ABSTRACT: The objective of this study was to assess the oxygen pulse and heart rate method (O2P-HR) using a respiration chamber at different measurement times for estimate the heat production (HP) of lambs fed increasing levels of sunflower meal in their diet. Twenty-four lambs were assigned to four experimental diets (0, 100, 200, and 300 g of sunflower meal kg-1 DM). Heat production was estimated using the O2P-HR (HPO2P) method and a respirometry chamber (HPRC). Measurements were obtained by simultaneously measuring heart rate (HR) and oxygen consumption over 3, 6, 9, 12, 15, 18, 21 and 24 h. A flow-through respirometry chamber for small ruminants was used to determine oxygen consumption (VO2) and carbon dioxide and methane production. Data on dietary treatment, measurement times and their interactions were analyzed as repeated measures using mixed model procedures and Restricted Maximum Likelihood (REML) estimation. The Pearson’s correlation coefficient was used to compare techniques. There was no effect of the different levels of sunflower meal inclusion on VO2 and heat production. The HPO2P (126.16 kcal/ BW0.75/day) was 2% higher than that of the HPRC (124.61 kcal/ BW0.75/day), and the correlation coefficients was 0.628. The coefficient of variation was greater for the HPO2P (21.33%) than for HPRC (11.44%). HR (beats/min), VO2 (mL/min/BW0.75) and O2P-HR (mL/beat) required measurement times of 24, 15 and 9 hours, respectively. A measurement time of 24 h was necessary to ensure a more accurate estimate of the heat production using the O2P-HR method. ABSTRACT O2PHR OPHR O2P O P (O2P-HR HP (HP diet Twentyfour Twenty 0, 0 (0 100 200 30 kg1 kg 1 kg- DM. DM . DM) HPOP HPO (HPO2P HPRC. (HPRC) (HR 3 6 12 18 2 flowthrough flow through VO (VO2 treatment REML (REML estimation Pearsons Pearson s techniques 126.16 12616 126 16 (126.1 kcal BW0.75/day BW075day BWday BW0 75 day BW 124.61 12461 124 61 (124.6 BW0.75/day, , 0628 628 0.628 21.33% 2133 33 (21.33% 11.44%. 1144 11.44% 11 44 (11.44%) beats/min, beatsmin beats/min beats min (beats/min) mL/min/BW0.75 mLminBW075 mLminBW mL (mL/min/BW0.75 mL/beat mLbeat beat (mL/beat hours respectively PHR OP ( 10 20 (HPRC (VO 126.1 1261 (126. 7 124.6 1246 (124. 062 62 0.62 21.33 213 (21.33 114 11.44 4 (11.44% (beats/min mL/min/BW0.7 mLminBW07 (mL/min/BW0.7 126. (126 124. (124 06 0.6 21.3 (21.3 11.4 (11.44 mL/min/BW0. mLminBW0 (mL/min/BW0. (12 0. 21. (21. 11. (11.4 mL/min/BW0 (mL/min/BW0 (1 (21 (11. mL/min/BW (mL/min/BW (2 (11

RESUMO: O objetivo com este estudo foi avaliar o método do pulso de oxigênio (O2P-FC) usando câmara respirométrica em diferentes tempos de medição para estimar a produção de calor de cordeiros alimentados com níveis crescentes de farelo de girassol na dieta. Vinte e quatro cordeiros foram distribuídos em quatro dietas experimentais (0,10, 20 e 30% de farelo de girassol). A produção de calor foi estimada pelo método de O2P-FC (PCO2P) e por câmara respirométrica (PCCR). As estimativas foram obtidas medindo-se simultaneamente a frequência cardíaca (FC) e o consumo de oxigênio (VO2) durante 3, 6, 9, 12, 15, 18, 21 e 24 horas. Uma câmara de respirométrica para pequenos ruminantes foi usada para determinar o VO2 e a produção de dióxido de carbono e metano. Os dados referentes a dieta experimental, tempos de medição e suas interações foram analisados como medidas repetidas usando os procedimentos de modelo misto e estimativa de máxima verossimilhança restrita. A correlação de Pearson foi usada para comparar as duas técnicas de estimativa da produção de calor. Não houve efeito dos diferentes níveis de inclusão de farelo de girassol sobre o consumo de oxigênio e produção de calor dos animais. A PCO2P (126,16 kcal/ PV0.75/dia) foi 2% maior que a PCCR (124,61 kcal/ PV0.75/dia), e o coeficiente de correlação foi de 62,8%. O coeficiente de variação foi maior para PCO2P (21,33%) comparado com PCCR (11,44%). A FC (batimentos/min), VO2 (mL/min/PC0,75) e o O2P-FC (mL/batimento) requerem tempos de medição de 24, 15 e 9 horas, respetivamente. É necessário a mensuração por 24 horas para garantir uma estimativa mais precisa da produção de calor usando o método de O2P-FC. RESUMO O2PFC OPFC O2P P (O2P-FC 0,10, 010 0 10 (0,10 2 30 girassol. . girassol) PCOP PCO (PCO2P PCCR. (PCCR) medindose medindo se (FC VO (VO2 3 6 12 18 metano experimental restrita animais 126,16 12616 126 16 (126,1 kcal PV0.75/dia PV075dia PVdia PV0 75 dia PV 124,61 12461 124 61 (124,6 PV0.75/dia, , 628 62 8 62,8% 21,33% 2133 33 (21,33% 11,44%. 1144 11,44% 11 44 (11,44%) batimentos/min, batimentosmin batimentos/min batimentos min (batimentos/min) mL/min/PC0,75 mLminPC075 mLminPC mL PC0 PC (mL/min/PC0,75 mL/batimento mLbatimento batimento (mL/batimento 1 respetivamente O2PFC. FC. PFC OP 0,10 01 (0,1 (PCCR (VO 126,1 1261 (126, 7 124,6 1246 (124, 62,8 21,33 213 (21,33 114 11,44 4 (11,44% (batimentos/min mL/min/PC0,7 mLminPC07 (mL/min/PC0,7 0,1 (0, 126, (126 124, (124 62, 21,3 (21,3 11,4 (11,44 mL/min/PC0, mLminPC0 (mL/min/PC0, 0, (0 (12 21, (21, 11, (11,4 mL/min/PC0 (mL/min/PC0 ( (1 (21 (11, mL/min/PC (mL/min/PC (2 (11

ABSTRACT This study aimed to evaluate the effects of sunflower meal (SFM) inclusion on the performance, nutrient digestibility, and respirometric parameters in sheep. Twenty-four Dorper × Santa Inês uncastrated males, with an average age of 5 mo and initial body weight (BW) of 27.91±6.0 kg, were distributed in a randomized block design with four treatment diets containing 0, 100, 200, and 300 g of SFM/kg of total dry matter, replacing soybean meal. Intake, weight gain, ingestive behavior, and in vitro digestibility were evaluated according to the SFM inclusion. The respirometric parameters were evaluated in an open-circuit respirometric chamber. There was a quadratic response in dry matter intake expressed according to the SFM inclusion, with minimum points of 90.56 g/kg 0.75 BW for inclusion levels of 96 g of SFM/kg. A linear decrease in the in vivo digestibility of dry matter, neutral detergent fiber, and non-fibrous carbohydrate and in vitro fermentation of dry matter and fibrous carbohydrates was observed in response to SFM inclusion. These results reflect the higher fiber content of the byproduct, which reduced the non-fibrous carbohydrates in the diets. Despite the change in nutrient availability, average daily gain (299 g/day), O 2 consumption (26.24 L/kg 0.75 BW), and CH 4 production (2.25 L/kg 0.75 BW) were not influenced by the SFM inclusion, indicating that changes in the nutritional value of the diet did not affect the animals’ energetic metabolism. Sunflower meal inclusion decreased the digestibility but did not affect the animal gain and the respirometric parameters. The SFM can replace soybean meal in the diet of growing lambs; however, it has a maximum inclusion point of 88 g SFM/kg for feed conversion, which is a necessary factor for evaluating the replacement cost. (SFM performance sheep Twentyfour Twenty males (BW 279160 27 91 6 0 27.91±6. kg 100 200 30 SFMkg Intake behavior opencircuit open circuit chamber 9056 90 56 90.5 gkg 075 75 0.7 9 nonfibrous non byproduct availability 299 (29 g/day, gday g/day , day g/day) 26.24 2624 26 24 (26.2 Lkg L BW, 2.25 225 25 (2.2 animals metabolism lambs however 8 conversion cost 27916 27.91±6 10 20 3 905 90. 07 7 0. 29 (2 26.2 262 (26. 2.2 22 (2. 2791 27.91± 1 ( 26. (26 2. 279 27.91 27.9 27.

ABSTRACT No-tillage system (NTS) plays a prominent role in conservation agriculture, however, its benefits can be further improved by adopting complementary soil management and conservation practices, such as using autumnal cover crops, contour seeding, and terraces. This study aimed to evaluate how soil biological activity responds to soil management and conservation systems. The treatments consisted of three macroplots with an area of 11.000 m2 each, as follows: a) Non-Terraced catchment (NTC), cultivated in NTS similar to most farmers of the region, in which the agricultural operations are carried out in the direction of the slope and without terraces used; b) Best Management Practices (BMPs) were adopted in NTS with additional autumnal cultivation of cover crops, and also the direction of machine traffic was transverse to the slope direction; and c) Terraced catchment (TC), cultivated in NTS was associated to mechanical practices to erosion control, using wide base terrace on level. Soil microbial properties sampled in the 0.00-0.10 m layer were evaluated during 2019, 2020, and 2021, all shortly after the summer crop harvest. Natural inoculum potential of arbuscular mycorrhizal fungi (AMF), respirometry, metabolic coefficient, acid phosphatase activity, and organic carbon and nitrogen in the microbial biomass were assessed. Averages of each microbiological properties were compared through the confidence intervals (p<0.05). The results showed a greater potential for AMF inoculum in BMPs and TC systems. The NTC showed the highest values of respirometry and metabolic quotient, releasing 31.7 and 27.3 % more CO2 compared to BMPs and TC, respectively. The BMPs and TC were able to retain 13.8 and 16.5 % more carbon in the microbial biomass and 8.0 and 8.8 % more nitrogen in the biomass than NTC, respectively. Adopting soil management and conservation practices such as autumn cover crops, level seeding, and wide base terrace on level improved the soil microbial properties, with an increase in AMF inoculum potential, higher levels of acid phosphatase activity, and increment of carbon and nitrogen in microbial biomass. Notillage No tillage (NTS agriculture however crops seeding systems 11000 11 000 11.00 follows NonTerraced Non , (NTC) region used b (BMPs c (TC) control 0.000.10 000010 0.00 0.10 0 00 10 0.00-0.1 2019 2020 2021 harvest AMF, (AMF) coefficient assessed p<0.05. p005 p p<0.05 . 05 (p<0.05) quotient 317 31 7 31. 273 27 3 27. CO respectively 138 13 8 13. 165 16 5 16. 80 8. 88 1100 1 11.0 (NTC (TC 0.000.1 00001 0.0 010 0.1 0.00-0. 201 202 (AMF p00 p<0.0 (p<0.05 2 110 11. 0.000. 0000 0. 01 0.00-0 20 p0 p<0. (p<0.0 0.000 0.00- p<0 (p<0. p< (p<0 (p< (p

ABSTRACT Measuring cardiorespiratory variables can be challenging in developing animals, especially when they use bimodal gas exchange to maintain metabolic activity. In tadpoles, gas exchange may occur through the integument and gills when breathing in the water and through the lungs when breathing air, with varying contributions of each respiratory structure during development. The interaction between aquatic and air breathing results in a complex physiological response that may affect the cardiac cycle. Measuring the heart rate (fH) together with aquatic and aerial gas exchange in anurans during their development can be challenging, since it may involve handling small animals and/or a certain degree of invasiveness (i.e., surgery to implant electrodes). Here, we evaluated concomitantly aquatic and aerial gas exchange, lung ventilation, and fH in three stages of development of the bullfrog Lithobates catesbeianus (Shaw, 1802). We built a novel, noninvasive, closed respirometry system capable of measuring fH, aerial and aquatic gas exchange simultaneously in animals of different sizes. Our integrative analysis revealed a decrease in the heart rate and an increase in oxygen consumption during the developmental stages of the bullfrog, but there was no adjustment of heart rate after or during air breathing. Moreover, tadpoles in metamorphosis showed higher oxygen consumption in air than in water, while aquatic breathing was responsible for releasing CO2. Our results are consistent with those found in the literature, yet our study represents the first non-invasive investigation to evaluate bimodal gas exchange and heart rate simultaneously. Moreover, our setup holds potential for further advancements that would allow for controlled water and air composition. This tool could greatly facilitate the investigation of how cardiorespiratory physiology responds to varying environmental conditions. activity cycle (fH andor i.e., ie i e (i.e. electrodes. electrodes . electrodes) Here ventilation Shaw, Shaw (Shaw 1802. 1802 1802) novel noninvasive sizes Moreover CO2 CO literature non invasive composition conditions i.e. (i.e 180 i.e 18 1

Understanding the morphological and physiological correlates of competitive behaviours can provide important insights into the ecology of competition, home range size and resource consumption. Here we first estimated and defined sexual dimorphism in a poorly studied African cerambycid species, Cacosceles newmannii (Thomson, 1877). We then assessed morphological and physiological attributes of male beetles in relation to their fighting behaviour. Suites of morphological and energetic measurements were carried out on adult males, the latter before and after male-male interactions. Aggressive behaviour and the outcomes of male fighting trials were assessed under controlled conditions. The species is highly sexually dimorphic in relation to mandible size. During male-male interactions, a continuum of behaviours with an increasing risk of injury and metabolic cost was observed. Grasping was prolonged in males with larger fighting apparatus, who also tended to use more energy during the encounter than males displaying other behaviours. Our results indicate that the mandible size in C. newmannii serves as an honest signal of fighting ability in this species. Additionally, energetic assessments in preparation for fighting, costs during a fight, and persistence of metabolic costs post-fighting may be useful for understanding the relative fitness costs of competition.

Resumo O objetivo deste estudo foi avaliar os efeitos do esterco de ovelha em solos agrícolas no comportamento de Folsomia candida e no crescimento e desenvolvimento inicial de Avena sativa. Para isso, um Latossolo foi submetido a diferentes doses de esterco de ovelha e posteriormente avaliado quanto ao comportamento de fuga e a sobrevivência de Folsomia candida por meio de ensaios ecotoxicológicos padronizados, desempenho inicial da aveia pelo teste de germinação e taxa respiratória basal do solo pela metodologia da respirometria. Houve um aumento na taxa de respiração basal do solo pela aplicação de esterco de ovelha e isso foi consistente com o aumento das doses. A taxa de sobrevivência e o comportamento de fuga dos colêmbolos não foram alterados e não houve alteração no desempenho inicial da aveia, indicando que esse esterco pode ser usado para fertilização orgânica de solos com baixo potencial poluente no solo.

Abstract The aim of this study was to evaluate the effects of sheep manure in agricultural soils on the behavior of Folsomia candida and initial growth and development of Avena sativa. For this, an Oxisol was submitted to different doses of sheep manure and was subsequently evaluated for Folsomia candida survival and avoidance behavior through standardized ecotoxicological assays, the initial performance of oats by germination test and the soil basal respiration rate by respirometry methodology. There was an increase in the basal respiration rate of the soil by the application of sheep manure and this was consistent with the increase of the doses. The survival rate and avoidance behavior of springtails were not altered and there was no change in the initial performance of oats, indicating that this manure can be used for organic fertilization of soils with low soil pollutant potential.

Abstract Microbial and enzymatic kinetics are important factors during the aerobic degradation of the organic fraction of municipal solid waste, these depend mainly on the incubation temperature and aeration rates. The objective of this research was to evaluate the process of aerobic degradation, by multiple variables and their combination to understand the interactions between aeration rates in aerobic degradation and their responses. Aeration rates were set at 0.032, 0.064, 0.125, 0.251 and 0.392 L of moist air kg-1 min-1 at 35 °C with inoculum. Microbial activity was evaluated indirectly by means of respirometry, that is, CO2 production and O2 consumption. Extracellular enzymatic activities (ie., pectinases, cellulases, xylanases and proteases) were quantified by releasing the reducing sugars. The different tests were carried out at the Metropolitan Autonomous University, Iztapalapa Unit in September 2019. Finding a strong positive relationship between xylanase and pectinase enzymatic activity and dry weight loss, along with increased cellulase and xylanase activities at higher aeration rates.

Resumen La cinética microbiana y enzimática son factores importantes durante la degradación aerobia de la fracción orgánica de los residuos sólidos urbanos, estas dependen principalmente de la temperatura de incubación y las tasas de aireación. El objetivo de esta investigación fue evaluar el proceso de degradación aerobia, por múltiples variables y su combinación para comprender las interacciones entre las tasas de aireación en la degradación aerobia y sus respuestas. Las tasas de aireación se fijaron en 0.032, 0.064, 0.125, 0.251 y 0.392 L de aire húmedo kg-1 min-1 a 35 °C con inóculo. La actividad microbiana se evaluó de forma indirecta por medio de la respirometria; es decir, la generación de CO2 y el consumo de O2. Las actividades enzimáticas extracelulares (es decir, pectinasas, celulasas, xilanasas y proteasas) se cuantificaron mediante la liberación de los azúcares reductores. Los diferentes ensayos se realizaron en la Universidad Autónoma Metropolitana Unidad Iztapalapa en septiembre de 2019. Encontrando una fuerte relación positiva entre la actividad enzimática xilanasa y pectinasa con la pérdida de peso en seco, junto con el aumento de las actividades celulasas y xilanasas a mayores tasas de aireación.

ABSTRACT The inhibitory effect of Ni (II), Zn (II), Pb (II) and Al (III) metal ions on microorganisms present in a activated sludge using closed respirometry is shown. The degree of inhibition was determined using sludge with different ages. The ion that exerted the greatest toxicity for the rector of the 5-day sludge age was Ni (II) and for the 10-day was Zn (II). The order of the inhibitory effect for each metal concentration and age of the studied sludges varies, compared to other studies. It was demonstrated that the sludge age and concentration of the metals had a statistically significant effect on the inhibition of the biomass.

RESUMEN Se muestra el efecto inhibitorio de los iones metálicos de Ni (II), Zn (II), Pb (II) y Al (III) sobre microorganismos presentes en un lodo activado mediante la respirometría cerrada. Se determinó el grado de inhibición empleando lodos con diferentes edades. El ión que ejerció mayor toxicidad para el rector de edad del lodo 5 días fue el Ni (II) y para el de 10 días fue el Zn (II). El orden del efecto inhibitorio para cada concentración del metal y edad del lodo estudiado varía, en comparación con otros estudios, debido a la diversidad microbiológica de los lodos activados y el comportamiento de los microorganismos. Quedó demostrado que la edad del lodo y la concentración de los metales tuvieron un efecto estadísticamente significativo sobre la inhibición de la biomasa.

RESUMO Sistemas anaeróbios modernos de tratamento de esgoto doméstico, embora bastante eficientes na remoção de matéria orgânica e sólidos em suspensão, não produzem um efluente com qualidade compatível com os padrões legais para descarga em corpos d’água. Por essa razão, esses sistemas têm de ser associados a unidades de pós-tratamento. Este trabalho trata de uma investigação experimental sobre a viabilidade de aplicação do sistema de lodo ativado como uma alternativa do pós-tratamento, especificamente para o caso em que se prevê o efluente final para fertirrigação. Na investigação experimental, utilizou-se um reator de bateladas sequenciais (RBS), em escala laboratorial, como unidade de pós-tratamento. Os resultados experimentais mostraram que o comportamento do sistema RBS pode ser descrito como o modelo geral de lodo ativado da Associação Internacional da Água (IWA, na sigla em inglês), que resulta na definição dos aspectos fundamentais: qualidade do efluente final, consumo de oxigênio e produção de lodo. Na otimização do reator RBS, desenvolveu-se um modelo que permite estabelecer o tempo de permanência mínimo para o pós-tratamento em função de dois parâmetros básicos: a constante de utilização de material orgânico biodegradável pelas bactérias heterotróficas do lodo gerado no sistema de pós tratamento e a sedimentabilidade desse lodo. A constante de utilização de material orgânico foi determinada por testes respirométricos. O lodo gerado no sistema de pós-tratamento surpreendentemente mostrou ter uma sedimentabilidade bem superior àquela normalmente encontrada em sistemas de lodo ativado tratando esgoto bruto, o que constitui um argumento sólido para a aplicação do sistema RBS na prática de pós-tratamento do efluente do reator upflow anaerobic slugde blanket (UASB).

ABSTRACT Modern anaerobic systems for domestic sewage treatment, although very effective in removing organic matter and suspended solids, do not produce a quality effluent that complies with the legal standards for discharge into water bodies. Therefore, such systems have to be associated with post treatment units. This paper deals with an experimental investigation into the feasibility of applying the activated sludge system as an alternative post-treatment, specifically for the case where reuse of the final wastewater for fertigation is expected. In the experimental investigation, a pilot-scale sequencing batch reactor (SBR), in laboratory scale, was used as a post-treatment unit. The experimental results showed that the behavior of the RBS system can be described with the general IWA model for activated sludge, resulting in the definition of the fundamental aspects: quality of the final effluent, oxygen consumption, and sludge production. In the optimization of the RBS reactor, a model was developed to establish the minimum retention time for the post-treatment in terms of two basic parameters: the biodegradable organic material utilization constant by heterotrophic bacteria sludge of the post-treatment system and the sedimentability of this sludge. The organic material utilization constant was determined by respirometry testing. The sludge generated in the post-treatment system surprisingly been shown to have a much higher sedimentability than that normally found in activated sludge systems dealing with raw sewage, which is a sound argument for applying the RBS system in the practice of post-treatment reactor effluent UASB

RESUMO Este trabalho teve como objetivo a determinação dos parâmetros cinéticos que descrevem o crescimento das bactérias heterotróficas e autotróficas nitrificantes em três sistemas de lodos ativados com aeração prolongada, operados com baixa aeração, a fim de se obter a remoção de nitrogênio de esgoto sanitário pelo processo de nitrificação e desnitrificação simultâneas (NDS). Em relação às remoções de matéria orgânica e nitrogênio, aplicando-se idade do lodo na faixa de 12 a 20 dias e concentrações de oxigênio dissolvido (OD) nos reatores em torno de 0,5 mg O2.L-1, foi possível obter eficiências superiores a 90% e um esgoto tratado com concentrações de nitrato inferiores a 7,0 mg N.L-1. Os experimentos realizados comprovam que, nas condições operacionais adotadas durante os testes respirométricos, as bactérias heterotróficas e autotróficas presentes nos lodos ativados estavam ativos e, ainda que baixa, a concentração de OD não foi limitante para o desenvolvimento da cinética dos processos envolvidos na remoção de materiais orgânico e nitrogenado.

ABSTRACT The objective of this work was to determine the kinetic parameters that describe the growth of heterotrophic and autotrophic nitrifying bacteria in three systems of activated sludge with prolonged aeration, operated with low aeration, with the objective of obtaining nitrogen removal of sanitary sewage by simultaneous nitrification and denitrification (SND). In relation to the removal of organic matter and nitrogen, by using sludge ages ranging from 12 to 20 days and OD concentrations in the reactors around 0.5 mgO2.L-1, it was possible to obtain efficiencies higher than 90% and a sewer treated with nitrate concentrations below 7.0 mgN.L-1. The experiments carried out prove that, under the operating conditions adopted during the respirometric tests, heterotrophic and autotrophic bacteria present in activated sludge were active and, although the low concentration of OD was not limiting for the development of the kinetics of the processes involved in the removal of organic and nitrogenous material.

Abstract The present study aimed to evaluate the biological responses of Colossoma macropomum to naphthalene injection and subsequent hypoxia exposure, emphasizing the expression of the tumor suppressor gene tp53. Tambaquis were intraperitoneally injected with naphthalene (50 mg/kg) and, after 96 hours, the fish were transferred to respirometry chambers and, submitted to progressive hypoxia for the determination of critical PO2. In a subsequent experiment, the fish received an intraperitoneal injection of naphthalene and were kept for 96 hours under normoxia. Successively, fish were challenged with acute hypoxia (PO2<PO2 crit) during 6 hours. We observed that the PO2 crit was not affected by naphthalene injection. Moreover, hematological parameters were modulated only in response to hypoxia. Fish with naphthalene injection plus hypoxia exposure presented altered activity of the GST and CAT enzymes. Exposure to naphthalene also resulted in DNA damages, which was not influenced by hypoxia. Hypoxia accentuated the hepatic lesions caused by naphthalene, as well as it also impaired the transcription of tp53 in naphtalene injected fish, demonstrating the risks of contaminating aquatic environments, especially environments where hypoxic conditions are common and occur on a daily or on seasonal basis, as in the Amazon basin.

RESUMO: O cloreto de potássio (KCl) é a fonte de potássio mais utilizada mundialmente e, devido ao uso contínuo desse fertilizante, pode ocorrer acúmulo de sais no solo e nas plantas. O excesso de íons desencadeia uma série de distúrbios fisiológicos, tornando-se um potencial biocida no solo. Objetivou-se avaliar o efeito da aplicação de doses de KCl e de resíduos culturais da bananeira no teor de cloreto do solo, na atividade microbiana e na amonificação. O delineamento experimental foi inteiramente casualizado com quatro repetições. Os tratamentos foram arranjados em um fatorial 2 x 4: 2 doses de resíduo vegetal (200 e 400 mg dm-3) x 4 doses de KCl (0, 167, 334 e 668 mg dm-3), além de um controle (sem aplicação de KCl e resíduo). Foram quantificados o CO2, o teor de amônio (N-NH4 +) e de cloreto (Cl-) do solo e as taxas de mineralização/imobilização, aos 4, 45 e 130 dias após a incubação (dai). O aumento da dose de KCl reduziu a atividade microbiana, aos 4 dai, independentemente da dose de resíduo adicionada. A atividade microbiana diminuiu, aos 130 dai: em todos os tratamentos, quando comparados ao período inicial. O acréscimo das quantidades de resíduos culturais da bananeira aumentou o teor de Cl- do solo e promoveu a imobilização do N-NH4 +. Conclui-se que doses de KCl maiores que 400 mg dm-3, associadas a presença desse resíduo, reduzem a atividade microbiana e a mineralização do N do solo.

ABSTRACT: Potassium chloride is the most widely used potassium source worldwide, and due to its continuous use, the accumulation of its salts in the soil and in plants is becoming more common. Excess available ions can cause a series of physiological disturbances in organisms and can become a biocide in the soil. The objective of this study was to evaluate the effects of the application of KCl and banana crop residues on soil chloride content, microbial activity, and soil ammonification. The experiment utilized a completely randomized 2 × 4 factorial design with four replicates. Treatments were as follows: two doses of vegetal residue (200 and 400 mg dm-3) × four doses of KCl (0, 167, 334, and 668 mg dm-3 of KCl) and a control (untreated soil). The CO2 emission, ammonium (N-NH4 +) and soil chloride (Cl-) content, and mineralization/immobilization rates of the soils in each treatment were measured 4, 45, and 130 days after incubation (dai). Higher KCl dosages reduced soil microbial activity at 4 dai, regardless of the residue dosage. Microbial activity was reduced at 130 dai in all treatments when compared to the initial period. Higher dosages of banana crop residues increased the Cl- content of the soil and promoted the immobilization of N-NH4 +. We concluded that dosages of KCl (above 400 mg dm-3), when applied to soils that already contain crop residues, reduce microbial activity and mineralization of N in the soil.

Abstract Accidents caused by leaks and/or spills on soils need to be addressed. Natural attenuation, biostimulation and bioaugmentation can be useful bioremediation strategies for decontamination processes in soils of diesel/biodiesel mixtures. The purpose of this study was to evaluate the degradation rate of the different fuels (B0, B20 and B100) in an ultisol under natural attenuation and biostimulation/bioaugmentation during 60 days of incubation in a controlled microcosm simulating a surface spill over soil. The degradation of different diesel/biodiesel mixtures was monitored for up to 60 days by dehydrogenase activity, respirometry by CO2 release, the most probable number of heterotrophic and degrading microorganism and gas chromatography. The bacterial inoculum employed for biostimulation/bioaugmentation strategy consisted of Bacillus megaterium, Bacillus pumilus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The two bioremediation strategies have showed great degradation rates. The natural attenuation was effective for B0 and B20 treatments. The addition of the bacterial consortium and macronutrients contributed to the increased degradation of pure biodiesel in relation to natural attenuation, with higher rates for CO2 release, enzymatic and degrading activity. It is suggested that the bacterial consortium has proven effective for presenting significant values for such parameters until the end of the 60-day incubation period.

ABSTRACT Basal metabolic rate (BMR) represents the lowest level of metabolic activity capable to sustain homeostasis in an endotherm and is an important tool to compare metabolic rates of different species. Echimyidae is the most specious family within caviomorph rodents, however, little is known about the biology of its species, such as Trinomys setosus (Desmarest, 1817) and Clyomys bishopi (Ávila-Pires & Wutke, 1981), a ground and an underground dwelling echimyid, respectively. The ambient temperature and circadian effects on metabolic rate were evaluated through closed-system respirometry for these two species, as well as the circadian effects on CO2 production and respiratory exchange ratio (RER). Trinomys setosus and C. bishopi showed the lowest metabolic rates (0.56 ± 0.02 mLO2.h-1.g-1 and 0.53 ± 0.03 mLO2.h-1.g-1, respectively) at 32 °C and during the light phase. Under laboratory conditions, T. setosus showed metabolic rate variation compatible with nocturnal activity, whereas C. bishopi activity cycle remains unclear. Both species showed BMR lower than expected by allometric regressions for rodents.

Resumen: Los contaminantes pseudo-persistentes presentes en aguas residuales, como los compuestos farmacéuticos, generan la necesidad de estudiar diferentes métodos que sean capaces de degradar dichos contaminantes para reducir su concentración en las fuentes hídricas y en las plantas de tratamiento, ya que podrían producir algunos inconvenientes en las mismas. En este estudio, se lleva a cabo el análisis de la degradación biológica de un antiinflamatorio no-esteroideo, diclofenaco, utilizando técnicas respirométricas. Se realizaron diferentes ensayos en modo batch utilizando un respirómetro tipo LFS (liquid-flowstatic), con lodos activados provenientes de una planta local de tratamiento de aguas residuales, para determinar la biodegradación aerobia del diclofenaco. La concentración inicial de diclofenaco estuvo en el rango de 5-100 mg/L. La degradación fue analizada mediante ensayos de DQO y medidas de OD. El perfil de consumo de OD fue obtenido para todas las muestras. Se obtuvieron remociones cercanas al 50% después de 285 min de reacción. Sin embargo, la degradación biológica aumentó hasta cerca del 80% de remoción del contaminante cuando el tiempo de reacción fue incrementado a 24hs. Con los resultados obtenidos se pudo establecer que los lodos activados utilizados son capaces de consumir este tipo de contaminante, sin embargo el tiempo de reacción es elevado y, en la mayoría de los casos, superior al requerido en las plantas de tratamiento.

Abstract: Pseudo-persistent contaminants in wastewater, as pharmaceutical compounds, create a need to study different methods capable to degrade these contaminants in order to reduce its concentration in water sources and treatment plants, since they could generate some problems therein. The biological treatment is often the main treatment in these WWTP. In this study, the analysis of the biological degradation of a non-steroidal anti-inflammatory, as diclofenac, was carried out using respirometric techniques.Different batch experiments were carried out in a respirometer LFS (liquid-flowstatic) type, with activated sludge from a local WWTP to determine the aerobic biodegradation of diclofenac. The initial concentration of diclofenac was in the range 5-100 mg/L. The degradation was analyzed by COD and OD measurements. The profile of OD consumption was obtained for all samples. Removals of 50% were obtained after 285 min of reaction. However, the aerobic degradation increased until 80% of pollutant removal after 24 hours of analysis. It was observed that the activated sludge was able to consume the pollutant, however the reaction times were very long considering the requirements of the WWTP.

Resumo: Os contaminantes pseudo-persistentes, como os compostos farmacêuticos, presentes nas aguas residuais geram a necessidade de estudar diferentes métodos que sejam capazes de degradar tais contaminantes para reduzir sua concentração nas fontes hídricas e nas plataformas de tratamento, já que poderiam produzir alguns inconvenientes para elas. Neste estudo, se realiza a análise da degradação biológica de um anti-inflamatório não-esteroide, diclofenaco, utilizando técnicas respirométricas. Foram realizados diferentes ensaios em modo batch utilizando um respirómetro tipo LFS (liquid-flowstatic), com lodos ativados procedentes de uma plataforma local de tratamento de águas residuais, para determinar a biodegradação aeróbia do diclofenaco. A concentração inicial de diclofenaco esteve na faixa de 5-100 mg/L. A degradação foi analisada através de ensaios de DQO e medidas de OD. O perfil de consumo de OD foi obtido para todas as amostras. Se obtiveram remoções aproximadas a 50% depois de 285 min de reação. Entretanto, a degradação biológica aumentou até aproximadamente 80% de remoção do contaminante quando o tempo de reação foi incrementado a 24hs. Com os resultados obtidos foi estabelecido que os lodos ativados utilizados são capazes de consumir este tipo de contaminante, entretanto o tempo de reação é elevado e, na maioria dos casos, superior ao requerido nas plataformas de tratamento.