In Brazil, the use of Eucalyptus is focused on the production of wood or pulp for the paper industry but without any general recovery of waste, with leaves and branches being left on the ground. One possibility is to use these residues as raw materials in the production of industrially relevant and value‐added compounds such as essential oil. The aim of the present study was to investigate the chemical composition, yield, anti‐inflammatory/antinociceptive activities, and acute toxicity in mice, as well as the antimicrobial effects of essential oils from the leaves of 7 varieties of Eucalyptus and hybrids against Escherichia coli, Staphylococcus aureus, and Candida albicans. The extraction of oils was carried out using hydrodistillation, and they were analyzed by gas chromatography coupled to mass spectrometry. Urocam and Grancam were the plants that obtained the highest oil yield, with yields of 3.32 and 2.30%, respectively. The main chemical components identified in these plants were 1.8 cineole and α‐pinene. The antinociceptive effect of the 7 oils (50 mg/kg, p.o.) was initially assessed in the acetic acid‐induced writhing test. In this assay, a significant (p < 0.05) antinociceptive/anti‐inflammatory effect was observed from 4 tested essential oils (E. benthamii, E. saligna, and the hybrids Urocam and Grancam) when compared to the vehicle‐treated group. This effect was then confirmed in the formalin‐induced paw licking test. No toxicological effects or alterations were observed in motor coordination after the administration of the studied oils to the animals. In the antimicrobial evaluation, the seven essential oils inhibited the growth of S. aureus, E. coli, and C. albicans at different concentrations. Collectively, these results demonstrate that the essential oil from the leaves and branches of Eucalyptus species and varieties present potential biomedical applications and represent a source of antimicrobial and/or anti‐inflammatory compounds.

Enzymatic catalysis for biodiesel production using low-cost, high-acid, lower-grade waste oils has attracted much attention recently due mainly to economic issues, renewability, and sustainable benefits. The performance of a commercial, low-cost lipase (Eversa ^® , Novozymes) was investigated in the hydrolysis and subsequent esterification reactions for fatty acid methyl esters (FAME) production. In order to reduce the costs of industrial enzymatic biodiesel production, enzyme was used in its soluble, free form. A model mixture comprising soybean oil with high free fatty acid (FFA) content (0, 25, 50, and 75 wt% oleic acid) and low-cost substrates such as non-edible macauba acid oil ( Acrocomia aculeata ) and waste cooking oil were employed for FAME production. FAME yields as high as 97% were reached using 2.5 wt% water, 1.5 methanol equivalent, and 1 wt% Eversa enzyme content in a 16-h reaction. The enzyme biodiesel process described in this study appears to be a promising alternative to the traditional biodiesel process and can contribute to making enzymatic biodiesel feasible .

Enzyme immobilization using a low-cost support that allows increasing operational stability and reutilization arise as a great economic advantage for the industry. In this work, it was explored different methods of Thermomyces lanuginosus lipase (NS-40116) immobilization in flexible polyurethane foam (PU). PU polymer was synthesized using polyether and toluene diisocyanate as monomers. PU-NS-40116 immobilized was evaluated in terms of stability in a range of pH (7.0 and 9.0), temperature (24, 50 and 60 °C) for 24 h, and storage stability (room temperature and 4 °C) for 30 days. The results showed that after 30 days of storage immobilized enzyme kept 80% of initial enzyme activity. PU support before and after immobilization process was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. Free and immobilized enzymes were compared in terms of hydrolysis of soybean oil. Immobilized enzyme by entrapment was evaluated in successive cycles of reuse showing catalytic activity above 50% even after 5 successive cycles of reuse, confirming the efficiency of immobilization process.