Oxidative stress caused by lead in the lichen Xanthoria parietina

The assessment of the air quality is a major concern to the current time. The monitoring and maintenance of air quality necessarily pass by detecting and estimating the overall air pollution. The use of lichens must be an assessmenttool to be studied. In our work we were interested about the toxicity of lead on the various parameters of stress in the lichen Xanthoria parietina. For this purpose, lichen thalli have been incubated at lead concentrations of 0, 0.5, 1.0, 5.0 and 10.0 mM, for time scale of 0, 24, 48 and 96 hours. The obtained results showed that lead has an action on the various studied parameters, and the intensity of oxidative stress observed in lichens thalli depends on the concentration, and time of exposure. Lead induced a decrease in chlorophyll and protein contents, and an increase in the contents of catalase, hydrogen peroxide and reduced glutathione. Furthermore, the results also showed that high concentrations of lead caused total destruction of reduced glutathione.(AU)

Gas exchange and growth of soursop under salt stress and H2O2 application methods / Trocas gasosas e crescimento de graviola sob estresse salino e métodos de aplicação de H2O2

The production of soursop seedlings in the Northeast region of Brazil has faced limitations due to the high concentrations of salts in the water, so it is necessary to use techniques that enable its cultivation, and the application of hydrogen peroxide to minimize the deleterious effects of salt stress stands out. In this context, the objective was to evaluate forms of application of hydrogen peroxide as an attenuator of salt stress on the gas exchange and growth of soursop seedlings cv. Morada Nova. The experiment was conducted under greenhouse conditions, in an Regolithic Neosol of sandy loam texture, from the municipality of Lagoa Seca - PB. A completely randomized design was used in a 5 × 4 factorial arrangement, whose treatments resulted from the combination of five levels of electrical conductivity of irrigation water - ECw (0.6 - control, 1.2, 1.8, 2.4 and 3.0 dS m-1) and four forms of hydrogen peroxide application (M1 - without H2O2 application, M2 - application by seed soaking, M3 - application by foliar spraying, and M4 - application by seed soaking + foliar spraying), with four replicates and two plants per experimental unit, totaling 160 plants. The concentration of H2O2 used in the different forms of application was 20 µM. Irrigation water salinity from 0.6 dS m-1 reduced the gas exchange and growth of soursop. The method of H2O2 application by foliar spraying minimized the effects of salt stress on gas exchange. The method of H2O2 application by seed soaking reduced the effect of salt stress on the growth of soursop at 85 days after sowing.

A produção de mudas de gravioleira na região semiárida do Brasil tem enfrentado limitações devido às elevadas concentrações de sais nas águas, sendo necessário o uso de técnicas que viabilizem seu cultivo, destacando-se a aplicação do peróxido de hidrogênio. Neste contexto, objetivou-se avaliar as formas de aplicação do peróxido de hidrogênio como atenuante do estresse salino nas trocas gasosas e no crescimento de mudas de gravioleira cv. Morada Nova. O estudo foi conduzido sob condições de casa de vegetação, em um Neossolo Regolítico de textura franco-arenosa, utilizando-se o delineamento inteiramente casualizado, no arranjo fatorial 5 × 4, cujos tratamentos resultaram da combinação de cinco níveis de condutividade elétrica da água de irrigação - CEa (0,6 - testemunha; 1,2; 1,8; 2,4 e 3,0 dS m-1) e quatro formas de aplicação de peróxido de hidrogênio (M1- sem aplicação de H2O2, M2 - aplicação via embebição das sementes, M3 -aplicação por pulverização foliar e M4 - aplicação via embebição das sementes + pulverização foliar), com quatro repetições e duas plantas por unidade experimental, perfazendo o total de 160 plantas. A concentração de H2O2 utilizada nas diferentes formas de aplicação foi de 20 µM. A salinidade da água de irrigação a partir de 0,6 dS m-1 diminuiu as trocas gasosas e o crescimento das plantas de gravioleira. O método de aplicação do H2O2 via pulverização foliar minimizou o efeito do estresse salino sobre as trocas gasosas. O método de aplicação do H2O2 via embebição das sementes diminuiu o estresse salino no crescimento de gravioleira aos 85 dias após o semeio.

Bacillus licheniformis SMIA-2 protease used as an additive in detergent formulations

Microbial proteases, especially from Bacillus spp., have been widely exploited for a broad variety of applications, such as the improvement of the cleaning efficiency of conventional detergents. In this work, the statistical design of the experiment was used to optimize the concentrations of a three-component mixture: Bacillus licheniformis SMIA-2 protease, Linear Alkylbenzene Sulphate and hydrogen peroxide, in an attempt to prepare an environmentally correct cleaning formulation. The results demonstrated that the combination of 1% (w/v) protease with 1.5% (w/v) LAS and 1% (w/v) H2O2 was effective in removing blood from cloth pieces and that a protease concentration decrease from 1.0% to 0.5% (w/v) would not have a signi&64257;cant impact on percent blood removal if LAS concentrations between 1.5-2.0% (w/v) in combination with lower (<0.5%, w/v) concentrations of H2O2 were used. Thus, the protease from Bacillus licheniformis SMIA-2 can be effectively incorporated into cleaning formulations together with LAS and hydrogen peroxide to formulate more sustainable detergents.

Bacillus licheniformis SMIA-2 protease used as an additive in detergent formulations

Microbial proteases, especially from Bacillus spp., have been widely exploited for a broad variety of applications, such as the improvement of the cleaning efficiency of conventional detergents. In this work, the statistical design of the experiment was used to optimize the concentrations of a three-component mixture: Bacillus licheniformis SMIA-2 protease, Linear Alkylbenzene Sulphate and hydrogen peroxide, in an attempt to prepare an environmentally correct cleaning formulation. The results demonstrated that the combination of 1% (w/v) protease with 1.5% (w/v) LAS and 1% (w/v) H2O2 was effective in removing blood from cloth pieces and that a protease concentration decrease from 1.0% to 0.5% (w/v) would not have a signi&64257;cant impact on percent blood removal if LAS concentrations between 1.5-2.0% (w/v) in combination with lower (<0.5%, w/v) concentrations of H2O2 were used. Thus, the protease from Bacillus licheniformis SMIA-2 can be effectively incorporated into cleaning formulations together with LAS and hydrogen peroxide to formulate more sustainable detergents.(AU)

Foliar application of H2O2 as salt stress attenuator in 'BRS Rubi do Cerrado' sour passion fruit / Aplicação foliar de H2O2 como atenuante do estresse salino em maracujazeiro-azedo 'BRS Rubi do Cerrado'

Irrigation with saline water causes a reduction in yield, especially in semi-arid regions. Cultivation strategies have been developed to mitigate salt stress on plants, such as the use of hydrogen peroxide. The objective of this study was to evaluate the attenuating effect of hydrogen peroxide on the gas exchange and growth of 'BRS Rubi do Cerrado' sour passion fruit cultivated under irrigation with saline water. The design was completely randomized in split-plot plots, with water salinity levels ECw (0.6, 1.2, 1.8, 2.4, and 3.0 dS m-1) considered the plots and the concentrations of hydrogen peroxide H2O2 (0, 15, 30, and 45 µM) considered the subplots, with three replicates. Gas exchange (stomatal conductance, transpiration, CO2 assimilation rate, intercellular CO2 concentration, instantaneous water use efficiency, and instantaneous carboxylation efficiency), and absolute and relative growth rates in stem diameter were evaluated. An increase in irrigation water salinity from 0.6 dS m-1 reduced gas exchange, and exogenous application of hydrogen peroxide did not promote a significant effect on gas exchange. However, foliar application of hydrogen peroxide at 15 µM increased the growth of 'BRS Rubi do Cerrado' sour passion fruit.(AU)

A irrigação com águas salinas causa redução na produtividade, principalmente nas regiões semiáridas. Estratégias de cultivo vêm sendo desenvolvidas, a exemplo uso de peróxido de hidrogênio para mitigar o estresse salino sobre as plantas. Objetivou-se avaliar o efeito atenuante do peróxido de hidrogênio sobre as trocas gasosas e o crescimento do maracujazeiro-azedo 'BRS Rubi do Cerrado' cultivado sob irrigação com águas salinas. O delineamento foi inteiramente casualizados em parcelas subdivididas, sendo os níveis de salinidade da água - CEa (0,6, 1,2, 1,8, 2,4 e 3,0 dS m-1) consideradas as parcelas, e as concentrações de peróxido de hidrogênio ­ H2O2 (0, 15, 30 e 45 µM) as subparcelas, com três repetições. Foram avaliadas as trocas gasosas (condutância estomática, transpiração, taxa de assimilação de CO2, concentração intercelular de CO2, eficiência instantânea no uso da água e eficiência instantânea de carboxilação), e a taxa de crescimento absoluto e relativo do caule. O aumento na salinidade da água de irrigação a partir da salinidade de 0,6 dS m-1 reduziu as trocas gasosas; a aplicação exógena de peróxido de hidrogênio não promoveu efeito significativos sob as trocas gasosas. A aplicação foliar de 15 µM de peróxido de hidrogênio aumentou o crescimento do maracujazeiro-azedo 'BRS Rubi do Cerrado'.(AU)

Oxidative stress and antioxidant defense in detoxification systems of snake venom-induced toxicity

Snakebites remain a major life-threatening event worldwide. It is still difficult to make a positive identification of snake species by clinicians in both Western medicine and Chinese medicine. The main reason for this is a shortage of diagnostic biomarkers and lack of knowledge about pathways of venom-induced toxicity. In traditional Chinese medicine, snakebites are considered to be treated with wind, fire, and wind-fire toxin, but additional studies are required. Methods: Cases of snakebite seen at the Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine were grouped as follows: fire toxin - including four cases of bites by Agkistrodon acutus and three bites by Trimeresurus stejnegeri - and wind-fire toxin - four cases of bites by vipers and three bites by cobras. Serum protein quantification was performed using LC-MS/MS. Differential abundance proteins (DAPs) were identified from comparison of snakebites of each snake species and healthy controls. The protein interaction network was constructed using STITCH database. Results: Principal component analysis and hierarchical clustering of 474 unique proteins exhibited protein expression profiles of wind-fire toxins that are distinct from that of fire toxins. Ninety-three DAPs were identified in each snakebite subgroup as compared with healthy control, of which 38 proteins were found to have significantly different expression levels and 55 proteins displayed no expression in one subgroup, by subgroup comparison. GO analysis revealed that the DAPs participated in bicarbonate/oxygen transport and hydrogen peroxide catabolic process, and affected carbon-oxygen lyase activity and heme binding. Thirty DAPs directly or indirectly acted on hydrogen peroxide in the interaction network of proteins and drug compounds. The network was clustered into four groups: lipid metabolism and transport; IGF-mediated growth; oxygen transport; and innate immunity. Conclusions: Our results show that the pathways of snake venom-induced toxicity may form a protein network of antioxidant defense by regulating oxidative stress through interaction with hydrogen peroxide.(AU)

Oxidative stress and antioxidant defense in detoxification systems of snake venom-induced toxicity

Snakebites remain a major life-threatening event worldwide. It is still difficult to make a positive identification of snake species by clinicians in both Western medicine and Chinese medicine. The main reason for this is a shortage of diagnostic biomarkers and lack of knowledge about pathways of venom-induced toxicity. In traditional Chinese medicine, snakebites are considered to be treated with wind, fire, and wind-fire toxin, but additional studies are required. Methods: Cases of snakebite seen at the Affiliated Hospital of Jiangxi University of Traditional Chinese Medicine were grouped as follows: fire toxin - including four cases of bites by Agkistrodon acutus and three bites by Trimeresurus stejnegeri - and wind-fire toxin - four cases of bites by vipers and three bites by cobras. Serum protein quantification was performed using LC-MS/MS. Differential abundance proteins (DAPs) were identified from comparison of snakebites of each snake species and healthy controls. The protein interaction network was constructed using STITCH database. Results: Principal component analysis and hierarchical clustering of 474 unique proteins exhibited protein expression profiles of wind-fire toxins that are distinct from that of fire toxins. Ninety-three DAPs were identified in each snakebite subgroup as compared with healthy control, of which 38 proteins were found to have significantly different expression levels and 55 proteins displayed no expression in one subgroup, by subgroup comparison. GO analysis revealed that the DAPs participated in bicarbonate/oxygen transport and hydrogen peroxide catabolic process, and affected carbon-oxygen lyase activity and heme binding. Thirty DAPs directly or indirectly acted on hydrogen peroxide in the interaction network of proteins and drug compounds. The network was clustered into four groups: lipid metabolism and transport; IGF-mediated growth; oxygen transport; and innate immunity. Conclusions: Our results show that the pathways of snake venom-induced toxicity may form a protein network of antioxidant defense by regulating oxidative stress through interaction with hydrogen peroxide.(AU)

Budburst and flowering intensity by the spraying of dormancy-breaking products in 'Eva' apple trees / Brotação e intensidade de floração pela aplicação de indutores de brotação em macieiras 'Eva'

Spraying of dormancy-breaking chemicals is a mandatory procedure to produce temperate fruits in low-chill regions. Although hydrogen cyanamide (HC) + mineral oil (MO) show efficiency enhancing budburst, the usage of HC is restricted in some countries due to its toxicity. Therefore, this research aimed to evaluate the efficiency of spraying different dormancy-breaking agents on ‘Eva apple tree buds, under the conditions of the Depressão Central of Rio Grande do Sul, Brazil. Different doses of Erger® (0, 2, 3, 4, 5%) + 3% Ca(NO3)2 were tested and compared with MO (4%) or MO (4%) + HC (0.6%). Budburst rate of apical and axillary buds, physiological alterations in buds, return bloom, yield and fruit weight were evaluated. Erger® treatments efficiently enhanced budburst, with a result equivalent to HC + MO treatment. The budburst rate increased as the Erger® dose increased, also causing the increment of the return bloom in the following year. However, doses of 4 and 5% caused the death of shoots. The activity of the peroxidases and the content of H2O2 in the buds were affected by the treatments. Yield and fruit mass were different in response to treatments, although the effect varied between years. Erger® + Ca(NO3)2 spraying increase budburst in apical and axillary buds of ‘Eva apple tree in low-chill conditions and doses up to 3% of the commercial product do not cause toxicity.(AU)

A aplicação de indutores de brotação é uma prática fundamental para a produção de frutíferas temperadas em regiões com menor quantidade de horas de frio. Apesar de cianamida hidrogena (CH) + óleo mineral (OM) apresentarem eficiência na indução da brotação de gemas de macieira, a toxicidade de CH ao aplicador resultou em restrições ao seu uso em alguns países. Assim, o objetivo do trabalho foi avaliar a eficiência da aplicação de diferentes indutores de brotação de gemas na macieira ‘Eva, nas condições da Depressão Central do RS. Testaram-se diferentes doses de Erger® (0, 2, 3, 4, 5%) + 3% Ca(NO3)2, comparados com OM (4%) ou OM (4%) + CH (0,6%). Foram avaliados a taxa de brotação de gemas apicais e axilares, alterações fisiológicas nas gemas, o retorno floral, a produção e a massa dos frutos. Os tratamentos de Erger® foram eficientes em aumentar a brotação de gemas, com resultados equivalentes ao tratamento CH + OM. A taxa de brotação de gemas aumentou em resposta ao aumento na dose de Erger®, provocando também incremento no retorno floral no ano seguinte, no entanto doses de 4 e 5% provocaram morte de ramos. A atividade de peroxidases e os teores de peróxidos de hidrogênio nas gemas apicais foram afetadas pelos tratamentos. A produção e a massa média dos frutos diferiram entre tratamentos, porém o efeito variou entre as safras. A aplicação de Erger® + Ca(NO3)2 aumenta a brotação de gemas apicais e axilares em macieiras ‘Eva em condição de baixo acúmulo de frio e doses de até 3% do produto comercial não causam toxidez.(AU)

Budburst and flowering intensity by the spraying of dormancy-breaking products in 'Eva' apple trees / Brotação e intensidade de floração pela aplicação de indutores de brotação em macieiras 'Eva'

Spraying of dormancy-breaking chemicals is a mandatory procedure to produce temperate fruits in low-chill regions. Although hydrogen cyanamide (HC) + mineral oil (MO) show efficiency enhancing budburst, the usage of HC is restricted in some countries due to its toxicity. Therefore, this research aimed to evaluate the efficiency of spraying different dormancy-breaking agents on ‘Eva’ apple tree buds, under the conditions of the Depressão Central of Rio Grande do Sul, Brazil. Different doses of Erger® (0, 2, 3, 4, 5%) + 3% Ca(NO3)2 were tested and compared with MO (4%) or MO (4%) + HC (0.6%). Budburst rate of apical and axillary buds, physiological alterations in buds, return bloom, yield and fruit weight were evaluated. Erger® treatments efficiently enhanced budburst, with a result equivalent to HC + MO treatment. The budburst rate increased as the Erger® dose increased, also causing the increment of the return bloom in the following year. However, doses of 4 and 5% caused the death of shoots. The activity of the peroxidases and the content of H2O2 in the buds were affected by the treatments. Yield and fruit mass were different in response to treatments, although the effect varied between years. Erger® + Ca(NO3)2 spraying increase budburst in apical and axillary buds of ‘Eva’ apple tree in low-chill conditions and doses up to 3% of the commercial product do not cause toxicity.

A aplicação de indutores de brotação é uma prática fundamental para a produção de frutíferas temperadas em regiões com menor quantidade de horas de frio. Apesar de cianamida hidrogena (CH) + óleo mineral (OM) apresentarem eficiência na indução da brotação de gemas de macieira, a toxicidade de CH ao aplicador resultou em restrições ao seu uso em alguns países. Assim, o objetivo do trabalho foi avaliar a eficiência da aplicação de diferentes indutores de brotação de gemas na macieira ‘Eva’, nas condições da Depressão Central do RS. Testaram-se diferentes doses de Erger® (0, 2, 3, 4, 5%) + 3% Ca(NO3)2, comparados com OM (4%) ou OM (4%) + CH (0,6%). Foram avaliados a taxa de brotação de gemas apicais e axilares, alterações fisiológicas nas gemas, o retorno floral, a produção e a massa dos frutos. Os tratamentos de Erger® foram eficientes em aumentar a brotação de gemas, com resultados equivalentes ao tratamento CH + OM. A taxa de brotação de gemas aumentou em resposta ao aumento na dose de Erger®, provocando também incremento no retorno floral no ano seguinte, no entanto doses de 4 e 5% provocaram morte de ramos. A atividade de peroxidases e os teores de peróxidos de hidrogênio nas gemas apicais foram afetadas pelos tratamentos. A produção e a massa média dos frutos diferiram entre tratamentos, porém o efeito variou entre as safras. A aplicação de Erger® + Ca(NO3)2 aumenta a brotação de gemas apicais e axilares em macieiras ‘Eva’ em condição de baixo acúmulo de frio e doses de até 3% do produto comercial não causam toxidez.

Comparison of the efficacy of hydrogen peroxide and salt for control of fungal infections on brown trout (Salmo trutta) eggs

Background: Fungal infections can cause serious problems infecting fish eggs, especially unfertilized or dead eggs. In the past, this problem was solved by using very effective chemicals such as malachite green and formalin. But, due to its toxicity and carcinogenicity, malachite green was banned for use in fish intended for human consumption. Formalin also has been banned in most countries. Chemicals and drugs recommended for use to treat fungal infections are hydrogen peroxide, salt, potassium permanganate etc. The goal of the present study was to determine and compare the efficacy of antifungal effects of hydrogen peroxide and sodium chloride on brown trout eggs.Materials, Methods & Results: The experiment was conducted in the brown trout hatchery, Šipovo, Bosnia and Herzegovina. The experimental groups contained 500 and 1,000 mg/L of hydrogen peroxide with 15 and 30 min of exposition; 1 and 2.5% of sodium chloride with 15 and 30 min of exposition and a negative control group (no chemical treatment). The treatment concentrations were calculated and prepared from hydrogen peroxide of 35% active ingredient, and sodium chloride (sterilized) of 100% active ingredient. Eggs for the study were spawned from 11 females and 4 males. The first treatment was performed on the fourth day, and each next treatment was performed at 3-day intervals. Six treatments were administered until the 19th day after the fertilization. The treatment of the eggs was provided until the eggs reached the eyed stage. The effectiveness of the chemical treatments was measured by a hatch rate. There was a significant difference between all treated groups and the negative control group (P < 0.05). Hydrogen peroxide with a concentration of 500 mg/L for 30 min was the most effective and demonstrated a higher hatching rate (75.7%). Sodium chloride treatments resulted in statistically significantly lower hatching rates than hydrogen peroxide treatments.[...]

Comparison of the efficacy of hydrogen peroxide and salt for control of fungal infections on brown trout (Salmo trutta) eggs

Background: Fungal infections can cause serious problems infecting fish eggs, especially unfertilized or dead eggs. In the past, this problem was solved by using very effective chemicals such as malachite green and formalin. But, due to its toxicity and carcinogenicity, malachite green was banned for use in fish intended for human consumption. Formalin also has been banned in most countries. Chemicals and drugs recommended for use to treat fungal infections are hydrogen peroxide, salt, potassium permanganate etc. The goal of the present study was to determine and compare the efficacy of antifungal effects of hydrogen peroxide and sodium chloride on brown trout eggs.Materials, Methods & Results: The experiment was conducted in the brown trout hatchery, Šipovo, Bosnia and Herzegovina. The experimental groups contained 500 and 1,000 mg/L of hydrogen peroxide with 15 and 30 min of exposition; 1 and 2.5% of sodium chloride with 15 and 30 min of exposition and a negative control group (no chemical treatment). The treatment concentrations were calculated and prepared from hydrogen peroxide of 35% active ingredient, and sodium chloride (sterilized) of 100% active ingredient. Eggs for the study were spawned from 11 females and 4 males. The first treatment was performed on the fourth day, and each next treatment was performed at 3-day intervals. Six treatments were administered until the 19th day after the fertilization. The treatment of the eggs was provided until the eggs reached the eyed stage. The effectiveness of the chemical treatments was measured by a hatch rate. There was a significant difference between all treated groups and the negative control group (P < 0.05). Hydrogen peroxide with a concentration of 500 mg/L for 30 min was the most effective and demonstrated a higher hatching rate (75.7%). Sodium chloride treatments resulted in statistically significantly lower hatching rates than hydrogen peroxide treatments.[...](AU)

Heterologous expression of a rice metallothionein isoform (OsMTI-1b) in Saccharomyces cerevisiae enhances cadmium, hydrogen peroxide and ethanol tolerance

Metallothioneins are a superfamily of low-molecular-weight, cysteine (Cys)-rich proteins that are believed to play important roles in protection against metal toxicity and oxidative stress. The main purpose of this study was to investigate the effect of heterologous expression of a rice metallothionein isoform (OsMTI-1b) on the tolerance of Saccharomyces cerevisiae to Cd2+, H2O2 and ethanol stress. The gene encoding OsMTI-1b was cloned into p426GPD as a yeast expression vector. The new construct was transformed to competent cells of S. cerevisiae. After verification of heterologous expression of OsMTI-1b, the new strain and control were grown under stress conditions. In comparison to control strain, the transformed S. cerevisiae cells expressing OsMTI-1b showed more tolerance to Cd2+ and accumulated more Cd2+ ions when they were grown in the medium containing CdCl2. In addition, the heterologous expression of GST-OsMTI-1b conferred H2O2 and ethanol tolerance to S. cerevisiae cells. The results indicate that heterologous expression of plant MT isoforms can enhance the tolerance of S. cerevisiae to multiple stresses.(AU)

Esterilização química para o cultivo in vitro de porta-enxerto de pessegueiro / Chemical sterilization of in vitro culture for peach rootstook

A esterilização dos meios de cultura é normalmente realizada por autoclavagem. Decorre que, este processo pode degradar ou reduzir a ação de compostos com efeito fisiológico desejável, como vitaminas e fitorreguladores. Objetivou-se avaliar a ação de agentes esterilizantes adicionados ao meio de cultura para o estabelecimento in vitro de umezeiro ‘Rigitano’. Para tanto, segmentos nodais foram inoculados em meio de cultura MS, preparado considerando os seguintes tratamentos: adição de hipoclorito de sódio (0,01 e 0,05% v/v); de dióxido de cloro (0,1; 0,5 e 1,0 % v/v); e de peróxido de hidrogênio (0,3; 0,7 e 1,5% v/v). O tratamento controle constou da ausência de agente esterilizante, autoclavado e não autoclavado. Em períodos variáveis de avaliação (7, 14 e 21 dias), foram determinadas sobrevivência dos explantes, contaminação total, contaminação por bactéria, contaminação por fungos e oxidação. Constatou-se a ocorrência de fungos dos gêneros Alternaria, Cladosporium, Penicillium, Trichoderma e Criptococcus. Podese concluir que o uso de peróxido de hidrogênio ou dióxido de cloro é eficiente para a esterilização química de meios de cultivo.

The culture media sterilization is typically performed by autoclaving. However, this process may degrade or reduce the action of compounds with desired physiological effect, such as vitamins and growth regulators. This study aimed to evaluate the effect of sterilizing agents added to the culture medium in vitro mume 'Rigitano' establishment. For this purpose, nodal segments were inoculated into culture medium prepared considering the following treatments: addition of sodium hypochlorite (0.01 and 0.05 % v/v), chlorine dioxide (0.1, 0.5 and 1% v/v) or hydrogen peroxide (0.3, 0.7 and 1.5 %, v/v). The control treatment consisted of the absence of sterilizing, autoclaved and non-autoclaved. In different periods (7, 14 and 21 days), it was determined survival explants, whole contamination, contamination by bacteria, fungi contamination and oxidation. It was found ocurrence of Alternaria, Cladosporim, Penicillium, Trichoderma and Cryptococcus fungal genera. It was conclude that the use of hydrogen peroxide or chlorine dioxide is effective for the chemical sterilization of culture media.

Esterilização química para o cultivo in vitro de porta-enxerto de pessegueiro / Chemical sterilization of in vitro culture for peach rootstook

A esterilização dos meios de cultura é normalmente realizada por autoclavagem. Decorre que, este processo pode degradar ou reduzir a ação de compostos com efeito fisiológico desejável, como vitaminas e fitorreguladores. Objetivou-se avaliar a ação de agentes esterilizantes adicionados ao meio de cultura para o estabelecimento in vitro de umezeiro ‘Rigitano. Para tanto, segmentos nodais foram inoculados em meio de cultura MS, preparado considerando os seguintes tratamentos: adição de hipoclorito de sódio (0,01 e 0,05% v/v); de dióxido de cloro (0,1; 0,5 e 1,0 % v/v); e de peróxido de hidrogênio (0,3; 0,7 e 1,5% v/v). O tratamento controle constou da ausência de agente esterilizante, autoclavado e não autoclavado. Em períodos variáveis de avaliação (7, 14 e 21 dias), foram determinadas sobrevivência dos explantes, contaminação total, contaminação por bactéria, contaminação por fungos e oxidação. Constatou-se a ocorrência de fungos dos gêneros Alternaria, Cladosporium, Penicillium, Trichoderma e Criptococcus. Podese concluir que o uso de peróxido de hidrogênio ou dióxido de cloro é eficiente para a esterilização química de meios de cultivo.(AU)

The culture media sterilization is typically performed by autoclaving. However, this process may degrade or reduce the action of compounds with desired physiological effect, such as vitamins and growth regulators. This study aimed to evaluate the effect of sterilizing agents added to the culture medium in vitro mume 'Rigitano' establishment. For this purpose, nodal segments were inoculated into culture medium prepared considering the following treatments: addition of sodium hypochlorite (0.01 and 0.05 % v/v), chlorine dioxide (0.1, 0.5 and 1% v/v) or hydrogen peroxide (0.3, 0.7 and 1.5 %, v/v). The control treatment consisted of the absence of sterilizing, autoclaved and non-autoclaved. In different periods (7, 14 and 21 days), it was determined survival explants, whole contamination, contamination by bacteria, fungi contamination and oxidation. It was found ocurrence of Alternaria, Cladosporim, Penicillium, Trichoderma and Cryptococcus fungal genera. It was conclude that the use of hydrogen peroxide or chlorine dioxide is effective for the chemical sterilization of culture media.(AU)

Preservatives and neutralizing substances in milk: analytical sensitivity of official specific and nonspecific tests, microbial inhibition effect, and residue persistence in milk / Sustâncias conservantes e neutralizantes no leite: sensibilidade analítica das provas oficiais específicas, provas inespecíficas, inibição microbiana e persistência de resíduos no leite

Milk fraud has been a recurring problem in Brazil; thus, it is important to know the effect of most frequently used preservatives and neutralizing substances as well as the detection capability of official tests. The objective of this study was to evaluate the analytical sensitivity of legislation-described tests and nonspecific microbial inhibition tests, and to investigate the effect of such substances on microbial growth inhibition and the persistence of detectable residues after 24/48h of refrigeration. Batches of raw milk, free from any contaminant, were divided into aliquots and mixed with different concentrations of formaldehyde, hydrogen peroxide, sodium hypochlorite, chlorine, chlorinated alkaline detergent, or sodium hydroxide. The analytical sensitivity of the official tests was 0.005%, 0.003%, and 0.013% for formaldehyde, hydrogen peroxide, and hypochlorite, respectively. Chlorine and chlorinated alkaline detergent were not detected by regulatory tests. In the tests for neutralizing substances, sodium hydroxide could not be detected when acidity was accurately neutralized. The yogurt culture test gave results similar to those obtained by official tests for the detection of specific substances. Concentrations of 0.05% of formaldehyde, 0.003% of hydrogen peroxide and 0.013% of sodium hypochlorite significantly reduced (P<0.05) the microbial counts in milk after 24 and 48h refrigeration. Formaldehyde and sodium hypochlorite remained detectable in milk after 48 and 24h of refrigeration, respectively; while hydrogen peroxide could not be detected after 24h. Official tests for the detection of milk fraud by the addition of preservatives and neutralizing substances present limitations and may be ineffective in detecting milk adulteration.(AU)

Fraudes no leite têm sido um problema recorrente no Brasil, tornando importante conhecer o efeito dos conservantes e neutralizantes utilizados com maior frequência, e a capacidade de detecção das provas oficiais. O objetivo deste trabalho foi avaliar a sensibilidade analítica de provas descritas pela legislação, das provas por inibição microbiana inespecífica, o efeito dessas substâncias na inibição do crescimento microbiano e a persistência de resíduos detectáveis após 48 horas de refrigeração. Lotes de leite cru, livres de sustâncias adulterantes, foram aliquotados e adicionados de diferentes concentrações de formaldeído, peróxido de hidrogênio, hipoclorito de sódio, cloro, detergente alcalino clorado e hidróxido de sódio. A sensibilidade analítica das provas oficiais foi: 0,005% para formaldeído; 0,003% para peróxido de hidrogênio e 0,013% para hipoclorito. Cloro e detergente alcalino clorado não foram detectados pelas provas oficiais. A prova de neutralizantes não detectou hidróxido de sódio quando a acidez foi neutralizada com precisão. A prova da cultura de iogurte apresentou resultados próximos ao das provas oficiais para substâncias específicas. Concentrações de 0,05% formaldeído, 0,003% de peróxido de hidrogênio e 0,013% de hipoclorito de sódio reduziram significativamente (P 0,05) a microbiota do leite após 24 e 48 horas de refrigeração. O formaldeído e hipoclorito de sódio permaneceram detectável no leite após 48 e 24 horas de refrigeração, respectivamente e o peróxido de hidrogênio não foi detectável após 24 horas. As provas oficiais para a pesquisa de fraudes por adição de conservantes e neutralizantes ao leite apresentam limitações e podem não ser capazes de detectar adulterações no leite.(AU)

Estratégias profiláticas contra estreptococose mediante diferentes metodologias de inativação, adjuvantes e suplementação com Mananoligossacarídeos em tilápias-do-nilo

O presente estudo teve como objetivo desenvolver estratégias profilácticas contra Streptococcus agalactiae mediante distintas metodologias de inativação, adjuvantes e suplementação com mananoligossacarídeos em tilápias-do-nilo. Para isto, no primeiro experimento foram comparadas três vacinas inativadas, usando três metodologias: formaldeído, peróxido de hidrogênio e manipulação de pH. Seguido, foi realizado um segundo experimento avaliando o efeito de dois adjuvantes na vacina selecionada e finalmente um terceiro experimento avaliando o efeito de mananoligossacarídeos durante o período pós- vacinação. Vinte oito dias após vacinação, os peixes foram desafiados com cepa homóloga de S. agalactiae utilizando uma dose letal (DL50%-15d). Além disso, se avaliou o efeito da vacinação nos níveis de anticorpos IgM anti-Streptococcus agalactiae, nas variáveis hematológicas e na resposta imune inata. Os resultados revelaram não diferença significativa entre as três metodologias e uma eficácia moderada. Adicionalmente, a vacina inativada com peróxido de hidrogênio e administrada principalmente com adjuvante incompleto de Freund conferiu ótima proteção contra S. agalactiae e a inclusão de MOS na dieta pós-vacinação até o desafio não interferiu na eficácia da vacina experimental com peróxido de hidrogênio.

The aim of the present study was to develop prophylactic strategies against Streptococcus agalactiae by using different inactivation methods, adjuvants and supplementation with mannan oligosaccharides (MOS) in Nile tilapias. For that, in the first trial were compared three inactivated vaccines by using three methods: formaldehyde, hydrogen peroxide and pH manipulation. The second trial compared the effect of two adjuvants on the hydrogen peroxide-inactivated vaccine and finally, the third trial investigated the effect of dietary supplementation with MOS after vaccination. Twenty-eight days after vaccination, fish were challenged with a homologous strain of S. agalactiae. In addition, were determined the anti-Streptococcus agalactiae IgM antibodies, hematological parameters and innate immune response. The results revealed no significant difference between the three methods and a moderate efficacy of the vaccines. Also, the results in this study demonstrated that hydrogen peroxide-inactivated vaccine administered with either aluminum hydroxide or FIA induce optimal levels of protection, with a superior performance for FIA vaccine and the dietary inclusion of MOS after vaccination for a period of 28 days had no influence on vaccine efficacy and confirmed the high efficacy of the novel hydrogen peroxide-inactivated vaccine.

Geração e desintoxicação enzimática de espécies reativas de oxigênio em plantas / Plant generation and enzymatic detoxification of reactive oxygen species

As condições de estresse biótico e abiótico impostas às plantas induzem a superprodução de espécies reativas de oxigênio (ROS), podendo causar danos às estruturas celulares e mesmo acarretar a morte da planta. As respostas bioquímicas e fisiológicas de plantas superiores ao estresse oxidativo incluem um eficiente sistema de defesa antioxidante, que envolve a atividade das enzimas superóxido dismutase, catalase, ascorbato peroxidase, peroxirredoxinas, dentre outras, além de metabólitos não enzimáticos, que, de forma conjunta, atuam na eliminação das ROS e na redução do dano oxidativo. Nesta revisão, serão abordados os principais sítios de produção de ROS e a ação de algumas enzimas do sistema de defesa antioxidante em plantas.(AU)

The biotic and abiotic stress conditions imposed on plants induces overproduction of reactive oxygen species (ROS), which can cause damage to cellular structures and even lead to the death of the plant. The biochemical and physiological responses of higher plants to oxidative stress includes an efficient antioxidant defense system, which involves the activity of the enzymes superoxide dismutase, catalase, ascorbate peroxidase, peroxiredoxines, among others, in addition to non-enzymatic metabolites, which, together, work on eliminating the ROS and in reducing oxidative damage. This review will address the main production sites of ROS and the action of some enzymes of antioxidative defense system in plants.(AU)

Embolia gasosa pulmonar em coelho causada por peróxido de hidrogênio – relato de caso / Pulmonary gas embolism in rabbit caused by hydrogen peroxide – case report

A embolia gasosa provocada pela utilização do peróxido de hidrogênio é um fenômeno que não é descrito na rotina clínica veterinária, neste sentido descreve-se a ocorrência de embolia gasosa venosa massiva em coelho durante a limpeza e desinfecção de um abscesso no masseter utilizando peróxido de hidrogênio a 3%. Ao injetar peróxido de hidrogênio sobre pressão na cavidade do abscesso, o animal teve uma parada cardiorrespiratória súbita e veio a óbito. A necropsia foram observadas inúmeras bolhas de ar (êmbolos gasosos) na veia cava caudal e tronco pulmonar, atelectasia e enfisema pulmonar. No exame histopatológico observou-se a presença de bolhas de ar em vasos da região adjacente ao abcesso e em artérias pulmonares bem como hemorragia intersticial pulmonar. Os rins, o fígado e o encéfalo apresentavam congestão. O colapso cardiorrespiratório súbito durante a utilização deste produto, associado aos achados de necropsia e histopatológicos sugerem que a embolia gasosa venosa massiva ocorreu devido à utilização do peróxido de hidrogênio. Devido à gravidade do caso apresentado e à possibilidade de ocorrência desta patologia, seu uso deve ser evitado em condições que determinem seu acúmulo em cavidades.

Gas embolism caused by the use of hydrogen peroxide is a phenomenon that is not described in clinical routine, in this sense describes the occurrence of massive venous air embolism in rabbits during cleaning and disinfection of an abscess in the masseter using hydrogen peroxide 3%. By injecting hydrogen peroxide under pressure in the cavity of the abscess, the animal had a sudden cardiac arrest and had died. At necropsy were observed numerous air bubbles (gaseous emboli) in the caudal vena cava and pulmonary artery, pulmonary emphysema and atelectasis. Histopathology observed in the presence of air bubbles in blood vessels in the region adjacent to the pulmonary arteries and abscesses as well as interstitial lung hemorrhage. The kidneys, liver and brain showed congestion. The sudden cardiorespiratory collapse when using this product, associated with the necropsy and histopathological findings suggest that the venous air embolism occurred due to massive use of hydrogen peroxide. Due to the severity of the case presented and the possibility of occurrence of this pathology, its use should be avoided in conditions that determine its accumulation in cavities.

Embolia gasosa pulmonar em coelho causada por peróxido de hidrogênio relato de caso / Pulmonary gas embolism in rabbit caused by hydrogen peroxide case report

A embolia gasosa provocada pela utilização do peróxido de hidrogênio é um fenômeno que não é descrito na rotina clínica veterinária, neste sentido descreve-se a ocorrência de embolia gasosa venosa massiva em coelho durante a limpeza e desinfecção de um abscesso no masseter utilizando peróxido de hidrogênio a 3%. Ao injetar peróxido de hidrogênio sobre pressão na cavidade do abscesso, o animal teve uma parada cardiorrespiratória súbita e veio a óbito. A necropsia foram observadas inúmeras bolhas de ar (êmbolos gasosos) na veia cava caudal e tronco pulmonar, atelectasia e enfisema pulmonar. No exame histopatológico observou-se a presença de bolhas de ar em vasos da região adjacente ao abcesso e em artérias pulmonares bem como hemorragia intersticial pulmonar. Os rins, o fígado e o encéfalo apresentavam congestão. O colapso cardiorrespiratório súbito durante a utilização deste produto, associado aos achados de necropsia e histopatológicos sugerem que a embolia gasosa venosa massiva ocorreu devido à utilização do peróxido de hidrogênio. Devido à gravidade do caso apresentado e à possibilidade de ocorrência desta patologia, seu uso deve ser evitado em condições que determinem seu acúmulo em cavidades.(AU)

Gas embolism caused by the use of hydrogen peroxide is a phenomenon that is not described in clinical routine, in this sense describes the occurrence of massive venous air embolism in rabbits during cleaning and disinfection of an abscess in the masseter using hydrogen peroxide 3%. By injecting hydrogen peroxide under pressure in the cavity of the abscess, the animal had a sudden cardiac arrest and had died. At necropsy were observed numerous air bubbles (gaseous emboli) in the caudal vena cava and pulmonary artery, pulmonary emphysema and atelectasis. Histopathology observed in the presence of air bubbles in blood vessels in the region adjacent to the pulmonary arteries and abscesses as well as interstitial lung hemorrhage. The kidneys, liver and brain showed congestion. The sudden cardiorespiratory collapse when using this product, associated with the necropsy and histopathological findings suggest that the venous air embolism occurred due to massive use of hydrogen peroxide. Due to the severity of the case presented and the possibility of occurrence of this pathology, its use should be avoided in conditions that determine its accumulation in cavities.(AU)

DESINFETANTES ALTERNATIVOS AO USO DE FORMALDEÍDO PARA DESINFECÇÃO DE OVOS FÉRTEIS.

Objetivou-se avaliar o efeito de diferentes procedimentos de desinfecção alternativos à fumigação com formaldeído sobre a redução da contagem microbiana da casca, qualidade de casca, rendimento de incubação, qualidade de pintos neonatos e contaminação microbiana do saco vitelínico de pintos de um dia. Um total de 10.080 ovos de galinhas de 42 semanas de idade, coletados dos ninhos, foi distribuído de maneira aleatória em delineamento em bloco ao acaso, entre os seguintes tratamentos: fumigação com paraformaldeído (13,33g/m3/20 min), fumigação com ozônio (5-10ppm/20 min), irradiação de luz UV-C (254nm; 6,36 mW/cm2; 60 s), pulverização com peróxido de hidrogênio (1,56%; 0,69ml/ovo), pulverização com ácido peracético (0,13%; 0,69ml/ovo), pulverização com água (0,69ml/ovo; controle úmido) e sem desinfecção (controle seco). Oito amostras com quatros ovos cada foram coletadas para contagem de Enterobacteriaceae e bactérias mesófilas aeróbicas totais presentes na casca dos ovos antes e após o momento de desinfecção em cada tratamento. Um total de 24 ovos por grupo foi coletado para avaliações da espessura e resistência da casca. Ao todo, 1.152 ovos de cada tratamento foram incubados, em 12 bandejas de 96 ovos cada, para avaliação dos percentuais de perda de dos ovos durante a incubação, eclodibilidade, eclodibilidade de ovos férteis, mortalidade embrionária (inicial, intermediária e final), peso dos pintos e percentual de pintos vendáveis ao nascimento. A avaliação das contagens de Enterobacteriaceae e bactérias mesófilas aeróbicas totais no saco vitelínico foram realizadas em 13 pintos de um dia de idade, oriundos de cada tratamento. Nenhuma diferença significativa entre os grupos foi encontrada para a contagem de Enterobacteriaceae e bactérias mesófilas aeróbicas totais na casca dos ovos antes da desinfecção (P>0,05). Após a aplicação dos tratamentos, a contagem de Enterobacteriaceae também não foi afetada pelos tratamentos (P>0,05). Somente os ovos dos grupos desinfetados com paraformaldeído e UV apresentaram significativa redução das contagens de bactérias aeróbicas totais quando comparados ao grupo controle e a esses mesmos grupos antes da desinfecção (P<0,05), contudo essa redução foi maior (P>0,05) nos ovos fumigados com formaldeído que nos ovos irradiados com luz UV. Foi observada maior perda de peso nos ovos (P<0,05) pulverizados com peróxido de hidrogênio, ácido peracético e água, e ausência de diferença significativa (P>0,05) para essa variável entre os ovos dos tratamentos formaldeído, ozônio, UV e controle seco. As demais variáveis avaliadas nesse experimento não foram afetadas pelos tratamentos (P>0,05). Por reduzir a contagem microbiana na casca dos ovos, não prejudicar a eclodibilidade, o percentual de pintos vendáveis e os aspectos microbiológicos dos pintos de um dia, a luz UV pode ser considerada um potencial desinfetante substituto ao formaldeído para desinfecção de ovos incubáveis.

The present study examined the effect of different disinfection procedures as an alternative to formaldehyde fumigation on eggshell microbial load, eggshell quality, hatching parameters, neonate chick quality and yolk sac contamination of day-old chicks. A total of 10,080 nest clean eggs were collected from a 42-wk-old Cobb commercial breeder flock and randomly distributed in a complete block design composed by the following treatments: paraformaldehyde fumigation (13.33 g/m3/20 min; FF); ozone fumigation (5-10 ppm/20 min; OZF); UV-C light irradiation (254nm ; 6.36 mW/cm2; 60 s; UVI); spraying with hydrogen peroxide (1.56%; 0,69 ml/egg; H2O2), with peracetic acid (0.13%; 0,69 ml/egg; PAA), with water (0,69 ml/egg; wet control; H2OCONT) and no disinfection procedure (dry control; DCONT) Eight samples (pool of four eggs each one) from each treatment were collected to enumerate the presence of Enterobacteriaceae and total aerobic bacteria on the eggshell before and after the disinfection procedure. A total of 24 eggs per group were collected to evaluate the eggshell resistance and thickness. A total of 1,152 eggs per treatment were placed in twelve 96-egg trays to evaluate eggs weight loss during incubation, hatchability, hatchability of fertile eggs, embryo mortality (initial, medium and late), chick weight and percentage of saleable chicks at hatch. The counts of Enterobacteriaceae and total aerobic bacteria present in the yolk sac were performed in thirteen day-old chicks originated from each treatment. No significant reductions were observed in Enterobacteriaceae and total aerobic bacteria population on eggshell between groups before the disinfection (P>0.05). After disinfection, Enterobacteriaceae count on eggshell was not affected by treatments (P>0.05). Only eggs from UVI and FF groups showed significant reduction (P<0.05) on total aerobic bacteria count on eggshell when compared to DCONT after disinfection, and compared to the same groups before the treatments; however, FF group showed greater reduction (P<0.05) than UVI group. It was observed an increase in egg weight loss in eggs from H2O2, PAA and H2OCONT (P<0.05) and no statistical difference (P>0.05) for this variable in eggs from FF, OZF, UVI and DCONT groups. The other variables evaluated in this study were not affected by treatments (P>0.05). It can be concluded that UVI is a potential alternative to disinfect hatching eggs, since it decreased bacterial load on eggshell without affecting hatchability, the percentage of saleable chicks and bacterial load on yolk sac from day-old chick.