Synthesis and characterization of Hypsizygus ulmarius extract mediated silver nanoparticles (AgNPs) and test their potentiality on antimicrobial and anticancer effects.

The prime aim of this research is to discover new, eco-friendly approaches to reducing agents for manufacturing silver nanoparticles (AgNPs) from fresh fruiting bodies of the edible mushroom Hypsizygus ulmarius (Hu). The confirmation of Hu-mediated AgNPs has been characterized by UV visible spectroscopy, XRD, FTIR, SEM with EDX, HRTEM, AFM, PSA, Zeta poetical and GCMS analysis. The absorption peak of Hu-AgNPs at 430 nm has been confirmed by UV-visible spectroscopy analysis. The findings of the particle size study show that AgNPs have a size distribution with an average of 20 nm. The Zeta potential of NPs reveals a significant build-up of negative charges on their surface. The additional hydrate layers that occurred at the surface of AgNPs are shown in the HR-TEM morphology images. The antibacterial activity results showed that Hu-AgNPs were highly effective against both bacterial pathogens, with gram-positive (+) and gram-negative (-) pathogens having a moderate inhibition effect on K. pneumoniae (5.3 ± 0.3 mm), E. coli (5.3 ± 0.1), and S. aureus (5.2 ± 0.3 mm). Hu-AgNPs (IC50 of 50.78 µg/mL) were found to have dose-dependent cytotoxic action against human lung cancer cell lines (A549). Inhibited cell viability by up to 64.31% after 24 h of treatment. To the best of our knowledge, this is the hand information on the myco-synthesis of AgNPs from the H. ulmarius mushroom extract and the results suggest that it can an excellent source for developing a multipurpose and eco-friendly nano product in future.

Novel antimicrobial bioplastic based on PLA-chitosan by addition of TiO2 and ZnO.

PURPOSE: The purpose of this study was to develop antimicrobial bioplastics based on Poly Lactic Acid (PLA) with the addition of chitosan-ZnO, and chitosan-TiO2 to improve antimicrobial properties. METHODS: For the preparation of the bioplastics, PLA with chitosan-ZnO or chitosan-TiO2 were used. The antimicrobial activity, mechanical and thermal properties, and water vapor permeability of bioplastics were evaluated. RESULTS: PLA-chitosan-ZnO indicated a robust antimicrobial activity against bacteria such as Salmonella typhi, Bacillus subtilis, Escherichia coli, Staphylococcus aureus, yeast such as Candida albicans, and fungus Aspergillus niger. No formation of new functional groups in PLA-chitosan-ZnO composites. In comparison to other PLA-based bioplastics, this bioplastic has medium tensile strength, tensile modulus, and elongation percentages with low barrier ability to water vapor. Chitosan-ZnO itself has a greater tensile strength compared to chitosan-TiO2. These two compounds undergo 2 stages of decomposition in a temperature range of 43 °C to 265 °C. The addition of PLA into chitosan-ZnO or chitosan TiO2 causes the bioplastics decomposed in a single stage. It also increases the decomposition temperature of bioplastic. However, compared to chitosan-ZnO or TiO2, the PLA-chitosan-ZnO or TiO2 bioplastics tend to produce a fragile composite indicating by decrease in their tensile strength. CONCLUSION: In general, the addition of chitosan-ZnO into in PLA-based bioplastic produces better antimicrobial properties compared to TiO2.

Biodegradation and biodetoxification of batik dye wastewater by laccase from Trametes hirsuta EDN 082 immobilised on light expanded clay aggregate.

The biodegradation and biodetoxification of batik industrial wastewater by laccase enzyme immobilised on light expanded clay aggregate (LECA) were investigated. Laccase from Trametes hirsuta EDN 082 was covalently immobilised by modifying the LECA surface using (3-aminopropyl)trimethoxysilane and glutaraldehyde. The enzymatic characterisation of LECA-laccase showed promising results with an enzyme loading of 6.67 U/g and an immobilisation yield of 66.7% at the initial laccase activity of 10 U/g LECA. LECA-laccase successfully degraded batik industrial wastewater containing indigosol dye up to 98.2%. In addition, the decolorisation extent was more than 95.4% after four cycles. The phytotoxicity assessment of Vigna radiata and the microbial toxicity of two pathogenic bacteria, Bacillus subtilis and Pseudomonas aeruginosa, showed biodetoxification of treated batik dye wastewater. The characterisation using 3D light microscopy, scanning electron microscopy and Fourier transform infrared for LECA-laccase confirmed that laccase was successfully immobilised on LECA, and the decolorisation achieved through the combination of adsorption and enzymatic degradation. This study offers an environmentally friendly, effective and affordable LECA-laccase as a method for batik dye wastewater treatment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02806-8.

Antimicrobial Imperata cylindrica paper coated with anionic nanocellulose crosslinked with cationic ions.

Recently, the interest in active packaging utilization has increased with population growth, food demand and new consumer trend like food delivery services. This new system, however, requires the use of additives to extend the food product quality and safety as well as in maintaining the shelf-life. This study was to prepare the antimicrobial paper from I. cylindrica coated anionic nanocellulose crosslinked cationic to create a system with the ability to actively control microbe growth in the packaging materials. The process involved pulping of I. cylindrica using semi-chemical and soda chemical method. The antimicrobial paper was prepared by printing the pulp suspension in 60 g/m2 grammage in mold followed by the spray of anionic nanocellulose and subsequent soaking of the paper in cationic solution. The results showed the I. cylindrica paper coated anionic nanocellulose crosslinked with H+ and Al3+ cations were successfully produced. The paper produced was also observed to have antimicrobial activity against Gram-negative of E. coli and S. typhi as well as Gram-positive of S. aureus and B. subtilis bacteria. Furthermore, the best coating method was found on antimicrobial paper coated anionic nanocellulose crosslinked Al3+ as evidenced by smoother and compact surface structure.