Microbes' role in environmental pollution and remediation: a bioeconomy focus approach.

Bioremediation stands as a promising solution amid the escalating challenges posed by environmental pollution. Over the past 25 years, the influx of synthetic chemicals and hazardous contaminants into ecosystems has required innovative approaches for mitigation and restoration. The resilience of these compounds stems from their non-natural existence, distressing both human and environmental health. Microbes take center stage in this scenario, demonstrating their ability of biodegradation to catalyze environmental remediation. Currently, the scientific community supports a straight connection between biorefinery and bioremediation concepts to encourage circular bio/economy practices. This review aimed to give a pre-overview of the state of the art regarding the main microorganisms employed in bioremediation processes and the different bioremediation approaches applied. Moreover, focus has been given to the implementation of bioremediation as a novel approach to agro-industrial waste management, highlighting how it is possible to reduce environmental pollution while still obtaining value-added products with commercial value, meeting the goals of a circular bioeconomy. The main drawbacks and challenges regarding the feasibility of bioremediation were also reported.

In/Visible - A Photographic Journey Into the Lives of Egg Donors in Spain.

The result of a collaboration between an anthropologist and a photographer, in this photo essay we aim to visualize the medical process of egg donation and the quotidian lives of egg donors in Spain. By extending their biographies beyond the moment of extraction, we shed light on the intertwined messiness of medical procedures and everyday life and the precarious circumstances in which egg donation takes place in Spain today. Our aim is to highlight the participants who, although they matter most in the egg donation economy, are concealed: the egg donors.

Evaluating the feasibility of medium chain oleochemical synthesis using microbial chain elongation.

Chain elongating bacteria are a unique guild of strictly anaerobic bacteria that have garnered interest for sustainable chemical manufacturing from carbon-rich wet and gaseous waste streams. They produce C6-C8 medium-chain fatty acids which are valuable platform chemicals that can be used directly, or derivatized to service a wide range of chemical industries. However, the application of chain elongating bacteria for synthesizing products beyond C6-C8 medium-chain fatty acids has not been evaluated. In this study, we assess the feasibility of expanding the product spectrum of chain elongating bacteria to C9-C12 fatty acids, along with the synthesis of C6 fatty alcohols, dicarboxylic acids, diols, and methyl ketones. We propose several metabolic engineering strategies to accomplish these conversions in chain elongating bacteria and utilize constraint-based metabolic modelling to predict pathway stoichiometries, assess thermodynamic feasibility, and estimate ATP and product yields. We also evaluate how producing alternative products impacts the growth rate of chain elongating bacteria via resource allocation modelling, revealing a trade-off between product carbon length and class versus cell growth rate. Together, these results highlight the potential for using chain elongating bacteria as a platform for diverse oleochemical biomanufacturing and offer a starting point for guiding future metabolic engineering efforts aimed at expanding their product range.

Retention of prions in the polychaete Hediste diversicolor and black soldier fly, Hermetia illucens, larvae after short-term experimental immersion and feeding with brain homogenate from scrapie infected sheep.

Finding alternative protein and lipid sources for aquafeeds is crucial for the sustainable growth of fed aquaculture. Upcycling industrial side streams and byproducts using extractive species can reduce waste and help reduce the sector's dependence on fish meal and fish oils. Polychaete worms (Hediste diversicolor) and black soldier fly (Hermetia illucens) larvae (BSFL) are promising candidates for converting waste materials into valuable protein and lipid sources. However, further research and evaluations are needed to ensure the safety and regulatory compliance of these alternative feed sources, especially regarding prions spreading potential in the unlikely case that prions would be introduced in the value chain via feedstocks. In the present investigation, BSFL and juvenile polychaetes that had received a massive dose of scrapie prions through immersion and oral inoculation were found to harbour detectable prions using an ultrasensitive amplification method known as PMCA. This observation suggests that both H. diversicolor and BSFL have the potential to serve as mechanical vectors for prions diseases. However, it is important to note that insects, lacking the prion protein gene, are incapable of propagating prions. Therefore, the quantity of prions present in the larvae will inevitably be lower than the amount of prions they encountered. This is the first study to report on the fate of prions through ingestion by these marine and terrestrial invertebrate species.

Integrated sustainability assessment of wood building products: The case of larch and chestnut cascading systems in Northern Italy.

Wood is increasingly being appreciated in construction due to its valuable environmental attributes. This paper explores the environmental and market performance of two wood supply chains in Northern Italy. Larch and chestnut wood are extracted and processed to obtain beams, planks, MDF panels and energy. LCA is performed to evaluate the environmental impacts of 1m3 of extracted wood through a cradle-to-gate approach. Then, a biogenic carbon analysis is carried out using the EN 16449:2014 standard including a comparison of different end-of-life treatments. Also, OSB is proposed as an alternative path for wood chips and contrasted to the current energy scenario. Moreover, solid wood beams and planks are compared with engineered wood products (EWPs). Lastly, a market analysis is conducted to assess the market trends of the different wood products studied. The LCA shows similar results for both wood species across most impact categories, with slightly higher values for the chestnut system. Most impacts are related to the production of MDF boards and the energy valorization of wood chips. Biogenic carbon analysis shows a negative balance of emissions with -314 and -205 kg of CO2 eq for larch and chestnut, respectively. It also suggests that OSB manufacturing can be a valuable alternative to the energy use of wood chips and that the end-of-life treatment with better results is recycling. The comparison of beams and planks with engineered wood products supports that solid wood poses a better environmental alternative in similar applications. Market analysis shows stagnation in the apparent consumption of wood products in the European market and a slight growth in the Italian one between 2018 and 2022. Overall, the systems studied suggest that the potential environmental benefits of using wood in construction are not being matched by current market trends.

Biobased heterogeneous renewable catalysts: Production technologies, innovations, biodiesel applications and circular bioeconomy.

The growing population and waste biomass accumulation are leading to increased environmental pollution and climate change. Waste biomass comprising of nutrient rich components has promising potential to produce value-added products for sustainable environmental solutions. This review explores the critical role of bio-based heterogeneous catalysts in enabling sustainable waste biomass utilization. In industrial chemical transformations, over 95% involve catalysts, with more than 90% being heterogeneous systems, prized for their robustness, ease of product separation, and reusability. Bio-based heterogeneous catalysts address the pressing need for sustainable waste biomass management, allowing the conversion of diverse waste biomasses into biodiesel as valuable products. Research on these catalysts, particularly for biodiesel production, has shown yields exceeding 90% with enhanced catalyst reusability. This surge in research is evident from the increasing number of published articles, notably in 2022 and 2023, highlighting growing interest and importance in the scientific community. The synthesis of these catalysts is examined, including novel approaches and techniques to enhance their efficiency, selectivity, and stability. The challenges with their feasible solutions of heterogeneous catalysts in catalyst-based processes are addressed. Altogether, this review underscores the immense potential of bio-based heterogeneous catalysts in sustainable waste biomass utilization, aligning with resource efficiency and environmental conservation goals while offering distinct insights and perspectives on the latest innovations in the field.

Barriers to commercial deployment of biorefineries: A multi-faceted review of obstacles across the innovation chain.

Realizing integrated biorefineries producing multiple fuels, chemicals and materials from sustainable biomass feedstocks holds promise for transitioning industries onto low-carbon trajectories. However, widespread commercial implementation remains elusive despite two decades of technological advancements. This review synthesizes current literature to provide a comprehensive analysis of key multi-dimensional barriers inhibiting the scale-up of biorefineries. The review discusses the technical challenges around biomass conversion processes. Economic viability concerns such as high capital costs and lack of market competitiveness are also assessed. The review also evaluates the regulatory and policy complexities that poses risks and uncertainties in the scaling up of biorefineries. Socio-political acceptance hurdles including community engagement and public perception are also reviewed. The interconnected nature of these challenges is emphasized and strategies are recommended to enable full potential realization, covering areas such as enhanced stakeholder collaboration, advanced process intensification, supportive policy frameworks, innovative financing models and strategic marketing initiatives. International pilots and cross-sectoral knowledge exchange are highlighted as priority enablers. In conclusion, this review synthesizes insights from extensive demonstration efforts to identify priorities and pathways for accelerating the global commercial transition towards sustainable biorefinery implementation. It aims to inform strategic decision-making and collaborative actions amongst stakeholders in research, industry and policy domains.

Transfer and bioaccumulation of chemical and biological contaminants in the marine polychaete Hediste diversicolor (OF müller 1776) when reared on salmon aquaculture sludge.

Side streams from aquaculture production such as fish sludge poses ample opportunities for biological upcycling, as the sludge contains high amounts of nutrients, energy and valuable biochemicals, making it an ideal food for extractive species. Sludge has been proposed as a feed stock for polychaete production, which in turn can be utilized live in shrimp aquaculture or as an aquafeed ingredient. However, the biosafety of such value chains has not yet been addressed. We conducted an experiment exposing the polychaete Hediste diversicolor to aquaculture sludge spiked with four different fish pathogens (Mycobacterium salmoniphilum, Yersinia ruckeri, Infectious Pancreatic Necrosis (IPN) and Infectious Salmon Anaemia (ISA)) known to cause diseases in Atlantic salmon (Salmo salar L.). Moreover, we assessed whether heavy metals and other potentially hazardous elements present in fish sludge bioaccumulates in the polychaetes. Neither of the bacteria nor viruses could be detected in the polychaetes after 14 days of continuous exposure. Seven of the 15 elements we analysed showed bioaccumulation factors significantly below one, meaning biodilution, while the other eight did not differ from one, meaning no bioaccumulation. None of the elements showed a significant bioaccumulation. Further on, none of the heavy metals found in the polychaetes at the end of our experiment exceeded the EU regulatory maximum levels for fish feed ingredients. The current results suggest that a H. diversicolor can reared on aquaculture sludge, and aquaculture sludge may serve as feed stock for polychaete production without the product exceeding EU regulations for contaminants in animal feed.

Exploring industrial lignocellulosic waste: Sources, types, and potential as high-value molecules.

Lignocellulosic biomass has a promising role in a circular bioeconomy and may be used to produce valuable molecules for green chemistry. Lignocellulosic biomass, such as food waste, agricultural waste, wood, paper or cardboard, corresponded to 15.7% of all waste produced in Europe in 2020, and has a high potential as a secondary raw material for industrial processes. This review first presents industrial lignocellulosic waste sources, in terms of their composition, quantities and types of lignocellulosic residues. Secondly, the possible high added-value chemicals obtained from transformation of lignocellulosic waste are detailed, as well as their potential for applications in the food industry, biomedical, energy or chemistry sectors, including as sources of polyphenols, enzymes, bioplastic precursors or biofuels. In a third part, various available transformation treatments, such as physical treatments with ultrasound or heat, chemical treatments with acids or bases, and biological treatments with enzymes or microorganisms, are presented. The last part discusses the perspectives of the use of lignocellulosic waste and the fact that decreasing the cost of transformation is one of the major issues for improving the use of lignocellulosic biomass in a circular economy and green chemistry approach, since it is currently often more expensive than petroleum-based counterparts.

Unlocking pilot-scale green diesel production from microalgae.

Microalgae have emerged as a promising source of biomass to produce renewable biofuels due to their ability to synthesize high-energy density compounds of commercial interest. This study proposes an approach for pilot-scale oil extraction, purification by fractional distillation, hydrocarbon characterization by gas chromatography coupled to mass spectrometry (GC-MS), evaluation of physicochemical parameters of the produced hydrocarbons, preliminary cost analysis, and challenges and future opportunities for green diesel on a commercial scale. Here, the microalgae Tetradesmus obliquus was cultivated in 12 m³ photobioreactors using biodigested swine waste as a culture medium. The resulting biomass was subjected to drying and harvesting, followed by oil extraction using a hot solvent extraction method, followed by distillation to purify the compounds. Three different extraction and distillation experiments were conducted, each using different solvent combinations. The results obtained revealed that extraction with a solvent blend, composed of hexane and ethanol, provided more significant yields compared to extraction with pure hexane. GC-MS analysis showed the presence of alkanes and alkenes in the oil samples, and the proportion of solvent used in the extraction directly influenced the production of alkanes. Additionally, specific hydrocarbons such as 4-methyl-1-decene, 8-heptadecene, 1-pentadecene, 9-heneicosene, and 2-dodecene were identified. The evaluation of the physicochemical parameters demonstrated that the calorific value of the distilled oil samples is within the range of typical values for petroleum diesel. However, it was observed that the distilled oil samples had higher sulfur content compared to conventional diesel. Regarding the cost analysis, it was found that it varies depending on the experimental conditions. In particular, the process using a solvent mixture of 70% hexane and 30% ethanol proved to be more economical than the others, since it extracted a greater quantity of oil with a lower initial biomass requirement. In summary, this microalgae-derived hydrocarbon production process is promising and offers insights for compound purification and future biofuel applications.

Various extracts of the brown seaweed Cystoseira barbata with different compositions exert biostimulant effects on seedling growth of wheat.

Worldwide, where the demand for novel and greener solutions for sustainable agricultural production is increasing, the use of eco-friendly products such as seaweed-derived biostimulants as pre-sowing treatment represent a promising and important approach for the future. Cystoseira barbata, a brown seaweed species abundant in the Mediterranean Region, was collected from the Marmara Sea and subjected to water, alkali, and acidic extractions, and the biostimulant activity of these extracts was tested on wheat (Triticum durum cv. Saricanak-98) using different rates through application to the seeds or germination medium (substrate) applications. The different extracts were characterized by mineral, total phenolic, free amino acid, mannitol, polysaccharide, antioxidant concentrations and hormone-like activity. The effects of the extracts on growth parameters, root morphology, esterase activity, and mineral nutrient concentrations of wheat seedlings were investigated. Our results suggest that the substrate application was more effective in enhancing the seedling performance compared to the seed treatment. High rates of seaweed extracts applied to substrates increased the shoot length and fresh weight of wheat seedlings by up to 20 and 25%, respectively. The substrate applications enhanced the root fresh weights of wheat seedlings by up to 25% when compared to control plants. Among the biostimulant extract applications, the water extract at the highest rate yielded the most promising results in terms of the measured parameters. Cystoseira barbata extracts with different compositions can be used as effective biostimulants to boost seedling growth. The local seaweed biomass affected by mucilage problems, has great potential as a bioeconomy resource and can contribute to sustainable practices for agriculture.

Valorizing date palm spikelets into activated carbon-derived composite for methyl orange adsorption: advancing circular bioeconomy in wastewater treatment-a comprehensive study on its equilibrium, kinetics, thermodynamics, and mechanisms.

Leveraging date palm spikelets (DPS) as a precursor, this study developed a DPS-derived composite (ZnO@DPS-AC) for water treatment, focusing on methyl orange (MO) removal. The composite was synthesized through ZnCl2 activation and pyrolysis at 600 °C. Comprehensive characterization was conducted using TGA, FTIR, XRD, SEM/EDS, and pHPZC. Characterization revealed a highly carbonaceous material (> 74% carbon) with significant porosity and surface functional groups. ZnO@DPS-AC demonstrated rapid MO removal, achieving over 45% reduction within 10 min and up to 99% efficiency under optimized conditions. The Langmuir model-calculated maximum adsorption capacity reached 226.81 mg/g at 20 °C. Adsorption mechanisms involved hydrogen bonding, π-π interactions, and pore filling. The composite showed effectiveness in treating real wastewater and removing other pollutants. This study highlights the potential of agricultural waste valorization in developing efficient, sustainable adsorbents for water remediation, contributing to circular bioeconomy principles.

Biodegradable films from soyhull cellulosic residue with UV protection and antioxidant properties improve the shelf-life of post-harvested raspberries.

Post-harvest loss of fruits and vegetables, and health risks and environmental impact of current plastic packaging warrant new biodegradable packaging. To this end, cellulosic residue from agricultural processing byproducts is suitable due to its renewability and sustainability. Herein, soyhulls cellulosic residue was extracted, solubilized in ZnCl2 solution, and crosslinked with calcium ions and glycerol to prepare biodegradable films. The film combination was optimized using Box Behnken Design and film properties were characterized. The optimized film is translucent and exhibits tensile strength, elongation at break, water vapor permeability, hydrophobicity, and IC50 of 6.3 ± 0.6 MPa, 30.2 ± 0.9%, 0.9 ± 0.3 × 10-10 gm-1 s-1 Pa-1, 72.6°, and 0.11 ± 0.1 g/mL, respectively. The water absorption kinetics follow the Peleg model and biodegrade within 25 days at 24% soil moisture. The film extends the shelf life of raspberries by 6 more days compared to polystyrene film. Overall, the value-added soyhull cellulosic films are advantageous in minimizing post-harvest loss and plastic-related issues, emphasizing the principles of the circular bioeconomy.

Life cycle analysis of apple pomace biorefining for biofuel and pectin production.

This study investigated the environmental impacts associated with converting apple pomace, a globally abundant resource, into biofuels and high-value products using a comparative consequential life cycle assessment. In three developed scenarios, an acid pretreatment method was applied and the pretreated liquid was used for ethanol and pectin production. The pretreated solids were utilized to produce different products: scenario 1 produced biogas, scenario 2 generated butanol, and scenario 3 yielded both biogas and butanol from the solids. The results demonstrated that scenario 1 exhibited the best performance compared to the other two scenarios, imposing the lowest environmental burdens across all damage categories, including human health, ecosystems, and resources. Despite the induced impacts, the benefits of avoided products, i.e., ethanol, natural gas, butanol, acetone, and pectin, compensated for these induced environmental impacts to some extent. The results also revealed that among all products generated through the biorefineries, first-generation ethanol substitution had the most significant positive environmental impacts. Overall, the biorefinery developed in scenario 1 represents the most feasible strategy for a circular bioeconomy. It performs 84.38 % and 72.98 % better than scenarios 2 and 3 in terms of human health, 85.34 % and 74.54 % better in terms of ecosystems, and more than 100 % better in terms of resources. Conversely, scenario 2 resulted in the highest net impacts across all damage categories. Furthermore, in scenario 1, the midpoint results showed 83.10 % and 71.08 % lower impacts on global warming, 85.15 % and 74.17 % lower impacts on terrestrial acidification, and 99.26 % and 98.53 % lower impacts on fossil resource scarcity compared to scenarios 2 and 3, respectively. In conclusion, the first scenario shows promise for the sustainable valorization of apple pomace.

Comprehensive assessment of cow manure hydrothermal treatment products for land application and energy recovery.

In this study, cow manure was hydrothermally treated in a 2-litre reactor for 1 h at temperatures between 100 °C and 260 °C. Both the raw manure and the solid and liquid products of the hydrothermal treatment were characterized to understand the fate of the inorganic elements and to assess the suitability of the products for land applications and energy recovery. Satisfactory elemental balances were obtained for the organic and most inorganic elements and indicated that most inorganic elements were incorporated into the solids with lower solubility, with the exception of potassium and sodium, which were mostly solubilized in the process water; calcium and chlorine were also solubilized to a lesser extent in the process water. Elemental composition and surface functional groups showed that hydrochar produced within the hydrothermal carbonization range (180-260 °C) seemed better suited for utilization as a soil amendment than raw cow manure. The potential for energy recovery lies in the anaerobic digestion of the process water, from which higher methane yields can be obtained than from raw cow manure. Lower temperatures in hydrothermal carbonization are considered a compromise for the safe land applications of cow manure, energy recovery from the process water, and enhanced dewaterability. These findings can help to eliminate bottlenecks in the upscaling of cow manure hydrothermal treatment and promote the circular bio-economy.

Fungal endo and exochitinase production, characterization, and application for Candida biofilm removal.

Chitinases are promising enzymes for a multitude of applications, including chitooligosaccharide (COS) synthesis for food and pharmaceutical uses and marine waste management. Owing to fungal diversity, fungal chitinases may offer alternatives for chitin degradation and industrial applications. The rapid reproduction cycle, inexpensive growth media, and ease of handling of fungi may also contribute to reducing enzyme production costs. Thus, this study aimed to identify fungal species with chitinolytic potential and optimize chitinase production by submerged culture and enzyme characterization using shrimp chitin. Three fungal species, Coriolopsis byrsina, Trichoderma reesei, and Trichoderma harzianum, were selected for chitinase production. The highest endochitinase production was achieved in C. byrsina after 168 h cultivation (0.3 U mL- 1). The optimal temperature for enzyme activity was similar for the three fungal species (up to 45 and 55 ºC for endochitinases and exochitinases, respectively). The effect of pH on activity indicated maximum hydrolysis in acidic pH (4-7). In addition, the crude T. reesei extract showed promising properties for removing Candida albicans biofilms. This study showed the possibility of using shrimp chitin to induce chitinase production and enzymes that can be applied in different industrial sectors.

Advancing a food loss and waste bioproduct industry: A critical review of policy approaches for application in an Australian context.

Food loss and waste (FLW) contains an abundance of nutrient components that can be extracted and converted into valuable bioproducts through biorefining (e.g., pharmaceuticals, cosmetics, nutrients). Australia has identified bioproducts from a FLW feedstock as one avenue through which it can meet its commitment to UN Sustainable Development Goal Target 12.3, aiming to halve food waste by 2030. An industry for bioproducts in Australia is, however, nascent and will require targeted and sustained policy intervention to advance in line with the production targets it has set to meet Target 12.3. The aim of this critical review is threefold. Firstly, it draws on the research literature to identify barriers to advancing a bioproduct industry from FLW. Secondly, it constructs a taxonomy of policies available to overcome these barriers and support industry development. Finally, it applies the taxonomy to established policy settings in Australia (examining both national settings and Queensland state settings) and the European Union (EU), where the industry and associated policy is more mature. Australia has few national policies directly targeting a bioproduct industry. A comparative assessment of policy settings allows this review to identify lessons Australia can draw from the EU experience as it advances its own industry. Findings demonstrate a complex and fragmented policy landscape. Key recommendations from the literature emphasise the need to establish coordinated strategic instruments; target research and development opportunities for optimised, sustainable processes; and implement appropriate incentives to establish a 'level playing field', as technology readiness increases. The critical requirement for policy stability and coherence, flags the need to lay groundwork policy in this area as a priority.

Potato Berries as a Valuable Source of Compounds Potentially Applicable in Crop Protection and Pharmaceutical Sectors: A Review.

Potato (Solanum tuberosum) is a major agricultural crop cultivated worldwide. To meet market demand, breeding programs focus on enhancing important agricultural traits such as disease resistance and improvement of tuber palatability. However, while potato tubers get a lot of attention from research, potato berries are mostly overlooked due to their level of toxicity and lack of usefulness for the food production sector. Generally, they remain unused in the production fields after harvesting the tuber. These berries are toxic due to high levels of glycoalkaloids, which might confer some interesting bioactivities. Berries of various solanaceous species contain bioactive secondary metabolites, suggesting that potato berries might contain similarly valuable metabolites. Therefore, possible applications of potato berries, e.g., in the protection of plants against pests and pathogens, as well as the medical exploitation of their anti-inflammatory, anticarcinogenic, and antifungal properties, are plausible. The presence of valuable compounds in potato berries could also contribute to the bioeconomy by providing a novel use for otherwise discarded agricultural side streams. Here we review the potential use of these berries for the extraction of compounds that can be exploited to produce pharmaceuticals and plant protection products.

Effect of Different Compatibilizers on the Properties of Green Low-Density Polyethylene Composites Reinforced with Bambusa Vulgaris Bamboo Fibers.

Low-density green polyethylene (LDGPE) composites reinforced with 5 wt% of bamboo fiber and 3 wt% of a compatibilizing agent (polyethylene grafted with maleic anhydride and tannin) were processed through extrusion and injection molding. Bamboo fiber, Bambusa Vulgaris, was characterized using Fourier-transform infrared spectroscopy (FTIR). The molded specimens were analyzed for their thermal, mechanical, and morphological properties. The estimated concentration was chosen to provide the best mechanical strength to the material studied. FTIR analysis of the fibers revealed the presence of groups characteristic of bamboo fiber and tannin. Differential scanning calorimetry revealed that both compatibilizing agents increased the matrix's degree of crystallinity. However, scanning electron microscopy (SEM) showed that, despite the presence of compatibilizing agents, there was no significant improvement in adhesion between the bamboo fibers and LDGPE.

A Circular Bioeconomy Approach to Using Post-Bioadsorbent Materials Intended for the Removal of Domestic Wastewater Contaminants as Potential Reinforcements.

Agro-industrial residue valorization under the umbrella of the circular bioeconomy (CBE) has prompted the search for further forward-thinking alternatives that encourage the mitigation of the industry's environmental footprint. From this perspective, second-life valorization (viz., thermoplastic composites) has been explored for agro-industrial waste (viz., oil palm empty fruit bunch fibers, OPEFBFs) that has already been used previously in other circular applications (viz., the removal of domestic wastewater contaminants). Particularly, this ongoing study evaluated the performance of raw residues (R-OPEFBFs) within three different size ranges (250-425, 425-600, 600-800 µm) both before and after their utilization in biofiltration processes (as post-adsorbents, P-OPEFBFs) to reinforce a polymer matrix of acrylic resin. The research examined the changes in R-OPEFBF composition and morphology caused by microorganisms in the biofilters and their impact on the mechanical properties of the composites. Smaller R-OPEFBFs (250-425 µm) demonstrated superior mechanical performance. Additionally, the composites with P-OPEFBFs displayed significant enhancements in their mechanical properties (3.9-40.3%) compared to those with R-OPEFBFs. The combination of the three fiber sizes improved the mechanical behavior of the composites, indicating the potential for both R-OPEFBFs and P-OPEFBFs as reinforcement materials in composite applications.