Research Articles

Lignocellulosic residues (guava leaves, cabbage leaves, pineapple peels, pomegranate peels, orange peels, banana pseudostem, and wheat bran) were used for the production of laccase (LaC) and lignin peroxidase (LiP) via solid-state fermentation (SSF) by fungi (Cerrena unicolor and Loweporus lividus). The results revealed that banana pseudostems presented higher LaC and LiP activities (49.8±1.4 U/g and 7.8±0.24 U/g, respectively) than other agricultural residues did. Banana pseudostems presented increased amounts of lignin (21±0.28%), cellulose (42.8±0.92%), and hemicelluloses (22.3±0.14%), which stimulated enzyme production. The data revealed that glucose (a carbon source), ammonium sulfate (a nitrogen source), an inducer (polysorbate 80, 0.15%), a pH of 4.5, and a 60% moisture content were optimal for LaC and LiP production. Two-level full factorial designs revealed that the variables moisture, pH, polysorbate 80, and glucose significantly influenced LaC and LiP production (p<0.001). A central composite design was applied to optimize the medium components, and glucose and polysorbate 80 influenced LaC and LiP production. The optimized medium (4.82 pH, 0.13% polysorbate 80, and 0.57% glucose) improved LaC (151.9 U/g) and LiP (19.2 U/g) production. The crude enzyme was used to decolorize the dyes. The degradation rates of acid yellow, bromo-chloroform purple, and reactive black 5 were >82%.

All-cellulose composites were prepared using a novel AlCl₃/ZnCl₂ molten salt solvent system, which allows for fabrication at room temperature. Unlike conventional NaOH/urea solvent systems, the proposed solvent demonstrates enhanced solubility and processing efficiency without requiring low-temperature conditions. The composites produced at room temperature, while they displayed enhanced wet strength properties, possessed a rather poor tensile strength and Young´s Modulus. When the composites were treated with the molten salt solvent system at a higher temperature, the composites displayed a marked performance improvement, suggesting that the solvent’s efficiency is temperature dependent. At higher temperatures comparable performance to NaOH/ urea produced all-cellulose composites was demonstrated. This dual advantage, room-temperature processing and improved properties at elevated temperatures, demonstrates the versatility of the AlCl₃/ZnCl₂ molten salt solvent system and the potential for energy-efficient, scalable production of sustainable all-cellulose composites.

This study investigates how consumers perceive the cultural sustainability of Neo-Chinese furniture through the lens of online reviews on two major e-commerce platforms in China: JD.com and Tmall. Employing a mixed-methods approach combining Word2Vec modeling, qualitative content analysis, and a cultural semiotics framework, 47,766 reviews were evaluated across eight representative brands. Consumer perceptions were categorized into three cultural layers—tangible (e.g., material quality, design form), behavioral (e.g., functional use, craftsmanship), and intangible (e.g., aesthetic taste, historical symbolism). The data revealed that Tmall reviews were 23% more likely to mention aesthetic attributes (viz., style, elegance), while JD reviews contained 35% more references to functional features and material credibility (viz., “solid wood,” “durability”). However, references to intangible cultural dimensions—such as traditional narratives or symbolic meaning—accounted for less than 8% of all keyword clusters on both platforms. This indicates a shared deficit in deep cultural cognition. The paper concludes by proposing platform-specific strategies to enhance cultural communication and engagement, contributing to the broader discourse on sustainable design and digital cultural branding.

The cryogenic mechanical behavior of polyethylene glycol (PEG) and hydroxyapatite (HAp) composites was studied using Dynamic Mechanical Analysis (DMA). The HAp was synthesized from chicken eggshells via a hydrothermal process, offering a sustainable, bio-derived source of calcium phosphate. The composites were fabricated through a wet mixing technique to ensure uniform distribution of HAp within the PEG matrix. Cryogenic characterization was conducted over a temperature range of minus 100 °C to 50 °C to evaluate the viscoelastic properties of the composites under extreme conditions. The results demonstrated a significant enhancement in the storage modulus (E′), with the 30 wt% PEG-HAp composite achieving a peak value of 1.128 GPa. This improvement is attributed to the effective impregnation and interfacial interaction between the PEG and HAp phases. These findings indicate the potential applicability of PEG/HAp composites in biomedical and cryogenic environments, although further studies are necessary to explore their specific functional roles in targeted applications. The study contributes to the advancement of biocomposite materials by elucidating the effects of cryogenic conditions on mechanical performance and supports the use of sustainable raw materials in composite fabrication.

Trichoderma sp. SG2, isolated from the Black Belt soils of Alabama, USA, is a potent natural producer of β-glucosidase and a broad spectrum of cellulolytic and xylanolytic enzymes. This study explored the saccharification of lignocellulosic biomass using crude enzymes from Trichoderma sp. SG2, various pretreatment strategies, mixed feedstock approaches to enhance sugar yield, and enzyme supplementation to reduce costs. Among the pretreatment methods tested for switchgrass, the most effective was sequential H₃PO₄–ethanol, followed by NaOH–H₂SO₄, H₃PO₄–acetone, H₂SO₄–NaOH, and single-agent treatments (H₂SO₄ alone or NaOH alone). Sugar yields were significantly improved by combining pretreated switchgrass with paper powder as a mixed feedstock. The highest glucose (15.8 g/L) and xylose (3.8 g/L) yields were achieved at 10% pretreated switchgrass after 72 h. A key finding was the significant cost reduction and enhanced saccharification efficiency achieved by supplementing SG2 crude enzyme with 50% of the recommended commercial enzyme dosage. Acid-pretreated switchgrass hydrolysis with SG2 enzyme and commercial enzyme supplementation emerged as the most effective strategy. These results highlight Trichoderma sp. SG2 as a promising candidate for developing cost-effective enzyme cocktails for lignocellulosic biomass hydrolysis where 30 to 40% cost of ethanol production process is accounted for enzyme cost.

Timber has natural fire resistance because of its predictable charring behavior. When subjected to high temperatures, timber undergoes pyrolysis, forming an insulating char layer that protects the inner structural core. Eurocode EN 1995-1-2 (2004), commonly known as Eurocode 5 where EC5 specifies 0.5 mm/min charring rate for temperate hardwoods, pertains to timber with density exceeding 450 kg/m³. This paper presents the development of a finite element model (FEM) to predict the charring rate of timber exposed to fire through innovative experimental and numerical approaches. Timber samples were exposed to controlled heat fluxes for 60 min, simulating real-world fire scenarios. The resulting char layer thickness was measured over time. The Malaysian tropical hardwood timber used was Resak (Cotylelobium and Vatica spp.) with density range from 932 kg/m³ to 1125 kg/m³. The proposed FEM was developed using ABAQUS software, which included thermal conductivity and specific heat to simulate the transient heat transfer and degradation processes in timber. It was found that the charring rate of Resak was 0.47 mm/min lower than the rates established in EC5 (2004). The model is validated through experimental data, demonstrating its accuracy in predicting char depth and temperature profiles under standard fire condition. The data are useful when designing the fire safety of timber structures from the Malaysian tropical timber species.

The development of high-performance polystyrene composites modified with recycling waste tire rubbers composed of natural and synthetic rubber mixture is highly desirable for a sustainable society. To tackle the intrinsic fire issue of waste tire rubber and polystyrene (WTRPS) composites for its advanced applications, the synergistic effect of fire additives MXene and poly(p-phenylene oxide) PPO on the performance of WTRPS composites was investigated in this work. The limited oxygen index values of WTRPS composites with MXene and PPO loading at 15 and 40 wt% were  increased to 23.0%, compared to that of WTRPS at 17.0%. Additionally, the heat release rate, total heat release, and peak of heat release rate of resulting composites showed obvious decreases, confirming their synergistic fire retardancy effects on WTRPS composites. The synergistic mechanism was based on the char effect of PPO, heat sink effect of MXene, and catalyst effect of titanium dioxide generated from MXene. The synergistic strategy in this work paves a new avenue to develop fire retarding bio-composites of wood flour reinforced polyhydroxyalkanoates along with environmentally friendly fire additives (e.g., MXene and lignin or phytic acid) for advanced applications.

This study focuses on the development of a xylose-inducible system to produce recombinant α-amylase from the bacterium Thermoactinomyces vulgaris 94-2A (amyTV) in the Bacillus expression system. To achieve this, a gene cassette was constructed using pWH1520 shuttle vector, containing a PxylA promoter comprising glucose box and amyTV gene. The cassette was initially cloned in Escherichia coli for replication and subsequently, introduced into the Bacillus subtilis (GSB26) for expression. To optimize the secretion of α-amylase, different concentrations of xylose were used as inducers. It was found that the maximum amylase activity was achieved when 2% xylose was used as the inducer. Furthermore, using glucose alone and in combination with xylose as inducers indicated that glucose acted as a catabolic repressor for amyTV expression. Moreover, protein was efficiently secreted and did not accumulate in the cellular fractions, even at high expression levels.

The article deals with composite materials based on caustic magnesite binder and wood fillers used in the fabrication of various types of objects in mechanical engineering, construction engineering, and oil and gas industries. Under operational conditions, caustic magnesite composites can be exposed to aggressive actions of microorganisms. This study looked into resistance of wood-filled composites upon exposure to byproducts of filamentous fungi (micromycetes). This research substantiated the choice of model medium for testing – byproducts of metabolism of micromycetes. Designed experiments were carried out. The samples were held in model solutions with different concentrations of aggressive medium agents. Lines of equal values of materials’ resistance were plotted. It was found from experiments that composites without fillers had a lower biocorrosive resistance compared to those filled with pine sawdust.

Milk and cream are often sold in beverage carton packaging. After use, the unconsumed liquid residues and adhering content remain in this packaging. These food residues end up in the recycling cycle, where they pose troubles in the aqueous processing. The aim of this empirical study was to quantify milk and cream residues in beverage carton packaging from recycling streams. 949 recovered cartons that had been filled with milk or cream and consumed in Germany, Austria, and the Czech Republic were analyzed by gravimetric measurement. For 1-liter cartons, the mean value of the residual quantity was 6.6 g residue for every liter filling quantity, with a range of 1.0 to 71.9 g/L. This corresponds to 0.66% residual quantity by mass, with an assumed density of 1.0 g/cm³. Considering a mean value for all the carton weights with residual quantity of 35.8 g for 1-liter cartons, here some cartons without closures, and 29.2 g without residual quantity, this results in a packaging material content of 81% by mass for recycling. The rest is food waste that ends up in the recycling stream. This can be a task for packaging designers to further improve easy-to-empty solutions.