Person:
Castro Ruiz, Laura

First Name

Laura

Last Name

Castro Ruiz

URI

https://hdl.handle.net/20.500.14352/81200

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Químicas

Department

Ingeniería Química y de Materiales

Identifiers

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Now showing 1 - 10 of 20

Batch and Continuous Chromate and Zinc Sorption from Electroplating Effluents Using Biogenic Iron Precipitates
(Minerals, 2021) Rocha, Fabiana; Muñoz Sánchez, Jesús Ángel; González González, Felisa; Blázquez Izquierdo, María Luisa; Castro Ruiz, Laura
Nanoparticles of iron precipitates produced by a microbial consortium are a suitable adsorbent for metal removal from electroplating industry wastewaters. Biogenic iron precipitates were utilized as adsorbents for chromate and zinc in batch conditions. Furthermore, the iron precipitates were embedded in alginate beads for metal removal in fixed-bed columns, and their performance was evaluated in a continuous system by varying different operational parameters such as flow rate, bed height, and feeding system (down- and up-flows). The influence of different adsorption variables in the saturation time, the amount of adsorbed potentially toxic metals, and the column performance was investigated, and the shape of the breakthrough curves was analyzed. The optimal column performance was achieved by increasing bed height and by decreasing feed flow rate and inlet metal concentration. The up-flow system significantly improved the metal uptake, avoiding the preferential flow channels.
Extracellular biosynthesis of gold nanoparticles using sugar beet pulp
(Chemical Engineering Journal, 2010) Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa; González González, Felisa; Muñoz Sánchez, Jesús Ángel; Ballester Pérez, Antonio
Sugar beet pulp was used as redactor agent for the synthesis of gold nanoparticles. The method developed is environmentally friendly and allows control of nanoparticles shapes by changing the initial pH value of aqueous HAuCl4 solutions. At low initial pH values, polygonal nanoparticles were obtained, mainly triangular and hexagonal shapes. Increasing the pH value, nanorods together with polygonal nanoparticles were produced. At higher initial pH, gold nanowires were formed. Gold biosorption took place at long reaction time, especially at low pH. This procedure could be useful to remove or recover metals from aqueous wastes. The synthesis of other metallic nanostructures such as silver and platinum could be achieved following a similar procedure.
Speeding up bioproduction of selenium nanoparticles by using Vibrio natriegens as microbial factory
(Scientific Reports, 2017) Fernández-Llamosas, Helga; Díaz, Eduardo; Carmona, Manuel; Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa
Selenium and selenium nanoparticles (SeNPs) are extensively used in biomedicine, electronics and some other industrial applications. The bioproduction of SeNPs is gaining interest as a green method to manufacture these biotechnologically relevant products. Several microorganisms have been used for the production of SeNPs either under aerobic or anaerobic conditions. Vibrio natriegens is a non-pathogenic fast-growing bacterium, easily cultured in different carbon sources and that has recently been engineered for easy genetic manipulation in the laboratory. Here we report that V. natriegens was able to perfectly grow aerobically in the presence of selenite concentrations up to 15 mM with a significant survival still observed at concentrations as high as 100 mM selenite. Electron microscopy and X-ray spectroscopy analyses demonstrate that V. natriegens cells growing aerobically in selenite-containing LB medium at 30 °C produced spherical electron-dense SeNPs whose size ranged from 100–400 nm. Selenite reduction just started at the beginning of the exponential growth phase and the release of SeNPs was observed after cell lysis. Remarkably, V. natriegens produced SeNPs faster than other described microorganisms that were proposed as model bioreactors for SeNPs production. Thus, the fast-growing V. natriegens bacterium becomes a suitable biocatalyst for bioremediation of selenite and for speeding-up the eco-friendly synthesis of SeNPs.
Anaerobic Bioreduction of Jarosites and Biofilm Formation by a Natural Microbial Consortium
(Minerals, 2019) Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa; González González, Felisa; Muñoz Sánchez, Jesús Ángel; Ballester Pérez, Antonio
Jarosite occurs naturally in acid sulphate soils and is a common feature of streams impacted by acid mine drainage (AMD). Biological reduction of iron-sulphate minerals, such as jarosite, has the potential to contribute to the natural attenuation of acid mine drainage sites. The reduction of different jarosites (including minerals containing precious and toxic metals) by a natural bacterial/microbial consortium was examined in this study. Jarosites was used as a sole terminal electron acceptor via the reductive dissolution of Fe(III) minerals. The production of Fe(II) and the presence of sulphate-reducing bacteria in the consortium lead to the precipitation of metal sulphides immobilizing toxic heavy metals. Microbial attachment and biofilm formation of minerals have a great impact on the production and transformation of minerals and can influence the mobility of metals. After the adaptation to different jarosites, a unique specie was found: Desulfosporosinus orientis. Desulfosporosinus species are sulphate-reducing bacteria and can be found in sulphate-rich heavy metal-polluted environments, such as acid mine/rock drainage sites, being responsible for the sulphides formation. D. orientis is an obligate anaerobic microorganism and is able to reduce Fe(III) D. orientis is an obligate anaerobic microorganism and is able to reduce Fe(III). Confocal laser scanning microscopy and fluorescent lectin-binding analyses (FLBA) were used to study the arrangement and composition of the exopolysaccharides/glycoconjugates in biofilms indicating the presence of mannose, glucose, and N-acetylglucosamine residues. This study provides insights to understand the processes leading to the mobility or retention of metals in mine waste and industrial landfill environments.
Characterization of exopolymeric substances (EPS) produced by Aeromonas hydrophila under reducing conditions
(Biofouling, 2014) Castro Ruiz, Laura; Zhang, Ruiyong; Muñoz Sánchez, Jesús Ángel; González González, Felisa; Blázquez Izquierdo, María Luisa; Sand, Wolfgang; Ballester Pérez, Antonio
The aim of this work was to investigate the production of extracellular polymeric substances (EPS) by Aeromonas hydrophila grown under anaerobic conditions. EPS composition was studied for planktonic cells, cells attached to carbon fibre supports using a soluble ferric iron source and cells grown with a solid ferric iron mineral (gossan). Conventional spectrophotometric methods, Fourier transform infrared (FTIR) and confocal laser scanning microscopy (CLSM) were used to determine the main components in the biofilm extracted from the cultures. The key EPS components were proteins, indicating their importance for electron transfer reactions. Carbohydrates were observed mostly on the mineral and contained terminal mannosyl and/or terminal glucose, fucose and N-acetylgalactosamine residues.
Aeromonas hydrophila produces conductive nanowires
(Research in Microbiology, 2014) Castro Ruiz, Laura; Vera, Mario; Muñoz Sánchez, Jesús Ángel; Blázquez Izquierdo, María Luisa; González González, Felisa; Sand, Wolfgang; Ballester Pérez, Antonio
Aeromonas hydrophila is a facultative anaerobe which, under conditions of oxygen depletion, uses Fe(III) as electron acceptor. A. hydrophila produces pili during growth with Fe(III). The study was focused on the characterization of the morphology, the electrical properties and the nature of the bacterial pili. Scanning electron microscopy and conductive-probe atomic force microscopy revealed the presence of filaments between cells and substrate and their conductive nature. Our results indicate that pili of A. hydrophila strain A might serve as biological nanowires, transferring electrons from the cell surface to the surface of Fe(III) oxides and, in addition, the possibility of playing a role in inter/intra species signaling. Quorum sensing (QS) is recognized as one of the main regulatory ways for extracellular polymeric substances (EPS) production and biofilm formation. We present evidence that nanowire formation can be regulated by addition of synthetic acyl-homoserine lactones (AHL). These conductive pili may be involved in various interactions, and their protein components might be usable in the future for biotechnological approaches in materials science.
Biological synthesis of metallic nanoparticles using algae
(IET Nanobiotechnology, 2013) Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa; Muñoz Sánchez, Jesús Ángel; González González, Felisa; Ballester Pérez, Antonio
The increasing demand and limited natural resources of noble metals make its recovery from dilute industrial wastes attractive, especially when using environmentally friendly methods. Nowadays, the high impact that nanotechnology is having in both science and society offers new research possibilities. Gold and silver nanoparticles were biosynthesised by a simple method using different algae as reducing agent. The authors explored the application of dead algae in an eco-friendly procedure. The nanoparticle formation was followed by UV–vis absorption spectroscopy and transmission electron microscopy. The functional groups involved in the bioreduction were studied by Fourier transform infrared spectroscopy.
Green synthesis of tellurium nanoparticles by tellurate and tellurite reduction using Aeromonas hydrophila under different aeration conditions
(Hydrometallurgy, 2020) Castro Ruiz, Laura; Li, Jing; González González, Felisa; Muñoz Sánchez, Jesús Ángel; Blázquez Izquierdo, María Luisa
Tellurium nanoparticles (TeNPs) are extensively used in biomedicine, electronics and some other industrial applications. Few microorganisms have been studied for the production of TeNPs either under aerobic or anaerobic conditions. Remarkably, this study is the first report of a bacteria able to perfectly grow anaerobically and aerobically in the presence of both tellurium oxyanions, TeO32− and TeO42−. Aeromonas hydrophila offers a clean and cost-effective synthesis of tellurium nanoparticles using a biological method and overcoming the main limitations of traditional synthesis, such as the requirement of a lot of energy and toxic reagents. The cells grew up to 75 mg/L of tellurium when tellurite was the precursor and up to 200 mg/L of tellurium with tellurate. The biogenic nanoparticles were extensively characterized in terms of morphology, structure and composition using SEM, TEM, XRD and EDX analysis. Different Te(0) nanostructures were biosynthesized varying growth conditions: crystalline nanorods (some of them reach more than 1000 nm in length due to Ostwald ripening), rosettes and irregularly shaped nanospheres. In addition, A. hydrophila developed various mechanisms to produce the elemental tellurium and to overcome the toxicity demonstrating the versatility of this microorganism to subsist in polluted environments and its potential for biotechnological applications in bioremediation including the green synthesis of TeNPs.
Anaerobic bioleaching of jarosites by Shewanella putrefaciens, influence of chelators and biofilm formation
(Hydrometallurgy, 2017) Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa; González González, Felisa; Muñoz Sánchez, Jesús Ángel; Ballester Pérez, Antonio
Development of clean mining processes is a topic of increasing interest. Biotechnology could be a cost-effective and environmentally friendly alternative to conventional methods. Jarosites can have important economic and environmental impacts because of their content of valuable metals. The anaerobic reductive dissolution of jarosites and gossan mineral by Shewanella putrefaciens strain CN2 and its secondary products have been investigated. In addition, the ability of S. putrefaciens to reduce insoluble Fe(III) in presence of chelators (citrate and EDTA) was examined. The main components in the biofilm extracted from the cultures were determined. In addition, it was observed the formation of extracellular polymeric substances (EPS) during the biological process.
Biosynthesis of silver and platinum nanoparticles using orange peel extract: characterisation and applications
(IET Nanobiotechnology, 2015) Castro Ruiz, Laura; Blázquez Izquierdo, María Luisa; González González, Felisa; Muñoz Sánchez, Jesús Ángel; Ballester Pérez, Antonio
This study focuses on the green synthesis of noble metal nanoparticles (silver (Ag) and platinum (Pt)) and how the size and shape of the nanoparticles produced can be controlled through changes in the initial pH value of the precursor solution. The nanoparticles were characterised by ultra-violet-visible spectroscopy, transmission electron microscopy and X-ray diffraction. This simple and environmentally friendly method allows the synthesis of diverse nanostructures in the absence of a surfactant or polymer to direct nanoparticle growth, and without externally adding seed crystallites. The antibacterial effects of Ag nanoparticles and catalytic properties of Pt nanoparticles were explored for future promising biotechnological approaches in different fields.