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1.
J Sci Food Agric ; 100(3): 1350-1357, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31617215

RESUMO

BACKGROUND: Non-conventional water sources and water-saving techniques can be valuable in semi-arid regions, although their long-term effects on citrus quality are little known. This study evaluated the effects of irrigation with two sources, transfer water (TW) and reclaimed water (RW), combined with two irrigation strategies, full irrigation (FI) and regulated deficit irrigation (RDI), on fruit quality of mandarins and grapefruits during eight growth seasons. RESULTS: Reclaimed water irrigation in mandarin, without water restriction, influenced maturity index (MI) less than TW-FI, because titratable acidity (TA) increased to a greater degree than soluble solid contents (SSC). Nevertheless, juice quality standards were satisfied. Regardless of the irrigation treatment (FI or RDI), a trend towards increasing fruit weight was also detected with RW. In grapefruit, its rootstock (Citrus macrophylla) enhanced salinity resilience with respect to the rootstock of mandarin ('Carrizo' citrange) and, hence, MI was not affected by RW. The RDI strategy, without saline stress (TW-RDI), increased, to a similar degree, both SSC and TA in mandarin fruit, not affecting the MI. In grapefruit, the water stress of RDI did improve the MI due to the TA did not change and SSC increased significantly, the TA did not change. The combination of both strategies, RW-RDI, decreased the MI only in some years because TA increased proportionally more than SSC in mandarin. CONCLUSIONS: The medium- and long-term feasibility of using RW and RDI to irrigate citrus was demonstrated. However, they must be performed cautiously and with appropriate management to avoid damaging fruit quality as a result of phytotoxic elements. © 2019 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/métodos , Citrus/crescimento & desenvolvimento , Frutas/química , Água/metabolismo , Citrus/química , Citrus/metabolismo , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Águas Salinas/análise , Águas Salinas/metabolismo , Água/análise
2.
Artigo em Inglês | MEDLINE | ID: mdl-31349697

RESUMO

Alternative irrigation between saline water and groundwater can alleviate shortages of available agricultural water while effectively slowing the adverse effects of saline water on the soil-crop system when compared with continuous irrigation with saline water and blending irrigation between saline water and groundwater. In 2018, we tested the effect on soil CO2 and N2O emissions by two types of irrigation regimes (alternating groundwater and saline water (GW-SW), and alternating groundwater, followed by two cycles of saline water (GW-SW-SW)) between groundwater and three levels of salinity of irrigation water (mineralization of 2 g/L, 3.5 g/L, and 5 g/L), analyzed the correlation between gas emissions and soil properties, calculated comprehensive global warming potential (GWP), and investigated the maize yield. The results show that, with the same alternate irrigation regime, cumulative CO2 emissions decreased with increasing irrigation water salinity, and cumulative N2O emissions increased. Cumulative CO2 emissions were higher in the GW-SW regime for the same irrigation water salinity, and cumulative N2O emissions were higher in the GW-SW-SW regime. The GW-SW-SW regime had less comprehensive GWP and maize yield as compared to the GW-SW regime. The 2 g/L salinity in both regimes showed larger comprehensive GWP and maize yield. The 3.5 g/L salinity under the GW-SW regime will be the best choice while considering that the smaller comprehensive GWP and the larger maize yield are appropriate for agricultural implication. Fertilizer type and irrigation amount can be taken into consideration in future research direction.


Assuntos
Irrigação Agrícola , Dióxido de Carbono/análise , Água Subterrânea/análise , Óxido Nitroso/análise , Águas Salinas/análise , Solo/química , China , Gases de Efeito Estufa/análise , Gases de Efeito Estufa/química , Água Subterrânea/química , Águas Salinas/química , Zea mays/crescimento & desenvolvimento
3.
J Sci Food Agric ; 99(13): 5842-5851, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31206706

RESUMO

BACKGROUND: The current need to produce food for a growing population, from diminishing natural resources, such as water and energy, and with minimum environmental degradation, demands the optimization of production. We compare the economic feasibility of tomato production in an open system with a perlite substrate, a closed system with the nutrient film technique (NFT), and a hydroponic crop (deep flow technique, DFT) using three levels of salinity that are found within the normal range for irrigation water quality in southeastern Spain. RESULTS: Production with DFT resulted in an increase in the cost of phytosanitary treatments and the cost of maintenance. Production with perlite resulted in an increase in the cost of irrigation water and fertilization, and the use of NFT resulted in an increase in energy costs. The point of price equilibrium was exceeded in the three soilless systems when using low salinity water, and in perlite, with intermediate salinity water. CONCLUSION: Profitability was reduced in the following order: perlite > NFT > DFT. There were positive results when using irrigation water with low salinity, and in the case of perlite, with intermediate salinity. In every case, salinity reduced the profitability of the operation, and this was greater when NFT was employed. The analysis of these soilless systems should be continued to determine the possibility of reducing cultivation costs. © 2019 Society of Chemical Industry.


Assuntos
Irrigação Agrícola/economia , Produção Agrícola/economia , Produção Agrícola/métodos , Lycopersicon esculentum/economia , Lycopersicon esculentum/crescimento & desenvolvimento , Águas Salinas/economia , Irrigação Agrícola/métodos , Análise Custo-Benefício , Lycopersicon esculentum/metabolismo , Águas Salinas/análise , Águas Salinas/metabolismo , Salinidade , Cloreto de Sódio/análise
4.
Mar Pollut Bull ; 138: 352-363, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30660284

RESUMO

This study focuses on the ecological health assessment of Chilika, a shallow lagoon present in east coast of India, through nutrient stoichiometry and trophic state index (TSI). Multivariate statistical analysis such as ANOVA, Pearson's correlation, Principal Component Analysis (PCA), and Discriminant Analysis (DA) were employed for data interpretation. Nutrient stoichiometry revealed that the Chilika Lagoon experiences phosphorus limitation with regard to nitrogen and silicate (N:P:Si = 16:1:16) throughout the study period. As per the computed TSI values, the southern sector (SS), central sector (CS), and outer channel (OC) were assigned with a mesotrophic status, whereas the northern sector (NS) was assigned with the eutrophic status. From PCA, total nitrogen was found to be negatively correlated with salinity and positively correlated with silicate, thus indicating that the major source of nitrogen in the lagoon was freshwater ingress by rivers with high silicate content. DA indicated that it was successful in discriminating the groups as predicted.


Assuntos
Ecologia , Ecossistema , Nitrogênio/análise , Águas Salinas/análise , Análise Discriminante , Água Doce/química , Índia , Análise Multivariada , Nutrientes/análise , Salinidade , Estações do Ano , Silicatos/análise
5.
Animal ; 13(1): 98-105, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29679996

RESUMO

Salinization of groundwater and soil is a prevalent global issue with serious consequences on animal health and production. The present study was conducted to investigate the capacity of Boer goats to adjust their salt intake from saline drinking water in a free-choice system. In total, 12 non-pregnant Boer goats aged between 1 and 8 years with an average BW of 46.4±8.3 kg were kept in individual pens for 4 weeks. In the control phase (1 week), only fresh water was supplied in five identical buckets for each pen. During the subsequent treatment phase (3 weeks), fresh water and four different concentrations (0.75, 1.0, 1.25 and 1.5% NaCl) of saline water were offered simultaneously in a free-choice system. The positions of the concentrations were changed daily at random. Cut hay and water were provided ad libitum, and a mineral supplement was allocated. Feed and water intake, mineral supplement intake, ambient temperature and relative humidity were recorded daily, whereas BW and body condition score were measured weekly. Dry matter intake, total water intake and total sodium intake were significantly (P<0.001) higher during the treatment phase. Body weight and body condition were not affected by saline water intake. Across the treatment phase, saline water consumption was significantly (P<0.001) lower in young (19.6±27.1 g/kg BW0.82 per day) than in adult goats (27.9±31.5 g/kg BW0.82 per day), indicating that young goats were more sensitive towards the saline water. All goats had a significant preference for fresh water (0% salt) over saline water. At the first offering of the simultaneous choice situation (week 2), animals did not differentiate between the salt concentration of 0.75% and 1.0%. However, with successive treatment (weeks 3 and 4), animals distinguished between saline water concentrations and preferred the 0.75% salt concentration. Salt concentrations of 1% to 1.5% were avoided. The total sodium intake of the goats ranged between 0.37 and 0.55 g /kg BW0.75 per day during the treatment phase, being 8- to 11-fold higher than the daily requirements of sodium for body maintenance. The results suggest that goats are able to differentiate between saline water concentrations and to adjust their sodium intake by quick adjustments in self-selection in a free-choice system. Compared with two-choice preference tests, the present free-choice situation allows evaluating changes in saline water acceptance with prolonged exposure.


Assuntos
Comportamento de Escolha , Água Potável/análise , Água Doce/análise , Cabras/fisiologia , Águas Salinas/análise , Ração Animal/análise , Animais , Feminino
6.
Sci Total Environ ; 649: 1514-1521, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30308919

RESUMO

Fecal indicator bacteria (FIB) have been used to assess fecal contamination in recreational water. However, enteric viruses have been shown to be more persistent in the environment and resistant to wastewater treatment than bacteria. Recently, U.S Environmental Protection Agency has proposed the use of coliphages as viral indicators to better protect against viral waterborne outbreaks. This study aimed to detect and determine correlation between coliphages (F-specific and somatic), fecal indicator bacteria (enterococci and fecal coliforms), and human enteric viruses (human adenovirus) in a subtropical brackish estuarine lake. Water samples were collected from 9 estuarine recreation sites on Lake Pontchartrain in southeast Louisiana. Water samples (n = 222, collected weekly) were analyzed for coliphages and fecal indicator bacteria using culture-based methods and large volume water samples (n = 54, collected monthly) were analyzed for human adenovirus using quantitative PCR. Somatic coliphage and F-specific coliphage were found in 93.7 and 65.2% of samples with geometric mean concentrations of 30 and 3 plaque forming units (PFU) per 100 mL, respectively. Enterococci, fecal coliforms, and adenovirus were found in all samples with geometric mean concentrations of 27 most probable number (MPN), 77 MPN, and 3.0 × 104 gene copies per 100 mL, respectively. Watersheds in suburban areas exhibited significantly higher concentrations of coliphages and fecal indicator bacteria, indicating potential fecal contamination from septic systems. There was no significant correlation (p > 0.05) observed between the presence of adenoviruses and fecal indicator bacteria and coliphages. The presence of human adenovirus in Lake Pontchartrain poses a significant public health problem for both recreational use and seafood harvesting as it increases exposure risks. This study demonstrated the lack of relationship between fecal indicators and human viral pathogen in Lake Pontchartrain supporting an alternative microbial surveillance system such as direct pathogen detection.


Assuntos
Adenovírus Humanos/isolamento & purificação , Colífagos/isolamento & purificação , Monitoramento Ambiental , Lagos/microbiologia , Biomarcadores Ambientais , Estuários , Fezes/microbiologia , Fezes/virologia , Lagos/virologia , Louisiana , Águas Salinas/análise , Microbiologia da Água
7.
Protist ; 169(5): 615-631, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30096708

RESUMO

To understand the diversity of the diatom genus Chaetoceros Ehrenberg, the C. lorenzianus complex was previously chosen as a model and three new species were described. In the present study, yet another new species, Chaetoceros pauciramosus sp. nov., was discovered from Chinese tropical waters and the temperate south-eastern Baltic Sea. In the latter locality it has been known since 2003 and identified as C. cf lorenzianus, and now found to comprise a dominating component of the autumn phytoplankton community. Vegetative cells and resting spores were examined by light and electron microscopy. The LSU and SSU of the nuclear rDNA were sequenced. The characters suggesting that C. pauciramosus belongs to C. lorenzianus complex are: 1) the vegetative cells contain four or more chloroplasts, 2) the cells have stiff setae and form regular straight chains, 3) the terminal setae differ in the direction from the intercalary setae. The relationship was well-supported by molecular phylogenetic analyses inferred from both LSU and SSU markers. The primary valve of the resting spore has two conical elevations, each with dichotomously branching processes, similar to other species in the C. lorenzianus complex. Each process forms a tree-like structure with the pointed distal tips which possess one or two thin spikes, that distinguishes C. pauciramosus from allied taxa. In the phylogenetic trees, Chaetoceros pauciramosus clustered with C. elegans, in agreement with their morphologically similar resting spores.


Assuntos
Diatomáceas/isolamento & purificação , Fitoplâncton/isolamento & purificação , Águas Salinas/análise , Água do Mar/parasitologia , China , DNA Ribossômico/genética , Diatomáceas/classificação , Diatomáceas/genética , Diatomáceas/crescimento & desenvolvimento , Filogenia , Fitoplâncton/classificação , Fitoplâncton/genética , Fitoplâncton/crescimento & desenvolvimento , Água do Mar/análise
8.
Mar Pollut Bull ; 131(Pt A): 460-467, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29886972

RESUMO

Bioavailable dissolved organic carbon (BDOC), nitrogen (BDON) and their degradation rate constants were measured for the Chilika Lagoon, India. Long-term laboratory incubation experiments (90 days) were conducted at a constant temperature (25 °C) to quantify the bioavailable dissolved organic matter (DOM) and the possible degradation rate coefficients. The results showed that 41 ±â€¯12% of dissolved organic carbon (DOC) and 47 ±â€¯17% of dissolved organic nitrogen (DON) were BDOC and BDON respectively, with their stoichiometry found to be higher than the Redfield ratio. A first order exponential non-linear fitting routine was used to estimate pool sizes. The degradation rate constant (k) for the BDOC varied from 0.127-0.329 d-1 and BDON from 0.043-0.306 d-1 during the study period. Half-lives of the BDOC and BDON ranged from 2.1-5.4 and 2.2-15.9 days, respectively. Overall, the results showed that a fraction of the labile DON was transported from the lagoon to the adjacent coastal sea.


Assuntos
Carbono/farmacocinética , Nitrogênio/farmacocinética , Águas Salinas/química , Disponibilidade Biológica , Carbono/análise , Índia , Nitrogênio/análise , Rios , Águas Salinas/análise , Análise Espaço-Temporal , Clima Tropical
9.
Environ Sci Pollut Res Int ; 25(4): 3030-3037, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25689918

RESUMO

Membrane bioreactor (MBR) effluent collected from a wastewater treatment plant installed at an industrial zone was used for reverse osmosis (RO) membrane tests in the laboratory. For this, two different GE Osmonics RO membranes (AK-BWRO and AD-SWRO) were employed. The results showed that AK-brackish water reverse osmosis (AK-BWRO) and AD-seawater reverse osmosis (AD-SWRO) membranes have almost similar rejection performances regarding analyzed parameters such as conductivity, salinity, color, chemical oxygen demand (COD), and total organic carbon (TOC). On the other hand, these membranes behaved quite differently considering their permeate water flux at the same applied pressure of 10 bar. AD-SWRO membrane was also tested at 20 bar. The results revealed that AD-SWRO membrane had almost the same rejections either at 10 or at 20 bar of applied pressure. Compared with irrigation water standards, AK-BWRO and AD-SWRO gave an effluent with low salinity value and sodium adsorption ratio (SAR) which makes it unsuitable for irrigation due to the infiltration problems risi0ng from unbalanced values of salinity and SAR. Combination of MBR effluent and RO effluent at respective proportions of 0.3:0.7 and 0.4:0.6 for AK-BWRO and AD-SWRO, respectively, are the optimum mixing ratios to overcome the infiltration hazard problem. Choice of less-sensitive crops to chloride and sodium ions is another strategy to overcome all hazards which may arise from above suggested mixing proportions.


Assuntos
Irrigação Agrícola/métodos , Reatores Biológicos , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Purificação da Água , Qualidade da Água , Membranas Artificiais , Osmose , Águas Salinas/análise , Salinidade , Água do Mar/análise
10.
J Sci Food Agric ; 98(3): 1071-1078, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28722753

RESUMO

BACKGROUND: Sweet pepper fruit quality disorders have been related mainly to an unbalanced nutrient supply and non-optimal growth conditions. Increases in the atmospheric CO2 concentration ([CO2 ]) have been associated with a reduction of transpiration, which can affect calcium (Ca) uptake as it is linked closely to water uptake. We investigated whether foliar application of Ca can counterbalance the effects of saline water and elevated [CO2 ]. RESULTS: High CO2 favoured generative growth instead of vegetative growth. Foliar Ca supply did not affect the marketable yield, but reduced the total yield when combined with salinity and 400 µmol mol-1 CO2 . Salinity affected negatively the total yield but this was overcome when CO2 was applied. The B and K concentrations were reduced by foliar Ca application, while Ca and Mn were increased at 400 µmol mol-1 CO2 . Salinity increased the Mn, Cl, and Na concentrations, regardless of the [CO2 ], and decreased K at 800 µmol mol-1 CO2 . The total protein was affected negatively only by elevated [CO2 ], and the total free amino acid concentration was reduced by all treatments. CONCLUSION: The effect of Ca application differed according to the other treatments applied. This procedure should be optimised to overcome future climate impacts on fruit quality. © 2017 Society of Chemical Industry.


Assuntos
Cálcio/metabolismo , Capsicum/metabolismo , Frutas/química , Águas Salinas/metabolismo , Cálcio/análise , Capsicum/química , Capsicum/crescimento & desenvolvimento , Dióxido de Carbono , Clorofila/metabolismo , Mudança Climática , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Fotossíntese , Águas Salinas/análise
11.
Environ Sci Pollut Res Int ; 24(22): 18680-18690, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28623506

RESUMO

This article discusses bioaccumulation and temporal variation of heavy metals in three edible lagoon fish species with references to gender. Cd and As were undetected in the three fish species (i.e., below the method detection limits of 1 µg Cd/kg wet weight and 2 µg As/kg wet weight) irrespective of the periods, and Cd was undetected in the water too (i.e., below the detection limit of 0.0003 mg/L). Except for Zn (which was mainly available as Zn2+ in the water), Pb was present largely as low labile metal-chloride complexes and As as HAsO42- as per Visual MINTEQ, version 3.1. Bio-transfer factors of Sn (which was also undetected in the water; below the detection limit of 0.05 mg/L), Hg, Pb, and Zn were <1 in both sexes, justifying that bioaccumulation was largely attributed to food rather than uptake from the water. Metal accumulation patterns differed drastically between the fish species. Arius maculatus (a carnivore) exhibited higher Zn, Hg, and Sn accumulations during the drier periods (June-September) compared with Mugil cephalus (a detritivore/herbivore) and Etroplus suratensis (an omnivore). Pb was detected only in A. maculatus (July-August) possibly due to biomagnification. Zn was present in higher levels in all species (irrespective of sex) compared with the other metals, but levels were below admissible limits. However, the relationship between temporal variation of Zn and gender in all species was insignificant. In M. cephalus, the temporal variation of Sn and Hg between the sexes was also insignificant. Female A. maculatus and E. suratensis showed higher Hg concentrations, while males showed higher Sn concentrations. Temporal variation patterns of Pb were unclear.


Assuntos
Monitoramento Ambiental , Peixes/metabolismo , Metais Pesados/metabolismo , Alimentos Marinhos/análise , Poluentes Químicos da Água/metabolismo , Animais , Feminino , Contaminação de Alimentos/análise , Masculino , Metais Pesados/análise , Águas Salinas/análise , Águas Salinas/química , Especificidade da Espécie , Fatores de Tempo , Poluentes Químicos da Água/análise
12.
Chemosphere ; 166: 323-333, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27710880

RESUMO

Total mercury (THg) and methylmercury (MeHg) concentrations were determined from sediment samples collected from thirty sampling stations in Port Klang, Malaysia. Three stations had THg concentrations exceeding the threshold effect level of the Florida Department of Environmental Protection and the Canadian interim sediment quality guidelines. THg and MeHg concentrations were found to be concentrated in the Lumut Strait where inputs from the two most urbanized rivers in the state converged (i.e. Klang River and Langat River). This suggests that Hg in the study area likely originated from the catchments of these rivers. MeHg made up 0.06-94.96% of the sediment's THg. There is significant positive correlation (p < 0.01) between THg and MeHg concentrations. Significant positive correlation (p < 0.05) was also observed between fine sediment particles (i.e. clay and silt) with MeHg concentrations. Sediment particle size, however, was not found to have any influence on THg concentrations in the sediment in the study area.


Assuntos
Monitoramento Ambiental/métodos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Águas Salinas/análise , Sedimentos Geológicos/análise , Malásia , Tamanho da Partícula , Fatores de Risco , Rios , Poluentes Químicos da Água/análise , Purificação da Água/métodos
13.
J Insect Physiol ; 98: 59-66, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27915134

RESUMO

Ongoing climate change is driving dramatic range shifts in diverse taxa worldwide, and species responses to global change are likely to be determined largely by population responses at geographical range margins. Here we investigate the metabolic and reproductive plasticity in response to water temperature and salinity variation of two populations of the eurythermic saline water bug Sigara selecta: one population located close to the northern edge of its distribution, in a relatively cold, thermally stable region (SE England - 'marginal'), and one close to the range centre, in a warmer and more thermally variable Mediterranean climate (SE Spain - 'core'). We compared metabolic and oviposition rates and egg size, following exposure to one of four different combinations of temperature (15 and 25°C) and salinity (10 and 35gL-1). Oviposition rate was significantly higher in the marginal population, although eggs laid were smaller overall. No significant differences in oxygen consumption rates were found between core and marginal populations, although the marginal population showed higher levels of plasticity in both metabolic and reproductive traits. Our results suggest that population-specific responses to environmental change are complex and may be mediated by differences in phenotypic plasticity. In S. selecta, the higher plasticity of the marginal population may facilitate both its persistence in current habitats and northward expansion with future climatic warming. The less plastic core population may be able to buffer current environmental variability with minor changes in metabolism and fecundity, but could be prone to extinction if temperature and salinity changes exceed physiological tolerance limits in the future.


Assuntos
Metabolismo Energético , Heterópteros/fisiologia , Oviposição , Termotolerância , Animais , Ecossistema , Europa (Continente) , Óvulo/fisiologia , Águas Salinas/análise , Espanha
14.
Water Sci Technol ; 73(12): 2986-97, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27332845

RESUMO

This study provides information for the design of sea outfalls to dispose of brine from desalination plants into shallow lagoons of the sea. The behavior of vertical dense jets was studied experimentally by discharging cold saline water vertically upward into a tank filled with hot freshwater under stagnant ambient conditions. The minimum return point dilution, µmin, was determined using thermocouples, and the maximum height, Z(m), and the lateral spread, R(sp), of the fountains were determined by observing shadowgraph pictures. The flow was turbulent and the densimetric Froude number Fr(0) varied from 9 to 18.8. Three mixing regimes were identified: deep, intermediate, and impinging mixing regimes. In the intermediate mixing regime, µ(min) and Z(m) were analyzed and compared with the results of deep water studies. The µ(min) and Z(m) values of fountains at an intermediate water depth were found to be higher than those of fountains at deep water depths. In the impinging regime, µ(min) decreases rapidly when a fountain starts to continuously impinge on the water surface, showing a noticeable disturbance in the water surface. Therefore, a good rule of thumb is to reduce the flow through multiport diffusers from desalination plants when the noticeable disturbance is observed from the top water surface.


Assuntos
Água Doce/análise , Águas Salinas/análise , Movimentos da Água , Purificação da Água/métodos , Difusão , Purificação da Água/instrumentação
15.
Arq. bras. med. vet. zootec ; 68(2): 404-414, mar.-abr. 2016. tab, graf
Artigo em Português | LILACS | ID: lil-779792

RESUMO

A mitilicultura no Brasil se baseia no mexilhão Perna perna (Linnaeus, 1758), que é encontrado em todo o litoral brasileiro, sendo especialmente abundante do Espírito Santo a Santa Catarina. Nos últimos anos, foi lançada a hipótese de que P. perna seja uma espécie exótica no litoral brasileiro. A hipótese se baseia na análise da malacofauna presente em sítios arqueológicos. Todas as contestações levantadas não remetem à uma conclusão, pois precisam de estudos específicos, com metodologias claras, aliando arqueologia, ecologia e biologia molecular. O objetivo deste trabalho foi estudar a condição de nativo ou exótico do mexilhão Perna perna no Brasil, a partir de levantamento dos resultados em sítios arqueológicos, de técnicas moleculares e de datação de conchas com C14. A datação indicou que as amostras de Perna perna do sítio arqueológico Rio do Meio/Jurerê, Florianópolis/SC, têm idade de 720±30 e 780±30 anos. O cálculo do tempo de divergência indicou que a separação das populações brasileiras e africanas ocorreu por volta de 200 mil anos. Os resultados apontam a presença da espécie no território brasileiro muito antes do descobrimento do Brasil pelos portugueses no ano de 1500, indicando que P. perna é de fato uma espécie nativa.


Mussel farming in Brazil is based on brown mussel Perna perna (Linnaeus, 1758), which is found throughout the Brazilian coast, especially abundant from Espírito Santo to Santa Catarina coast. In recent years it was suggested that Perna perna is an exotic species for the Brazilian coast. The hypothesis is based on the analysis of the zooarchaeology studies in archaeological sites in Brazil. All objections raised do not offer a conclusion, because they need specific studies with clear methodology, combining archeology, ecology and molecular biology. The aim of this work was to study the condition of the brown mussel Perna perna in Brazil if native or exotic, from survey results in archaeological sites, molecular techniques and dating of shells with C14. The dating indicated that the shells were 720±30 and 780±30 years, respectively. The calculation of divergence time indicated that the separation of the African and Brazilian mussel populations occurred around 200 thousand years ago. The results indicate the presence of the P. perna species in Brazilian territory long before the discovery of Brazil by the Portuguese in 1500, indicating that P. perna is actually a native species of Brazil.


Assuntos
Animais , Aquicultura , Águas Salinas/análise , Biologia Molecular , Perna (Organismo) , Exoesqueleto/anatomia & histologia , Variação Genética , Moluscos
16.
Environ Geochem Health ; 38(1): 99-110, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25750033

RESUMO

Leaching experiments were conducted to investigate the effects of desalination levels and sediment depths on potential bioavailability of heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in tidal flat soils. The data showed that both the desalination levels (p < 0.001) and soil depths (p < 0.001) had significant effects on the concentrations of acid-volatile sulfide (AVS). AVS concentrations generally exhibited increasing trends with an increase in depth and decreasing trends with enhanced desalination levels. The desalination levels had significant (p < 0.05) effects on the concentrations of simultaneously extracted metal (SEM; Cd, Cr, Cu, Fe, Mn, Pb, and Zn). Moreover, the concentrations of SEM (Cd, Cr, Cu, Fe, Mn, Pb, and Zn) generally tended to decrease with an increase in the desalination level. The desalination treatment significantly reduced the ratios of SEM/AVS compared with control. However, the ratios of SEM/AVS increased with enhanced desalination levels in treatments. Results reveal that low desalination treatment is better for reducing toxicity to benthic organisms than high desalination treatment. Since these reclaimed tidal flats with low desalinisation are suitable for saline water aquaculture, transforming the present land use of reclaimed tidal flats from fresh water aquaculture into saline water aquaculture may reduce health risk of heavy metals remained in sediments. These results will also contribute to our understanding of the dynamic behavior of heavy metals in the reclamation of tidal flats during leaching and the role of the ratio of SEM/AVS predictions on assessing the ecological risks of reclaimed tidal flats.


Assuntos
Organismos Aquáticos/metabolismo , Sedimentos Geológicos/análise , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Disponibilidade Biológica , China , Água Doce/análise , Microscopia Eletrônica de Varredura , Medição de Risco , Águas Salinas/análise
17.
Water Res ; 70: 300-12, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25543240

RESUMO

Transparent exopolymer particles (TEP) and their precursors produced by phyto-/bacterio-planktons in fresh and marine aquatic environments are increasingly considered as a major contributor to organic/particulate and biological fouling in micro-/ultra-filtration and reverse osmosis membrane (RO) systems. However, currently established methods which are based on Alcian blue (AB) staining and spectrophotometric techniques do not measure TEP-precursors and have the tendency to overestimate concentration in brackish/saline water samples due to interference of salinity on AB staining. Here we propose a new semi-quantitative method which allows measurement of both TEP and their colloidal precursors without the interference of salinity. TEP and their precursors are first retained on 10 kDa membrane, rinsed with ultra-pure water, and re-suspended in ultra-pure water by sonication and stained with AB, followed by exclusion of TEP-AB precipitates by filtration and absorbance measurement of residual AB. The concentration is then determined based on the reduction of AB absorbance due to reaction with acidic polysaccharides, blank correction and calibration with Xanthan gum standard. The extraction procedure allows concentration of TEP and their pre-cursors which makes it possible to analyse samples with a wide range of concentrations (down to <0.1 mg Xeq/L). This was demonstrated through application of the method for monitoring these compounds in algal cultures and a full-scale RO plant. The monitoring also revealed that concentrations of the colloidal precursors were substantially higher than the concentration of TEP themselves. In the RO plant, complete TEP removal was observed over the pre-treatment processes (coagulation-sedimentation-filtration and ultrafiltration) but the TEP precursors were not completely removed, emphasising the importance of measuring this colloidal component to better understand the role of TEP and acidic polysaccharides in RO membrane fouling.


Assuntos
Azul Alciano/química , Coloides/análise , Monitoramento Ambiental/métodos , Água Doce/análise , Polímeros/análise , Águas Salinas/análise , Incrustação Biológica , Polissacarídeos/química , Purificação da Água
18.
An. R. Acad. Farm ; 81(5): 54-63, 2015. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-146985

RESUMO

Se ha estudiado la microbiota autóctona y alóctona del agua mineral del Balneario Villa de Olmedo (Valladolid). El número total de microorganismos en el agua ha sido de 4,5 x 103/mL y el número de bacterias viables heterótrofas menor de 5 ufc/mL. No se han encontrado indicadores fecales ni microorganismos patógenos por lo que estas aguas cumplen con la normativa española de aguas de consumo. La microbiota autóctona está constituida, principalmente, por bacilos Gram negativos de la clase Gammaproteobacteria (68,5%) y, en menor proporción, por cocos Gram positivos (14,3%). La especie más frecuente ha sido Pseudomonas stutzeri (37,2%). Se han detectado bacterias con actividades amonificantes, nitrificantes, proteolíticas y amilolíticas en 100 mL de agua, que contribuyen a la autodepuración del agua


The autochthon and alocthon microbiota of the mineral water of the Villa de Olmedo Spa have been studied. The total number of microorganisms in the water was of 4.5 x103/mL and the number of heterotrophic viable bacteria was lower than 5 cfu/mL. Neither faecal indicators nor pathogenic microorganisms were found; therefore these waters comply with the Spanish regulations on drinking water. The autochthon microbiota mostly belongs to Gram negative bacilli, from the Class Gammaproteobacteria (68.5%) and in smaller percentage to the Gram positive cocci (14.3%). The most frequently found species was Pseudomonas stutzeri. Moreover ammonifying, nitrifiying, proteolytic and amylolytic bacteria have been detected in 100 mL of water, all of them involved in self-purification process of wáter


Assuntos
Águas Termais/análise , Águas Termais/classificação , Águas Termais/métodos , Fontes Termais/análise , Fontes Termais/química , Água Subterrânea/análise , Água Subterrânea/química , Geologia/métodos , Captação de Águas Subterrâneas/análise , Captação de Águas Subterrâneas/métodos , Fluxo de Águas Subterrâneas/análise , Águas Salinas/análise , Solos Salitrosos/análise , Salinidade
19.
Int. microbiol ; 15(1): 33-41, mar. 2012. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-102990

RESUMO

Methanogens have been reported in complex microbial communities from hypersaline environments, but little is known about their phylogenetic diversity. In this work, methane concentrations in environmental gas samples were determined while methane production rates were measured in microcosm experiments with competitive and non-competitive substrates. In addition, the phylogenetic diversity of methanogens in microbial mats from two geographical locations was analyzed: the well studied Guerrero Negro hypersaline ecosystem, and a site not previously investigated, namely Laguna San Ignacio, Baja California Sur, Mexico. Methanogenesis in these microbial mats was suspected based on the detection of methane (in the range of 0.00086 to 3.204 %) in environmental gas samples. Microcosm experiments confirmed methane production by the mats and demonstrated that it was promoted only by non-competitive substrates (trimethylamine and methanol), suggesting that methylotrophy is the main characteristic process by which these hypersaline microbial mats produce methane. Phylogenetic analysis of amino acid sequences of the methyl coenzyme-M reductase (mcrA) gene from natural and manipulated samples revealed various methylotrophic methanogens belonging exclusively to the family Methanosarcinaceae. Moderately halophilic microorganisms of the genus Methanohalophilus were predominant (>60 % of mcrA sequences retrieved). Slightly halophilic and marine microorganisms of the genera Methanococcoides and Methanolobus, respectively, were also identified, but in lower abundances (AU)


No disponible


Assuntos
Methanosarcinaceae/genética , Águas Salinas/análise , Variação Genética , Análise Microbiológica/métodos , Análise da Água
20.
Braz. j. microbiol ; 42(4): 1506-1515, Oct.-Dec. 2011. graf, tab
Artigo em Inglês | LILACS | ID: lil-614617

RESUMO

Treatment and safe disposal of tannery saline wastewater, a primary effluent stream that is generated by soaking salt-laden hides and skin is one of the major problems faced by the leather manufacturing industries. Conventional treatment methods like solar evaporation ponds and land composting are not eco-friendly as they deteriorate the ground water quality. Though, this waste stream is comprised of high concentration of dissolved proteins the presence of high salinity (1-6 percent NaCl by wt) makes it non-biodegradable. Enzymatic treatment is one of the positive alternatives for management of such kind of waste streams. A novel salt-tolerant alkaline protease obtained from P.aeruginosa (isolated from tannery saline wastewater) was used for enzymatic degradation studies. The effect of various physical factors including pH, temperature, incubation time, protein source and salinity on the activity of identified protease were investigated. Kinetic parameters (Km , Vmax) were calculated for the identified alkaline protease at varying substrate concentrations. Tannery saline wastewater treated with identified salt tolerant protease showed 75 percent protein removal at 6 h duration and 2 percent (v/v) protease addition was found to be the optimum dosage value.


Assuntos
Águas Residuárias/análise , Águas Salinas/análise , Análise de Tratabilidade/análise , Indústria do Couro/análise , Peptídeo Hidrolases/análise , Pseudomonas aeruginosa/isolamento & purificação , Microbiologia Ambiental , Métodos , Técnicas , Amostras de Água
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