RESUMO
Extracts obtained from plants have significantly contributed to the creation of new drugs due to their medicinal properties, which are provided by the presence of bioactive components. This has led to a growing interest from the pharmaceutical industry in using this type of extract for the creation of increasingly advanced medications. The main components sought are antibacterial agents from sustainable and renewable sources, whether of animal or vegetable origin or derived from other natural components. Tissues become a source of microbial proliferation, especially when in contact with the human body, which can cause serious diseases. In line with this, the goal of this research was to create an antibacterial Melon-de-São-Caetano (Momordica charantia) leaf microemulsion for application on material surfaces. This microemulsified system is an effective alternative for solubilizing functional agents, and being thermodynamically stable, it is efficient for long-term use. For this study, an extract of Momordica charantia leaves (EMC) was obtained, and microemulsions with different EMC concentrations (P1, P2, and P3) were produced. The extract and microemulsions were investigated using Fourier Transform Infrared (FTIR) spectroscopy, particle size, zeta potential, thermal stress, pH, electrical conductivity, Transmission Electron Microscopy (TEM), and antibacterial analysis (Staphylococcus aureus). In summary, the proposed objective was met, and EMC, SME, and the P2 and P3 microemulsions showed positive results against S. aureus, with the P3 microemulsified system being the most effective with a 12.5 mm inhibition halo. Therefore, the product developed in this research has the potential for application on surfaces, providing antibacterial action.
RESUMO
The development of clean and renewable energy sources is currently one of the most important challenges facing the world. Although research interests in algae-based energy have been increasing in the last decade, only a small percentage of the bewildering diversity exhibited by microalgae has been investigated for biodiesel production. In this work, seven strains of green microalgae belonging to the genera Scenedesmus, Tetradesmus and Desmodesmus were grown in liquid medium with or without a nitrogen (N) source-at two different irradiances (120 ± 20 and 200 ± 20 µmol photons m-2 s-1)-to evaluate biomass production and FAME (fatty acid methyl esters) content for biodiesel production. The strains of Tetradesmus obliquus and Desmodesmus abundans grown in N-deprived medium showed the highest FAME content (22.0% and 34.6%, respectively); lipid profile characterization highlighted the abundance of saturated FAME (as C16:0 and C18:0) that favors better viscosity (flow properties) and applicability of biodiesel at low temperatures. Light microscopy and confocal laser scanning microscopy observations were employed as a fast method to monitor the vital status of cells and lipid droplet accumulation after Nile red staining in different culture conditions.
