Background The use of synthetic insecticides is one of the most common strategies for controlling disease vectors such as mosquitos. However, their overuse can result in serious risks to human health, to the environment, as well as to the selection of insecticidal resistant insect strains. The development of efficient and eco-friendly insect control is urgent, and essential oils have been presented as potential alternatives to synthetic insecticides. Moreover, nanoencapsulation techniques can enhance their efficiency by protecting from degradation and providing a controlled release rate. Results We assessed the potential of chitosan nanoparticles in encapsulating Siparuna guianensis essential oil, and maintaining its efficiency and prolonging its activity for the control of Aedes aegypti larvae. The encapsulation was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), with an encapsulation efficiency ranging from 84.8% to 88.0%. Toxicity studies have demonstrated efficacy against mosquito larvae over 50% for 19 days with 100% mortality during the first week. This persistent action is presumably due to the enhanced contact and slow and maintained release conferred by chitosan nanoparticles. Furthermore, the exposure of aquatic non-target organisms (e.g. embryos and small adult fishes) revealed adequate selectivity of these nanoparticles. Conclusions The encapsulation of S . guianensis essential oil in chitosan nanoparticles showed promising potential as a larvicide control alternative and should be considered within strategies for fighting Ae . aegypti .

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The use of plant essential oils has been adopted as less hazardous to the environment and human health than synthetic insecticides used for the control of insects that transmit diseases. Despite of exerting insecticidal activities against several insect disease vectors, the potential impacts on non-target organisms exerted by essential oils extracted from Lippia sidoides (Cham.) have not received adequate attention. Here, we evaluated the susceptibility and potential changes in consumption rates of honey bees, Apis mellifera (L.), when exposed to essential oils extracted from L. sidoides. Was exposed forager bees to honey syrup (50% v/v) containing L. sidoides essential oil for 5 h. After this exposure period, the bees received regular honey syrup for another 19 h period. Six essential oil concentrations was used, namely 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 µL of essential oil/mL of syrup, and evaluated the syrup consumption and bees mortality in both periods (at the 5th and 24th h). The results reveal that independent of the essential oil concentration, the forager bees fed significantly less on L. sidoides essential oil-containing honey syrup. However, feeding on L. sidoides essential oil-containing honey syrup did not cause significant mortality when compared with bees that were not exposed to the essential oils. Thus, the results demonstrate that L. sidoides essential oils exhibited adequate selectivity against honey bees.

A crescente demanda por energias renováveis promovem a produção de biocombustíveis por meio da utilização de biomassas, o bioetanol e biodiesel são matrizes energéticas eco-sustentáveis. Embora sua composição seja variada de acordo com a sua origem, as biomassas quando submetidas a pré-tratamentos adequados são blocos químicos para produção de enzimas. A capacidade dos fungos endofíticos colonizarem ambientes suscetíveis a constantes interações metabólicas os tornam candidatos favoráveis na produção de enzimas extracelulares com potencial aplicação na produção de biocombustíveis, uma vez que são aplicados como pré-tratamento biológico de biomassas. Neste contexto, esta revisão contextualiza as fontes de biomassas e recolhe dados sobre estirpes fúngicas endofíticas e técnicas moleculares e de bioprocessos para o rastreio e produção de enzimas. Nós objetivamos evidenciar o atual cenário dos fungos endofíticos e suas enzimas para desconstrução da biomassa lignocelulósica e para catalise da reação de esterificação, bem como as etapas do processo produtivo de etanol e biodiesel, respectivamente.