Research Articles

Freshwater weeds (Eichhornia crassipes, Lemna minor, Azolla pinnata, Myriophyllum indicum and Nymphoides peltatum) were used as fermentation substrates to increase production of peroxidase enzyme. The pretreated freshwater weeds released sugars which favoured bacterial growth and peroxidase yields. The cellulose content of macroalgae ranged from 15.9±0.42 to 26.4±0.18% and the maximum amount was detected in L. minor (26.4±0.18%). Lignin content was high (8.3±0.4%) in A. pinnata and hemicellulose content was highest (26.5±0.92%) in E. crassipes. Peroxidase production was high in the L. minor biomass (7.28 ±0.41 U/g), followed by E. crassipes (6.72±0.3 U/g). The isolated bacteria C18 produced dye degrading-enzymes such as tyrosinase (2.74±0.3 U/mL), lignin peroxidase (0.71±0.02 U/mL), NADH-DCIP reductase (1.49±0.03 U/mL), laccase (29.8±1.1 U/mL), and azoreductases (35.4±0.15 U/mL). Central composite design and response surface methodology were used to improve peroxidase production by Bacillus flexus. Peroxidase production improved with an increase in initial pH value, low levels of glucose, and ammonium sulphate. B. flexus decolourized methyl red (>75%) and Congo red (>60%) in the culture medium. Lemna minor is a cost-effective culture medium for peroxidase production. The enzyme-based bioremediation reduces toxic pollutants in water systems, thereby potentially reducing health risks due to environmental exposure.

Despite their dubious safety, nanoparticles (NPs) are beneficial in many areas, particularly in agriculture. Though a variety of commercial nano- fertilizers, pesticides, and insecticides are available, little is known about their potential detrimental effects on plant cells. A Se/ZnO nanoparticle complex was synthesized utilizing Ficus nitida fruit extract as both a reducing and stabilizing agent, yielding an eco-friendly product.The common food plant Allium cepa was treated with Se/ZnO NP suspension. Transmission electron microscopic analyses of the NPs were performed, including  Dynamic Light Scattering (DLS), zeta potential, X-ray diffraction, and FTIR characterizations.This study examined the cytological impact and chromosomal patterns of Allium cepa root meristems after treatment by Se/ZnO-NPs. Results show that all applied concentrations of NPs decreased the mitotic index (MI). The many chromosomal defects that were caused by NPs included disrupted and sticky chromosomes. Aflatoxin levels (B1, B2, G1, G2) were quantified in vegetables inoculated with Aspergillus flavus. Tomatoes and potatoes showed the highest contamination, in contrast, garlic and beet exhibited minimal or undetectable levels, suggesting resistance. The effect of Se/ZnO-NPs (0 to 40 ppm) on A. flavus growth and aflatoxin production was evaluated. While 5 ppm stimulated growth, higher concentrations significantly reduced both biomass and aflatoxins. These findings suggest that Se/ZnO- NPs treatment as an effective strategy to suppress A. flavus and its toxin production in contaminated crops.

This study focuses on the development and characterization of lightweight hybrid epoxy composites reinforced with neem gum (NG) and coconut dust (CD), targeting sustainable structural applications. Composites were fabricated with a constant 70% epoxy resin and varying NG and CD contents (5NG25CD, 10NG20CD, 15NG15CD, 20NG10CD, and 25NG5CD). Among these, the 15NG15CD composition demonstrated optimal performance, achieving a tensile strength of 42.1 MPa, flexural strength of 83.2 MPa, impact strength of 6.12 J, and Shore D hardness of 82. Water absorption tests showed significantly reduced moisture uptake (25.6%), indicating enhanced dimensional stability. Sound absorption tests revealed a peak sound absorption coefficient of 0.35 for the 20NG10CD composite, followed by 0.33 for 15NG15CD, indicating effective acoustic damping characteristics across all variants (ranging from 0.24 to 0.35). Scanning electron microscopy (SEM) revealed strong interfacial adhesion and uniform particle dispersion within the epoxy matrix, contributing to superior mechanical properties. These eco-friendly, lightweight composites exhibited excellent strength, moisture resistance, and versatility, making them suitable for lightweight structural components, automotive interiors, and sustainable packaging solutions.

Mycelium-based biocomposites (MBC) offer a sustainable alternative to synthetic materials due to their biodegradability and low environmental impact. This study examined the structural and mechanical properties of mycelium films produced from nine fungal species representing monomitic, dimitic, and trimitic hyphal systems. These species were selected following preliminary screening of 21 strains for growth characteristics and mechanical performance. Growth rates varied significantly, with Irpex lacteus exhibiting the fastest growth (8 mm/day), while Fomes fomentarius and Daedaleopsis confragosa grew more slowly but exhibited superior mechanical strength. Tensile testing identified D. confragosa as the strongest fungus (6.51 MPa), followed by F. fomentarius, although considerable variability was noted. Ganoderma spp. and Trametes spp. showed moderate to low tensile strength. No consistent correlation was found between mycelium density and tensile strength, nor did chitin content alone explain mechanical performance. For instance, I. lacteus had the highest chitin content but weak tensile properties. Scanning electron microscopy revealed differences in hyphal diameter, density, and cell wall structure, indicating that factors such as glucan-chitin interactions and hyphal morphology influence mechanical behavior. These findings highlight the potential of less investigated fungal species in advancing MBC development.

Tetra Pak (TP)/bamboo fiber (BF) composites were prepared using waste TP and bamboo fiber as the main raw materials. Twelve inorganic flame retardant systems were used to modify the flame retardancy of TP/BF composites. Specimens were evaluated with the limiting oxygen index test, water absorption test, dry shrinkage and wet expansion test, mechanical property test, and Fourier transform infrared spectroscopy (FTIR). The results showed that the composite flame retardant systems outperformed the single flame retardant system, with the limiting oxygen index reaching up to 37.6%. Retardant addition lowered the modulus of elasticity (MOE), modulus or rupture (MOR), and internal bond (IB) and impaired dimensional stability, the extent varying with type and dosage.  Among them, the TP/BF composites modified by systems Z3, Z8, Z9, and Z12 satisfied GB/T 11718-2021requirements for ordinary, furniture, and building medium-density fiberboards. FTIR showed the presence of chemical bonds of various functional groups that would be consistent with the development of adhesion within the composite.

Rapid and accurate detection of crude protein and starch content in alfalfa-potato pomace pellets is crucial for improving their processing and enhancing nutritional quality. In this study, hyperspectral images of alfalfa-potato pomace pellets in the near-infrared (NIR) range (900 to 1700 nm) were acquired. A support vector regression (SVR) model was developed by combining various spectral preprocessing methods and effective wavelength selection techniques. Textural features from the surface of the first principal component (PC1) image sample were also extracted using the gray-level co-occurrence matrix (GLCM) and fused with the spectral data, significantly improving the model’s prediction accuracy. The results indicated that the SNV-GB-COR-SVR model performed best in predicting crude protein content, with an R²p of 0.907 and an RMSEP of 0.5548, while the SNV-CARS-ENT-SVR model was most effective in predicting starch content, with an R²p of 0.7915 and an RMSEP of 1.3970.

Hybrid epoxy composites were reinforced with a constant 20 wt% of Luffa acutangula fiber (LAF) and varying Sal wood sawdust (SWD) content ranging from 0 to 25 wt%. The evaluation covered mechanical properties including tensile, flexural, impact strengths, hardness, and water absorption behavior. Results indicated a notable enhancement in all mechanical properties up to 15 wt% SWD, with a slight reduction observed beyond this point. The composite with 20LAF/15SWD exhibited superior performance, achieving tensile, flexural, and impact strengths of 46 MPa, 66 MPa, and 3.12 J, respectively. Shore D hardness and water absorption tests confirmed increased material rigidity and decreased moisture affinity up to the 15 wt% SWD level. Scanning electron microscopy revealed improved fiber–matrix bonding and homogeneous filler distribution at the optimal formulation. These findings highlight the potential of combining Luffa acutangula fiber and sawdust as sustainable reinforcements for high-performance biocomposites.

A carbon adsorbent material with a specific surface area of 342 m²/g was prepared via chemical activation, using lignin as the raw material and CsCl as the activator. The adsorbent’s structure was characterized and its performance for methylene blue solution was investigated. Additionally, adsorption experiments of crystalline violet dye were conducted at different temperatures to study the adsorption thermodynamics. The results indicated that the prepared activated carbon material featured a smooth surface with abundant pores. Its adsorption capacity for methylene blue reached 161 mg/g, enabling rapid and efficient adsorption of methylene blue solution. Additionally, it exhibited excellent adsorption performance for crystalline violet solution: at 40 °C, the saturated adsorption capacity reached 243 mg/g with a removal of 93%, and the adsorption process was confirmed to be a spontaneous thermodynamic reaction. The experiments confirmed that CsCl can serve as an activator for activating lignin-based raw materials to prepare carbon samples.

Wood anatomical characterization is a key method for species identification and for combating illegal logging. This study aimed to provide a detailed macroscopic anatomical characterization of twelve wood species from the Brazilian Amazon, supporting species identification in forensic analysis and contributing to educational resources in wood anatomy. The samples were collected from a sawmill in Colniza, northern Mato Grosso, Brazil. Three woods were identified at the species level, and nine were identified at the genus level. Cedrela sp., Hymenaea sp., Hymenolobium sp., Handroanthus sp., and Peltogyne sp. presented well-demarcated growth rings. Diffuse porosity was common, except in Cedrela sp. In Manilkara sp., vessels occurred in radial chains, whereas Handroanthus sp. was notable for pore obstructions caused by a yellowish substance. The main parenchyma type was aliform and/or confluent, along with marginal bands. Six species displayed storied rays. Macroscopic analysis proved effective for wood identification, as parenchyma, vessel, and growth-ring features were sufficient to identify these commercial species at the genus level.

This study aimed to determine the optimal enzyme combination conditions for improving the saccharification efficiency of softwood biomass (Larix kaempferi). For this purpose, cellulase derived from Trichoderma sp. KMF006 was combined with a commercial enzyme (Cellic® CTec3). Comparative hydrolysis experiments with individual enzymes showed that L. kaempferi exhibited a lower glucose yield than hardwood, suggesting the need for a complementary enzyme combination. A Plackett-Burman Design (PBD) was used to identify significant variables, including substrate concentration, enzyme loading, pH, and the KMF006 blending ratio. The significant factors were further optimized using a Box-Behnken Design (BBD). The optimal conditions were determined to be a substrate concentration of 9% (w/v), enzyme loading of 60 FPU/g-glucan, pH of 6.0, and the KMF006 blending ratio of 25.5%. The predicted maximum glucose yield under these conditions was 63.9%, representing a 21.8% increase compared to CTec3 alone and a 32.4% increase compared to KMF006 alone. These results suggest that up to 25% of the commercial enzyme dosage can be substituted with KMF006 without compromising hydrolysis performance. Overall, this study demonstrates the feasibility of an enzyme combination approach for enhancing softwood saccharification.