Promotion of Plant Growth in Arid Zones by Selected Trichoderma spp. Strains with Adaptation Plasticity to Alkaline pH.

Trichoderma species are filamentous fungi that support plant health and confer improved growth, disease resistance, and abiotic stress tolerance. The objective of this study is to describe the physiological characteristics of the abundance and structure of Trichoderma model strains from arid zones and evaluate and describe their possible adaptation and modulation in alkaline pH. The presence of biotic factors such as phytopathogens forces farmers to take more actions such as using pesticides. In addition, factors such as the lack of water worldwide lead to losses in agricultural production. Therefore, the search for biocontrol microorganisms that support drought opens the door to the search for variations in the molecular mechanisms involved in these phenomena. In our case, we isolated 11 tested Trichoderma fungal strains from samples collected both from the rhizosphere and roots from two endemic plants. We probed their molecular markers to obtain their identity and assessed their resistance to alkaline conditions, as well as their response to mycoparasitism, plant growth promotion, and drought stress. The findings were worthy of being analyzed in depth. Three fungal taxa/species were grouped by phylogenetic/phenotypic characteristics; three T. harzianum strains showed outstanding capabilities to adapt to alkalinity stress. They also showed antagonistic activity against three phytopathogenic fungi. Additionally, we provided evidence of significant growth promotion in Sorghum bicolor seedlings under endemic agriculture conditions and a reduction in drought damage with Trichoderma infection. Finally, beneficial fungi adapted to specific ambient niches use various molecular mechanisms to survive and modulate their metabolism.

Global variation in freshwater physico-chemistry and its influence on chemical toxicity in aquatic wildlife.

Chemical pollution is one of the major threats to global freshwater biodiversity and will be exacerbated through changes in temperature and rainfall patterns, acid-base chemistry, and reduced freshwater availability due to climate change. In this review we show how physico-chemical features of natural fresh waters, including pH, temperature, oxygen, carbon dioxide, divalent cations, anions, carbonate alkalinity, salinity and dissolved organic matter, can affect the environmental risk to aquatic wildlife of pollutant chemicals. We evidence how these features of freshwater physico-chemistry directly and/or indirectly affect the solubility, speciation, bioavailability and uptake of chemicals [including via alterations in the trans-epithelial electric potential (TEP) across the gills or skin] as well as the internal physiology/biochemistry of the organisms, and hence ultimately toxicity. We also show how toxicity can vary with species and ontogeny. We use a new database of global freshwater chemistry (GLORICH) to demonstrate the huge variability (often >1000-fold) for these physico-chemical variables in natural fresh waters, and hence their importance to ecotoxicology. We emphasise that a better understanding of chemical toxicity and more accurate environmental risk assessment requires greater consideration of the natural water physico-chemistry in which the organisms we seek to protect live.

Azo dyes decolorization under high alkalinity and salinity conditions by Halomonas sp. in batch and packed bed reactor.

Biodecolorization and biodegradation of azo dyes are a challenge due to their recalcitrance and the characteristics of textile effluents. This study presents the use of Halomonas sp. in the decolorization of azo dyes Reactive Black 5 (RB5), Remazol Brilliant Violet 5R (RV5), and Reactive Orange 16 (RO16) under high alkalinity and salinity conditions. Firstly, the effect of air supply, pH, salinity and dye concentration was evaluated. Halomonas sp. was able to remove above 84% of all dyes in a wide range of pH (6-11) and salt concentrations (2-10%). The decolorization efficiency of RB5, RV5, and RO16 was found to be ≥ 90% after 24, 13 and 3 h, respectively, at 50 mg L-1 of dyes. The process was monitored by HPLC-DAD, finding a reduction of dyes along the time. Further, Halomonas sp. was immobilized in volcanic rocks and used in a packed bed reactor for 72 days, achieving a removal rate of 3.48, 5.73, and 8.52 mg L-1 h-1, for RB5, RV5 and RO16, respectively, at 11.8 h. The study has confirmed the potential of Halomonas sp. to decolorize azo dyes under high salinity and alkalinity conditions and opened a scope for future research in the treatment of textile effluents.

Biocontrol potential of saline- or alkaline-tolerant Trichoderma asperellum mutants against three pathogenic fungi under saline or alkaline stress conditions.

Salinity and alkalinity are major abiotic stresses that limit growth and development of poplar. We investigated biocontrol potential of saline- and alkaline-tolerant mutants of Trichoderma asperellum to mediate the effects of salinity or alkalinity stresses on Populus davidiana×P. alba var. pyramidalis (PdPap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using an Agrobacterium tumefaciens mediated transformation system; this process yielded sixty five positive transformants (T1-T65). The salinity tolerant mutant, T59, grew in Potato Dextrose Agar (PDA) containing up to 10% (1709.40mM) NaCl. Under NaCl-rich conditions, T59 was most effective in inhibiting Alternaria alternata (52.00%). The alkalinity tolerant mutants, T3 and T5, grew in PDA containing up to 0.4% (47.62mM) NaHCO3. The ability of the T3 and T5 mutants to inhibit Fusarium oxysporum declined as NaHCO3 concentrations increased. NaHCO3 tolerance of the PdPap seedlings improved following treatment with the spores of the WT, T3, and T5 strains. The salinity tolerant mutant (T59) and two alkalinity tolerant mutants (T3 and T5) generated in this study can be applied to decrease the incidence of pathogenic fungi infection under saline or alkaline stress.

Biocontrol potential of saline- or alkaline-tolerant Trichoderma asperellum mutants against three pathogenic fungi under saline or alkaline stress conditions

ABSTRACT Salinity and alkalinity are major abiotic stresses that limit growth and development of poplar. We investigated biocontrol potential of saline- and alkaline-tolerant mutants of Trichoderma asperellum to mediate the effects of salinity or alkalinity stresses on Populus davidiana × P. alba var. pyramidalis (PdPap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using an Agrobacterium tumefaciens mediated transformation system; this process yielded sixty five positive transformants (T1-T65). The salinity tolerant mutant, T59, grew in Potato Dextrose Agar (PDA) containing up to 10% (1709.40 mM) NaCl. Under NaCl-rich conditions, T59 was most effective in inhibiting Alternaria alternata (52.00%). The alkalinity tolerant mutants, T3 and T5, grew in PDA containing up to 0.4% (47.62 mM) NaHCO3. The ability of the T3 and T5 mutants to inhibit Fusarium oxysporum declined as NaHCO3 concentrations increased. NaHCO3 tolerance of the PdPap seedlings improved following treatment with the spores of the WT, T3, and T5 strains. The salinity tolerant mutant (T59) and two alkalinity tolerant mutants (T3 and T5) generated in this study can be applied to decrease the incidence of pathogenic fungi infection under saline or alkaline stress.

Biocontrol potential of saline- or alkaline-tolerant Trichoderma asperellum mutants against three pathogenic fungi under saline or alkaline stress conditions

ABSTRACT Salinity and alkalinity are major abiotic stresses that limit growth and development of poplar. We investigated biocontrol potential of saline- and alkaline-tolerant mutants of Trichoderma asperellum to mediate the effects of salinity or alkalinity stresses on Populus davidiana × P. alba var. pyramidalis (PdPap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using an Agrobacterium tumefaciens mediated transformation system; this process yielded sixty five positive transformants (T1T65). The salinity tolerant mutant, T59, grew in Potato Dextrose Agar (PDA) containing up to 10% (1709.40 mM) NaCl. Under NaCl-rich conditions, T59 was most effective in inhibiting Alternaria alternata (52.00%). The alkalinity tolerant mutants, T3 and T5, grew in PDA containing up to 0.4% (47.62 mM) NaHCO3. The ability of the T3 and T5 mutants to inhibit Fusarium oxysporum declined as NaHCO3 concentrations increased. NaHCO3 tolerance of the PdPap seedlings improved following treatment with the spores of the WT, T3, and T5 strains. The salinity tolerant mutant (T59) and two alkalinity tolerant mutants (T3 and T5) generated in this study can be applied to decrease the incidence of pathogenic fungi infection under saline or alkaline stress.

Biocontrol potential of saline - or alkaline - tolerant Trichoderma asperellum mutants against three pathogenic fungi under saline or alkaline stress conditions

Salinity and alkalinity are major abiotic stresses that limit growth and development of poplar. We investigated biocontrol potential of saline- and alkaline-tolerant mutants of Trichoderma asperellum to mediate the effects of salinity or alkalinity stresses on Populus davidiana × P. alba var. pyramidalis (PdPap poplar) seedlings. A T-DNA insertion mutant library of T. asperellum was constructed using an Agrobacterium tumefaciens mediated transformation system; this process yielded sixty five positive transformants (T1–T65). The salinity tolerant mutant, T59, grew in Potato Dextrose Agar (PDA) containing up to 10% (1709.40 mM) NaCl. Under NaCl-rich conditions, T59 was most effective in inhibiting Alternaria alternata (52.00%). The alkalinity tolerant mutants, T3 and T5, grew in PDA containing up to 0.4% (47.62 mM) NaHCO3. The ability of the T3 and T5 mutants to inhibit Fusarium oxysporum declined as NaHCO3 concentrations increased. NaHCO3 tolerance of the PdPap seedlings improved following treatment with the spores of the WT, T3, and T5 strains. The salinity tolerant mutant (T59) and two alkalinity tolerant mutants (T3 and T5) generated in this study can be applied to decrease the incidence of pathogenic fungi infection under saline or alkaline stress.(AU)

Microbiological and physical-chemical characteristics of the water used to Tambaqui Colossoma macropomum species, in Maranhão State / Características microbiológicas e físico-químicas da água utilizada na criação de peixes da espécie tambaqui “Colossoma macropomum”, na Baixada Maranhense

Brazil has favorable hydrographic and climatic conditions for the development of fish farming. The success of this activity depends on the quality of the water, since it directly influences its productivity. Therefore, in order to verify the microbiological and physico - chemical characteristics of the water in the creation of the tambaqui (Colossoma macropomum) species in fish farming in São Bento, a municipality located in the. State, 16 water samples from six fish farms were evaluated for the physical parameters (Temperature, transparency, dissolved oxygen, pH, turbidity, color, alkalinity, hardness, nitrate and nitrite) and microbiological (coliforms and heterotrophic mesophilic bacteria). According to the findings, all samples were contaminated by total and thermotolerant coliforms, 13 (77.15%) were outside the standards recommended by the legislation. As for the mesophilic aerobic heterotrophic bacteria, the mean counts ranged from 30.6 x 102 to 4.7 x 104 CFU / mL. As for the physical-chemical parameters, it was verified that the temperature ranged from 27.4°C to 30°C; PH 5.0 to 8.2; Transparency ranged from 0 to 46 cm; Turbidity from 12 to 1,251 NTU, the color from 0 to 666.50 UH; Dissolved oxygen from 7.1 to 14.7 mg / L; Alkalinity of 17.5 to 412 mg / L; Hardness from 14.6 to 1027.8 mg / L; Nitrate from 1 to 160 mg / L and nitrite from 0.01 to 0.45 mg / L. The findings show that the water of fish farms has inadequate microbiological and physico-chemical characteristics for fish farming.

O Brasil possui condições hidrográficas e climáticas favoráveis para o desenvolvimento da piscicultura. O sucesso dessa atividade depende da qualidade da água, visto que esta influencia diretamente em sua produtividade. Portanto, com o objetivo de verificar as características microbiológicas e físico - químicas da água na criação da espécie tambaqui (Colossoma macropomum) em piscicultura de São Bento, município localizado na Baixada Maranhense, foram avaliadas 16 amostras de água de seis pisciculturas quanto aos parâmetros físico–químicos (temperatura, transparência, oxigênio dissolvido, PH, turbidez, cor, alcalinidade, dureza, nitrato e nitrito) e microbiológicos (coliformes e bactérias heterotróficas mesófilas). Conforme os achados, todas as amostras estavam contaminadas por coliformes totais e termotolerantes, sendo que 13 (77,15%) estavam fora dos padrões recomendados pela legislação. Quanto às bactérias heterotróficas aeróbias mesófilas, os valores médios das contagens variaram de 30,6 x 102 a 4,7 x 104 UFC/mL. Quanto aos parâmetros físico-químicos, verificou-se que a temperatura variou de 27,4 °C a 30 ºC; pH de 5,0 a 8,2; transparência variou de 0 a 46 cm; turbidez de 12 a 1.251 UNT, a cor de 0 a 666,50 UH; oxigênio dissolvido de 7,1 a 14, 7 mg/L; alcalinidade de 17,5 a 412 mg/L; dureza de 14,6 a 1027,8 mg/L; nitrato de 1 a 160 mg/L e nitrito de 0,01 a 0,45 mg/L. Os achados evidenciam que a água das pisciculturas investigadas apresenta características microbiológicas e físico-químicas inadequadas para criação de peixes.

Microbiological and physical-chemical characteristics of the water used to Tambaqui Colossoma macropomum species, in Maranhão State / Características microbiológicas e físico-químicas da água utilizada na criação de peixes da espécie tambaqui “Colossoma macropomum”, na Baixada Maranhense

Brazil has favorable hydrographic and climatic conditions for the development of fish farming. The success of this activity depends on the quality of the water, since it directly influences its productivity. Therefore, in order to verify the microbiological and physico - chemical characteristics of the water in the creation of the tambaqui (Colossoma macropomum) species in fish farming in São Bento, a municipality located in the. State, 16 water samples from six fish farms were evaluated for the physical parameters (Temperature, transparency, dissolved oxygen, pH, turbidity, color, alkalinity, hardness, nitrate and nitrite) and microbiological (coliforms and heterotrophic mesophilic bacteria). According to the findings, all samples were contaminated by total and thermotolerant coliforms, 13 (77.15%) were outside the standards recommended by the legislation. As for the mesophilic aerobic heterotrophic bacteria, the mean counts ranged from 30.6 x 102 to 4.7 x 104 CFU / mL. As for the physical-chemical parameters, it was verified that the temperature ranged from 27.4°C to 30°C; PH 5.0 to 8.2; Transparency ranged from 0 to 46 cm; Turbidity from 12 to 1,251 NTU, the color from 0 to 666.50 UH; Dissolved oxygen from 7.1 to 14.7 mg / L; Alkalinity of 17.5 to 412 mg / L; Hardness from 14.6 to 1027.8 mg / L; Nitrate from 1 to 160 mg / L and nitrite from 0.01 to 0.45 mg / L. The findings show that the water of fish farms has inadequate microbiological and physico-chemical characteristics for fish farming.(AU)

O Brasil possui condições hidrográficas e climáticas favoráveis para o desenvolvimento da piscicultura. O sucesso dessa atividade depende da qualidade da água, visto que esta influencia diretamente em sua produtividade. Portanto, com o objetivo de verificar as características microbiológicas e físico - químicas da água na criação da espécie tambaqui (Colossoma macropomum) em piscicultura de São Bento, município localizado na Baixada Maranhense, foram avaliadas 16 amostras de água de seis pisciculturas quanto aos parâmetros físico–químicos (temperatura, transparência, oxigênio dissolvido, PH, turbidez, cor, alcalinidade, dureza, nitrato e nitrito) e microbiológicos (coliformes e bactérias heterotróficas mesófilas). Conforme os achados, todas as amostras estavam contaminadas por coliformes totais e termotolerantes, sendo que 13 (77,15%) estavam fora dos padrões recomendados pela legislação. Quanto às bactérias heterotróficas aeróbias mesófilas, os valores médios das contagens variaram de 30,6 x 102 a 4,7 x 104 UFC/mL. Quanto aos parâmetros físico-químicos, verificou-se que a temperatura variou de 27,4 °C a 30 ºC; pH de 5,0 a 8,2; transparência variou de 0 a 46 cm; turbidez de 12 a 1.251 UNT, a cor de 0 a 666,50 UH; oxigênio dissolvido de 7,1 a 14, 7 mg/L; alcalinidade de 17,5 a 412 mg/L; dureza de 14,6 a 1027,8 mg/L; nitrato de 1 a 160 mg/L e nitrito de 0,01 a 0,45 mg/L. Os achados evidenciam que a água das pisciculturas investigadas apresenta características microbiológicas e físico-químicas inadequadas para criação de peixes.(AU)

Reducing Salinity by Flooding an Extremely Alkaline and Saline Soil Changes the Bacterial Community but Its Effect on the Archaeal Community Is Limited.

Regular flooding of the soil to reduce salinity will change soil characteristics, but also the microbial community structure. Soil of the former lake Texcoco with electrolytic conductivity (EC) 157.4 dS m-1 and pH 10.3 was flooded monthly in the laboratory under controlled conditions for 10 months while soil characteristics were determined and the archaeal and bacterial community structure monitored by means of 454 pyrosequencing of the 16S rRNA gene. The EC of the soil dropped from 157.8 to 1.7 dS m-1 and the clay content decreased from 430 to 270 g kg-1 after ten floodings, but the pH (10.3) did not change significantly over time. Flooding the soil had a limited effect on the archaeal community structure and only the relative abundance of Haloferax-like 16S rRNA phylotypes changed significantly. Differences in archaeal population structure were more defined by the initial physicochemical properties of the soil sample than by a reduction in salinity. Flooding, however, had a stronger effect on bacterial community structure than on the archaeal community structure. A wide range of bacterial taxa was affected significantly by changes in the soil characteristics, i.e., four phyla, nine classes, 17 orders, and 28 families. The most marked change occurred after only one flooding characterized by a sharp decrease in the relative abundance of bacterial groups belonging to the Gammaproteobacteria, e.g., Halomonadaceae (Oceanospirillales), Pseudomonadaceae, and Xanthomonadaceae and an increase in that of the [Rhodothermales] (Bacteroidetes), Nitriliruptorales (Actinobacteria), and unassigned Bacteria. It was found that flooding the soil sharply reduced the EC, but also the soil clay content. Flooding the soil had a limited effect on the archaeal community structure, but altered the bacterial community structure significantly.

Bacterial treatment of alkaline cement kiln dust using Bacillus halodurans strain KG1

Abstract This study was conducted to isolate an acid-producing, alkaliphilic bacterium to reduce the alkalinity of cement industry waste (cement kiln dust). Gram-positive isolate KG1 grew well at pH values of 6–12, temperatures of 28–50 °C, and NaCl concentrations of 0–16% and thus was further screened for its potential to reduce the pH of an alkaline medium. Phenotypic characteristics of the KG1 isolate were consistent with those of the genus Bacillus, and the highest level of 16S rRNA gene sequence similarity was found with Bacillus halodurans strain DSM 497 (94.7%). On the basis of its phenotypic characteristics and genotypic distinctiveness from other phylogenetic neighbors belonging to alkaliphilic Bacillus species, the isolated strain was designated B. halodurans strain KG1, with GenBank accession number JQ307184 (= NCIM 5439). Isolate KG1 reduced the alkalinity (by 83.64%) and the chloride content (by 86.96%) of cement kiln dust and showed a potential to be used in the cement industry for a variety of applications.

Bacterial treatment of alkaline cement kiln dust using Bacillus halodurans strain KG1.

This study was conducted to isolate an acid-producing, alkaliphilic bacterium to reduce the alkalinity of cement industry waste (cement kiln dust). Gram-positive isolate KG1 grew well at pH values of 6-12, temperatures of 28-50°C, and NaCl concentrations of 0-16% and thus was further screened for its potential to reduce the pH of an alkaline medium. Phenotypic characteristics of the KG1 isolate were consistent with those of the genus Bacillus, and the highest level of 16S rRNA gene sequence similarity was found with Bacillus halodurans strain DSM 497 (94.7%). On the basis of its phenotypic characteristics and genotypic distinctiveness from other phylogenetic neighbors belonging to alkaliphilic Bacillus species, the isolated strain was designated B. halodurans strain KG1, with GenBank accession number JQ307184 (= NCIM 5439). Isolate KG1 reduced the alkalinity (by 83.64%) and the chloride content (by 86.96%) of cement kiln dust and showed a potential to be used in the cement industry for a variety of applications.

Bacterial treatment of alkaline cement kiln dust using Bacillus halodurans strain KG1

This study was conducted to isolate an acid-producing, alkaliphilic bacterium to reduce the alkalinity of cement industry waste (cement kiln dust). Gram-positive isolate KG1 grew well at pH values of 612, temperatures of 2850 °C, and NaCl concentrations of 016% and thus was further screened for its potential to reduce the pH of an alkaline medium. Phenotypic characteristics of the KG1 isolate were consistent with those of the genus Bacillus, and the highest level of 16S rRNA gene sequence similarity was found with Bacillus halodurans strain DSM 497 (94.7%). On the basis of its phenotypic characteristics and genotypic distinctiveness from other phylogenetic neighbors belonging to alkaliphilic Bacillus species, the isolated strain was designated B. halodurans strain KG1, with GenBank accession number JQ307184 (= NCIM 5439). Isolate KG1 reduced the alkalinity (by 83.64%) and the chloride content (by 86.96%) of cement kiln dust and showed a potential to be used in the cement industry for a variety of applications. (AU)

Freshwater parameters in the state of Rio Grande do Sul, southern Brazil, and their influence on fish distribution and aquaculture

This study analyzed the relationship between several water quality parameters (pH, hardness, alkalinity, turbidity, iron and manganese) levels measured over a 16 year period with fish distribution and aquaculture in the state of Rio Grande do Sul, Southern Brazil. The mean pH values were within a neutral range (6.5-7.5), but the maximum and minimum values reached inappropriate levels for fish farming in some cities. Alkalinity levels were very low (except in the southwest region of the state), which may have contributed to pH variation. Hardness, turbidity, iron (except the region near Caçapava do Sul City) and manganese were within safe ranges for fish farming; however, turbidity levels occasionally increased to levels outside the safe range. In conclusion, the water quality in the Rio Grande do Sul, in general, can be considered adequate for aquaculture, but the fish farmers must be aware of the methods to reduce turbidity, such as the use of calcium sulfate.(AU)

Este estudo analisou a relação entre vários parâmetros de qualidade da água (pH, dureza, alcalinidade, turbidez, ferro e manganês durante 16 anos) com a distribuição de peixes e piscicultura no estado do Rio Grande do Sul, Brasil. O pH ficou em média em uma faixa neutra (6,5-7,5), mas valores máximos e mínimos atingiram níveis não apropriados para a piscicultura em algumas cidades. Os valores de alcalinidade foram baixos (exceto na região sudoeste do estado), o que poderia contribuir para oscilações no pH. Dureza, turbidez, ferro (exceto na região próxima à cidade de Caçapava do Sul) e manganês ficaram dentro de níveis aceitáveis para a piscicultura, mas a turbidez ocasionalmente elevou-se a níveis fora dessa faixa aceitável e os piscicultores devem ter algum mecanismo para reduzi-los. Em conclusão, de forma geral a qualidade da água do Rio Grande do Sul pode ser considerada adequada para a aquicultura, mas os piscicultores devem conhecer métodos para corrigir a turbidez, como a utilização de sulfato de cálcio.(AU)

Freshwater parameters in the state of Rio Grande do Sul, southern Brazil, and their influence on fish distribution and aquaculture

This study analyzed the relationship between several water quality parameters (pH, hardness, alkalinity, turbidity, iron and manganese) levels measured over a 16 year period with fish distribution and aquaculture in the state of Rio Grande do Sul, Southern Brazil. The mean pH values were within a neutral range (6.5-7.5), but the maximum and minimum values reached inappropriate levels for fish farming in some cities. Alkalinity levels were very low (except in the southwest region of the state), which may have contributed to pH variation. Hardness, turbidity, iron (except the region near Caçapava do Sul City) and manganese were within safe ranges for fish farming; however, turbidity levels occasionally increased to levels outside the safe range. In conclusion, the water quality in the Rio Grande do Sul, in general, can be considered adequate for aquaculture, but the fish farmers must be aware of the methods to reduce turbidity, such as the use of calcium sulfate.(AU)

Este estudo analisou a relação entre vários parâmetros de qualidade da água (pH, dureza, alcalinidade, turbidez, ferro e manganês durante 16 anos) com a distribuição de peixes e piscicultura no estado do Rio Grande do Sul, Brasil. O pH ficou em média em uma faixa neutra (6,5-7,5), mas valores máximos e mínimos atingiram níveis não apropriados para a piscicultura em algumas cidades. Os valores de alcalinidade foram baixos (exceto na região sudoeste do estado), o que poderia contribuir para oscilações no pH. Dureza, turbidez, ferro (exceto na região próxima à cidade de Caçapava do Sul) e manganês ficaram dentro de níveis aceitáveis para a piscicultura, mas a turbidez ocasionalmente elevou-se a níveis fora dessa faixa aceitável e os piscicultores devem ter algum mecanismo para reduzi-los. Em conclusão, de forma geral a qualidade da água do Rio Grande do Sul pode ser considerada adequada para a aquicultura, mas os piscicultores devem conhecer métodos para corrigir a turbidez, como a utilização de sulfato de cálcio.(AU)

Influence of alkalinity and VFAs on the performance of an UASB reactor with recirculation for the treatment of Tequila vinasses.

The main problem linked to the stability of upflow anaerobic sludge blanket (UASB) reactors during the treatment of Tequila vinasse is the high acidity and the null alkalinity present in this effluent. This research evaluates the effect of alkalinity and volatile fatty acids (VFAs) concentration on the performance of an UASB reactor with recirculation of the effluent for removing organic matter and biogas production from Tequila vinasses. Recirculation of the effluent reduces the impact of VFAs and organic matter concentration present in the influent, inducing the stability of the reactor. The UASB reactor was operated during 235 days at organic loading rates from 2.5 to 20.0 kg m(-3) d(-1), attaining a removal efficiency of COD greater than 75% with a methane yield of 335 ml CH4 g(-1) COD at SPT, maintaining a ratio of VFAs/Alk ≤ 0.5. Therefore, an optimal ratio of VFAs/Alk was established for the system operating in stable conditions for the treatment of Tequila vinasses. Under these conditions, the alkalinity was recuperated by the system itself, without the addition of external alkalinity.

Reduction of aflatoxin B1 during tortilla production and identification of degradation by-products by direct-injection electrospray mass spectrometry (DIESI-MS) / Reducción de la aflatoxina B1 durante la producción de tortilla y la identificación de los productos de degradación por espectrometría de masas con ionización por electrospray de inyección-directa (DIESI-MS)

Objective. To determine the effect of pH, and exposure time over the inactivation of aflatoxin B1 (AFB1) during the tortilla making process as well as the degradative molecules generated. Materials and methods. Inactivation of AFB1 in maize-dough with alkaline pH and in alkaline methanolic solutions was determined by HPLC. Kinetics of time exposure of AFB1 in methanolic solution and the degradative products were analyzed by direct injection electrospray mass spectometry (DIESI-MS). Results. The alkaline pH of the maize-dough after nixtamalización between 10.2, and 30-40 minutes of resting at room temperature allows the 100% reduction of AFB1. DIESI-MS analysis of the extracts indicated the presence of two degradation molecules from AFB1. Conclusion. The alkaline pH of maize-dough and resting time are the principal factors involved in diminishing AFB1 levels in tortillas. A procedure to the tortilla making process is proposed, which allows the reduction of remnant AFB1, avoiding the accumulative effect over consumers.

Objetivo. Determinar el efecto del pH alcalino de la masa de maíz y el tiempo de exposición sobre la aflatoxina B1 (AFB1) durante la producción de tortillas e identificar los posibles productos de degradación mediante DIESI-MS. Material y métodos. La inactivación de la AFB1 a pH alcalino y diferentes tiempos de exposición en masa nixtamalizada y en soluciones metanólicas fueron determinadas por HPLC. La cinética de degradación de AFB1, y los productos de degradación en soluciones metanólicas se determinaron por DIESI-MS. Resultados. El pH alcalino de la masa y 30 a 40 minutos de reposo redujeron en 100% la AFB1 adicionada. Se identificaron dos moléculas de degradación. Conclusión. Los principales factores involucrados en la disminución de la AFB1 durante la producción de tortillas son la hidrólisis alcalina y el tiempo de reposo. Se propone un procedimiento para la producción de tortilla que reducirá la AFB1 residual evitando el efecto acumulativo en los consumidores.

Akaline, saline and mixed saline-alkaline stresses induce physiological and morpho-anatomical changes in Lotus tenuis shoots.

Saline, alkaline and mixed saline-alkaline conditions frequently co-occur in soil. In this work, we compared these plant stress sources on the legume Lotus tenuis, regarding their effects on shoot growth and leaf and stem anatomy. In addition, we aimed to gain insight on the plant physiological status of stressed plants. We performed pot experiments with four treatments: control without salt (pH = 5.8; EC = 1.2 dS·m(-1)) and three stress conditions, saline (100 mM NaCl, pH = 5.8; EC = 11.0 dS·m(-1)), alkaline (10 mM NaHCO3, pH = 8.0, EC = 1.9 dS·m(-1)) and mixed salt-alkaline (10 mM NaHCO3 + 100 mM NaCl, pH = 8.0, EC = 11.0 dS·m(-1)). Neutral and alkaline salts produced a similar level of growth inhibition on L. tenuis shoots, whereas their mixture exacerbated their detrimental effects. Our results showed that none of the analysed morpho-anatomical parameters categorically differentiated one stress from the other. However, NaCl- and NaHCO3 -derived stress could be discriminated to different extents and/or directions of changes in some of the anatomical traits. For example, alkalinity led to increased stomatal opening, unlike NaCl-treated plants, where a reduction in stomatal aperture was observed. Similarly, plants from the mixed saline-alkaline treatment characteristically lacked palisade mesophyll in their leaves. The stem cross-section and vessel areas, as well as the number of vascular bundles in the sectioned stem were reduced in all treatments. A rise in the number of vessel elements in the xylem was recorded in NaCl-treated plants, but not in those treated exclusively with NaHCO3.

Alternative liming blends for fish culture / Misturas alternativas para calagem em piscicultura

Calcium carbonate (limestone) is a safe but slow-acting product for aquaculture liming.Calcium oxide (lime) is a fast-acting but dangerous product. It would be interesting to have simultaneouslya safe and fast-acting liming product. The present work aimed to evaluate two alternative liming blends fortilapia culture. The culture water was initially acidified with HCl. Next, the same quantity of CaCO3(control), Na2CO3+CaSO4 or Na2CO3+CaCl2 was applied to the culture water. There were also nonlimedtanks. One hundred and twenty Nile tilapia juveniles (1.6 ± 0.1 g) were stocked in twenty 250-Lculture tanks for 10 weeks. All products used were similarly efficient in increasing the alkalinity of water.The probable better environment for algal growth in the limed tanks caused an increase in the DO2concentrations and a decrease in CO2, total ammonia nitrogen, nitrite and phosphorus, in relation to thenon-limed tanks. The highest final body weight of fish was observed in the Na2CO3+CaCl2 tanks. Thelowest final body weight was verified in the CaCO3 tanks. It was concluded that the alternative blend ofNa2CO3 plus CaCl2 is a better liming product than the standard CaCO3 for Nile tilapia culture.Keywords: limestone, lime, tilapia, alkalinity, aquaculture.

Carbonato de cálcio é um produto seguro, mas de ação lenta para calagem em aquicultura.O óxido de cálcio é um produto de ação rápida, mas perigoso. Seria de interesse ter um produto paracalagem em aquicultura que fosse simultaneamente seguro e de ação rápida. O presente projeto de pesquisateve por objetivo avaliar duas misturas alternativas para calagem no cultivo de tilápia. A água de cultivo foiinicialmente acidificada com HCl. Em seguida, a mesma quantidade de CaCO3 (controle),Na2CO3+CaSO4 ou Na2CO3+CaCl2 foi aplicada à água. Havia ainda tanques não submetidos à calagem.Cento e vinte juvenis de tilápia do Nilo (1,6 ± 0,1 g) foram estocados em 20 tanques de cultivo de 250 Lpor dez semanas. Todos os produtos testados foram igualmente eficientes no aumento da alcalinidade daágua. Os tanques submetidos à calagem apresentaram maiores concentrações de O2D e menores de CO2livre, nitrogênio amoniacal total, nitrito e fósforo. O maior e o menor peso corporal final dos peixes foramobservados nos tanques Na2CO3+CaCl2 e CaCO3, respectivamente. Concluiu-se que a mistura alternativaNa2CO3+CaCl2 é superior ao CaCO3 na calagem de tanques de tilápia do Nilo.

Alternative liming blends for fish culture / Misturas alternativas para calagem em piscicultura

Calcium carbonate (limestone) is a safe but slow-acting product for aquaculture liming.Calcium oxide (lime) is a fast-acting but dangerous product. It would be interesting to have simultaneouslya safe and fast-acting liming product. The present work aimed to evaluate two alternative liming blends fortilapia culture. The culture water was initially acidified with HCl. Next, the same quantity of CaCO3(control), Na2CO3+CaSO4 or Na2CO3+CaCl2 was applied to the culture water. There were also nonlimedtanks. One hundred and twenty Nile tilapia juveniles (1.6 ± 0.1 g) were stocked in twenty 250-Lculture tanks for 10 weeks. All products used were similarly efficient in increasing the alkalinity of water.The probable better environment for algal growth in the limed tanks caused an increase in the DO2concentrations and a decrease in CO2, total ammonia nitrogen, nitrite and phosphorus, in relation to thenon-limed tanks. The highest final body weight of fish was observed in the Na2CO3+CaCl2 tanks. Thelowest final body weight was verified in the CaCO3 tanks. It was concluded that the alternative blend ofNa2CO3 plus CaCl2 is a better liming product than the standard CaCO3 for Nile tilapia culture.Keywords: limestone, lime, tilapia, alkalinity, aquaculture.(AU)

Carbonato de cálcio é um produto seguro, mas de ação lenta para calagem em aquicultura.O óxido de cálcio é um produto de ação rápida, mas perigoso. Seria de interesse ter um produto paracalagem em aquicultura que fosse simultaneamente seguro e de ação rápida. O presente projeto de pesquisateve por objetivo avaliar duas misturas alternativas para calagem no cultivo de tilápia. A água de cultivo foiinicialmente acidificada com HCl. Em seguida, a mesma quantidade de CaCO3 (controle),Na2CO3+CaSO4 ou Na2CO3+CaCl2 foi aplicada à água. Havia ainda tanques não submetidos à calagem.Cento e vinte juvenis de tilápia do Nilo (1,6 ± 0,1 g) foram estocados em 20 tanques de cultivo de 250 Lpor dez semanas. Todos os produtos testados foram igualmente eficientes no aumento da alcalinidade daágua. Os tanques submetidos à calagem apresentaram maiores concentrações de O2D e menores de CO2livre, nitrogênio amoniacal total, nitrito e fósforo. O maior e o menor peso corporal final dos peixes foramobservados nos tanques Na2CO3+CaCl2 e CaCO3, respectivamente. Concluiu-se que a mistura alternativaNa2CO3+CaCl2 é superior ao CaCO3 na calagem de tanques de tilápia do Nilo.(AU)