Chemical Engineering Journal

Fermentation of C1 gases is an emerging technology where waste gases are bio converted into value-added products. This study navigates the gas fermentation potential of Gordonia rubripertincta to produce carotenoids. The crucial carbon monoxide dehydrogenase (CODH) enzyme, necessary for gas uptake by the microbe, was found to be present in G. rubripertincta through blastp on NCBI website. The organism was then used for gas fermentation experiments in a continuous stirred tank reactor (CSTR) in different modes of reactor operation resulting in the production of about 500 mg pigment/g WCW (wet cell weight). Two important reactor parameters, molybdenum content and pH, were optimized for enhanced carotenoid production. Overall, G. rubripertincta was observed to be an efficient candidate organism for C1 gas fermentation. KEY HIGHLIGHTSO_LIGordonia rubripertincta synthesises aerobic carbon monoxide dehydrogenase enzyme. C_LIO_LIIt is a potential gas fermenting microbe that gives carotenoids as product. C_LIO_LIThe gas uptake efficiency of the microbe is more in fed-batch discontinued mode. C_LIO_LIIn FB-D, the resultant carotenoids are 500+9 mg/g wet cell weight (WCW). C_LIO_LIMo/pH of 20 mg/7.0 resulted in highest carotenoids, i.e., 134+41 mg/g WCW. C_LI GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=87 SRC="FIGDIR/small/722808v1_ufig1.gif" ALT="Figure 1"> View larger version (28K): org.highwire.dtl.DTLVardef@8b1185org.highwire.dtl.DTLVardef@2b6f90org.highwire.dtl.DTLVardef@1a9697dorg.highwire.dtl.DTLVardef@14c9dc8_HPS_FORMAT_FIGEXP M_FIG C_FIG

Bio-based materials are known for their excellent biodegradability and, in some cases, their potential to fix carbon dioxide. Owing to these properties, they are increasingly being utilized as environmentally friendly alternatives across various applications. In this study, we focused on using living cells themselves as material components, aiming to evaluate their potential as substitutes for conventional plastic-based thermal insulators. We selected two types of cells, photosynthetic purple non-sulfur bacterium Rhodovulum sulfidophilum and tobacco BY-2 plant suspension cells. After optimizing solidification conditions through the addition of pectin and cellulose nanofibers, we measured the thermal conductivity of the solidified cells under atmospheric pressure. The results showed that R. sulfidophilum exhibited 0.0553 W/m{middle dot}K, while BY-2 exhibited a thermal conductivity of 0.043 W/m{middle dot}K. Both values indicate relatively low thermal conductivity compared to existing bio-based materials, suggesting high insulation performance. Among the solidified cells, the solidified BY-2 cells showed minimal variation in thermal insulation performance under pressure changes, and had a low thermal emissivity as revealed by FT-IR analysis. Based on these findings, we propose that cell-derived materials can serve as potentially biodegradable bio-based thermal insulation materials.

The mass-rearing of black soldier fly (Hermetia illucens) larvae (BSFL) is a promising solution for converting organic waste into high-quality insect protein, but preventing larval escape from open-top rearing containers remains a major management challenge. Conventional escape-control methods are often unreliable or impractical. To address this, we developed and evaluated a novel physical barrier, the anti-climbing tape, featuring regularly arranged macroscale protrusions designed to disrupt larval locomotion on vertical surfaces. We conducted a series of experiments to examine the design parameters of the anti-climbing tapes, including the gap size between protrusions and the number of protrusion rows. Our results demonstrate that the anti-climbing tape prevents escape via a dual mechanism: (1) physical obstruction, in which gaps narrower than the larval body width block larvae from passing through, and (2) adhesion reduction, in which the elevated protrusion array decreases the effective contact area for wet adhesion while increasing gravitational torque acting on the larval body. The effectiveness of these mechanisms was dependent on larval size. A design featuring 0.5-mm gaps and a 15-row protrusion array completely prevented the escape of later-instar larvae (>10 mm) in a 20-day large-scale trial, whereas the method was less effective for smaller larvae. In conclusion, the anti-climbing tape provides a robust and chemical-free approach to BSFL escape in mass rearing. To ensure reliable performance, its design parameters, both gap size and array width must be optimised to suppress the mechanical and adhesive components of larval climbing according to the target larval size. Conflict of interestS. Jang and M. Shimoda are inventors on a Japanese patent application (No. 2022-172252, filed November 27, 2022) related to the method described in this manuscript. FundingThis study was supported by Korea-Japan Joint Government Scholarship Program for the Students in Science and Engineering Departments, the Korean Scholarship Foundation, and the University of Tokyo Foundations Support Fund for International Students.

As the United Kingdom (UK) targets net-zero emissions by 2050, anaerobic digestion (AD) has become a cornerstone of renewable energy infrastructure. However, mathematical models, such as the Anaerobic Digestion Model No. 1 (ADM1), often struggle with high-solids agricultural feedstocks because they rely on Chemical Oxygen Demand (COD), a metric that introduces significant experimental error. To overcome this, this study applies an established mass-based ADM1 framework tailored for the co-digestion of maize silage and cow manure sourced from a UK AD site. This study uses a parallel reactor framework, using two identical laboratory-scale reactors to physically replicate the dynamic conditions of the full-scale site. A Global Sensitivity Analysis was first conducted, identifying biomass decay and carbohydrate breakdown rates as the most influential factors affecting system stability and model accuracy. The model was calibrated using data from the first reactor and then tested against an independent second reactor subjected to significant organic loading stress. Results show high predictive capabilities, with the model achieving a R2 of 0.81 for biogas production during calibration. The model maintained high predictive accuracy during the validation test of the second physical twin, achieving an R2 of 0.85, proving that the framework is robust and not overfitted to a single dataset. While predicting rapid fluctuations in pH and alkalinity remains challenging, the mass-based approach effectively forecasts gas yields and process stability. This methodology provides a reliable foundation for robust process modelling, offering a scalable tool for the UK biogas sector to optimise AD. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=93 SRC="FIGDIR/small/721061v1_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@92c7e2org.highwire.dtl.DTLVardef@80d723org.highwire.dtl.DTLVardef@ac3d24org.highwire.dtl.DTLVardef@1e21a51_HPS_FORMAT_FIGEXP M_FIG C_FIG

This article presents the development of an advanced modeling and simulation platform for carbon capture systems, with a focus on integrated process analysis from upstream CO2 capture through to bioethanol production. The platform supports the evaluation of CO2 mitigation technology by coupling mathematical bioprocess models with an interactive desktop application. The biological system employs Chlorella vulgaris microalgae to fix CO2 through photosynthesis and generate carbohydrate substrates, which are subsequently converted to bioethanol by Saccharomyces cerevisiae yeast via fermentation. The simulation integrates three established kinetic models--the Monod, Logistic, and Luedeking-Piret models--to predict biomass growth, substrate consumption, and ethanol yield under varying operational conditions. A closed-loop CO2 recycling subsystem captures fermentation off-gases and reintroduces them into the bioreactor, enhancing overall carbon utilization efficiency. Three representative simulation scenarios demonstrated process efficiencies ranging from 1.09% to 93.78% of the theoretical maximum CO2-to-ethanol conversion efficiency, confirming the platforms capacity to evaluate a wide operational envelope. The Electron/React-based desktop application provides real-time visualization, interactive 3D bioreactor models, and a simulation history module, making it accessible to researchers, engineers, and students. The platform serves as a digital twin that bridges rigorous bioprocess mathematics with intuitive user interaction, providing a cost-effective tool for designing and optimizing sustainable carbon capture and biofuel production systems.

Source-separated organics (SSO) are widely processed via anaerobic digestion to produce biogas, yet alternative conversion pathways could generate higher-value products. Here, we demonstrate long-term continuous production and recovery of medium-chain carboxylic acids (MCCAs) from SSO via microbial chain elongation using a bench-scale anaerobic bioreactor operated for 911 days. The reactor was fed with SSO samples collected from two full-scale municipal organics processing facilities in Toronto, Canada, capturing facility-specific and seasonal variability in SSO composition. MCCA production depended strongly on the availability of lactate as an electron donor, which varied with SSO preprocessing operations and outdoor collection temperatures. To mitigate product inhibition, an in-line extraction system using hollow-fiber polydimethylsiloxane (PDMS, also known as silicone) membranes was integrated with the anaerobic membrane bioreactor, providing a robust and solvent-free alternative to solvent-based extraction methods. Maximum MCCA yields reached 0.31 g MCCA/ g VSfeed, with notable octanoic acid production (up to 20% of total MCCA), and production rates up to 0.84 g L-1 d-1. Acidification of the alkaline extract produced a phase-separated MCCA-rich oil ([~]95% purity) without addition of downstream separation steps. Microbial community analysis of the reactor revealed enrichment of putative chain-elongating bacteria, including Eubacterium and Pseudoramibacter species, while shifts in SSO feedstock microbiomes influenced substrate availability and product spectra. These results demonstrate the feasibility of sustained MCCA production from municipal organic waste streams and highlight opportunities to integrate chain elongation with existing anaerobic digestion infrastructure.

Prodigiosin is a red pigment produced by various bacteria, including Serratia marcescens. Despite its wide and promising range of biological activities, the large-scale production of prodigiosin is currently limited by its high cost and low yields. Here we propose and optimize an innovative, low-cost, peanut-based solid culture medium that enhances the yield of prodigiosin produced by Serratia marcescens. Colorimetric assays revealed that peanut significantly stimulates prodigiosin synthesis. Further HPLC-MS analysis allowed us to unambiguously identify prodigiosin and shows that our medium specifically improves the yield of prodigiosin. Overall, our innovative culture medium could help lower prodigiosin production costs and, ultimately, open new industrial applications.

Malic acid is a C4 dicarboxylic acid traditionally produced from petroleum and widely used in the food industry. As a sustainable alternative, it can also be produced as a value-added platform chemical from biomass. Previously, the Escherichia coli strain XZ658 was engineered to produce L-malate via the carbon-fixation reductive branch of the TCA cycle. In this study, we further improved this system by relieving allosteric regulation of citrate synthase, addressing redox imbalance, and enhancing malate export. These modifications approximately doubled the L-malate titer in the final strain MO128 compared to XZ658 under simple batch fermentation conditions. The process achieved a high mass yield of 1.2 g malate g-{superscript 1} glucose, highlighting the carbon-fixation capacity of the reductive TCA pathway for fermentative malate production.

Reducing the cost and environmental impact of cell culture media is an important goal for cultivated meat, the process of generating meat in vitro using proliferating animal cells. While prior approaches have demonstrated the use of microbial lysates to replace expensive animal-based fetal bovine serum (FBS) in media, these formulations still rely on large quantities of growth factors such as fibroblast-like growth factor 2 (FGF2). Here, we demonstrate the use of FGF2-expressing Vibrio natriegens to create whole-cell lysates that replace both FBS and FGF2 in cell culture media for cultivated meat applications. This medium, named "VN40FGF", supports rapid proliferation of immortalized bovine muscle satellite cells (iBSCs) in the absence of supplemented FGF2. Cells grown in VN40FGF maintain phenotype and differentiation capacity. We also demonstrate that engineered V. natriegens can grow in spent cell culture media, further improving sustainability and economics, and reducing potential eutrophication concerns associated with waste disposal. Our approach combines multiple strategies for reducing the total number of media inputs, demonstrating opportunities for more economical and sustainable cell culture, especially for cultivated meats.

Microbial fuel cell offers a promising approach to improve wastewater quality and generate bioenergy from dark fermented effluents. In this study, the use of dark-fermented palm oil mill effluent as an electron donor for bioelectricity generation was investigated using a double-chambered microbial fuel cell (MFC). The MFCs were operated at room temperature (29 {+/-} 2{degrees}C), anode electrolytes adjusted to pH 7, and a chemical catholyte as the oxidizing agent. The maximum power {+/-} 8.07 mW/m2 and 155.16 {+/-} 12.88 mA/m2, respectively, were generated from the MFCs inoculated with sludge, which was 5.9 times higher than control without inoculum. Microbial community analysis revealed the enrichment of fermentative and electrogenic representative taxa from the phyla Bacillota, Bacteroidota and Pseudomonadota on the anode electrodes. Optimizations of the running conditions were carried out, suggesting the optimum parameters of 0.5 k{Omega} external resistance, anolyte initial pH 9, and 75% DFPOME substrate concentration. Operation under the optimized conditions increased current production, wastewater treatment, and Coulombic efficiency compared to the non-optimized conditions. Multiple configurations were also evaluated, showing higher cumulative voltage, power, and current densities with the stacked MFC connections, compared to single MFC units. Parallel circuit connection produced higher power and current density than serial connection. This study demonstrated the feasibility of MFC as a promising downstream treatment for biohydrogen production processes, towards higher treatment efficiency and resource recovery.

This study investigates the potential of the garden rhizosphere as a source of electrochemically active bacteria (EAB) for operating microbial fuel cells (MFCs). We evaluated a diverse array of garden flora, including vegetables (lettuce, Chinese cabbage), flowering plants (August lily, peppermint), and woody species (pine, oak, ginkgo, and bush clover). Among the tested groups, MFCs inoculated with peppermint and ginkgo rhizosphere microbiotas exhibited the highest current densities within their respective categories, significantly outperforming control groups without plant components. 16S rRNA gene microbial community analysis revealed that the initial rhizosphere environment acts as a decisive selective pressure, shaping distinct anode biofilms based on plant types (herbaceous vs. woody). Despite these structural differences in microbial assembly, high current generation was achieved in both peppermint and ginkgo systems, suggesting a high degree of functional redundancy within the rhizosphere-derived consortia. These findings demonstrate that various garden ecosystems can serve as robust biological reservoirs for MFC operation, where diverse microbial configurations are capable of sustaining efficient bio-electrochemical energy conversion.

Odd-chain carboxylates such as valerate and heptanoate are ecologically relevant metabolites and promising platform chemicals, yet the factors leading to their formation during secondary lactate fermentations remain poorly understood. Here, a continuous anaerobic bioreactor was operated for 297 days under mildly acidic conditions to evaluate how lactate:propionate molar ratios shape product spectrum in lactate fermentations. Valerate was the predominant odd-chain product under all conditions, reaching concentrations up to 110 mM, while heptanoate accumulated only at low levels (<10 mM). At low lactate concentrations (10-20 g/L), product selectivity strongly depended on the lactate:propionate ratio. When lactate:propionate ratios were around 1.2 mol/mol, odd-chain products were favored, whereas higher ratios (up to 4.8 mol/mol) shifted metabolism toward caproate and butyrate formation. However, this trend was not maintained at higher lactate concentrations (30-40 g/L; lactate not fully consumed), where odd-chain selectivities remained high even at lactate:propionate ratios of 4.8 mol/mol. Pathway analysis indicated that under high-lactate conditions up to 30% of lactate was redirected toward propionate and acetate formation, likely via the acrylate pathway. Microbial community analysis revealed a stable dominance of Caproiciproducens spp., that could be correlated to valerate production. Overall, this work provides mechanistic insights into the ecology of lactate fermentations and offers a framework for steering product selectivity in engineered anaerobic systems. HighlightsValerate was the dominant product, reaching up to 110 mM. Lactate:propionate ratios drive product selectivities. High lactate concentrations activated in situ propionate formation pathways. Caproiciproducens dominance was associated with sustained valerate production.

Human pluripotent stem cells (hPSCs) hold significant promise for regenerative medicine, yet optimizing their expansion in three-dimensional bioreactor systems remains challenging due to complex interactions between mechanical forces, metabolic constraints, and aggregate formation dynamics. This study developed and validated a mechanistic mathematical model to predict hPSC proliferation dynamics in vertical-wheel bioreactor (VWBR) systems, incorporating the effects of shear stress and energy dissipation rate (EDR) on cell growth and aggregate dynamics. Seven model variants employing different kinetic formulations for shear stress and energy dissipation rate effects were systematically evaluated through model selection, identifiability analyses, and experimental validation. Experimental data from six bioreactor conditions varying in initial cell density (2 x 104-15 x 104 cells/mL), agitation rate (30-60 RPM), and working volume (100-500 mL) were used for model calibration and selection. Bayesian Information Criterion analysis identified a model combining Michaelis-Menten kinetics for shear stress inhibition with a EDR-mediated aggregate detachment formulation as the best-performing variant, achieving a Mean Relative Prediction Error of 13.97%, comparable to the experimental variability of 16.29%. Independent validation experiments using leave-out data gathered under different media exchange schedules confirmed model accuracy with prediction errors below 14%, consistent with observed experimental variability around 12%. The validated model was used to optimize the media exchange protocol, leading to a 37.5% reduction in media consumption with only a 13.5% reduction in final cell yield, demonstrating its utility for prospective, quantitative bioprocess design in VWBR systems.

Environmental pollution from leather industries have become a menace. The microbial remediation of industrial waste and its reuse for agriculture could be a beneficial outcome. In present study, the bioremediated Cr III in the effluents are further converted to value product - Chromium oxide NP. This ensures double edged benefit as effluent is bioremediated and Chromium oxide NP with several applications is derived. A noteworthy advancement of the research involved the green synthesis of chromium oxide nanoparticles using Tridax procumbens. The effluent bioremediated can be used for agricultural purposes. By effectively characterizing tannery effluent and isolating chromium-tolerant bacteria, the study not only demonstrate a practical bioremediation solution but also showcase the potential of green synthesis in producing chromium oxide nanoparticles. In conclusion, this research marks a significant advancement in environmental science, leveraging both biological and nanotechnological innovations to address pressing challenges in pollution control. The present study focuses on a novel process of obtaining chromium oxide nanoparticle from tannery effluent with several applications derived from bioremediated tannery effluent using a cost-effective and eco-friendly process. The nanoparticle has a stable particle size and exhibit antioxidant, anti-diabetic properties. This product offers a breakthrough solution for the leather industry and healthcare sector. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/720289v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@192e96borg.highwire.dtl.DTLVardef@1aae28org.highwire.dtl.DTLVardef@19fd282org.highwire.dtl.DTLVardef@1b562f9_HPS_FORMAT_FIGEXP M_FIG C_FIG

Current mechanical and chemical recycling strategies address less than 10% of global plastic waste, necessitating alternative valorization routes. Biological upcycling via enzymatic depolymerization combined with microbial conversion of the resulting monomers offers a promising pathway to transform mixed plastic waste into valuable alternatives. Here, we employed a single engineered Pseudomonas putida KT2440 for simultaneous co-utilization of five plastic monomers including ethylene glycol, terephthalic acid, adipic acid, 1,4-butanediol, and L-lactic acid, which can be derived from enzymatic hydrolysis of polyethylene terephthalate (PET), polybutylene adipate-co-terephthalate (PBAT), polyester-polyurethanes (PUs), and polylactic acid (PLA). Continuous fermentation over 21 days with alternating mixed-monomer feeds achieved steady state growth and complete substrate depletion, yielding adaptive mutations that informed iterative strain improvement. Further engineering enabled the biosynthesis of (R)-3-hydroxybutyrate (R-3HB), and 0.70 g L-1 R-3HB was produced directly from enzymatic hydrolysates of blended PET, PBAT, and TPU. These results establish a viable bio-based approach for upcycling realistic mixed plastics into value-added bioproducts.

Microbial fuel cells (MFCs) represent a promising technology for the simultaneous treatment of wastewater and bioelectricity generation. In this study, the MFCs are conceived as functional modules to be integrated into hydroponic cultivation systems, acting as a prosthetic rhizosphere capable of coupling wastewater treatment and bioelectrochemical activity with plant nutrition improvement. We compared the electrochemical performance of different microbial consortia comprising the electroactive bacterium Shewanella oneidensis, the plant growth promoting rhizobacterium (PGPR) Pseudomonas putida, and the plant biomass-degrading fungus Ophiostoma piceae, along with the supplementation with the quorum sensing (QS) analogue molecule 1{square} dodecanol. These microbial consortia are tested in MFCs fed with wastewater and root exudates to analyze enhanced feedstock assimilation, electricity production, and the generation of plant growth-promoting substances (PGPS). From an electrochemical perspective, we evaluated planktonic growth, anode adhesion, substrate consumption, and the production of redox-active molecules and PGPS such as flavins and siderophores respectively alongside key electrical production parameters, including current output and power. Among the different microbial configurations tested, the consortium combining S. oneidensis, P. putida, and O. piceae exhibited the highest electrical production potential. Moreover, within this framework, we detected the extracellular production of siderophores in MFCs containing P. putida, suggesting a potential role supporting hydroponic crop growth. Furthermore, the addition of 1-dodecanol led to an improvement of the bioelectrochemical parameters. These results highlight the potential of synthetic microbial consortia in MFC-based systems not only to enhance electricity generation from wastewater but also to provide added value in integrated hydroponic applications through rhizosphere-like functions.

Developing structured cultivated meat requires integrated solutions that combine scalable cell sources with edible, foodgrade materials capable of supporting highdensity growth and differentiation. Here, we evaluate bovine mesenchymal stem cells derived from embryonic stem cells (ESCderived iMSCs) as a scalable adipogenic cell source and develop an integrated workflow combining these cells with edible plantbased scaffolds for structured biomass generation. Cell identity and functionality were assessed using transcriptomic, morphological, gene expression, flow cytometric, and adipogenic differentiation analyses, in both adherent and suspension culture systems. In parallel, lentil, pea, and soy-based scaffold formulations were screened for cell attachment, proliferation, and biomass accumulation. Soybased scaffolds supported uniform cell distribution and robust growth and outperformed lentil-based scaffolds. Under dynamic culture conditions, bovine iMSCs cultured on soy-based scaffolds achieved highdensity growth, showing biomass accumulation (cell wet weight/scaffold wet weight) reached an average cell wet weight to scaffold wet weight ratio of 15% within three days. Cultures demonstrated active glucose metabolism and retained adipogenic differentiation capacity, confirmed by lipid accumulation and positive oil red O staining. These findings demonstrate an integrated cell-scaffold platform for rapid threedimensional biomass generation. This approach supports the development of a cell culture strategy for structured cultivated meat by combining defined cell sources with foodgrade scaffold technologies to improve scalability, structure, and nutritional relevance. HighlightsO_LIBovine ESC-derived iMSCs enable scalable adipogenic cell production C_LIO_LIEdible soy-based scaffolds support 3D attachment and biomass accumulation C_LIO_LIDynamic culture achieved [~]15% cell wet weight fraction within 3 days C_LIO_LIiMSCs retained adipogenic differentiation capacity on edible scaffolds C_LIO_LIIntegrated cell-scaffold culture supports structured cultivated meat prototypes C_LI

In vegetarian diets, phytate is known to disrupt the adsorption of minerals. Fortifying foods with phytase, a therapeutic enzyme known to mitigate phytate, might increase the uptake of important nutrients. Phytase is susceptible to environmental stress such as heat and acidic conditions encountered during food processing. Therefore, we developed and optimized a core-shell microparticle composed of a phytase-chitosan core and a shell consisting of cross-linked alginate-{kappa}-carrageenan. Ethanol was used to precipitate the microparticles, and the ethanol concentration was optimized along with the chitosan and phytase ratio and the alginate-carrageenan concentration, to form stable core-shell microparticles. The optimized core-shell microparticles have a loading capacity of 32.7% with a high encapsulation efficiency of 80.3% and uniform micro-size with a diameter of 3.2 {micro}m and a poly-dispersity index of 0.178. Loaded phytase retained 62.7% enzymatic activity after heat treatment and digestion conditions. These results indicate that core-shell microparticles are suitable for retaining enzyme activity within the food matrix under typical food processing conditions. HighlightsO_LIDevelopment of size-controlled core-shell microparticles to protect phytase C_LIO_LIPhytase-chitosan microparticles are surrounded by an alginate-{kappa}-carrageenan shell C_LIO_LIOptimization achieved 32.7% loading capacity with a uniform size of 3.2 {micro}m C_LIO_LICore-shell microparticles retained 62.7% enzyme activity after heat and digestion C_LIO_LIPhytase powder (2 mg) is required for a single maize meal C_LI

Nanoplastics generated from plastic waste in our ecosystems are becoming increasingly prevalent as bulk plastics exposed to natural factors like water and sunlight fragment to the nanoscale over time. These incidental nanoplastics span a wide range of physicochemical properties, which makes studying nanoplastic interactions in biological systems difficult. Here, we characterized the behavior of incidental nanoplastics generated through mechanical abrasion within coacervate droplets to probe the surface properties of the nanoplastics. We used elastin-like polypeptides (ELPs) to create hydrophobic or charged coacervate microenvironments. Using optical microscopy and fluorescence quantification, we observed that nanoplastics made from polyethylene terephthalate (nPET), nylon 6 (nPA), and polystyrene (nPS) exhibited distinct partitioning behavior with more favorable interactions with hydrophobic droplets. This indicated that the hydrophobic polymer backbone was the predominate surface feature despite exposed functional groups of the incidental nanoplastics, in contrast to findings with model carboxylated latex nanospheres (nPS-COOH). Furthermore, the selective partitioning of incidental nanoplastics into the hydrophobic droplets was able to capture over 80% of nPET in solution, and after recovery of the protein droplet, was able to cumulatively capture over 75% of the nPET feedstock across multiple cycles. This work explores the nuanced surface characteristics of incidental nanoplastics, expands the application of coacervates as chemical probes, and demonstrates a biopolymer approach for effective nanoplastic removal.

Mushroom production generates large amounts of by-products, particularly stipes, which can represent up to half of the fruiting body biomass. Due to their similar composition to mushroom caps, these residues represent a promising substrate for the development of value-added foods. In this study, oyster mushroom stipes were used as a substrate for solid-state fermentation (SSF) with a Neurospora crassa strain isolated in Albacete to produce a novel meat analogue inspired by the oncom. Fermentation generated a cohesive matrix bound by hyphae that adopted the shape of the mold and exhibited a meat-like color, although with a softer texture. Nutritional analysis revealed a product with relatively low protein content but a complete amino acid profile, enriched in dietary fiber and containing unsaturated fatty acids. These results demonstrate that SSF with N. crassa provides a strategy to upcycle oyster mushroom by-products into fiber-rich meat analogues with potential applications in sustainable food systems.