São Vicente - IEMAR - Instituto de Estudos Avançados do Mar
URI Permanente para esta coleçãohttps://hdl.handle.net/11449/253783
Navegar
Submissões Recentes
PublicaçãoArtigo Marine Hazard Assessment of Soluble and Nanostructured Forms of the Booster Biocide DCOIT in Tropical Waters(2023-03-01) Perina, Fernando ; Ottoni, Cristiane
; Santos, Juliana ; Santos, Vithória ; Silva, Mariana ; Campos, Bruno ; Fontes, Mayana ; Santana, Debora ; Maia, Frederico ; Abessa, Denis ; Martins, Roberto ; University of Aveiro ; Universidade Estadual Paulista (UNESP) ; Universidade de Lisboa ; Lda The encapsulation of antifouling compounds, such as DCOIT (4,5-Dichloro-2-octylisothiazol-3(2H)-one), in mesoporous silica nanocapsules (SiNC) has recently been demonstrated to be an eco-friendly alternative to decrease biocide toxicity towards marine non-target species. However, the lack of information on the chronic effects of such nanomaterials on non-target tropical species is critical for a more comprehensive environmental risk assessment. Thus, the present study aimed to assess the chronic toxicity and hazard of the soluble and encapsulated forms of DCOIT on neotropical marine species. Chronic tests were conducted with six ecologically relevant species. No effect concentration (NOEC) values were combined with NOEC values reported for tropical species to assess the hazard using the probabilistic approach to derive each predicted no effect concentration (PNEC). The SiNC-DCOIT was three- to ten-fold less toxic than soluble DCOIT. Probabilistic-based PNECs were set at 0.0001 and 0.0097 µg DCOIT L−1 for the biocide soluble and nanostructured forms, respectively. The immobilization of DCOIT into SiNC led to an 84-fold hazard decrease, confirming that the encapsulation of DCOIT into SiNC is a promising eco-friendly alternative technique, even in a chronic exposure scenario. Therefore, the present study will contribute to better management of the environmental risk of such innovative products in the tropical marine environment.PublicaçãoArtigo In Situ Trametes versicolor Laccase Biocathode Performance Assessment in Dual-Chamber Microbial Fuel Cells(2023-01-01) Ottoni, Cristiane; do Valle Trotta, Caterina ; Martins, Gilberto ; Matos, Joana ; Maiorano, Alfredo Eduardo ; Brito, António G. ; Peixoto, Luciana ; Universidade Estadual Paulista (UNESP) ; Tapada da Ajuda ; University of Minho ; Institute of Technological Research of São Paulo State White-rot fungi (WRF) synthesize ligninolytic extracellular oxidative enzymes such as laccase (Lcc), which has been described as one of the most interesting types of redox enzymes that can improve microbial fuel cell (MFC) performance. Therefore, and in order to test that performance, WRF Trametes versicolor MUM 04.100 was immobilized in nylon sponge and fixed in the MFC cathode chamber, while Lcc activity, bioelectricity production, and organic matter removal were monitored. It was found that current density measured in the MFC supplemented with fungi was 2.1 times higher (42.81 ± 4.91 mA/m2) than current density obtained in the control MFC (absence of fungus in the cathode chamber, 20.31 ± 4.30 mA/m2). Maximum Lcc activity (23.08 U/L) and the highest value of organic matter removal (COD) (92%) from domestic wastewater was obtained on the last cycle after biofilm maturation and glycerol pulse. This work evidences that Lcc continuously synthesized by MUM 04.100 immobilized in the biocathode is a promising approach to enhance MFC power performance and wastewater treatment.PublicaçãoArtigo Biosynthesis of silver nanoparticles using actinomycetes, phytotoxicity on rice seeds, and potential application in the biocontrol of phytopathogens(2023-01-01) Zwar, Ingrid P.; Trotta, Caterina do Valle ; Ziotti, Ana B. S. ; Lima Neto, Milton ; Araújo, Welington L. ; de Melo, Itamar S. ; Ottoni, Cristiane A. ; de Souza, Ana O. ; Instituto Butantan ; Universidade Estadual Paulista (UNESP) ; Universidade de São Paulo (USP) ; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) ; Universidade de Lisboa To find effective silver nanoparticles (AgNPs) for control of phytopathogens, in this study, two strains of actinomycetes isolated from the soil of the Brazilian biome Caatinga (Caat5–35) and from mangrove sediment (Canv1–58) were utilized. The strains were identified by using the 16S rRNA gene sequencing as Streptomyces sp., related to Streptomyces mimosus species. The obtained AgNPs were coded as AgNPs 35 and AgNPs58 and characterized by size and morphology using dynamic light scattering, zeta potential, transmission electron microscopy, and Fourier transformed infrared (FTIR). The antifungal activity of the AgNPs35 and AgNPs58 was evaluated in vitro by the minimal inhibitory concentration (MIC) assay on the phytopathogens, Alternaria solani, Alternaria alternata, and Colletotrichum gloeosporioides. The phytotoxic effect was evaluated by the germination rate and seedling growth of rice (Oryza sativa). AgNPs35 and AgNPs58 showed surface plasmon resonance and average sizes of 30 and 60 nm, respectively. Both AgNPs presented spherical shape and the FTIR analysis confirmed the presence of functional groups such as free amines and hydroxyls of biomolecules bounded to the external layer of the nanoparticles. Both AgNPs inhibited the growth of the three phytopathogens tested, and A. alternate was the most sensible (MIC ≤ 4 µM). Moreover, the AgNPs35 and AgNPs58 did not induce phytotoxic effects on the germination and development of rice seedlings. In conclusion, these AgNPs are promising candidates to biocontrol of these phytopathogens without endangering rice plants.PublicaçãoArtigo Differential physiological responses of a biogenic silver nanoparticle and its production matrix silver nitrate in Sorghum bicolor(2021-01-01) Ziotti, Ana Beatriz Sicchieri; Ottoni, Cristiane Angélica ; Correa, Cláudia Neves ; de Almeida, Odair José Garcia ; de Souza, Ana Olivia ; Neto, Milton Costa Lima ; Universidade Estadual Paulista (Unesp) ; Instituto Butantan Silver nanoparticles (AgNP) have been extensively applied in different industrial areas, mainly due to their antibiotic properties. One of the environmental concerns with AgNP is its incorrect disposal, which might lead to severe environmental pollution. The interplay between AgNP and plants is receiving increasing attention. However, little is known regarding the phytotoxic effects of biogenic AgNP on terrestrial plants. This study aimed to compare the effects of a biogenic AgNP and AgNO3 in Sorghum bicolor seedlings. Seeds were germinated in increasing concentrations of a biogenic AgNP and AgNO3 (0, 10, 100, 500, and 1000 μM) in a growth chamber with controlled conditions. The establishment and development of the seedlings were evaluated for 15 days. Physiological and morpho-anatomical indicators of stress, enzymatic, and non-enzymatic antioxidants and photosynthetic yields were assessed. The results showed that both AgNP and AgNO3 disturbed germination and the establishment of sorghum seedlings. AgNO3 released more free Ag+ spontaneously compared to AgNP, promoting increased Ag+ toxicity. Furthermore, plants exposed to AgNP triggered more efficient protective mechanisms compared with plants exposed to AgNO3. Also, the topology and connectivity of the correlation-based networks were more impacted by the exposure of AgNO3 than AgNP. In conclusion, it is plausible to say that the biogenic AgNP is less toxic to sorghum than its matrix AgNO3.PublicaçãoArtigo Borohydride Reduction Method for PdIn/C Electrocatalysts Synthesis towards Glycerol Electrooxidation under Alkaline Condition(2021-04-01) Nandenha, Júlio ; Ramos, Carlos Eduardo Domingues ; da Silva, Sirlane G. ; de Souza, Rodrigo Fernando Brambilla ; Fontes, Eric Hossein ; Ottoni, Cristiane Angélica; Neto, Almir Oliveira ; IPEN/CNEN-SP ; Universidade Estadual Paulista (Unesp) Pd−In/C electrocatalysts were synthesized by the adapted borohydride reduction method in different atomic ratios. Electrocatalysts were evaluated by conventional electrochemical techniques and direct glycerol fuel cells. X-ray diffraction profiles indicated the structure of Pd and In (fcc) phases, as well as the presence of In higher oxidation states. Regarding Transmission electron microscopy, it showed the particle‘s average diameters between 6.1–12.7 nm. All PdIn/C electrocatalysts showed high current values for −0.30 V vs. Ag/AgCl, which the best one was PdIn/C 90 : 10. Higher performance for glycerol oxidation was observed in polarization curves at 90 °C for PdIn/C (30 : 70) composition.PublicaçãoArtigo Effect of agitation speed and aeration rate on fructosyltransferase production of Aspergillus oryzae IPT-301 in stirred tank bioreactor(2020-12-01) Maiorano, Alfredo Eduardo ; da Silva, Elda Sabino ; Perna, Rafael Firmani ; Ottoni, Cristiane Angélica; Piccoli, Rosane Aparecida Moniz ; Fernandez, Rubén Cuervo ; Maresma, Beatriz Guilarte ; de Andrade Rodrigues, Maria Filomena ; Institute for Technological Research (IPT) ; Instituto Cubano de Investigaciones de los Derivados de la Caña de Azúcar (ICIDCA) ; Federal University of Alfenas (ICT/UNIFAL-MG) ; Universidade Estadual Paulista (Unesp) Objective: Fructooligosaccharides (FOS) are prebiotic substances that have been extensively incorporated in different products of food industry mostly for their bifidogenic properties and economic value. The main commercial FOS production comes from the biotransformation of sucrose and intracellular and extracellular microbial enzymes–fructosyltransferases (FTase). Aspergillus oryzae IPT-301 produces FTase. In order to increase its production, this study focuses on evaluating the effects of different agitation speed and aeration rates which affect yields in a stirred tank bioreactor. Results: Agitation had more influence on cell growth than aeration. The maximum intracellular FTase activity and the volumetric productivity of total intracellular FTase were obtained at 800 rpm and 0.75 vvm, and reached values of 2100 U g−1 and 667 U dm−3 h−1, respectively. The agitation speed had a strong influence on the activity of extracellular FTase produced which reached the maximum amount of 53 U cm−3. The higher value of total activity obtained was 22,831 U dm−3 at 0.75 vvm and 800 rpm. Conclusion: Aeration rates and agitation speed showed strong influence upon the growth and production of fructosyltransferase from Aspergillus oryzae IPT-301 in media containing sucrose as carbon source. The control of aeration rate and agitation speed can be a valuable fermentation strategy to improve enzyme production.PublicaçãoArtigo Microwave absorbing properties of glass fiber/epoxy resin composites tailored with frequency selective surface based on nonwoven of carbon fibers metalized with nickel(2020-08-01) Silveira, Daniel C.; Gomes, Newton A. S. ; Rezende, Mirabel C. ; Botelho, Edson C. ; Universidade Estadual Paulista (Unesp) ; Technological Institute of Aeronautics (ITA) ; Universidade de São Paulo (USP) Radar absorbing structures (RAS) based on frequency selective surface (FSS) can be prepared to meet tailored properties in reducing electromagnetic interference in the microwave range, in addition to presenting mechanical properties suitable for structural applications. This article presents a study involving RAS processed by appropriate lamination and molding of glass fiber/epoxy resin prepreg and nonwoven of carbon fiber recovered with nickel and containing patterned unit cells to evaluate their electromagnetic behavior in X-band. The electromagnetic characterization shows good microwave attenuation results obtained by the RAS FSS with circular unit cells (maximum energy absorption of 89.8% at 12.2 GHz) and also with square unit cells (absorption of 82.8% at 12.3 GHz).PublicaçãoArtigo Environmental impact of biogenic silver nanoparticles in soil and aquatic organisms(2020-01-01) Ottoni, C. A.; Lima Neto, M. C. ; Léo, P. ; Ortolan, B. D. ; Barbieri, E. ; De Souza, A. O. ; Universidade Estadual Paulista (Unesp) ; Instituto de Pesquisa Tecnológica do Estado de São Paulo ; APTA - SAASP- Governo do Estado de São Paulo ; Instituto Butantan Synthetic silver nanoparticles (AgNPs) are being extensively used in our daily lives; however, they may also pose a risk to public health and environment. Nowadays, biological AgNPs are considered an excellent alternative, since their synthesis occurs by a green technology of low cost and easy scaling. However, studies with these biological nanomaterials (NM) are still limited. Thus, a more careful assessment of their industrial application, economic feasibility and ecotoxicological impacts is crucial. The aim of this study was to investigate the effects of different concentrations of mangrove fungus Aspergillus tubingensis AgNPs on the aerobic heterotrophs soil microorganisms, rice seeds (Oryza sativa) and zebrafish (Danio rerio). Biogenic AgNPs were less harmful for soil microbiota compared to AgNO3. On rice seeds, the AgNPs displayed a dose-dependent inhibitory effect on germination and their subsequent growth and development. The percentage of inhibition of rice seed germination was 30, 69 and 80% for 0.01, 0.1 and 0.5 mM AgNPs, respectively. After 24 h of AgNPs exposition at a limit concentration of 0.2 mM, it did not induce mortality of the zebrafish D. rerio. Overall, A. tubingensis AgNPs can be considered as a suitable alternative to synthetic nanoparticles.PublicaçãoArtigo 
Acesso Aberto Microbial fuel cell-induced production of fungal laccase to degrade the anthraquinone dye Remazol Brilliant Blue R(2019-09-01) Simões, Marta Filipa ; Maiorano, Alfredo Eduardo ; dos Santos, Jonas Gomes ; Peixoto, Luciana ; de Souza, Rodrigo Fernando Brambilla ; Neto, Almir Oliveira ; Brito, António Guerreiro ; Ottoni, Cristiane Angélica; Edge Hill University ; Instituto de Pesquisas Tecnológicas do Estado de São Paulo ; University of Minho ; Instituto de Pesquisas Energéticas e Nucleares ; University of Lisbon ; Universidade Estadual Paulista (Unesp) The anthraquinone dye Remazol Brilliant Blue R is largely used in the textile industry. However, its removal from wastewaters is costly and complex. Many methods have been tested to solve this ecological problem, but there is still a need for efficient methods. We propose here an alternative use of a two-chambered microbial fuel cell (MFC), fuelled with domestic wastewater in the anodic chamber, to degrade a simulated textile dye effluent made of Remazol Brilliant Blue R inoculated with an immobilised fungal strain, Pleurotus ostreatus URM 4809, as a laccase producer, in the cathodic chamber. The MFC showed continuous synthesis of laccase in the cathodic chamber, which, in turn, promoted the rapid decolourisation, of more than 86% of the textile dye effluent. The yield was further increased by the addition of glycerol. Electrochemical monitoring also indicated an increase in power density and current density. After 20 days of MFC operation, 62.1% of organic matter was removed in the anodic compartment, thus leaving the effluent with a much lower toxicity.