Essential oils (EOs) are complex mixtures of volatile and semi-volatile organic compounds that originate from different plant tissues, including flowers, buds, leaves and bark. According to their chemical composition, EOs have a characteristic aroma and present a wide spectrum of applications, namely in the food, agricultural, environmental, cosmetic and pharmaceutical sectors. These applications are mainly due to their biological properties. However, EOs are unstable and easily degradable if not protected from external factors such as oxidation, heat and light. Therefore, there is growing interest in the encapsulation of EOs, since polymeric nanocarriers serve as a barrier between the oil and the environment. In this context, nanoencapsulation seems to be an interesting approach as it not only prevents the exposure and degradation of EOs and their bioactive constituents by creating a physical barrier, but it also facilitates their controlled release, thus resulting in greater bioavailability and efficiency. In this review, we focused on selecting recent articles whose objective concerned the nanoencapsulation of essential oils from different plant species and highlighted their chemical constituents and their potential biotechnological applications. We also present the fundamentals of the most commonly used encapsulation methods, and the biopolymer carriers that are suitable for encapsulating EOs.

The endophytic fungal community of the Amazonian medicinal plant Arrabidaea chica (Bignoniaceae) was evaluated based on the hypothesis that microbial communities associated with plant species in the Amazon region may produce metabolites with interesting bioactive properties. Therefore, the antimicrobial and antioxidant activities of the fungal extracts were investigated. A total of 107 endophytic fungi were grown in liquid medium and the metabolites were extracted with ethyl acetate. In the screening of fungal extracts for antimicrobial activity, the fungus identified as Botryosphaeria mamane CF2-13 was the most promising, with activity against E. coli, S. epidermidis, P. mirabilis, B. subtilis, S. marcescens, K. pneumoniae, S. enterica, A. brasiliensis, C. albicans, C. tropicalis and, especially, against S. aureus and C. parapsilosis (MIC = 0.312 mg/mL). Screening for antioxidant potential using the DPPH elimination assay showed that the Colletotrichum sp. CG1-7 endophyte extract exhibited potential activity with an EC₅₀ of 11 µg/mL, which is equivalent to quercetin (8 µg/mL). The FRAP method confirmed the antioxidant potential of the fungal extracts. The presence of phenolic compounds and flavonoids in the active extracts was confirmed using TLC. These results indicate that two of the fungi isolated from A. chica exhibit significant antimicrobial and antioxidant potential.

Background/Objectives: The emergence of antimicrobial resistance represents a critical global health threat, requiring the discovery of novel bioactive compounds. Fungi from Amazonian biodiversity are promising sources of secondary metabolites with potential antimicrobial activity. This study aimed to investigate the production of antimicrobial compounds by two Amazonian fungal strains using the OSMAC (One Strain–Many Compounds) approach. Methods: Two fungal strains, Talaromyces pinophilus CCM-UEA-F0414 and Penicillium paxilli CCM-UEA-F0591, were cultivated under five distinct culture media to modulate secondary metabolite production. Ethyl acetate extracts were prepared and evaluated for antimicrobial activity against Gram-positive and Gram-negative bacteria, as well as pathogenic yeasts. Chemical characterization was performed using thin-layer chromatography (TLC), Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet–Visible (UV-Vis) spectroscopy, and Ultra-High-Performance Liquid Chromatography with Diode Array Detection (uHPLC-DAD). Results: The extracts exhibited significant antimicrobial activity, with minimum inhibitory concentrations (MICs) ranging from 78 to 5000 µg/mL. Chemical analyses revealed the presence of phenolic compounds, particularly caffeic and chlorogenic acids. Variations in the culture media substantially affected both the metabolite profiles and antimicrobial efficacy of the extracts. Conclusions: The OSMAC strategy effectively enhanced the metabolic diversity of the Amazonian fungal strains, leading to the production of bioactive metabolites with antimicrobial potential. These findings support the importance of optimizing culture conditions to unlock the biosynthetic capacity of Amazonian fungi as promising sources of antimicrobial agents.

Edible mushrooms have a number of medicinal properties and this study aimed to investigate the antimicrobial activity of Pleurotus eryngii DPUA1816 in metabolic broths after being grown in submerged cultivation. Mycelial fragments of pure P. eryngii culture was inoculated in sweet potato culture medium and incubated at 150 rpm for 15 days at 25°C. Pleurotus eryngii was also cultivated for 18 days under the same conditions, the mycelial biomass was separated by filtration for quantification. The supernatant was used in the diffusion test in agar and performed against Escherichia coli CCCD-E005, Staphylococcus aureus CCCD-S009, Pseudomonas aeruginosa CCCD-P004, Candida albicans CCCD-CC001, Candida parapsilosis CCCD-CC004 and Candida tropicalis CCCD-CC002. The samples showed no inhibitory activity against bacteria, however they showed some activity against C. albicans (12.17 mm), C. parapsilosis (27.67 mm) and C. tropicalis (13.67 mm). After being cultivated for 18 days, P. eryngii was able to inhibit all yeasts after 12 days of culture, with an inhibition halo of 29.33 mm at 16 days against C. parapsilosis. This study demonstrates the antifungal potential filtered liquids from P. eryngii cultivated in purple-skinned sweet potato culture medium, which suggests the possibility of the use of this species by the pharmaceutical industry as a natural source of biological action.

Endophytic fungi are recognized for their capacity to produce bioactive metabolites, yet their metabolic output is strongly modulated by preservation strategies. This study evaluated the influence of three long-term preservation methods—PDA slants with mineral oil (PB), Castellani’s method (PC), and filter paper with mineral oil (PF)—on the production of phenolic compounds and antioxidant activity by the Amazonian endophytes Cophinforma mamane and Aspergillus niger. Post-reactivation morphological analyses revealed method-dependent changes in colony pigmentation, texture, and sporulation intensity. PB preservation induced the most vigorous growth and enhanced sporulation in A. niger. For extracellular metabolites (AcOEt extracts), PB yielded the highest total phenolic content in A. niger (258.24 mg GAE/g), whereas PF and PC favored C. mamane (154.48 and 153.33 mg GAE/g). For intracellular ethanolic extracts, PB was most effective for C. mamane, producing 206.19 mg GAE/g for total phenols and the highest antioxidant activities (EC₅₀ = 1.40 mg/mL and FRAP = 95.61 µmol TE/g). HPLC–DAD identified protocatechuic acid as the predominant compound, which was especially abundant in PC and PF-preserved A. niger (60.76 and 85.38 µg/mg, respectively). Multivariate correlations indicated syringic (r = 0.53) and p-coumaric (r = 0.63) acids as the main contributors to antioxidant potential. These findings demonstrate that preservation methods may positively or negatively modulate fungal biosynthetic capacity, underscoring the importance of species-specific preservation protocols for maintaining metabolic stability in culture collections.

Objective: Checking the frequency of reagent samples for syphilis in pregnant women treated at the Distrital Leste Laboratory in the city of Manaus from January 2016 to December 2018, comparing the positive VDRL (Venereal Disease Research Laboratory) cases with the confirmatory FTA-Abs (Fluorescent Treponemal Antibody Absorption Test). Methods: The study was cross-sectional and assessed the results of two syphilis diagnostic tests, VDRL and FTA-Abs. Data were obtained using the database of the electronic program SoftLab® and the Laboratory Environment Manager (GAL) and were quantitatively analyzed. Results: In 2016, 9,028 VDRL tests were performed on pregnant women, 8,562 tests in 2017 and 5,064 in 2018. From this total, 1020 tested positive for syphilis; 392 in 2016, 320 in 2017 and 308 in 2018, increasing from 4 to 6%. Comparison with the FTA-Abs was only made possible in 2016 when the diagnosis was confirmed in 82% of the tests. Conclusion: It was possible to check the frequency of pregnant women with positive and confirmatory results from 2016 to 2018, showing that although this pathology is easily preventable, it remains a challenging public health issue in pregnant women.