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1.
Artigo em Inglês | MEDLINE | ID: mdl-38687451

RESUMO

The use of biofuels has grown in the last decades as a consequence of the direct environmental impacts of fossil fuel use. Elucidating structure, diversity, species interactions, and assembly mechanisms of microbiomes is crucial for understanding the influence of environmental disturbances. However, little is known about how contamination with biofuel/petrofuel blends alters the soil microbiome. Here, we studied the dynamics in the soil microbiome structure and composition of four field areas under long-term contamination with biofuel/fossil fuel blends (ethanol 10% and gasoline 90%-E10; ethanol 25% and gasoline 75%-E25; soybean biodiesel 20% and diesel 80%-B20) submitted to different bioremediation treatments along a temporal gradient. Soil microbiomes from biodiesel-polluted areas exhibited higher richness and diversity index values and more complex microbial communities than ethanol-polluted areas. Additionally, monitored natural attenuation B20-polluted areas were less affected by perturbations caused by bioremediation treatments. As a consequence, once biostimulation was applied, the degradation was slower compared with areas previously actively treated. In soils with low diversity and richness, the impact of bioremediation treatments on the microbiomes was greater, and as a result, the hydrocarbon degradation extent was higher. The network analysis showed that all abundant keystone taxa corresponded to well-known degraders, suggesting that the abundant species are core targets for biostimulation in soil remediation processes. Altogether, these findings showed that the knowledge gained through the study of microbiomes in contaminated areas may help design and conduct optimized bioremediation approaches, paving the way for future rationalized and efficient pollutant mitigation strategies.

2.
Bioprocess Biosyst Eng ; 46(3): 393-428, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35943595

RESUMO

Petroleum hydrocarbons and toxic metals are sources of environmental contamination and are harmful to all ecosystems. Fungi have metabolic and morphological plasticity that turn them into potential prototypes for technological development in biological remediation of these contaminants due to their ability to interact with a specific contaminant and/or produced metabolites. Although fungal bioinoculants producing enzymes, biosurfactants, polymers, pigments and organic acids have potential to be protagonists in mycoremediation of hydrocarbons and toxic metals, they can still be only adjuvants together with bacteria, microalgae, plants or animals in such processes. However, the sudden accelerated development of emerging technologies related to the use of potential fungal bioproducts such as bioinoculants, enzymes and biosurfactants in the remediation of these contaminants, has boosted fungal bioprocesses to achieve higher performance and possible real application. In this review, we explore scientific and technological advances in bioprocesses related to the production and/or application of these potential fungal bioproducts when used in remediation of hydrocarbons and toxic metals from an integral perspective of biotechnological process development. In turn, it sheds light to overcome existing technological limitations or enable new experimental designs in the remediation of these and other emerging contaminants.


Assuntos
Petróleo , Animais , Biodegradação Ambiental , Ecossistema , Hidrocarbonetos , Compostos Orgânicos
3.
Front Microbiol ; 12: 752288, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659189

RESUMO

Beneficial 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing bacteria promote plant growth and stress resistance, constituting a sustainable alternative to the excessive use of chemicals in agriculture. In this work, the increased plant growth promotion activity of the ACC deaminase-producing Pseudomonas thivervalensis SC5, its ability to limit the growth of phytopathogens, and the genomics behind these important properties are described in detail. P. thivervalensis SC5 displayed several active plant growth promotion traits and significantly increased cucumber plant growth and resistance against salt stress (100mmol/L NaCl) under greenhouse conditions. Strain SC5 also limited the in vitro growth of the pathogens Botrytis cinerea and Pseudomonas syringae DC3000 indicating active biological control activities. Comprehensive analysis revealed that P. thivervalensis SC5 genome is rich in genetic elements involved in nutrient acquisition (N, P, S, and Fe); osmotic stress tolerance (e.g., glycine-betaine, trehalose, and ectoine biosynthesis); motility, chemotaxis and attachment to plant tissues; root exudate metabolism including the modulation of plant phenolics (e.g., hydroxycinnamic acids), lignin, and flavonoids (e.g., quercetin); resistance against plant defenses (e.g., reactive oxygens species-ROS); plant hormone modulation (e.g., ethylene, auxins, cytokinins, and salicylic acid), and bacterial and fungal phytopathogen antagonistic traits (e.g., 2,4-diacetylphloroglucinol, HCN, a fragin-like non ribosomal peptide, bacteriocins, a lantipeptide, and quorum-quenching activities), bringing detailed insights into the action of this versatile plant-growth-promoting bacterium. Ultimately, the combination of both increased plant growth promotion/protection and biological control abilities makes P. thivervalensis SC5 a prime candidate for its development as a biofertilizer/biostimulant/biocontrol product. The genomic analysis of this bacterium brings new insights into the functioning of Pseudomonas and their role in beneficial plant-microbe interactions.

4.
Genomics ; 113(6): 3523-3532, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34400240

RESUMO

Serratia marcescens is a global spread nosocomial pathogen. This rod-shaped bacterium displays a broad host range and worldwide geographical distribution. Here we analyze an international collection of this multidrug-resistant, opportunistic pathogen from 35 countries to infer its population structure. We show that S. marcescens comprises 12 lineages; Sm1, Sm4, and Sm10 harbor 78.3% of the known environmental strains. Sm5, Sm6, and Sm7 comprise only human-associated strains which harbor smallest pangenomes, genomic fluidity and lowest levels of core recombination, indicating niche specialization. Sm7 and Sm9 lineages exhibit the most concerning resistome; blaKPC-2 plasmid is widespread in Sm7, whereas Sm9, also an anthropogenic-exclusive lineage, presents highest plasmid/lineage size ratio and plasmid-diversity encoding metallo-beta-lactamases comprising blaNDM-1. The heterogeneity of resistance patterns of S. marcescens lineages elucidated herein highlights the relevance of surveillance programs, using whole-genome sequencing, to provide insights into the molecular epidemiology of carbapenemase producing strains of this species.


Assuntos
Serratia marcescens , beta-Lactamases , Antibacterianos , Humanos , Plasmídeos/genética , Serratia marcescens/genética , Sequenciamento Completo do Genoma , beta-Lactamases/genética
5.
Bioprocess Biosyst Eng ; 44(10): 2003-2034, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34131819

RESUMO

Biosurfactants are in demand by the global market as natural commodities that can be added to commercial products or use in environmental applications. These biomolecules reduce the surface/interfacial tension between fluid phases and exhibit superior stability to chemical surfactants under different physico-chemical conditions. Biotechnological production of biosurfactants is still emerging. Fungi are promising producers of these molecules with unique chemical structures, such as sophorolipids, mannosylerythritol lipids, cellobiose lipids, xylolipids, polyol lipids and hydrophobins. In this review, we aimed to contextualize concepts related to fungal biosurfactant production and its application in industry and the environment. Concepts related to the thermodynamic and physico-chemical properties of biosurfactants are presented, which allows detailed analysis of their structural and application. Promising niches for isolating biosurfactant-producing fungi are presented, as well as screening methodologies are discussed. Finally, strategies related to process parameters and variables, simultaneous production, process optimization through statistical and genetic tools, downstream processing and some aspects of commercial products formulations are presented.


Assuntos
Biotecnologia/métodos , Fungos/metabolismo , Tensoativos/metabolismo , Metabolismo dos Lipídeos , Tensão Superficial , Termodinâmica
6.
Eng. sanit. ambient ; 25(4): 607-617, jul.-ago. 2020. tab, graf
Artigo em Português | LILACS-Express | LILACS | ID: biblio-1133801

RESUMO

RESUMO O presente estudo tem como objetivo avaliar o efeito da aplicação de diferentes concentrações de biossólido de lodo de esgoto, submetido a tratamento térmico, no estabelecimento de espécies herbáceas (aveia preta, ervilhaca e azevém) e nos atributos químicos e microbiológicos de um solo degradado pela mineração de carvão. O experimento foi instalado em área degradada pela mineração de carvão, localizada no munícipio de Treviso (SC), sendo os tratamentos compostos pelas concentrações de 0, 6,25, 100, 250 e 500 Mg ha-1 de biossólido, em parcelas de 2×2 m. Foram cultivadas espécies de aveia preta, ervilhaca e azevém de maneira consorciada, avaliando-se os parâmetros das plantas e os atributos químicos do solo nas profundidades 0-5, 5-10 e 10-20 cm. O biossólido proporcionou a elevação do pH do solo e o aumento dos teores disponíveis de P, K e carbono orgânico total e não influenciou na colonização micorrízica, na respiração basal do solo e na nodulação radicular. O uso do resíduo biossólido como substrato em áreas degradadas é uma alternativa para sua disposição final pela economia ao utilizá-lo como fertilizante, além dos benefícios ambientais, associados ao seu uso.


ABSTRACT This study aims to evaluate the effects of different concentrations of sewage sludge biosolid concentrations, submitted to thermal treatment, in the establishment of herbaceous species (black oats, vetches, and ryegrass) and in the chemical and microbiological attributes of a soil degraded by coal mining. The experiment was installed in an area degraded by coal mining, in Treviso/SC, with treatments composed of concentrations of 0; 6.25; 100; 250; and 500 Mg ha-1 of biosolids, in 2×2 m plots. Species of black oat, vetch, and ryegrass were grown in a consortium manner, evaluating the plant parameters and chemical attributes of the soil at depths 0-5, 5-10, and 10-20 cm. The biosolids provided improvements in soil fertility, such as pH elevation, increased levels available of P, K, and total organic carbon, in addition to not influencing mycorrhizal colonization, basal soil respiration, and root nodulation. The use of biosolid waste as a substrate in degraded areas is an alternative to its final disposal due to the economy when using it as a fertilizer, in addition to the environmental benefits associated with its use.

7.
MycoKeys ; 62: 53-73, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32076382

RESUMO

A new monotypic sequestrate genus, Longistriata is described based on collections from the Neotropical forest of Atlantic forest in Paraíba, Northeast Brazil - an area known for its high degree of endemism. The striking features of this new fungus are the hypogeous habit, the vivid yellow peridium in mature basidiomes, broadly ellipsoid basidiospores with a distinct wall that is ornamented with longitudinal striations and lageniform cystidia with rounded apices. Phylogenetic analysis, based on LSU and tef-1α regions, showed that the type species, Longistriata flava, is phylogenetically sister to the monotypic sequestrate African genus Mackintoshia in Boletaceae. Together these two species formed the earliest diverging lineage in the subfamily Zangioideae. Longistriata flava is found in nutrient-poor white sand habitats where plants in the genera Coccoloba (Polygonaceae) and Guapira (Nyctaginaceae) are the only potential ectomycorrhizal host symbionts.

8.
Arch Microbiol ; 200(8): 1227-1237, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29947837

RESUMO

Sulfate-reducing bacteria (SRB) and a biochar array were used to reduce sulfate concentrations and the levels of metals in acid mine drainage (AMD) waters. Cow manure SRB-enriched biochar promoted sulfate reductions of 41% compared to original AMD, and 39% compared to other treatments (control, AMD sediment, sludge). Treatments reduced levels of all analyzed metals below Brazilian official standards. DGGE showed a significant relation between SRB-source and SRB-structural community, where cow manure and sludge presented the more cohesive community structure throughout the monitoring (180 days). The study showed that AMD treatment alternatives can be applied and are effective in reducing the contamination of wastewaters.


Assuntos
Carvão Vegetal/química , Desulfovibrio/metabolismo , Esterco/análise , Esgotos/microbiologia , Sulfatos/química , Purificação da Água/métodos , Ácidos/química , Animais , Brasil , Bovinos , Feminino , Metais/análise , Mineração/métodos , Aves Domésticas
9.
PLoS One ; 13(5): e0196984, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29738553

RESUMO

Like many other species of trees native to the Brazilian Mata Atlântica (Atlantic Forest), the Myrtaceae, such as the Red Araza (Psidium cattleianum Sabine), are widely cited as arbuscular mycorrhizal formers. Nevertheless, recent studies show evidence that Myrtaceae from different tropical, subtropical and neotropical ecosystems can also prompt the formation of ectomycorrhizae, indicating that this species' ectomycorrhizal status should be further explored. Because of this, this research effort studied the in vitro interaction between the Red Araza and two ectomycorrhizal fungi isolates, belonging to the Pisolithus microcarpus (D17) and Scleroderma citrinum (UFSC-Sc133) species. An analysis was performed to determine the formation of ectomycorrhizal structures, or lack thereof, and the developmental differences between the in vitro mycorrhized and non-mycorrhized plants. The analysis proved that indeed an ectomycorrhizal association was developed between the Red Araza, and the D17 and UFSC-Sc133 isolates, a fact never before registered in the existing literature. After an in vitro period of 110 days, it was confirmed that the D17 and UFSC-Sc133 isolates formed mycorrhizal colonization of 91.6% and 15.7%, respectively. Furthermore, both isolates also promoted root thickening, and the formation of a fungal mantle and a Hartig net. However, when compared to the Control plants, the fungal isolates did not contribute to an increase in the development of the subject plants, possibly due to the specific experimental conditions used, such as a high humidity environment and high availability of nutrients in the symbiotic substrate.


Assuntos
Micorrizas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Psidium/microbiologia , Simbiose/genética , Brasil , Ecossistema , Florestas , Psidium/crescimento & desenvolvimento
10.
Genome Announc ; 6(16)2018 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-29674537

RESUMO

The near-complete genome sequence of Pseudomonas palleroniana MAB3, a 1-aminocyclopropane-1-carboxylate deaminase-producing bacterium isolated from an environmental soil Amanita mushroom, is presented here. The genome of P. palleroniana MAB3 contains a single circular chromosome of 6.29 Mb and an average GC content of 60.5%.

11.
Plant Physiol Biochem ; 122: 46-56, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29175636

RESUMO

Arbuscular mycorrhizal fungi (AMF) improve plant ability to uptake P and tolerate heavy metals. This study aimed to evaluate the effect of available P and the inoculation of Rhizophagus clarus in a Cu-contaminated soil (i) on the activity of acid phosphatases (soil and plant), the presence of glomalin, and (ii) in the biochemical and physiological status of Mucuna cinereum. A Typic Hapludalf soil artificially contaminated by adding 60 mg kg-1 Cu was used in a 3 × 2 factorial design with three replicates. Treatments consisted of three P levels: 0, 40, and 100 mg kg-1 P. Each P treatment level was inoculated (+AMF)/non-inoculated (-AMF) with 200 spores of R. clarus per pot, and plants grown for 45 days. The addition of at least 40 mg kg-1 P and the inoculation of plants with R. clarus proved to be efficient to reduce Cu phytotoxicity and increase dry matter yield. Mycorrhization and phosphate fertilization reduced the activity of enzymes regulating oxidative stress (SOD and POD), and altered the chlorophyll a fluorescence parameters, due to the lower stress caused by available Cu. These results suggest a synergism between the application of P and the inoculation with R. clarus, favoring the growth of M. cinereum in a Cu-contaminated soil. This study shows that AMF inoculation represents an interesting alternative to P fertilization to improve plant development when exposed to excess Cu.


Assuntos
Cobre/farmacologia , Resistência à Doença/efeitos dos fármacos , Glomeromycota/crescimento & desenvolvimento , Mucuna , Fósforo/metabolismo , Poluentes do Solo/farmacologia , Mucuna/metabolismo , Mucuna/microbiologia , Estresse Oxidativo/efeitos dos fármacos
13.
Arch Microbiol ; 199(7): 991-1001, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28382474

RESUMO

Coal open pit mining in the South of Santa Catarina state (Brazil) was inappropriately developed, affecting approximately 6.700 ha. Re-vegetation is an alternative for the recovery of these areas. Furthermore, the use of herbaceous legumes inoculated with nitrogen fixing bacteria is motivated due to the difficulty implementing a vegetation cover in these areas, mainly due to low nutrient availability. Therefore, the aim of this work was to evaluate, among 16 autochthonous rhizobia isolated from the coal mining areas, those with the greatest potential to increase growth of the herbaceous legumes Vicia sativa and Calopogonium mucunoides. Tests were conducted in greenhouse containing 17 inoculation treatments (16 autochthonous rhizobia + Brazilian recommended strain for each plant species), plus two treatments without inoculation (with and without mineral nitrogen). After 60 days, nodulation, growth, N uptake, and symbiotic efficiency were evaluated. Isolates characterization was assessed by the production of indole acetic acid, ACC deaminase, siderophores, and inorganic phosphate solubilization. The classification of the isolates was performed by 16 S rDNA gene sequencing. Only isolates UFSC-M4 and UFSC-M8 were able to nodulate C. mucunoides. Among rhizobia capable of nodulating V. sativa, only UFSC-M8 was considered efficient. It was found the presence of more than one growth-promoting attributes in the same organism, and isolate UFSC-M8 presented all of them. Isolates were classified as belonging to Rhizobium, Burkholderia and Curtobacterium. The results suggest the inoculation of Vicia sativa with strain UFSC-M8, classified as Rhizobium sp., as a promising alternative for the revegetation of coal mining degraded areas.


Assuntos
Actinobacteria/classificação , Burkholderia/classificação , Fabaceae/microbiologia , Rhizobium/classificação , Nódulos Radiculares de Plantas/microbiologia , Vicia sativa/microbiologia , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Brasil , Burkholderia/genética , Burkholderia/isolamento & purificação , Carbono-Carbono Liases/metabolismo , Carvão Mineral , DNA Ribossômico/genética , Ácidos Indolacéticos/metabolismo , Fixação de Nitrogênio , RNA Ribossômico 16S/genética , Rhizobium/genética , Rhizobium/isolamento & purificação , Simbiose/genética , Vicia sativa/crescimento & desenvolvimento
14.
Int J Phytoremediation ; 19(2): 113-120, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27491701

RESUMO

Vetiver (Chrysopogon zizanioides) is a fast-growing, high biomass producing plant employed for environmental rehabilitation. The study evaluated the effects of arbuscular mycorrhizal fungi (AMF) on the growth and trace element phytoextracting capabilities of vetiver in a substrate containing coalmine wastes in Southern Brazil. AMF included Acaulospora colombiana, Acaulospora morrowiae, Acaulospora scrobiculata, Dentiscutata heterogama, Gigaspora margarita, and Rhizophagus clarus. Among those, A. colombiana, G. margarita, and R. clarus promoted higher growth. AMF stimulated average increments in the accumulated P of 82% (roots), 194% (shoots first harvest-90 days) and 300% (shoots second harvest-165 days) and affected the phytoextraction of trace elements by vetiver, with larger concentrations in the roots. Plants inoculated with A. colombiana, A. morrowiae, and A. scrobiculata, in addition to the control, presented the highest levels of Cu and Zn in the roots. Overall, G. margarita stimulated the highest production of biomass, and, therefore, showed the most significant levels of trace elements in the plants. This work shows the benefits of certain AMF (especially A. morrowiae, G. margarita, and R. clarus) for the production of biomass and P uptake by vetiver, demonstrating the potential of those species for the rehabilitation of coal-mine-degraded soils.


Assuntos
Vetiveria/metabolismo , Glomeromycota/metabolismo , Micorrizas/metabolismo , Poluentes do Solo/metabolismo , Oligoelementos/metabolismo , Biodegradação Ambiental , Brasil , Carvão Mineral , Mineração
15.
Appl Microbiol Biotechnol ; 101(3): 1013-1024, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27687991

RESUMO

The study had the objective of examining the aspects involved in the cultivation of ectomycorrhizal fungi for the production of commercially sustainable inoculant to attend the demands of the seedling nursery industry. It focused on certain parameters, such as the oxygen consumption levels, during the cultivation of the ectomycorrhizal fungus Rhizopogon nigrescens CBMAI 1472, which was performed in a 5-L airlift bioreactor. The dynamic method was employed to determine the volumetric coefficient for the oxygen transfer (k L a) and the specific oxygen uptake rate (Q O2 ). The results indicate that specific growth rates (µ X ) and oxygen consumption decline rapidly with time, affected mainly by increases in biomass concentration (X). Increases in X are obtained primarily by increases in the size of pellets that are formed, altering, consequently, the cultivation dynamics. This is the result of natural increases in transferring resistance that are observed in these environments. Therefore, to avoid critical conditions that affect viability and the productivity of the process, particular settings are discussed.


Assuntos
Basidiomycota/crescimento & desenvolvimento , Basidiomycota/metabolismo , Reatores Biológicos , Consumo de Oxigênio , Oxigênio/metabolismo , Basidiomycota/isolamento & purificação , Biomassa , Micorrizas/crescimento & desenvolvimento , Micorrizas/metabolismo
16.
Mycologia ; 108(5): 954-966, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27549616

RESUMO

Restingomyces reticulatus gen. et sp. nov. is a recently discovered false truffle species from Atlantic "restinga" rainforest in northeastern Brazil. Molecular and morphological characters separate this new sequestrate species from other described taxa in the order Phallales (Phallomycetidae, Basidiomycota). In our phylogenetic analysis based on nuc 28S rDNA and atp6, R. reticulatus forms a sister clade to Trappea darkeri and Phallobata alba, with the three taxa forming the earliest diverging lineage within Phallales. Morphological and molecular data warrant the recognition of the new genus and species, described here, and we also amend the taxonomic description for the family Trappeaceae.


Assuntos
Basidiomycota/classificação , Basidiomycota/isolamento & purificação , Basidiomycota/citologia , Basidiomycota/genética , Biometria , Brasil , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Microscopia , ATPases Mitocondriais Próton-Translocadoras/genética , Fotografação , Filogenia , RNA Ribossômico 28S/genética , Floresta Úmida , Análise de Sequência de DNA
17.
Plant Physiol Biochem ; 103: 199-207, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27002244

RESUMO

Soils used for the cultivation of grapes generally have a long history of copper (Cu) based fungicide applications. As a result, these soils can accumulate Cu at levels that are capable of causing toxicity in plants that co-inhabit the vineyards. The aim of the present study was to evaluate growth parameters and oxidative stress in black oat plants grown in vineyard soils contaminated with high levels of Cu. Soil samples were collected from the Serra Gaúcha and Campanha Gaúcha regions, which are the main wine producing regions in the state of Rio Grande do Sul, in southern Brazil. Experiments were conducted in a greenhouse in 2009, with soils containing Cu concentrations from 2.2 to 328.7 mg kg(-1). Evaluated parameters included plant root and shoot dry matter, Cu concentration in the plant's tissues, and enzymatic and non-enzymatic biochemical parameters related to oxidative stress in the shoots of plants harvested 15 and 40 days after emergence. The Cu absorbed by plants predominantly accumulated in the roots, with little to no translocation to the shoots. Even so, oat plants showed symptoms of toxicity when grown in soils containing high Cu concentrations. The enzymatic and non-enzymatic antioxidant systems of oat plants were unable to reverse the imposed oxidative stress conditions.


Assuntos
Avena/efeitos dos fármacos , Cobre/farmacologia , Fungicidas Industriais/farmacologia , Poluentes do Solo/farmacologia , Antioxidantes/metabolismo , Avena/química , Avena/fisiologia , Brasil , Cobre/metabolismo , Fungicidas Industriais/metabolismo , Especificidade de Órgãos , Estresse Oxidativo , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/fisiologia , Solo/química , Poluentes do Solo/metabolismo , Vitis
18.
Ecotoxicol Environ Saf ; 129: 109-19, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27011111

RESUMO

The occurrence of high levels of Cu in vineyard soils is often the result of intensive use of fungicides for the preventive control of foliar diseases and can cause toxicity to plants. Nowadays many grape growers in Southern Brazil have replaced Cu-based with Zn-based products. The aim of the study was to evaluate whether the increase in Zn concentration in a soil with high Cu contents can interfere with the dynamics of these elements, and if this increase in Zn may cause toxicity to maize (Zea mays L.). Soil samples were collected in two areas, one in a vineyard with more than 30 years of cultivation and high concentration of Cu and the other on a natural grassland area adjacent to the vineyard. Different doses of Cu and Zn were added to the soil, and the adsorption isotherms were built following the Langmuir's model. In a second experiment, the vineyard soil was spiked with different Zn concentrations (0, 30, 60, 90, 180, and 270mg Zn kg(-1)) in 3kg pots where maize was grown in a greenhouse for 35 days. When Cu and Zn were added together, there was a reduction in the quantities adsorbed, especially for Zn. Zn addition decreased the total plant dry matter and specific leaf mass. Furthermore, with the increase in the activity of catalase, an activation of the antioxidant system was observed. However, the system was not sufficiently effective to reverse the stress levels imposed on soil, especially in plants grown in the highest doses of Zn. At doses higher than 90Znmgkg(-1) in the Cu-contaminated vineyard soil, maize plants were no longer able to activate the protection mechanism and suffered from metal stress, resulting in suppressed dry matter yields due to impaired functioning of the photosynthetic apparatus and changes in the enzymatic activity of plants. Replacement of Cu- by Zn-based fungicides to avoid Cu toxicity has resulted in soil vineyards contaminated with these metals and damaging of plant photosynthetic apparatus and enzyme activity.


Assuntos
Cobre , Poluentes do Solo , Zea mays/efeitos dos fármacos , Zinco , Adsorção , Brasil , Cobre/química , Cobre/toxicidade , Fazendas , Fungicidas Industriais , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Solo/química , Poluentes do Solo/química , Poluentes do Solo/toxicidade , Vitis , Zea mays/crescimento & desenvolvimento , Zinco/química , Zinco/toxicidade
19.
World J Microbiol Biotechnol ; 31(11): 1655-64, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26250548

RESUMO

In recent decades, the concentration of trace elements has increased in soil and water, mainly by industrialization and urbanization. Recovery of contaminated areas is generally complex. In that respect, microorganisms can be of vital importance by making significant contributions towards the establishment of plants and the stabilization of impacted areas. Among the available strategies for environmental recovery, bioremediation and phytoremediation outstand. Arbuscular mycorrhizal fungi (AMF) are considered the most important type of mycorrhizae for phytoremediation. AMF have broad occurrence in contaminated soils, and evidences suggest they improve plant tolerance to excess of certain trace elements. In this review, the use of AMF in phytoremediation and mechanisms involved in their trace element tolerance are discussed. Additionally, we present some techniques used to study the retention of trace elements by AMF, as well as a summary of studies showing major benefits of AMF for phytoremediation.


Assuntos
Micorrizas/fisiologia , Poluentes do Solo/análise , Oligoelementos/metabolismo , Biodegradação Ambiental , Raízes de Plantas/microbiologia , Plantas/microbiologia , Microbiologia do Solo
20.
Fungal Biol ; 114(2-3): 224-34, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20943133

RESUMO

Phylogenetic relationships among Geastrales, Gomphales, Hysterangiales, and Phallales were estimated via combined sequences: nuclear large subunit ribosomal DNA (nuc-25S-rDNA), mitochondrial small subunit ribosomal DNA (mit-12S-rDNA), and mitochondrial atp6 DNA (mit-atp6-DNA). Eighty-one taxa comprising 19 genera and 58 species were investigated, including members of the Clathraceae, Gautieriaceae, Geastraceae, Gomphaceae, Hysterangiaceae, Phallaceae, Protophallaceae, and Sphaerobolaceae. Although some nodes deep in the tree could not be fully resolved, some well-supported lineages were recovered, and the interrelationships among Gloeocantharellus, Gomphus, Phaeoclavulina, and Turbinellus, and the placement of Ramaria are better understood. Both Gomphus sensu lato and Ramaria sensu lato comprise paraphyletic lineages within the Gomphaceae. Relationships of the subgenera of Ramaria sensu lato to each other and to other members of the Gomphales were clarified. Within Gomphus sensu lato, Gomphus sensu stricto, Turbinellus, Gloeocantharellus and Phaeoclavulina are separated by the presence/absence of clamp connections, spore ornamentation (echinulate, verrucose, subreticulate or reticulate), and basidiomal morphology (fan-shaped, funnel-shaped or ramarioid). Gautieria, a sequestrate genus in the Gautieriaceae, was recovered as monophyletic and nested with members of Ramaria subgenus Ramaria. This agrees with previous observations of traits shared by these two ectomycorrhizal taxa, such as the presence of fungal mats in the soil. Clavariadelphus was recovered as a sister group to Beenakia, Kavinia, and Lentaria. The results reaffirm relationships between the Geastrales, Gomphales, Hysterangiales, and the Phallales, suggesting extensive convergence in basidiomal morphology among members of these groups. A more extensive sampling that focuses on other loci (protein-coding genes have been shown to be phylogenetically informative) may be useful to answer questions about evolutionary relationships among these fungal groups.


Assuntos
Basidiomycota/classificação , Basidiomycota/genética , DNA Mitocondrial/genética , DNA Ribossômico/genética , ATPases Mitocondriais Próton-Translocadoras/genética , Filogenia , DNA Fúngico/análise , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , DNA Ribossômico/classificação , Mitocôndrias/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Especificidade da Espécie
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