Halophilic microorganisms are potentially capable as platforms to produce low-cost biosurfactants. However, the robustness of bioprocesses is still a challenge and, therefore, it is essential to understand the effects of microbiological culture conditions through bioreactor engineering. Based on a design of experiments (DOE) and a response surface methodology (RSM) tailored and taken from the literature, the present work focuses on the evaluation of a composite central design (CCD) under batch cultures in stirred-tank bioreactors with the halophilic bacteria Salibacterium sp. 4CTb in order to determine the operative conditions that favor mass transfer and optimize the production of a lipopeptide. The results obtained showed profiles highlighting the most favorable culture conditions, which lead to an emulsification index (E₂₄%) higher than 70%. Moreover, through the behavior of dissolved oxygen (DO), it was possible to experimentally evaluate the higher volumetric coefficient of mass transfer in the presence of lipopeptide (k_La = 31 1/h) as a key criterion for the synthesis of the biosurfactant on further cell expansion.

Spondias mombin L. has been used in traditional medicine to treat some cases such as infections and inflammations. Some researchers have reported that its biological components, such as carotenoids, carotenes, and phenols, have been characterized primarily by HPLC analysis. Here, we report on the characterization of Spondias mombin L. seed oil by Raman spectroscopy, and the profile identification of fatty acids by ¹H-NMR and ¹³C-NMR spectroscopy. The oil was extracted from different weight volumes of seeds using organic solvent, and each batch was characterized. The analysis of the fatty acid profile by NMR indicated that the seed oil is highly unsaturated (monounsaturated: 29.4% and polyunsaturated: 43.5%). Molecular Raman vibrations at 1006, 1158 and 1523 cm⁻¹ showed the presence of carotenoids, which in turn performed an antioxidant activity. This was demonstrated by a 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) method. The cell viability in colon cancer cells was promoted in the presence of the oil. The compounds identified in this study from seed oil could be an interesting proposal for food or pharmaceutical applications.

Butyl oleate synthesis by the lipase B from Candida antarctica (CalB) under extreme halophilic conditions was investigated in the present research through the AOT/Water/Isooctane reverse micellar system. The impact of aqueous content (${\mathrm{W}}_{\mathrm{o}}=\frac{\left[{\mathrm{H}}_2\mathrm{O}\right]}{\left[Surfactant\right]}$) and NaCl variation on the enzymatic activity of CalB in the butyl oleate reaction in reverse micelles was explored. The results indicated that, based on the increase of NaCl, it is remarkable to achieve higher enzymatic activity up to 444.85 $\frac{\mathsf{\mu }\mathrm{mol}}{\min }$ at 5 M NaCl and Wo = 10, as the best esterification conditions at pH 7.2 and 30 °C. However, it was clear that butyl oleate synthesis by lipase CalB increased based on the reduction in the average reverse micelle size, where reverse micelle sizes were determined by dynamic light scattering (DLS). This increase in butyl oleate synthesis demonstrated the potential of reverse micelles as systems that enhance mass transport phenomena in heterogeneous biocatalysis. Furthermore, reverse micelles are promising systems for extreme halophilic lipases research.

Microbial degradation of aromatic hydrocarbons is an emerging technology, and it is well recognized for its economic methods, efficiency, and safety; however, its exploration is still scarce and greater emphasis on cyanobacteria–bacterial mutualistic interactions is needed. We evaluated and characterized the phenanthrene biodegradation capacity of consortium dominated by Fischerella sp. under holoxenic conditions with aerobic heterotrophic bacteria and their molecular identification through 16S rRNA Illumina sequencing. Results indicated that our microbial consortium can degrade up to 92% of phenanthrene in five days. Bioinformatic analyses revealed that consortium was dominated by Fischerella sp., however different members of Nostocaceae and Weeksellaceae, as well as several other bacteria, such as Chryseobacterium, and Porphyrobacter, were found to be putatively involved in the biological degradation of phenanthrene. This work contributes to a better understanding of biodegradation of phenanthrene by cyanobacteria and identify the microbial diversity related.

The discovery and design of antiviral agents have gained unprecedented significance due to the emergence of global health threats. The use of synthetic chemistry has enabled the modification of existing molecules and the creation of entirely novel compounds. In our laboratory, we have enzymatically synthesized a novel bioconjugate, lithocholic acid oleate (LO), derived from lithocholic acid (LCA), a bile acid that has been proven by researchers to exhibit antiviral activity in vitro. The study presented herein describes the preparative synthesis, formulation, and evaluation of LO both in vitro and in vivo for its antiviral activity against human herpes simplex virus 1 (HSV-1) as a model of viral infection. Evaluation of cytotoxicity using A549 cells indicated that a combination of LO (400 μM) and LCA (30 μM) exhibited a favorable safety profile while effectively inhibiting HSV-1 infection comparable to acyclovir treatment. Furthermore, in the in vivo assay, animals treated with an oily formulation containing 7% LO; 0.50% LCA; and 3% oleic acid (OA), 48 h prior to virus exposure, showed results even superior to a 5% acyclovir commercial formulation in terms of scar formation and wound recovery. These promising results enable the development of new preventive products against HSV-1 and probably other viruses.

For several decades, the electrical admittance has been very useful for the determination of physical quantities, such as the characterization of some electrical properties of interest in organic samples. In this work, an electrical system based on graphite electrodes to determine the amount of living biomass of the cyanobacteria Fischerella sp. is proposed. Cyanobacteria are phototrophic microorganisms with applications on bioremediation, pharmaceutics, medicine, among others. The strain was characterized in BG-11 medium and cultured at different biomass concentrations. Samples were evaluated by electrical admittance and contrasted by the technique of dry weight in order to correlate the results registered by the/a proposal electric circuit. Scanning frequencies from admittance went in an order from 10 Hz to 1 000 000 Hz. Also, they showed a reproducibility, getting deviations of 6.45 × 10-5. This electrical system can be used to evaluate Fischerella sp. living biomass concentrations with high reliability.