Processing and characterization of antimicrobial bioplastic films based on green microalgae Scenedesmus obliquus extract-loaded polyurethane.

The green microalga Scenedesmus obliquus, isolated from the Egyptian environment, was used for the synthesis of bio-based plastic materials. Polyurethane (PU) was blended with different proportions (0%, 10%, 20%, and 40%) of chloroform extract to form bioplastic films. The bioplastic films were characterized using water vapor transmission rate measurements and scanning electron microscopy (SEM). The WVTR of pure PU was 193.37 g/m2. day, while the values of algae/PU films were 129.74, 122.56, and 99.75 g/m2.day. S. obliquus reported having Palmitic, which possesses antimicrobial activity and acts as an effective antimicrobial agent in the synthesized bioplastic films. Antimicrobial activity of the algal extract and the synthesized bioplastic films were tested against two Gram-positive bacteria; Staphylococcus aureus, Enterococcus faecalis, two Gram-negative bacteria; Escherichia coli, Pseudomonas aeruginosa, and Candida albicans as a model for fungi. The results indicated that S. obliquus extract exhibited a clear antimicrobial activity against all tested microbes. The antimicrobial rate of bioplastic films containing 40% of the extract reached 100% after 2 h of contact with E. coli and E. faecalis. In conclusion, this study offers a promising future for the use of biodegradable antimicrobial bioplastic films as an affordable and environmentally friendly alternative to plastics in many applications.

Green enhancement of wood plastic composite based on agriculture wastes compatibility via fungal enzymes.

This study deals with the production of natural fiber plastic composites (NFPCs) to reduce environmental pollution with agricultural and plastic waste. Where the NFPCs were prepared from waste/pure polyethylene (WPE) (pure polyethylene (50%)/recycled polyethylene (50%)) and modified sunflower waste via an eco-friendly and economic biological process. The sunflower fibers (SF) were treated via whole selective fungal isolate, namely, Rhizopus oryzae (acc no. OM912662) using two different incubation conditions; submerged (Sub), and solid-state fermentation (SSF) to enhance the fibers' compatibility with WPE. The treated and untreated fibers were added to WPE with various concentrations (10 and 20 wt%). The morphology and structure of fibers were characterised by a scanning electron microscope (SEM) and attenuated total reflection-Fourier transform infrared (ATR-FTIR). Furthermore, the mechanical properties, morphology, biodegradation and water vapour transmission rate (WVTR) for the prepared NFPCs were investigated. The results showed that compatibility, mechanical properties and biodegradation of NFPCs were improved by the addition of sunflower fibers treated by SSF conditions.

Preparation and characterization of novel bionanocomposites based on garlic extract for preserving fresh Nile tilapia fish fillets.

In this paper we describe the preparation of a new bionanocomposite based on carboxymethyl cellulose (CMC), Arabic gum (AG) and gelatin (GL), incorporating garlic extract (GE) and TiO2 nanoparticles (TiO2-NPs). The prepared bionanocomposites were evaluated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Energy Dispersive X-ray Analysis (EDX), and scanning electron microscopy (SEM), and were evaluated for their antimicrobial effect. The permeability and thermal and mechanical properties of the films were assessed. The water vapor transmission rate (WVTR), oxygen transmission rate (OTR), and mechanical, thermal and antimicrobial properties of the prepared bionanocomposite films were enhanced by the addition of GE and TiO2-NPs. The effects of GE and TiO2-NPs in combination incorporated into a CMC/AG/GL blend as an edible coating on the quality of fresh Nile tilapia fish fillets during refrigerated storage were evaluated. The microbiological status and weight loss of fresh Nile tilapia fish fillets were periodically tested for 21 days during storage at 4 °C. The results indicated that GE combined with TiO2-NPs has a synergistic influence on the enhancement of the preservation properties of CMC/AG/GL/GE-TiO2 bionanocomposites for refrigerated tilapia fish fillets, which could control microbial growth, and decrease weight loss during the storage of tilapia fish fillets.