Endophytic fungi are those that present part of their life cycle in healthy tissues of different plant hosts in symbiosis without causing harm. At the same time, fungus-plant symbiosis makes it possible for microorganisms to synthesize their own bioactive secondary metabolites while in stationary stage. Such microorganism-derived secondary metabolites contribute. Therefore, this work aimed to. To accomplish this, the endophytic fungus Trichoderma asperellum was isolated from Bertholletia excelsa (Brazil nut) almonds. The fungus was cultivated and extracted with ethyl acetate, obtaining AM07Ac. Then, using HPTLC (High-performance thin-layer chromatography) and Nuclear Magnetic Resonance (1H NMR), β-amyrin, kaempferol, and brucine were identified as major compounds. Further in vivo assays in Zebrafish demonstrated the activity of AM07Ac on melanogenesis by producing a concentration-response inhibitory effect, which, through an in silico study, proved to be related to the noted major compounds known to inhibit tyrosinase activity. The inhibition of tyrosinase prevents melanin accumulation in skin. Therefore, these results imply the importance of investigating microorganisms and their pharmacological activities, in particular the endophytic fungus Trichoderma asperellum as a generator of active metabolites for melanogenesis modulation.

This work aimed to carry out a bioremediation study to evaluate the resistance of Penicillium sp. isolated from kefir grains for the treatment of copper. The fungal culture medium was prepared using a 2% malt-agar medium at pH 7.0 in which Penicillium sp. was inoculated. Penicillium sp. growing in a liquid medium showed a decrease in biomass in presence of Cu(NO3)2 (800 mg.L-1), suggesting that the metal impacts the growth rate of the fungus. Moreover, the combined factors of pH and the presence of the inorganic contaminant impacted the radial growth of the fungus, causing inhibition of 73% at pH 4.0, 75% at pH 7.0, and 77% at pH 9.0 in liquid medium compared to control. However, images obtained with scanning electron microscopy showed the integrity of the fungus cell, even at high doses of copper in the medium. Therefore, it can be concluded that Penicillium sp. isolated from kefir grain can bioremediate the environment and that the harmful effects of heavy metals can be minimized as a result biosorption. Although the growth of Penicillium sp. is inhibited, such retardation requires high doses of copper nitrate, thus ensuring the use of this microorganism for protection against the harmful effects of non-essential copper in the environment.

Objective: In this work, we evaluated the chemical composition by chromatography coupled to mass spectrometry, antimicrobial and insecticidal activity of essential oils (TrEO) and nanoeffu-sion (NTrEO) of oil from Tetradenia riparia leaves. We also evaluated the acute toxicity in Mus musculus. The results showed that S. aureus showed greater susceptibility to TrEO, with a minimum inhibitory concentration (MIC) of 125 µg.mL-1, when compared to P. aeruginosa, E. coli, which presented a MIC of 250 µg.mL-1. There was a greater toxic effect on TrEO (LC50 = 630.29 µg.mL-1) and NTrEO (LC50 = 713.68 µg.mL-1) larvae, effect on pupae (LC50 = 630.29 µg.mL-1) and NTrEO (LC50 = 713.68 µg.mL-1) and ovicide (LC50 = 631.184 µg.mL-1) and NTrEO (LC50 = 146.701 µg.mL-1) of Ae. aegypti after 24 h of exposure, when compared to other exposure periods. Chemical analysis re-vealed 20 components, aromadendrene oxide (23.47%) being the main component. Female and male mice were used to assess toxicity and oral administration of NTrEO to mice did not result in acute toxicity. Thus, the essential oil of T. riparia and its nanoemulsion have insecticidal and an-timicrobial potential for Ae. aegypti, S. aureus, E. coli, P. aeruginosa, and has a high toxicological safety threshold at the concentrations evaluated in this study.

Mercury contamination in the Amazon is a significant public health concern arising from both natural sources and intensive mining activities in the region. This metal is used to separate Au from sediments, forming an amalgam that facilitates the extraction of precious metals. Accordingly, this study aimed to address the following question: What is the impact of mining on mercury contamination in the animal and human populations of the Amazon? The overall objective of this study was to conduct a systematic review of the existing literature to identify gaps in geographic coverage and assess the impact of Hg contamination on human and animal populations in the Amazon region. Our hypothesis was that higher mercury concentrations in tissue samples would be found closer to the mining areas. We employed the PECO and PRISMA-ScR protocols to collect articles published between 2017 and 2023, selected based on criteria representing projected points on a map within the biogeographic boundaries of the Amazon. Mercury concentrations increase with trophic levels, reaching high values of 3.7 µg/g in the muscles of predatory fish and 34.9 µg/g in human hair. The average level of mercury in humans exceeds 6 µg/g, surpassing tolerance levels. Although mining regions show high concentrations of Hg, the highest incidence was observed among populations with fish-based diets. Research on fish is crucial for assessing the risk to human health, given that fish are the main source of protein in the region.