Browsing by Author "Crugeira, Pedro Jorge Louro"
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- Biosynthesis of antioxidant xanthan gum by Xanthomonas campestris using substrates added with moist olive pomacePublication . Crugeira, Pedro Jorge Louro; Almeida, Heloísa H.S.; Marcet, Ismael; Rendueles, Manuel; Pires, Marcella Golini; Rafael, Helder Martins; Rodrigues, Ana Isabel G.; Santamaria-Echart, Arantzazu; Rafael, Helder; Barreiro, M.F.; Golini Pires, MarcellaMoist olive pomace (MOP) is a high moisture content by-product of the olive oil industry. Managing this recalcitrant residue (transport, storage, and drying) is a priority demanding investment in finding alternative valorisation routes. In this context, the biosynthesis of xanthan gum (XG) incorporating MOP in the substrate (0.0 %, 5.0 %, 10.0 %, 15.0 %, 20.0 %, 25.0 %, 30.0 % and 50.0 %) to induce bacterial stress was attempted. XG biosynthesis yield was quantified, and the product was characterised by structural analysis (FTIR), thermal behaviour (TG), rheology and antioxidant capacity. Relative to the control (sample with no added MOP), a significant increase in XG biosynthesis was found for concentrations up to 30.0 % MOP. In particular, for XG produced with 15 % MOP, a 50.91 % (p < 0.0001) increase was achieved, together with 395.78 % for viscosity. In general, XG produced with MOP presence showed antioxidant activity, a value-added property, especially for applications in the food, pharmaceutical and cosmetic areas. The results indicated that the stress imposed by the MOP induced a microbial response leading to XG production increase, structural and viscosity modifications, and antioxidant properties incorporation. Overall, this work points out a new MOP application contributing to the sustainability of the olive oil productive chain from a biobased circular economy perspective.
- Copper-induced exopolysaccharide production by Lelliottia amnigena strain LABEMPublication . Sampaio, Igor Carvalho F.; Moura, Isabela Viana L. de; Crugeira, Pedro Jorge Louro; Widmer, Luiz Fernando; Oliveira, Jairo P. de; Cassini, Servio T.A.; Almeida, Paulo Fernando deExopolysaccharide (EPS) prodcution is a general mechanism employed by bacteria to thrive under stressful conditions. We report an increase in the production of EPS by Lelliottia amnigena strain LABEM through CuSO4 exposure along with the use of low-cost carbon sources, namely sucrose (SUC) and crude glycerin (CG). The production of EPS was analyzed in relation to yield, and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and thermogravimetric analysis. L. amnigena grew in up to 1.0 mM CuSO4, with a maximum EPS yield of 51.8% at 0.6 mM CuSO4. The absence of copper detection in the enhanced EPS batches is innovative, indicating a potential reduction in purification steps and heavy metal removal from the produced EPS. This suggests a possible low copper affinity of the produced EPS until the production of 0.8 mM CuSO4. Microbial supplementation with CuSO4 also enhanced EPS thermostability and surface roughness, showcasing intriguing properties applicable to drilling fluids and pharmaceutical uses. High-performance liquid chromatography (HPLC) and FTIR showed the polysaccharide nature of the products and the presence of the highly valuable EPS constituent fucose. The results illustrate the relationship between exopolysaccharide and heavy metal exposure, with a focus on enhancing bioprocesses. This expands our understanding and applications beyond heavy metal adsorption and removal. EPS properties and composition suggest diverse applications, such as food additives and in other processes that employ fucose polymer. Future experiments should explore the various applications of this exopolysaccharide and the scale-up of the technology.
- Disclosing the potential of Cupressus leylandii A.B. Jacks & Dallim, Eucalyptus globulus Labill., Aloysia citrodora Paláu, and Melissa officinalis L. hydrosols as eco-friendly antimicrobial agentsPublication . Almeida, Heloísa H.S.; Crugeira, Pedro Jorge Louro; Amaral, Joana S.; Rodrigues, Alírio; Barreiro, M.F.Antimicrobial resistance is a major global health concern, threatening the effective prevention and treatment of infections caused by microorganisms. These factors boosted the study of safe and green alternatives, with hydrosols, the by-products of essential oils extraction, emerging as promising natural antimicrobial agents. In this context, four hydrosols obtained from Cupressus leylandii A.B. Jacks & Dallim, Eucalyptus globulus Labill., Aloysia citrodora Paláu and Melissa officinalis L. were studied. Their chemical composition comprises neral, geranial, 1,8-cineole, terpinen- 4-ol, and oplopanonyl acetate, compounds with recognised antimicrobial activity. Concerning antimicrobial activity, significant differences were found using different hydrosol concentrations (10–20% v/v) in comparison to a control (without hydrosol), showing the potential of the tested hydrosols to inhibit the microbial growth of Escherichia coli, Staphylococcus aureus, and Candida albicans. A. citrodora hydrosol was the most effective one, inhibiting 90% of E. coli growth and 80% of C. albicans growth, for both hydrosol concentrations (p < 0.0001). With hydrosol concentration increase, it was possible to observe an improved antimicrobial activity with significant reductions (p < 0.0001). The findings of this work indicate the viability of reusing and valuing the hydrosols, encouraging the development of green applications for different fields (e.g., food, agriculture, pharmaceuticals, and cosmetics).
- Effect of photostimulation through red LED light radiation on natural fermentation of table olives: An innovative case study with Negrinha the Freixo varietyPublication . Martins, Fátima; Ramalhosa, Elsa; Rodrigues, Nuno; Pereira, J.A.; Baptista, Paula; Barreiro, M.F.; Crugeira, Pedro Jorge LouroIn this study, for the first time, red LED light radiation was applied to the fermentation process of table olives using the Negrinha de Freixo variety. Photostimulation using LED light emission (630 ± 10 nm) is proposed to shorten and speed up this stage and reduce time to market. Several physical-chemical characteristics and microorganisms (total microbial count of mesophilic aerobic, molds, yeasts, and lactic acid bacteria) and their sequence during fermentation were monitored. The fermentation occurred for 122 days, with two irradiation periods for red LED light. The nutritional composition and sensory analysis were performed at the end of the process. Fermentation under red LED light increased the viable yeast and lactic acid bacteria (LAB) cell counts and decreased the total phenolics in olives. Even though significant differences were observed in some color parameters, the hue values were of the same order of magnitude and similar for both samples. Furthermore, the red LED light did not play a relevant change in the texture profile, preventing the softening of the fruit pulp. Similarly, LED light did not modify the existing type of microflora but increased species abundance, resulting in desirable properties and activities. The species identified were yeasts - Candida boidinii, Pichia membranifaciens, and Saccharomyces cerevisiae, and bacteria - Lactobacillus plantarum and Leuconostoc mesenteroides, being the fermentative process dominated by S. cerevisiae and L. plantarum. At the end of fermentation (122 days), the irradiated olives showed less bitterness and acidity, higher hardness, and lower negative sensory attributes than non-irradiated. Thus, the results of this study indicate that red LED light application can be an innovative technology for table olives production.
- Exploring Innovative Exogenous Green Stimulus Methods for Boosting Bioprocesses: Electric, Magnetic and Ultrasound Stimulation TechniquesPublication . Sampaio, Igor Carvalho Fontes; Moura, Isabela Viana Lopes de; Crugeira, Pedro Jorge Louro; Chinalia, Fábio Alexandre; Matos, Josilene Borges Tores Lima; Jones, Cleveland Maximino; Almeida, Paulo Fernando deThis book chapter provides an overview of the innovative exogenous green stimulus methods of electric, magnetic, and ultrasound stimulation and their appli- cations in boosting bioprocesses. These non-invasive and non-toxic techniques have been shown to enhance the metabolic activity and stress response of various micro- bial systems, including bacteria, yeasts, fungi, and microalgae, leading to increased yields of valuable bioproducts and bioremediation technologies. The chapter begins with an introduction to the concept of these green stimulus and the rationale behind its use in bioprocessing. This is followed by a discussion of the different principles and mechanisms of electric, magnetic, and ultrasound stimulation, including the physical and biological effects that underpin their efficacy. Additionally, the chapter covers the application of these techniques in various bioprocesses, including micro- bial fermentation, biosynthesis of enzymes, and bioconversion of biomass. Examples are provided to illustrate the benefits of green stimulus in enhancing the production of specific bioproducts, such as biofuels, pharmaceuticals, and biopolymers. Finally, we conclude with a critical evaluation of the potential of these techniques in the bioprocessing industry, highlighting the challenges and limitations that need to be addressed to fully harness their potential.
- Oilfield carbonated produced water recycling coupled to exopolysaccharide transformation by lelliottia amnigenaPublication . Sampaio, Igor Carvalho Fontes; Ferreira, Joalene de Azevedo Santos; Crugeira, Pedro Jorge Louro; Oliveira, Ian M. da Silva; Santos, Jacson Nunes; Matos, Josilene Borges Torres Lima; Pinheiro, Antonio Luiz Barbosa; Almeida, Paulo Fernando deIt was tested the production of a viscous exopolysaccharide (EPS) by Lelliottia amnigena using different concentrations (10, 15, 25, 50 and 100%) of produced water (PW) and Dialyzed PW (DPW) at 100% concentration, with a nutrient medium based on glycerin and sucrose as carbon sources in 44 h batches. There was an increase in EPS recovery when used PW up to a concentration of 25%. The viscosity of the EPS solutions was maintained with DPW and up to 15% of PW, such a condition resulted in 9.34 gL− 1 of EPS, representing an increase of 84.9% compared to the control (P < 0.0001). The PW 15% increased the viscosity per produced liter by 114.3% (P < 0.0001). Scanning electron microscopy and Energy-dispersive X-ray spectroscopy analysis showed that EPS adsorbed mineral constituents of the substrate and its characterization by Fourier Transform Infrared Spectroscopy was similar to an external control of a commercial EPS produced by an Enterobacter A47 strain. PW at 15% becomes an alternative to increase the EPS production process and can contribute to the mitigation of environmental damage through sustainable PW management in the oilfield chain.
- Patente Nacional Nº 118006 - Método de produção de goma xantana com bagaço húmido da azeitona e aumento do biopolímero produzidoPublication . Crugeira, Pedro Jorge Louro; Barreiro, M.F.; Almeida, Heloísa Helena Scorsato de; Pires, Marcella Golini; Rafael, Helder Martins; Golini Pires, MarcellaO presente invento refere-se a um processo de produção de goma xantana, a partir da cepa de Xanthomonas campestris atcc 33913, com o uso do bagaço húmido da azeitona, proveniente da extração do azeite em sistema contínuo de duas fases. O método utiliza o bagaço húmido de azeitona pasteurizado até uma concentração de 45% suplementado com 2,0% de sacarose para meio de produção. Os polifenóis, poliálcoois e ácidos orgânicos existentes no resíduo induzem o estresse microbiano e consequente aumento da produção do exopolissacarídeo, como resposta à adaptabilidade celular e proteção às condições desfavoráveis. O dissacarídeo funciona como fonte de carbono, conseguindo-se uma relação aproximada de carbono/nitrogénio de 10:1, favorável a produção. A reutilização do bagaço húmido, resíduo recalcitrante, insere-se no processo sustentável e de inclusão no sistema de economia circular, reduzindo o custo do bioprocesso. O presente invento é aplicável, por exemplo, nas indústrias alimentares, farmacêuticas, agrícolas e petrolíferas.
- Photodynamic antimicrobial therapy (A-PDT) using 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB and λ640 ± 5ηm LED light in patients undertaking orthodontic treatmentPublication . Soares, Luiz G.P.; Almeida, Cristiane G. de; Crugeira, Pedro Jorge Louro; Nunes, Iago P.F.; Silva, Anna P.L.T. da; Almeida, Jeovana A.; Cangussu, Maria C.T.; Almeida, Paulo Fernando de; Habib, Fernando A.L.; Pinheiro, Antonio Luiz BarbosaOrthodontic treatment involves the use of apparatuses that impairs oral hygiene making patients susceptible to periodontal diseases and caries. To prevent increased antimicrobial resistance A-PDT has shown itself a feasible option. The aim of this investigation was to assess the efficiency of A-PDT employing 1,9-Dimethyl-Methylene Blue zinc chloride double salt -DMMB as a photosensitizing agent combined with red LED irradiation (lambda 640 +/- 5 eta m) against oral biofilm of patients undertaking orthodontic treatment. Twenty-one patients agreed to participate. Four biofilm collections were carried out on brackets and gingiva around inferior central incisors; first was carried out before any treatment (Control); second followed five minutes of pre-irradiation, the third was immediately after the first AmPDT, and the last after a second AmPDT. Then, a microbiological routine for microorganism growth was carried out and, after 24-h, CFU counting was performed. There was significant difference between all groups. No significant difference was seen between Control and Photosensitizer and AmpDT1 and AmPDT2 groups. Significant differences were observed between Control and AmPDT1 and AmPDT2 groups, Photosensitizer and AmPDT1 and AmPDT2 groups. It was concluded that double AmPDT using DMBB in nano concentration and red LED was capable to meaningfully decrease the number of CFUs in or-thodontic patients.
- Photodynamic inactivation of Staphylococcus aureus by ecological antibacterial solutions associating LED (ʎ 450 ± 10 nm) with curcumin and olive leaf extractsPublication . Crugeira, Pedro Jorge Louro; Almeida, Heloísa H.S.; Teixeira, Liandra Gracher; Barreiro, M.F.Antimicrobial resistance is a problem in contemporary society, with Staphylococcus aureus standing out as a threat due to its ability to colonize, its pathogenicity, and its expression of several virulence factors. In this context, antimicrobial photodynamic inactivation (aPDI) emerges as an alternative to conventional microbicidal or microbiostatic systems, enabling numerous and successive applications without developing side effects and microbial resistance. In this context, an aPDI system against cultures of S. aureus based on a water-in-oil (W/O) emulsion incorporating curcumin as the photosensitizer (PS), with and without olive leaf extract (OLE), was developed and the antibacterial efficacy evaluated under LED activation (lambda 450 +/- 10 nm) by depositing an energy density of 14 J/cm(2). The produced emulsified systems showed no significant differences in the droplet size and morphology, remaining stable along the tested period of 30 days. The bacterial reduction achieved after the first aPDI application for the emulsions added with curcumin and curcumin combined with the OLE was 5 log10 CFU. mL(-1) and 6 log10 CFU.mL(-1), respectively, revealing a significant difference between the two groups (p < 0.0001). After the second aPDI application, an increased microbial reduction (7 log10 CFU.mL(-1)) was observed for both studied groups even with a low significant difference (p < 0.05). The PS loading through an emulsified system for aPDI obtained a bactericidal action against S. aureus, increased by applying two aPDI, showing a significant synergy between photodynamic inactivation, OLE delivery and antibacterial activity. In addition, the developed solutions were produced using natural products by an ecologically correct process.
- Photoinactivation of sulfate-reducing bacteria using 1,9-dimethyl-methylene blue – DMMB and laser lightPublication . Santos, Gustavo Vital dos; Moura, Hesrom Fernandes Serra; Crugeira, Pedro Jorge Louro; Silva, Anna Paula Lima Teixeira da; Castro, Isabele Cardoso Vieira de; Costa, Wellington Luís Reis; Almeida, Paulo Fernando de; Pinheiro, Antonio Luiz BarbosaAnnually, the oil and gas industry faces equipment losses and product quality degradation due to the presence of sulfate-reducing bacteria (SRB). Given the negative impact of SRB, this study evaluates the use of photoinactivation (PI) with zinc chloride double salt of 1,9-Dimethyl-Methylene Blue (DMMB) as a photosensitizer (PS) in varying concentrations and combined with Laser light at different exposures in an SRB consortium. For culture growth, a modified Postgate C medium (without ferrous sulfate) was used, and cell quantification was performed on 100 μL aliquots of the consortium, read on a spectrophotometer (λ600 nm) in an oxygen- and lightfree environment at room temperature. Statistical analyses included two-way ANOVA and ANOVA with interaction to separately and jointly evaluate the effects of PS and light in PI. Results indicated microbial activity in all groups, with an antimicrobial inhibition rate exceeding 50 % (p < 0.05) for concentrations above 1.5 μg/mL of DMMB. PI efficacy significantly depended on DMMB concentration and light density, achieving a 70.58 % (55.73–70.58, with a mean of 66.71 %) reduction (p < 0.05) with 1.5 μg/mL of DMMB and a 70.15 % (65–70.15, with a mean of 68.21 %) reduction with 2.0 μg/mL at an intensity of 21.6 J/cm2. In conclusion, PI presents a promising alternative to biocides in the oil and gas industry, offering easy application, avoiding bacterial resistance, being environmentally safe, and compatible with other SRB population control techniques.