadly accept eating foods grown CBE fertilizers. Households with heads that used mobile phones, or whose heads were older, or married, or had a better education and agricultural incomes were more likely to strongly agree that they were knowledgeable and supportive of CBE practices and would eat CBE foods (foods grown on processed organic waste). However, the reverse was true for households that were severely food insecure or lived farther from towns. Rwandan and Ethiopian households compared to DRC were less likely to eat CB foods. Policies to stimulate CBE investments in all three countries were largely absent, and quality scientific evidence to guide their development and implementation is currently insufficient.

Bio-Vitrimers for Sustainable Circular Bio-Economy

The aim to achieve sustainable development goals (SDG) and cut CO₂-emission is forcing researchers to develop bio-based materials over conventional polymers. Since most of the established bio-based polymeric materials demonstrate prominent sustainability, however, performance, cost, and durability limit their utilization in real-time applications. Additionally, a sustainable circular bioeconomy (CE) ensures SDGs deliver material production, where it ceases the linear approach from production to waste. Simultaneously, sustainable circular bio-economy promoted materials should exhibit the prominent properties to involve and substitute conventional materials. These interceptions can be resolved through state-of-the-art bio-vitrimeric materials that display durability/mechanical properties such as thermosets and processability/malleability such as thermoplastics. This article emphasizes the current need for vitrimers based on bio-derived chemicals; as well as to summarize the developed bio-based vitrimers (including reprocessing, recycling and self-healing properties) and their requirements for a sustainable circular economy in future prospects.

Nanochitin: Chemistry, Structure, Assembly, and Applications

Chitin, a fascinating biopolymer found in living organisms, fulfills current demands of availability, sustainability, biocompatibility, biodegradability, functionality, and renewability. A feature of chitin is its ability to structure into hierarchical assemblies, spanning the nano- and macroscales, imparting toughness and resistance (chemical, biological, among others) to multicomponent materials as well as adding adaptability, tunability, and versatility. Retaining the inherent structural characteristics of chitin and its colloidal features in dispersed media has been central to its use, considering it as a building block for the construction of emerging materials. Top-down chitin designs have been reported and differentiate from the traditional molecular-level, bottom-up synthesis and assembly for material development. Such topics are the focus of this Review, which also covers the origins and biological characteristics of chitin and their influence on the morphological and physical-chemical properties. We discuss recent achievements in the isolation, deconstruction, and fractionation of chitin nanostructures of varying axial aspects (nanofibrils and nanorods) along with methods for their modification and assembly into functional materials. We highlight the role of nanochitin in its native architecture and as a component of materials subjected to multiscale interactions, leading to highly dynamic and functional structures. We introduce the most recent advances in the applications of nanochitin-derived materials and industrialization efforts, following green manufacturing principles. Finally, we offer a critical perspective about the adoption of nanochitin in the context of advanced, sustainable materials.

Logistics and Supply Chain Modelling for the Biobased Economy: A Systematic Literature Review and Research Agenda

One way to mitigate the negative impacts of climate change, is for society to move towards a biobased economy, where fossil resources are replaced by biobased ones. This replacement requires the development of biobased supply chains that differ significantly from the conventional supply chain. For example, seasonality and variability of the feedstocks create specific challenges for biobased systems and call for customized solutions for the design and operation of biobased chains. As a result, the modelling efforts to support decision-making processes for biobased logistics and supply chains have some different requirements. This paper presents a systematic literature review on logistics and supply chain modelling studies for the biobased economy published in a period of 2011–2020. The literature analysis shows that most modelling studies for the biobased economy are strategic optimization models aiming to minimize economic impact. As biomass source, forest and agricultural residues are mostly used, and fuel and energy are the most common biobased applications. Modelling strategies, biomass sources and applications are however diversifying, which is what we encourage for future research. Also, not only focusing on economic optimization but also optimizing social and environmental performance is an important future research direction, to deal with the sustainability challenges the world is facing.

Use of agro-industrial by-products containing tannins for the integrated control of gastrointestinal nematodes in ruminants

Previous studies have illustrated that different bioactive legume fodders containing condensed tannins might represent one of the options for integrated sustainable control of gastrointestinal nematodes (GIN) in ruminants, which may help address the worldwide development of resistance to synthetic anthelmintics. More recently, impetus has been given to assess the potential antiparasitic activity of less conventional resources, represented by different agro-industrial by-products (AIBPs). This review presents in vitro and in vivo results obtained with a range of tannin-containing AIBPs of various geographical and botanical origins, namely AIBP of nuts, temperate and tropical barks, carob, coffee and cocoa. They tend to confirm the "proof of concept" for their antiparasitic effects and also for other aspects of ruminant production in an agro-ecological context. Socio-economic aspects of the exploitation of such non-conventional resources are also discussed as potential models of the circular economy, by using waste. The different modes of use of these resources are presented in this review, as well as strengths, weaknesses, opportunities, and threats (SWOT) analyses to illustrate the advantages and limitations of on-farm use.

A Circularity Evaluation of New Feed Categories in The Netherlands—Squaring the Circle: A Review

The concept of circularity is currently proposed to address key sustainability issues affecting and affected by livestock production. Through a desk study, this paper evaluates some feed sources that are being developed in The Netherlands as an alternative to current feeds, namely food waste; seaweed; and localized production and alternative plant-based feed sources. These feed categories are evaluated according to four circularity criteria. The first two criteria concern standard circularity principles aimed at both stopping and preventing environmental damage as well as a focus on natural resources use efficiency: (1) safeguard the health of ecosystems and (2) avoid the production of unnecessary products and use/recycle biomass effectively, as well as evaluating possible food–feed competition. In addition, two ‘people’ and ‘animal’ centred principles have been integrated: (3) fairness and accessibility and (4) animal health and wellbeing. The article concludes that people and animal centred principles are key to thinking of, developing, implementing, and evaluating circularity initiatives. Moreover, the article suggests that categories such as the local production of soya (approx. 132 ha) or seaweed (approx. 10–15 ha) are as yet irrelevant regarding production volumes within the Dutch context. However, some feed sources such as seaweed, insects, livestock leftovers produced at farms and abattoirs, and food waste might strengthen the transition towards more circular and sustainable practices.

Exploring the prospects of the fifth quarter in the 21st century

A variable proportion of slaughtered livestock, generally referred to as the fifth quarter, is not part of the edible dressed meat and regarded as animal byproduct. In order for the fifth quarter to play a significant role in the current effort toward a circular bio-based economy, it has to successfully support food security, social inclusivity, environmental sustainability, and a viable economy. The high volume of these low-value streams and their nutrient-dense nature can facilitate their position as a very important candidate to explore within the context of a circular bio-based economy to achieve some of the United Nations Sustainable Development Goals (UN-SDGs). While these sources have been traditionally used for various applications across different cultures and industries, it seems evident that their full potential has not yet been exploited, leaving these products more like an environmental burden rather than valuable resources. With innovation and well-targeted interdisciplinary collaborations, the potential of the fifth quarter can be fully realized. The present review intends to explore these low-value streams, their current utilization, and their potential to tackle the global challenges of increasing protein demands while preventing environmental degradation. Factors that limit widespread applications of the fifth quarter across industries and cultures will also be discussed.

The Role of Bioeconomy in the Future Energy Scenario: A State-of-the-Art Review

The bioeconomy aims at decreasing reliance on fossil fuels, preventing or reducing climate change, eliminating insecurity, and efficiently using resources; however, fierce controversy exists on conceivable pathways to accomplish these objectives. The transport sector alone, which encompasses all other industrial sectors, has grown with regard to its energy demand by 50% over the past 30 years. The aim of this paper is to promote a dialogue as to whether an economy based on biomass can be more sustainable than today’s existing economies, considering that the economy needs to expand and be boosted, while creating a cascading and recycling system. This semi-systematic review paper discusses four research questions based on findings from the last 20 years: (i) What are the crucial issues in the ongoing debate on the development of a sustainable bioeconomy concept? (ii) Where are the major conflicting points and focuses? (iii) How does the bioeconomy follow current urbanization and land-abandonment trends? (iv) How will the crisis linked to the COVID-19 pandemic change these previous scenarios? As it is not easy to currently predict which pathway will be the most effective, whether it be the one taken as of now or a specific novel pathway, this article recommends following a strategy that is diverse regarding its approaches to shaping the bioeconomy and further funding of renewable energy sources, along with the involvement of urban planning. In addition, conclusions are validated through a questionnaire completed by 51 experts in the field.

Waste-to-nutrition: a review of current and emerging conversion pathways

Residual biomass is acknowledged as a key sustainable feedstock for the transition towards circular and low fossil carbon economies to supply whether energy, chemical, material and food products or services. The latter is receiving increasing attention, in particular in the perspective of decoupling nutrition from arable land demand. In order to provide a comprehensive overview of the technical possibilities to convert residual biomasses into edible ingredients, we reviewed over 950 scientific and industrial records documenting existing and emerging waste-to-nutrition pathways, involving over 150 different feedstocks here grouped under 10 umbrella categories: (i) wood-related residual biomass, (ii) primary crop residues, (iii) manure, (iv) food waste, (v) sludge and wastewater, (vi) green residual biomass, (vii) slaughterhouse by-products, (viii) agrifood co-products, (ix) C₁ gases and (x) others. The review includes a detailed description of these pathways, as well as the processes they involve. As a result, we proposed four generic building blocks to systematize waste-to-nutrition conversion sequence patterns, namely enhancement, cracking, extraction and bioconversion. We further introduce a multidimensional representation of the biomasses suitability as potential as nutritional sources according to (i) their content in anti-nutritional compounds, (ii) their degree of structural complexity and (iii) their concentration of macro- and micronutrients. Finally, we suggest that the different pathways can be grouped into eight large families of approaches: (i) insect biorefinery, (ii) green biorefinery, (iii) lignocellulosic biorefinery, (iv) non-soluble protein recovery, (v) gas-intermediate biorefinery, (vi) liquid substrate alternative, (vii) solid-substrate fermentation and (viii) more-out-of-slaughterhouse by-products. The proposed framework aims to support future research in waste recovery and valorization within food systems, along with stimulating reflections on the improvement of resources' cascading use.

The Second Life of Citrus Fruit Waste: A Valuable Source of Bioactive Compounds

Citrus fruits (CF) are among the most widely cultivated fruit crops throughout the world and their production is constantly increasing along with consumers' demand. Therefore, huge amounts of waste are annually generated through CF processing, causing high costs for their disposal, as well as environmental and human health damage, if inappropriately performed. According to the most recent indications of an economic, environmental and pharmaceutical nature, CF processing residues must be transformed from a waste to be disposed to a valuable resource to be reused. Based on a circular economy model, CF residues (i.e., seeds, exhausted peel, pressed pulp, secondary juice and leaves) have increasingly been re-evaluated to also obtain, but not limited to, valuable compounds to be employed in the food, packaging, cosmetic and pharmaceutical industries. However, the use of CF by-products is still limited because of their underestimated nutritional and economic value, hence more awareness and knowledge are needed to overcome traditional approaches for their disposal. This review summarizes recent evidence on the pharmacological potential of CF waste to support the switch towards a more environmentally sustainable society.