GUÁMAN BAUTISTA, LINDA PRISCILA
Preferred name
GUÁMAN BAUTISTA, LINDA PRISCILA
Main Affiliation
CENBIO - Centro de Investigación Biomédica
Web Site
Scopus Author ID
57190735993
27 results
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Item type:Publication, Production of Polyhydroxyalkanoates Copolymers by Recombinant <b><i>Pseudomonas</i></b> in Plasmid- and Antibiotic-Free Cultures(S. Karger AG, 2018) ;Edmar Ramos Oliveira-Filho; ;Thatiane Teixeira Mendonça ;Paul F. LongMarilda Keico Taciro<jats:p>Three different polyhydroxyalkanoate (PHA) synthase genes (<i>Ralstonia eutropha</i> H16, <i>Aeromonas</i> sp. TSM81 or <i>Aeromonas hydrophila</i> ATCC7966 <i>phaC</i>) were introduced into the chromosome of two <i>Pseudomonas</i> strains: a native medium-chain-length 3-polyhydroxyalkanoate (PHA<sub>MCL</sub>) producer (<i>Pseudomonas</i> sp. LFM046) and a UV-induced mutant strain unable to produce PHA (<i>Pseudomonas</i> sp. LFM461). We reported for the first time the insertion of a chromosomal copy of <i>phaC</i> using the transposon system mini-Tn<i>7</i>. Stable antibiotic marker-free and plasmid-free recombinants were obtained. Subsequently, P(3HB-<i>co</i>-3HA<sub>MCL</sub>) was produced by these recombinants using glucose as the sole carbon source, without the need for co-substrates and under antibiotic-free conditions. A recombinant harboring <i>A. hydrophila phaC</i> produced a terpolyester composed of 84.2 mol% of 3-hydroxybutyrate, 6.3 mol% of 3-hydroxyhexanoate, and 9.5 mol% of 3-hydroxydecanoate from only glucose. Hence, we were successful in increasing the industrial potential of <i>Pseudomonas</i> sp. LFM461 strain by producing PHA copolymers containing 3HB and 3HA<sub>MCL</sub> using an unrelated carbon source, for the first time in a plasmid- and antibiotic-free bioprocess.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Designing cytochrome P450 enzymes for use in cancer gene therapy(Frontiers Media SA, 2024-05-24) ;Saskya E. Carrera-Pacheco ;Alexander Mueller ;Juan A. Puente-Pineda; Cancer is a significant global socioeconomic burden, as millions of new cases and deaths occur annually. In 2020, almost 10 million cancer deaths were recorded worldwide. Advancements in cancer gene therapy have revolutionized the landscape of cancer treatment. An approach with promising potential for cancer gene therapy is introducing genes to cancer cells that encode for chemotherapy prodrug metabolizing enzymes, such as Cytochrome P450 (CYP) enzymes, which can contribute to the effective elimination of cancer cells. This can be achieved through gene-directed enzyme prodrug therapy (GDEPT). CYP enzymes can be genetically engineered to improve anticancer prodrug conversion to its active metabolites and to minimize chemotherapy side effects by reducing the prodrug dosage. Rational design, directed evolution, and phylogenetic methods are some approaches to developing tailored CYP enzymes for cancer therapy. Here, we provide a compilation of genetic modifications performed on CYP enzymes aiming to build highly efficient therapeutic genes capable of bio-activating different chemotherapeutic prodrugs. Additionally, this review summarizes promising preclinical and clinical trials highlighting engineered CYP enzymes’ potential in GDEPT. Finally, the challenges, limitations, and future directions of using CYP enzymes for GDEPT in cancer gene therapy are discussed. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Protective role of butyrate in obesity and diabetes: New insights(Frontiers Media SA, 2022-11-24); ;Carlos Barba-Ostria; <jats:p>Studies in human microbiota dysbiosis have shown that short-chain fatty acids (SCFAs) like propionate, acetate, and particularly butyrate, positively affect energy homeostasis, behavior, and inflammation. This positive effect can be demonstrated in the reduction of butyrate-producing bacteria observed in the gut microbiota of individuals with type 2 diabetes (T2DM) and other energy-associated metabolic alterations. Butyrate is the major end product of dietary fiber bacterial fermentation in the large intestine and serves as the primary energy source for colonocytes. In addition, it plays a key role in reducing glycemia and improving body weight control and insulin sensitivity. The major mechanisms involved in butyrate regulation include key signaling pathways such as AMPK, p38, HDAC inhibition, and cAMP production/signaling. Treatment strategies using butyrate aim to increase its intestine levels, bioavailability, and improvement in delivery either through direct supplementation or by increasing dietary fiber in the diet, which ultimately generates a higher production of butyrate in the gut. In the final part of this review, we present a summary of the most relevant studies currently being carried out in humans.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Exploring the Multifaceted Biological Activities of Anthocyanins Isolated from Two Andean Berries(MDPI AG, 2024-08-21) ;Carlos Barba-Ostria ;Saskya E. Carrera-Pacheco; ; Natural pigments extracted from plant species are used in foods, cosmetics, and pharmaceuticals. This study evaluates the comprehensive biological activities of anthocyanins isolated from Andean blueberry (Vaccinium floribundum Kunth) and Andean blackberry (Rubus glaucus Benth), focusing on their antimicrobial, antioxidant, antitumoral, anti-inflammatory, and hemolytic properties. Chemical characterization revealed significant anthocyanin content with complex mass spectrometric profiles indicating diverse glycosylation patterns that may influence their bioactivity. The antimicrobial assays showed that the extracts were particularly effective against Gram-positive bacteria, with minimal inhibitory concentrations (MICs) as low as 1 mg/mL for Rubus glaucus, indicating strong potential for therapeutic use. The antioxidant capacity of the berries was substantial, albeit slightly lower than that of ascorbic acid. The extracts also exhibited notable antitumoral activity in various cancer cell lines, showing promise as adjunctive or preventive treatments. The anti-inflammatory effects were confirmed by inhibiting nitric oxide production in macrophage cells, highlighting their potential in managing inflammatory diseases. In terms of hemolytic activity, Rubus glaucus exhibited dose-dependent effects, potentially attributable to anthocyanins and phenolics, while Vaccinium floribundum demonstrated no significant hemolytic activity, underscoring its safety. These findings suggest that anthocyanins from Andean berries possess potent biological activities, which could be leveraged for health benefits in pharmaceutical and nutraceutical applications. Further studies are needed to isolate specific bioactive compounds and investigate their synergistic effects in clinical and real-world contexts. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Microencapsulation of Anthocyanins from Zea mays and Solanum tuberosum: Impacts on Antioxidant, Antimicrobial, and Cytotoxic Activities(MDPI AG, 2024-11-27) ;Carlos Barba-Ostria ;Yenddy Carrero ;Jéssica Guamán-Bautista ;Orestes LópezChristian ArandaObjectives: This study investigates the biological activities of microencapsulated anthocyanins extracted from two Andean ancestral edible plants, Solanum tuberosum, and Zea mays, with a focus on their potential applications in functional foods and therapeutics. The primary objective was to evaluate their antioxidant, antimicrobial, and cytotoxic properties alongside structural and functional analyses of the microencapsulation process. Methods: Anthocyanins were extracted and microencapsulated using maltodextrin as a carrier. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were employed to analyze the stability and structure of the microencapsulated particles. The antioxidant, antimicrobial, and cytotoxic activities of the microencapsulated were assessed through established assays. Results:S. tuberosum exhibited superior antioxidant capacity and potent anticancer activity against HepG2 and THJ29T cell lines, while Z. mays demonstrated significant antimicrobial efficacy against multidrug-resistant bacterial strains and biofilm-forming pathogens. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) confirmed the stabilization of anthocyanins within a maltodextrin matrix, enhancing their bioavailability and application potential. Conclusions: These results highlight the versatility of microencapsulated anthocyanins as bioactive agents for industrial and therapeutic applications. Future studies should explore in vivo validation and synergistic formulations to optimize their efficacy and broaden their use in nutraceutical and pharmaceutical fields. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Bioactive Phenolic Compounds from Rambutan - Nephelium lappaceum L. - Shell: Encapsulation, Structural Stability, and Multifunctional Activities(MDPI AG, 2025-11-09) ;Carlos Barba Ostria ;Orestes López ;Alexis Debut; Rambutan (Nephelium lappaceum) shell, an agro-industrial by-product, is a rich source of phenolic acids and minor anthocyanins, but its direct use is limited by instability and low bioavailability. We extracted phenolic-rich fractions and produced maltodextrin microcapsules by spray drying, then confirmed chemical entrapment and amorphization by FTIR, SEM, and XRD. The formulation showed high encapsulation efficiency and high antioxidant capacity (DPPH), selective bactericidal activity against Pseudomonas aeruginosa and Burkholderia cepacia, and strong inhibition of Staphylococcus aureus and Listeria monocytogenes biofilms, while exhibiting negligible hemolysis (<2%) across tested concentrations. Antitumor effects were moderate with low selectivity in vitro, indicating that phenolic-acid-driven redox modulation may require fractionation or delivery optimization for oncology applications. Overall, spray-dried microcapsules provided structural stability and safety while concentrating multifunctional activities relevant to food and biomedical uses. By valorizing a tropical waste stream into a bioactive, hemocompatible ingredient, this work aligns with societal goals on health and sustainable production (SDG 3 and SDG 12) and offers a scalable route to deploy underutilized phenolic resources.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Gene silencing based on RNA-guided catalytically inactive Cas9 (dCas9): a new tool for genetic engineering in Leptospira(Springer Science and Business Media LLC, 2019-02-12) ;L. G. V. Fernandes; ;S. A. Vasconcellos ;Marcos B. HeinemannM. Picardeau<jats:title>Abstract</jats:title><jats:p>Leptospirosis is a worldwide zoonosis caused by pathogenic bacteria of the genus <jats:italic>Leptospira</jats:italic>, which also includes free-living saprophyte strains. Many aspects of leptospiral basic biology and virulence mechanisms remain unexplored mainly due to the lack of effective genetic tools available for these bacteria. Recently, the type II CRISPR/Cas system from <jats:italic>Streptococcus pyogenes</jats:italic> has been widely used as an efficient genome engineering tool in bacteria by inducing double-strand breaks (DSBs) in the desired genomic targets caused by an RNA-guided DNA endonuclease called Cas9, and the DSB repair associated machinery. In the present work, plasmids expressing heterologous <jats:italic>S. pyogenes</jats:italic> Cas9 in <jats:italic>L. biflexa</jats:italic> cells were generated, and the enzyme could be expressed with no apparent toxicity to leptospiral cells. However, <jats:italic>L. biflexa</jats:italic> cells were unable to repair RNA-guided Cas9-induced DSBs. Thus, we used a catalytically dead Cas9 (dCas9) to obtain gene silencing rather than disruption, in a strategy called CRISPR interference (CRISPRi). We demonstrated complete gene silencing in <jats:italic>L. biflexa</jats:italic> cells when both dCas9 and single-guide RNA (sgRNA) targeting the coding strand of the β-galactosidase gene were expressed simultaneously. Furthermore, when the system was applied for silencing the <jats:italic>dnaK</jats:italic> gene, no colonies were recovered, indicating that DnaK protein is essential in <jats:italic>Leptospira</jats:italic>. In addition, flagellar motor switch FliG gene silencing resulted in reduced bacterial motility. To the best of our knowledge, this is the first work applying the CRISPRi system in <jats:italic>Leptospira</jats:italic> and spirochetes in general, expanding the tools available for understanding leptospiral biology.</jats:p> - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Green Synthesis of Silver Oxide Nanoparticles from Mauritia flexuosa Fruit Extract: Characterization and Bioactivity Assessment(MDPI AG, 2024-11-22); ;David Vaca-Vega ;Karla Vizuete ;Saskya E. Carrera-PachecoThe increasing prevalence of multidrug-resistant (MDR) pathogens, persistent biofilms, oxidative stress, and cancerous cell proliferation poses significant challenges in healthcare and environmental settings, highlighting the urgent need for innovative and sustainable therapeutic solutions. The exploration of nanotechnology, particularly the use of green-synthesized nanoparticles, offers a promising avenue to address these complex biological challenges due to their multifunctional properties and biocompatibility. Utilizing a green synthesis approach, Mauritia flexuosa Mf-Ag2ONPs were synthesized and characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy coupled with scanning electron microscopy (EDS-SEM), UV-Vis spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The Mf-Ag2ONPs exhibited potent antibacterial effects against both non-resistant and MDR bacterial strains, with minimum inhibitory concentrations (MICs) ranging from 11.25 to 45 µg/mL. Mf-Ag2ONPs also demonstrated significant antifungal efficacy, particularly against Candida glabrata, with an MIC of 5.63 µg/mL. Moreover, the nanoparticles showed strong biofilm inhibition capabilities and substantial antioxidant properties, underscoring their potential to combat oxidative stress. Additionally, Mf-Ag2ONPs exhibited pronounced anticancer properties against various cancer cell lines, displaying low IC50 values across various cancer cell lines while maintaining minimal hemolytic activity at therapeutic concentrations. These findings suggest that Mf-Ag2ONPs synthesized via an eco-friendly approach offer a promising alternative for biomedical applications, including antimicrobial, antifungal, antioxidant, and anticancer therapies, warranting further in vivo studies to fully exploit their therapeutic potential. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Clinical, molecular, and epidemiological characterization of the SARS-CoV-2 virus and the Coronavirus Disease 2019 (COVID-19), a comprehensive literature review(Elsevier BV, 2020-09) ;Esteban Ortiz-Prado ;Katherine Simbaña-Rivera ;Lenin Gómez- Barreno ;Mario Rubio-Neira - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Phytochemical Composition and Biological Properties of Macleania rupestris Fruit Extract: Insights into Its Antimicrobial and Antioxidant Activity(MDPI AG, 2025-03-27); ; ;Elena Coyago-Cruz; Jéssica Guamán-BautistaMacleania rupestris, a fruit-bearing species of the Ericaceae family, has traditionally been used for its potential medicinal properties. Background/Objectives: This study investigates the phytochemical composition and antimicrobial activity of M. rupestris fruit extract, focusing on its antibacterial, antibiofilm, and antifungal effects. Methods: M. rupestris (Kunth) A.C.Sm. berries (code: 4456, Herbario QUPS-Ecuador) were collected from the cloud forest Montano Alto, Cuenca-Ecuador, and the extract was obtained using an ethanolic-based extraction and chemically characterized. The antibacterial and antifungal activity of the fruit extract was assessed against seven multidrug-resistant bacteria strains and four fungal strains using the microdilution method. The biofilm inhibition potential was evaluated using a microplate assay with the crystal violet staining method. The antioxidant activity was evaluated using DPPH and ABTS assays. Results: The bioactive compounds showed 853.9 mg phenols/100 g DW, 573.2 mg organic acid/100 g DW, and 21.5 mg C-3-gl/100 g DW of anthocyanins. The antibacterial assays demonstrated significant inhibitory activity against Enterococcus faecalis, Enterococcus faecium, Escherichia coli, and Staphylococcus epidermidis, with MIC values ranging from 1.25 to 5 mg/mL. Additionally, the biofilm inhibition assays confirmed the potential of M. rupestris extract to disrupt bacterial biofilms, particularly in S. aureus and L. monocytogenes. Nevertheless, no significant antifungal activity was observed against Candida spp., suggesting selective antimicrobial properties. Finally, the antioxidant activity was strong (1.62 mmol TE/100 g DW by DPPH and 3.28 mmol TE/100 g DW by ABTS). Conclusions: These findings indicate that M. rupestris possesses promising antibacterial, antibiofilm, and antioxidant properties, which may be attributed to its phenolic and organic acid composition. Further fractionation and targeted bioassays are required to elucidate the specific bioactive compounds responsible for these effects and explore their potential applications in antimicrobial formulations.
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