Bioresources and Bioproducts

This review evaluates pretreatment strategies for blending the organic fraction of municipal solid waste (OFMSW) with agricultural residues to recover fermentable sugars. Three mechanistic benefits have been hypothesized for such blends: ash-mineral pH buffering, endogenous protein reduction of non-productive cellulase–lignin binding, and inhibitor dilution. These mechanisms are inferred from analogous lignocellulosic systems rather than measured directly in OFMSW–agricultural residue combinations, and their translation into saccharification gains remains substrate- and pretreatment-specific. A synergy index framework with a four-tier classification (true synergy, additive, substitution, and process complementarity) is applied to reclassify the available evidence, alongside an assessment of pretreatment chemistry, enzymatic hydrolysis outcomes, and techno-economic feasibility. Integrated sequential pretreatment, particularly acid-catalyzed steam explosion and deacetylation with mechanical refining, proved most robust for heterogeneous feeds. The strongest Tier I synergy is found for SO₂-catalyzed steam explosion of hybrid poplar–wheat straw (SI 1.29–1.33; 22% monomeric sugar gain). OFMSW combined with organosolv beechwood cellulose at 35–45% OFMSW reached 58–68% saccharification (44–46 g sugar L⁻¹), a Tier III–IV outcome. Matched-control saccharification data for OFMSW–agricultural residue blends specifically have not been reported. Co-processing corn stover with wet organic waste reduced CO₂ mitigation cost from $236 to $67 per ton CO₂-eq under bio-CNG upgrading. Formal synergy quantification, blend-specific inhibitor profiling, and high-solids process intensification are the central prerequisites for commercial translation. Full article

The growing worldwide need for sustainable, high-quality protein sources has intensified interest in single-cell protein (SCP) production, particularly mycoproteins derived from filamentous fungi. This shift is further driven by global sustainability priorities articulated by regulatory bodies, which promote resource efficiency, waste valorization, and sustainable food systems. Despite their high carbohydrate potential, the agricultural sector generates vast quantities of starch-rich by-products. Examples include broken rice, cassava peels, potato waste, and cereal-processing residues, which remain largely underutilized and thereby contribute substantially to environmental pollution. This literature review examines the potential of starch-based agricultural by-products as low-cost, renewable feedstocks for fungal SCP production in support of the Sustainable Development Goals (SDGs). These by-products include broken rice, cassava peels, potato waste, and cereal processing residues, which remain largely underutilized despite their high carbohydrate content. Key topics include pretreatment strategies, fungal fermentation with Neurospora and Fusarium spp., and process optimization to maximize biomass yield and feedstock valorization. Life cycle assessments (LCAs) indicate reduced greenhouse gas emissions compared with conventional protein sources, highlighting the potential of starch residues in circular bioeconomy systems. Furthermore, considerations related to process design, environmental benefits, and techno-economic feasibility are evaluated in the context of converting starch residues into fungal protein. In summary, the evidence suggests that valorizing starch by-products for mycoprotein fermentation, used both as a protein alternative and as an ingredient, represents a promising strategy to reduce waste management and production costs and support global food sustainability. Full article

Japan’s import market for wood pellets has expanded rapidly since the introduction of the feed-in tariff (FIT) scheme in 2012, with imports exceeding six million tonnes in 2024, positioning Japan as the world’s second-largest wood pellet importer. Despite this expansion, empirical evidence on its demand structure remains limited. This study employs a Dynamic Linear Approximate Almost Ideal Demand System (Dynamic LA-AIDS) model incorporating demand inertia stemming from long-term fuel supply contracts to analyze Japan’s wood pellet import demand from 2012Q1 to 2025Q3. The results reveal a distinct two-tiered structure: North American pellets behave as a strategic necessity, exhibiting price-inelastic demand and a tendency toward a stable long-run procurement pattern following price and expenditure shocks, suggesting procurement practices that prioritize supply security under long-term contracts. In contrast, Vietnamese pellets behave as a price-sensitive commodity, displaying price-elastic demand and relatively sustained responsiveness following such shocks. These results indicate a dual procurement strategy under the FIT scheme that balances stability and cost flexibility. Importantly, the Japanese demand structure differs from the more uniformly price-inelastic patterns observed in the EU and South Korean markets, providing new insights into how institutional frameworks shape biomass allocation and market responsiveness in renewable energy systems. Full article

Children are largely absent from circular economy and bioeconomy research, limiting opportunities for early development of systems thinking, sustainability competencies, and inclusive knowledge production. This paper presents a qualitative case study of the Horizon 2020 AgroCycle project (2016–2019), examining how primary school children were engaged as co-researchers through a transdisciplinary, participatory model. Analysis draws on project deliverables, educational resources, workshop records, internal reports, and dissemination materials. The study shows how children and adult co-researchers explored waste valorisation, bioresource transformation, and biobased material innovation in Irish schools. Valorisation in the context of the bioeconomy is the process of converting residues from farming, food, forestry and marine sources into high-value products such as biofertilisers, biofuels and biochemicals. It situates AgroCycle within European sustainability policy, highlighting its influence on subsequent initiatives, including Horizon Europe BioBeo and BiOrbic, Research Ireland’s Centre for Bioeconomy. By combining qualitative case study methodology with reflective practitioner analysis, the paper demonstrates how child-centred, transdisciplinary research can enhance sustainability education, support SDG-aligned competencies, and promote inclusive approaches to circular economy and bioeconomy transitions. Full article

Ganoderma mushrooms produce bioactive metabolites with therapeutic potential, yet their tissue-level distribution is not well characterized. This study quantified triterpenoids, β-glucans, and phenolics across six anatomical sections of fruiting bodies from five wild Ganoderma species. Twenty-six triterpenoids were identified. Laccate species showed thicker context tissue enriched in ganoderic and lucidenic acids, resembling the chemotype of G. lucidum. Matte species displayed greater triterpenoid diversity, including elfvingic, applanoxidic, and ganoderenic analogues. Maximum contents reached 3.5% triterpenoids, 34.3% β-glucans, 20.8 mg TE·g⁻¹ (ABTS), 175.2 µmol Fe²⁺·g⁻¹ (FRAP), and 23.5 mg GAE·g⁻¹ phenolics. Triterpenoids and phenolics were highest in outer cap tissues, while β-glucans predominated in context layers. These patterns reflect functional tissue roles and developmental variation. The tissue distribution of metabolites in wild Ganoderma presented here identifies surface tissues as a major source of triterpenoids and phenolics, and internal tissues as a source of β-glucans. These traits represent selection targets for extraction and selective breeding to produce strains with thicker context tissue and higher triterpenoid and β-glucan yields. Full article

Growing global energy demand and concerns over climate change and fossil fuel depletion have increased interest in sustainable bioproducts such as ethanol. Unlike first-generation (1G) ethanol derived from food crops (e.g., corn), second-generation (2G) ethanol is produced from lignocellulosic biomass, an abundant non-food resource that addresses key sustainability concerns. Consolidated bioprocessing (CBP) integrates enzyme production, hydrolysis, and fermentation into a single step, using either microbial consortia or engineered microorganisms, thereby simplifying the process and potentially reducing costs compared with separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). However, CBP systems are complex due to dynamic interactions among microbial communities, metabolic pathways, and process conditions. Addressing this complexity requires modeling approaches that capture nonlinear relationships and support robust process optimization. Machine learning (ML)-based models offer data-driven tools to represent complex bioprocess dynamics, improve predictive accuracy, and optimize bioproduct formation, thereby supporting progress toward commercial viability. Although CBP can be applied to a range of bioproducts, this review primarily focuses on lignocellulosic ethanol and closely related biofuels. The review provides a comprehensive overview of key CBP processes, the current state of CBP modeling, major limitations, and the emerging role of ML in addressing modeling challenges. It summarizes recent modeling techniques for CBP, including polynomial models and response surface methodologies, and discusses regression and neural network approaches in detail. Both first-principles and data-driven modeling strategies are considered, highlighting advances that can improve the scalability and efficiency of CBP for bioproduction. Overall, this review offers perspectives on modeling-enabled pathways for utilizing low-cost lignocellulosic biomass in sustainable bioprocessing. Full article

Lignocellulosic bio-based materials, such as wood, biocomposites, and natural fibers, exhibit desirable structural properties. This comprehensive review emphasizes the foundational and latest advancements in bioinspired improvement strategies, such as direct mineralization, biomineralization, lignocellulosic nanomaterials, protein-based treatments, and metal-chelating processes. Significant focus was placed on biomimetics, emulating natural protective mechanisms, with discussions on relevant topics including hierarchical mineral deposition, free-radical formation and quenching, and selective metal ion binding, and relating them to lignocellulosic bio-based material property improvements, particularly against fire and fungi. This review evaluates the effectiveness of different bioinspired processes: mineralized and biomineralized composites improve thermal stability, nanocellulose and lignin nanoparticles provide physical, thermal, and chemical barriers, proteins offer biochemical inhibition and mineral templating, and chelators interfere with fungal oxidative pathways while simultaneously improving fire retardancy through selective binding with metal ions. Synergistic approaches integrating various mechanisms could potentially lead to long-lasting and multifunctional protection. This review also highlights the research gaps, challenges, and potential for future applications. Full article

Biodegradable waste is commonly treated as a problem to be managed, but it can be a valuable resource when considered within a circular bioeconomy perspective. This article develops a practical and systems-based frame work for integrating biodegradable waste, ranging from municipal food scraps to wastewater biosolids, into valuable resources. It explores real-world strategies for transforming waste into value-added products, including composting, anaerobic digestion, biochemical conversion, and the creation of bio-based materials. The review also highlights key drivers and barriers, including technical, regulatory, and social factors, which shape the feasibility and impact of circular solutions. A visual model illustrates the full cycle, from identifying waste streams to reintegrating recovered resources. The paper also highlights case studies from Toronto, Milan and Brazil as examples of successful implementation. Overall, this paper emphasizes a pragmatic yet regenerative shift toward organic resource recovery aligned with sustainability and decarbonization goals. Full article

Sugarcane bagasse (SCB) is a lignocellulosic byproduct with low biodegradability, limiting its potential for biological processes such as biogas production. The objective of this study was to evaluate whether a short-term biological pretreatment with the cellulolytic bacterium Proteus mirabilis KC94 could enhance SCB hydrolysis, improve nutrient balance, and increase biomethane potential (BMP). Three treatments were compared: untreated bagasse (UB), sterilized bagasse (SB), and KC94-pretreated bagasse (PB). Glucose release was highest in PB (61.83 ± 0.8 mg/mL), indicating enhanced cellulose degradation in PB relative to UB (53.19 ± 0.9 mg/mL) and SB (44.00 ± 0.5 mg/mL). Elemental analysis revealed a more balanced nutrient profile in PB, characterized by optimal carbon and nitrogen levels, and reduced sulfur content, indicating microbial assimilation and potential biological desulfurization. Scanning electron microscopy revealed pronounced structural disruption, increased porosity, and fiber delamination in PB, confirming the efficacy of KC94-mediated lignocellulosic pretreatment. BMP assays conducted over a 31-day incubation period revealed that PB produced the highest cumulative methane yield (99 ± 0.7 mL CH₄/g VS), representing 19% and 25% increases over UB and SB, respectively. PB biomethanation was also faster compared to the other two substrates. These findings demonstrate the novelty of a 5-day bacterial pretreatment strategy, which significantly improves lignocellulosic hydrolysis and methane yield. Specifically, P. mirabilis KC94 pretreatment increased glucose release by 16–40% and cumulative methane yield by 19–25% compared to untreated and sterilized controls. This cost-effective and environmentally friendly approach highlights the potential of P. mirabilis KC94 to valorize sugarcane bagasse, advancing sustainable energy recovery and circular bioeconomy practices. Full article

Wood is a primary bioproduct widely utilized as timber in construction and carpentry. Characterization of its properties, particularly moisture response, is essential for industrial performance. The Fiber Saturation Point (FSP) influences the dimensional stability and efficiency of industrial processes such as drying. This study determines the maximum dimensional variation and the FSP of Eucalyptus nitens solid wood from plantations in Northwestern Spain, studying 354 specimens of 20 × 20 × 50 mm. Mean and median values were calculated considering and omitting outliers. Additionally, a graphical FSP value was obtained by applying the statistical theory of the center of gravity, defined as the intersection of lines derived from the two-dimensional data distribution. For maximum dimensional variation, the analysis yielded mean values of 5.2% [±1.53] and 11.2% [±2.84] and medians of 4.8% and 10.4%, in radial and tangential directions, respectively. The mean FSP was 29.9% [±7.95], the median 28.9%, and the graphical estimate 30.8%. Establishing the FSP defines the critical moisture threshold at which significant changes in physical and mechanical properties, as well as dimensional alterations, occur in this bioresource, particularly for its use as a bioproduct in carpentry and construction or for industrial wood drying. Full article

Fatty acid desaturase 12 (FAD12) is a key enzyme in fatty acid biosynthesis, responsible for converting oleic acid to linoleic acid through desaturase activity. Euglena gracilis (Euglena) is an emerging platform for the industrial production of various metabolites, including lipids. However, a comprehensive understanding of Euglena’s fatty acid biosynthesis pathways remains incomplete, posing a significant barrier to the commercialization of Euglena bioproducts. To address this gap, we employed a bioinformatics approach to identify a Euglena gracilis FAD12 (Eg FAD12). We analyzed the evolutionary relationship of Eg FAD12 with its homologs from other organisms and revealed that the three canonical histidine box motifs are conserved among FAD12s. To characterize EgFAD12, we cloned it into the pEAQ-hyperstrans vector and overexpressed it in Nicotiana benthamiana to take advantage of its endogenous fatty acid pool, which could act as a substrate. The heterologous expression of FAD12 in N. benthamiana led to an increased linoleic acid content, demonstrating the suspected desaturase activity. To further confirm the function of Eg FAD12, we performed CRISPR-Cas9-mediated knockout of Eg FAD12 in Euglena, which resulted in a drastic reduction in linoleic acid (C18:2) without compromising biomass yield or lipid content. This work advances our understanding of fatty acid biosynthesis in Euglena and will aid in its adoption as a platform for producing customized lipids. Full article

Methane is a potent greenhouse gas that requires its emissions to be mitigated. A significant source for methane emissions is in the form of the biogas that is produced from anaerobic digestion in wastewater reclamation and landfill facilities. Biogas has a high valorization potential in the form of its bioconversion into ectoines, an active ingredient in skin care products, by halotolerant alkaliphilic methanotrophs. Cultures of Methylotuvimicrobium alcaliphilum 20Z were grown in bench scale stirred-tank reactors to determine factors to improve methane uptake and removal. Tangential flow filtration was also implemented for a bio-milking method to recover ectoine from culture media. Methane uptake and reactor productivity increased, with a temperature of 28 °C compared with 21 °C. Decreasing the methane gas bubble diameter by decreasing the sparger pore size from 1 mm to 0.5 µm significantly improved methane removal and reactor productivity by increasing mass transfer. Premixing methane and air before sparging into the reactor saw a higher removal of methane, while sparging methane and air separately created an increase in reactor productivity. Maximum methane removal efficiency was observed to be 70.56% ± 0.54 which translated to a CH₄-EC of 93.82 ± 3.36 g CH₄ m⁻³ h⁻¹. Maximum ectoine yields was observed to be 0.579 mg ectoine L⁻¹ h⁻¹. Full article

Spontaneous combustion of charcoal is still not fully understood, generating uncertainties among producers, regulatory agencies, and the scientific community. This study evaluated the influence of final pyrolysis temperature (350, 450, 550, and 650 °C) on the properties of Eucalyptus spp. charcoal and its relation to ignition behavior. Gravimetric yield, proximate composition, calorific value, and ignition temperature were determined. Charcoal yield decreased by 31% between 350 °C and 650 °C. Fixed carbon content increased from ~65% to ~93%, accompanied by a reduction in volatile matter (~35% to ~6%) and a corresponding rise in calorific value. Step-heating experiments, conducted in a furnace with infrared camera monitoring, showed that ignition temperature increased from ~273 °C in charcoal produced at 350 °C to ~424 °C in charcoal produced at 650 °C. Strong correlations indicated that higher fixed carbon and lower volatile matter contents are directly associated with higher ignition temperatures. These results demonstrate that increasing the final pyrolysis temperature improves both the thermal stability and the energy quality of charcoal, although at the expense of gravimetric yield. Since the methodology was based on forced heating rather than spontaneous combustion under near-ambient conditions, complementary tests are required to evaluate spontaneous combustion propensity. Overall, the findings provide practical insights to balance yield, quality, and safety while reinforcing the importance of standardized assessment protocols to ensure safer storage and transport of charcoal. Full article

The growing challenge of managing end-of-life creosote-treated railroad ties, along with the increasing demand for effective water treatment solutions, has highlighted the potential of converting railroad tie biomass into functional biochar through pyrolysis. Pyrolysis temperatures ranging from 250 °C to 700 °C were evaluated to determine their influence on biochar yield, physicochemical properties, and adsorption performance for nitrate and phosphate. The findings revealed that increasing pyrolysis temperature enhanced biochar surface area and porosity, reaching 454.9 m²/g at 700 °C. Elemental analyses showed maximum carbonization at 550 °C, with carbon content peaking at 80%, reflecting the development of more stable aromatic structures. SEM and FTIR analyses confirmed these structural changes, including the emergence of extensive pore networks and aromatic frameworks. Biochar produced at 600 °C demonstrated high nitrate (80%) and phosphate (79%) removal efficiencies, following Freundlich isotherm models. Magnesium-modified biochar further improved nitrate adsorption, reaching 90% removal at 5 ppm. Importantly, polycyclic aromatic hydrocarbons in the biochar decreased significantly at higher temperatures, ensuring environmental safety. This work demonstrates the dual environmental benefits of converting hazardous railroad tie waste into value-added biochar for nutrient removal in water treatment applications, offering a sustainable and scalable solution for circular waste management. Full article

Filtrate from dewatering anaerobically digested biosolids is a side-stream of wastewater treatment that contains high concentrations of nitrogen and phosphorus compounds that can serve as nutrients for cultivating microalgae biomass as biofilms for bioproduct production at Water Resource Recovery Facilities (WRRFs). One system used to cultivate attached microalgae biofilms is the rotating algal biofilm reactor (RABR). A pilot RABR with 72 m² growth surface area, 11.5 m² footprint area, and a liquid volume of 11,500 L was operated in an outdoor environment at the largest WRRF in Utah, U.S.A, the Central Valley Water Reclamation Facility (CVWRF). The configuration of the RABR was altered from the previous configuration with regard to temperature and duty cycle with the goal to maximize biomass productivity. Results included an increase in dry biomass productivity on a footprint basis from 8.8 g/m²/day to 26.8 g/m²/day (205%) while power requirements changed from 28.3 W to 91 W. The increase in biomass productivity has direct benefits for bioproducts including bioplastic, biofertilizer, and the extraction of lipids for conversion to biofuels. Full article

Due to the ever-increasing energy demand, Algeria’s sustainable energy crisis is a significant problem. Plant and crop residues can be a solution to this problem if they are used for bioethanol production, a viable alternative to fossil fuels. This study explores the potential of existing agricultural crop residues to overcome the sustainable energy crisis in Algeria. Agricultural residues such as cereals, roots and tubers, pulses, oil crops, vegetables, and fruits have great potential to solve the problem. The agricultural residues that are normally wasted can be utilized to produce bioethanol, which provides sustainable energy and also help to obtain a clean environment. It has been found that 1.65 million tons of bioethanol can be produced from Algeria’s available residues, which is equivalent to 44.10 petajoule of energy. Cereal and fruit residues contribute to most bioethanol generation, about 47.22% and 23.38%, respectively. In addition, bioethanol generated from residue can be used in Algeria’s transportation sector. Considering Algeria’s current energy condition, gasoline blended with ethanol such as E10 and E5 can be used in Algerian vehicles since no modification of vehicles is needed for utilizing these fuels. Research indicates that lignocellulosic biomass sources in Algeria, such as Alfa, olive pomace, and cereal straw, could provide up to 0.67 million tons of oil equivalent (Mtoe), representing approximately 4.37% of the energy consumption of the transport sector in Algeria. Algeria has the potential to produce up to 73.5 Mtoe and 57.9 Mtoe of renewable energy utilizing the energy crops. This study will also encourage relevant policymakers to develop sustainable energy policies that will enhance the renewable energy share in Algerian energy dynamics. Full article

Heavy metals (HMs) including cadmium (Cd), lead (Pb), arsenic (As), zinc (Zn), copper (Cu), chromium (Cr), and nickel (Ni) pose significant challenges to bioenergy crop production due to their persistence, toxicity, and bioaccumulation in soils and plants. This study not only summarizes the mechanisms of HM absorption, translocation, and accumulation in bioenergy crops, but also critically assesses their impact on crop development, biomass quality, and biorefinery processes. Heavy metals disrupt key physiological processes and modify lignocellulosic composition, which is important for biofuel and biogas production. Global soil contamination from sources like industrial emissions, mining, and agricultural activities exacerbates these problems, posing a threat to both energy security and environmental sustainability. Sustainable management strategies, including phytoremediation, microbial bioremediation, soil amendments, and genetic engineering, are explored to mitigate HM effects while enhancing crop resilience. This review emphasizes the importance of integrating techniques to balance bioenergy production with environmental and human health and safety, including the use of HM-tolerant crop varieties, enhanced biorefinery processes, and robust policy frameworks. Future research should focus on developing scalable remediation technologies and interdisciplinary solutions that align with the United Nations’ Sustainable Development Goals and meet global bioenergy needs. Full article