Carolina Yáñez

Pontificia Universidad Católica de Valparaíso | PUCV · Institute of Biology

Обзор посвящен проблеме антагонизма металлов при полиэлементном загрязнении почв выбросами промышленных предприятий. Обсуждается, что известный эффект снижения цинком токсичности меди в водных экосистемах может быть распространен на почву. Описаны результаты нескольких исследований, в которых доказано снижение цинком токсичности меди для растений и...

A significant portion of the current knowledge regarding the use of iron nanoparticles for remediating metal-contaminated soils is derived from laboratory experiments, leaving several unanswered questions. This article presents a field experiment comparing the efficacy of magnetite nanoparticles and microparticles for the immobilization of metals a...

Ecotoxicological studies on soil metal toxicity often rely on artificially contaminated soils. A major difficulty in using soils contaminated by anthropogenic activities (e.g., mining and agriculture) is the presence of multiple metals, which can make it impossible to distinguish the toxic effects of a particular metal. Therefore, sites with monome...

Zinc is an essential nutrient for humans, animals, and plants. Zinc uptake by crops is dictated by zinc availability in the soil, which in turn may be dictated, at least in part, by soil mineralogy. Little is known about the phytoavailability of Zn in Andisols, which are important agricultural soils in volcanic regions, such as Japan, New Zealand,...

To assess the extent of soil contamination with a potentially toxic element, it is important to determine the background concentration of that element in the soil. In this study we decided to investigate the relationship between trace element concentrations in soils and the lithology of their parent rocks. We collected 85 topsoils (0–20 cm) samples...

The potential use of zero-valent iron (ZVI) nanoparticles (i.e., <100 nm in size) for the remediation of metal-contaminated soils has sparked a flurry of research in recent years. However, even reading a large number of these papers cannot completely dispel doubts that ZVI nanoparticles are indeed superior to ZVI microparticles (e.g., iron powder o...

Forest fires alter soil microbial communities that are essential to support ecosystem recovery following land burning. These alterations have different responses according to soil abiotic pre-and post-fire conditions and fire severity, among others, and tend to decrease along vegetation recovery over time. Thus, understanding the effects of fires o...

Metal contamination of soil has become a serious environmental problem worldwide. Many studies have attempted to infer metal ecotoxicity from soil microbial responses. However, much of the data from these studies tends to be inconsistent and difficult to interpret. We hypothesized that microbial response would be a useful indicator of metal toxicit...

This article summarizes the authors' 10-year study of soil phytoremediation in an anthropogeni-cally contaminated area around a copper smelter in the Valparaiso region of central Chile. It analyzes the risk that contaminated soils pose to public health. Phytostabilization and phytoextraction were considered as the main methods of soil phytoremediat...

ABSTRACT The concept of attitude toward soil is emerging, with a slim choice of scales available to collect hard data. There is also a dearth of standard scales to acquire precise data on students’ knowledge of soil. Therefore, the objectives of the present study were: (1) to devise appropriate scales to quantify theoretical soil knowledge and atti...

Scientists around the world have long been searching for effective strategies to reduce the bioavailability of metals in contaminated soils. In case of metal-spiked soils, some studies have proposed gypsum as a soil amendment to alleviate metal phytotoxicity. However, for real field-collected soils, evidence on the efficacy of gypsum as a metal phy...

Обобщены авторские исследования по фиторемедиации почв на техногенно-загрязненной территории вблизи медеплавильного предприятия в области Вальпараисо центрального района Чили за десятилетний период. Проанализирован риск воздействия загрязненной почвы на здоровье населения. Рассмотрены фитостабилизация и фитоэкстракция как основные методы фиторемеди...

Pseudomonas syringae pv. actinidiae (Psa) is the causal agent of a bacterial canker in kiwifruit plants and has caused economic losses worldwide. Currently, the primary strategies to control this pathogen include the use of copper-based compounds and even antibiotics. However, the emergence of isolates of Psa that are resistant to these agrochemica...

Chile as a major international Cu producer faces serious soil contamination issues in mining areas. Currently Chile does not have any specific law governing the maximum permissible concentrations of metals in soils to protect ecosystems and human health. Chile heavily relies on the use of environmental laws of 14 foreign countries; the choice of th...

Microbial life inhabiting hypersaline environments belong to a limited group of extremophile or extremotolerant taxa. Natural or artificial hypersaline environments are not limited to high concentrations of NaCl, and under such conditions, specific adaptation mechanisms are necessary to permit microbial survival and growth. Argentina, Bolivia, and...

All organisms live in close association with a variety of microorganisms called microbiota. Furthermore, several studies support a fundamental role of the microbiota on the host health and homeostasis. In this context, the aim of this work was to determine the structure and diversity of the microbiota associated with the scallop Argopecten purpurat...

In recent years, Chilean kiwifruit production has been affected by the phytopathogen Pseudomonas syringae pv. actinidiae (Psa), which has caused losses to the industry. In this study, we report the genotypic and phenotypic characterization of 18 Psa isolates obtained from Chilean kiwifruits orchards between 2012 and 2016 from different geographic o...

The Salar de Huasco is an evaporitic basin located in the Chilean Altiplano, which presents extreme environmental conditions for life, i.e. high altitude (3800 m.a.s.l.), negative water balance, a wide salinity range, high daily temperature changes and the occurrence of the highest registered solar radiation on the planet (> 1200 W m⁻²). This ecosy...

Microbiological bioassays of nitrification and nitrogen mineralization have been used for evaluation of soil quality on metal-contaminated soils. We evaluated the effectiveness of nitrification and nitrogen mineralization bioassays as quality indicators of soil degradation caused by metal contamination. We performed standard tests based on protocol...

Chile has had a long mining history and is currently considered the most important copper (Cu) producer in the world. The environmental problems historically associated with Cu mining are widely known in north and central areas of the country, particularly in relation to the contamination of agricultural soils by metals and metalloids. Copper is th...

The topic of restoration and conservation actions is very broad. In this chapter, we limit the discussion to phytoremediation of soils polluted by copper mining, focusing on two remediation options: phytostabilization and phytoextraction. We present Chilean studies for each of these two options of remediation of metal-polluted, acidic soils in a si...

Microbiological bioassays of nitrification and nitrogen mineralization have been used for evaluation of soil quality of metal-contaminated soils. It has been argued that the identification of the toxic metal thresholds in soil should be based on field-collected soils rather than on artificially-contaminated soils. However, the use of field-collecte...

Microbiological properties have been used to evaluate soil quality in metal-contaminated soils. However, the use of microbiological properties in soil quality criteria presents several difficulties. The presence of various contaminants in the soil and unavoidable differences in the physicochemical soil properties, along different sampling areas, ca...

Background Copper mining has led to Cu pollution in agricultural soils. In this report, the effects of Cu pollution on bacterial communities of agricultural soils from Valparaiso region, central Chile, were studied. Denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA genes was used for the characterization of bacterial communities from C...

Peatlands effectively retain heavy metals and prevent stream and watershed contamination. Sulfate reduction is considered the most significant process of metal immobilization in natural wetlands and microbial sulfate reduction is the presumed mechanism that results in the precipitation of metal sulfides. In this study, we examined the biogeochemica...

Mercury-polluted environments are often contaminated with other heavy metals. Therefore, bacteria with resistance to several heavy metals may be useful for bioremediation. Cupriavidus metallidurans CH34 is a model heavy metal-resistant bacterium, but possesses a low resistance to mercury compounds. To improve inorganic and organic mercury resistanc...

Spatial relationships between concentrations of Cd, Fe, Mn, S, and Zn and bacterial genes for dissimilatory sulfate reduction were studied in soils of the Manning peatland region in western New York. Peat cores were collected within a field exhibiting areas of Zn phytotoxicity, and pH and elemental concentrations were determined with depth. The oxi...

A washed suspension of the bacteria Escherichia coli, pre-grown on a complex culture medium, was stored in sterilized drinking water for 21 days at 25 degrees C in glass flasks in order to assess the effect of iron corrosion products on the persistenceof the bacteria in drinking water. Four conditions were tested: aerobic with 50 mM lepidocrocite (...

The presence of iron, used both as a nutrient and as an electron acceptor, was demonstrated to give an advantage to Escherichia coli bacteria in drinking water. Slight additions of ferrous sulfate to water with initial low iron concentrations led to a significant increase in the number of E. coli bacteria. The presence of ferric oxide in water unde...

Most copper bioleaching plants operate with a high concentration of sulfate salts, caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. Since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population present in the high-sulfate (150 gl(-1)) lea...

The effect of a powerful inhibitor, BRL 42715, on beta-lactamase from Shigella flexneri UCSF-129, to overcome the problem of shigellosis and its resistance to ampicillin, was studied. The I50 was determined for BRL 42715 [C6-(N1-methyl-1,2,3 triazolylmethylene)penem] as 0.0049 microgram/ml being 20-fold lower than the best inhibitor, 6-beta-iodopen...