El compostaje de cáscara de Musa paradisiaca L. para la producción de biogás y biometano como estrategia de preservación de la salud ambiental / Musa paradisiaca L. husk composting for biogas and biomethane production as a strategy for preserving environmental health

A medida que a se avanza en el siglo XXI, los sistemas de energía deben alejarse de los combustibles fósiles y aumentar la capacidad de las energías renovables si se quieren cumplir los objetivos de temperaturas máximas del Acuerdo de París. Sin embargo, debido a los desafíos en la adopción de tecnologías bajas en carbono, ciertas áreas de los sistemas energéticos globales son difíciles de controlar y descarburar. Por otra parte, el compostaje es una de las prácticas de gestión de residuos orgánicos más importantes que se puede utilizar para lograr la sostenibilidad del suelo y del medio ambiente. El compost tiene un mínimo impacto en algunas emisiones, y puede ayudar a controlar la huella de carbono y limitar los efectos ambientales negativos de los métodos de eliminación de desechos más deficientes. La investigación tuvo por objetivo determinar la calidad de producir biogás y biometano a partir de la cáscara de plátano (Musa paradisiaca L.). Metodológicamente se desarrolló una investigación aplicada, con nivel de investigación de tipo experimental. Las cáscaras de plátano se colectaron de la planta de compostaje de la Municipalidad Provincial de Leoncio Prado, Perú. De la muestra se prepararon cinco sub muestras para la producción de biogás y cinco muestras adicionales para la producción de biometano. Los sistemas mostraron una producción de 0,067 m3 BG/Kg ST de biogás y 0,059 m3CH4/Kg ST de biometano, que generó subproductos como el biol y biosol. Estos resultados presentaron una baja toxicidad al ser sometidos a pruebas germinativas, concluyéndose que solo el 11,5% de la cáscara introducida al biorreactor se degrado y de esta fracción solo el 2,8% se convirtió en biogás(AU)

As progress is being made in the 21st century, energy systems must move away from fossil fuels and increase the capacity of renewable energies if you want to meet the maximum temperatures objectives of the Paris Agreement. However, due to the challenges in the adoption of low carbon technologies, certain areas of global energy systems are difficult to control and decarbure. On the other hand, composting is one of the most important organic waste management practices that can be used to achieve soil and environmental sustainability. The compost has a minimum impact on some emissions, and can help control the carbon footprint and limit the negative environmental effects of the most deficient waste removal methods. The research aimed to determine the quality of producing biogas and biomethane from the banana peel (Musa paradisiaca L.). Methodologically, an applied investigation was developed, with experimental research level. The banana peels were collected from the composting plant of the Provincial Municipality of Leoncio Prado, Peru. From the sample, five sub samples were prepared for the production of biogas and five additional samples for biomethane production. The systems showed a production of 0.067 m3 bg/kg ST of biogas and 0.059 m3ch4/kg ST of biomethane, which generated by -products such as biol and biosol. These results presented a low toxicity when they were subjected to germinative evidence, concluding that only 11.5% of the shell introduced into the bioreactor was degraded and of this fraction only 2.8% became biogas(AU)

Valorização de resíduos orgânicos e redução de desperdício no ramo industrial de fornecimento de suprimentos alimentares para restaurantes do tipo "fast-food" / Organic waste recovery and waste reduction in the food supply industry for fast-food restaurants

Esta dissertação busca estudar formas para valorização de resíduos orgânicos (RO) por meio da técnica de digestão anaeróbia e redução de desperdício em empresa do ramo industrial alimentício responsável pelo fornecimento de suprimentos alimentares para restaurantes do tipo "fast-food". O panorama atual dos resíduos sólidos no Brasil indica que a fração orgânica representa mais da metade de sua composição, descartando como rejeito o que, nos moldes da economia circular, pode ser tratado como resíduo, sendo reinserido na cadeia produtiva e promovendo assim, grande redução dos impactos ambientais causados por sua destinação inadequada. A digestão anaeróbia consiste em viável alternativa para o aproveitamento de um valoroso subproduto dos resíduos orgânicos (RO), o metano; esse tratamento promove entalpia do resíduo e garante sua valorização de forma ampla. O resíduo abordado neste estudo consiste em itens que compõem sanduíches de rede "fast food", os quais serão avaliados de acordo com seu potencial de produção de metano; além disso, foi feita uma análise dos critérios utilizados pela empresa deste estudo para classificar o alimento como avaria, possibilitando a abertura de caminhos no quesito redução de desperdícios, tornando ínfima a quantidade destinada a aterros. Os resíduos orgânicos gerados pela empresa foram analisados em escalada de bancada identificando sua viabilidade para a produção de metano através de conjuntos eudiômetros, porém a rápida velocidade de hidrólise resultou em acidificação dos resíduos impedindo a ocorrência da metanogênese. Os resultados demonstraram a grande importância de ampliar o espectro de análises incluindo dados como relação Carbono/Nitrogênio e DQO (Demanda Química de Oxigênio) e DBO (Demanda Bioquímica de Oxigênio) para equilibrar parâmetros capazes de permitir a ocorrência de todas as etapas da biodigestão, uma vez que a estrutura disponível no desenvolvimento desta pesquisa não permitiu tal aprofundamento. Um manual de redução de desperdícios com foco nos Rs foi desenvolvido a fim de aprimorar processos de descarte que resultam hoje em grande geração de resíduos no cenário deste estudo.

This dissertation seeks to study ways to valorize organic waste (OR) through the technique of anaerobic digestion and waste reduction in a food industrial company responsible for the supply of food supplies for "fast-food" restaurants. The current scenario of solid waste in Brazil indicates that the organic fraction represents more than half of its composition, discarding as waste what, in the circular economy molds, can be treated as waste, being reinserted in the production chain and thus promoting a large reduction of environmental impacts caused by its improper disposal. Anaerobic digestion is a viable alternative for the use of a valuable by-product of organic waste (OR), the methane; this treatment promotes enthalpy of the waste and ensures its recovery in a broad way. The waste addressed in this study consists of items that make up "fast food" sandwiches, which will be evaluated according to their potential for methane production; furthermore, an analysis was made of the criteria used by the company of this study to classify the food as a malfunction, enabling the opening of ways in the waste reduction item, making the amount destined to landfills minimal. The organic waste generated by the company was analyzed in bench scale, identifying its viability for methane production through eudiometer sets, but the fast speed of hydrolysis resulted in acidification of the waste preventing the occurrence of methanogenesis. The results showed the great importance of broadening the spectrum of analyses by including data such as Carbon/Nitrogen ratio and COD (Chemical Oxygen Demand) and BOD (Biochemical Oxygen Demand) to balance parameters capable of allowing the occurrence of all stages of biodigestion, since the structure available in the development of this research did not allow such deepening. A waste reduction manual focused on the Rs was developed in order to improve disposal processes that currently result in large waste generation in the scenario of this study.

Effect of Agitation on Anaerobic Co-Digestion of Swine Manure and Food Waste

Abstract The synergism of food waste associated with swine manure can provide an increase in biogas production, besides promoting greater stability in the anaerobic co-digestion process. To verify this effect, co-digestion tests were performed in two reactors, one with agitation, and the other without agitation. In both systems, gasometers were used to measure biogas production in an experiment lasting two hydraulic retention times (HRT). On each feeding day, the temperatures of the ambient and of the effluent taken from the reactors were measured, and samples of the food waste and effluent were collected to perform analysis of pH, total solids (TS), volatile solids (VS), fixed solids (FS), volatile acidity (AV), and total alkalinity (TA). In addition, the chemical oxygen demand (COD) was determined every five days, and gas composition was determined at the beginning of the second HRT. As important results, in both reactors a decrease in pH was verified due to the weakening of the buffer effect of the medium. This was due to the low alkalinity found in the food waste, causing an increase in acidity in the contents of the reactors. The volume of biogas produced was higher in the reactor with agitation, which meant an increased efficiency of the process. Finally, a low methane content was verified through chromatographic analyses, indicating a reduction in the activity of the microorganisms present in the medium. Thus, it is concluded that agitation linked to anaerobic co-digestion of swine manure with food waste exerted a positive effect on biogas production.

Evaluation of triclosan toxic effects on the methanogenic activity

BACKGROUND: Triclosan (TCS) is an antimicrobial agent widely used in health care and consumer products. This compound is present in sludge of wastewater treatment plants (WWTPs), and because of its bactericidal characteristics, it can inhibit the methanogenic activity in anaerobic digestion (AD) technology. The aim of this study was to evaluate the toxic effects of TCS on the methanogenic activity. RESULTS: Batch anaerobic reactors were used with TCS concentrations of 7.8, 15.7, 23.5, and 31.4 mg/L. These assays consisted in three successive feedings (I, II, and III), wherein the sludge was exposed to each TCS concentration and volatile fatty acid (VFA) substrate. For evaluation of the residual sludge activity during feeding III, only VFA was used. The results showed that the increase in TCS concentrations correlated with the reduction in methane (CH4) production. In this case, the minimum values were achieved for TCS concentration of 31.4 mg/L with CH4 levels between 101.9 and 245.3 during feedings I, II, and III. Regarding the effect of TCS on VFA consumption, an inhibitory effect was detected for TCS concentrations of 23.5 and 31.4 mg/L, with concentrations of acetic, butyric, and propionic acids at the end of the assay (37 d) between 153.6 and 206.8, 62.5 and 60.1, and 93.4 and 110 mg/L, respectively. Regarding the removal of TCS during AD, these values were above 47%. Conclusion: TCS is an inhibitor of methanogenic activity with a decrease between 63 and 70% during the different feedings. The CH4 production was not recovered during feeding III, with inhibition percentages of 21­72%.

Insights into the microbial community structure of anaerobic digestion of municipal solid waste landfill leachate for methane production by adaptive thermophilic granular sludge

BACKGROUND: The amount of municipal solid waste (MSW) gradually increased along with the rapid development of modern cities. A large amount of landfill leachate are generated with excessive chemical oxygen demand (COD), which create a great deal of pressure on the environment-friendly treatment process. Anaerobic digestion is an ideal technique to solve the above problem. RESULTS: A thermophilic granular sludge was successfully adapted for anaerobic digestion of MSW leachate (from an aging large-scale landfill) for methane production. The COD degradation efficiency improved by 81.8%, while the methane production rate reached 117.3 mL CH4/(g VS d), which was 2.34-fold more than the control condition. The bacterial and archaeal communities involved in the process were revealed by 16S rRNA gene high-throughput pyrosequencing. The richness of the bacterial community decreased in the process of thermophilic granular sludge, while the archaeal community structure presented a reverse phenomenon. The bacterial genus, Methanosaeta was the most abundant during the mesophilic process, while Methanobacterium, Methanoculleus, Methanosaeta and Methanosarcina were more evenly distributed. The more balanced community distribution between hydrogenotrophic and acetotrophic methanogens implied a closer interaction between the microbes, which further contributed to higher methane productivity. The detailed relationship between the key functional communities and anaerobic digestion performances were demonstrated via the multivariate canonical correspondence analysis. Conclusions: With the assistance of adaptive thermophilic granular sludge, microbial community structure was more evenly distributed, while both of COD degradation rate and methane production was improved during anaerobic digestion of MSW landfill leachate.

Key microbial populations involved in anaerobic degradation of phenol and p-cresol using different inocula

Background: Anaerobic digestion is an alternative bioprocess used to treat effluents containing toxic compounds such as phenol and p-cresol. Selection of an adequate sludge as inoculum containing an adapted microbial consortium is a relevant factor to improve the removal of these pollutants. The objective of this study is to identify the key microorganisms involved in the anaerobic digestion of phenol and p-cresol and elucidate the relevance of the bamA gene abundance (a marker gene for aromatic degraders) in the process, in order to establish new strategies for inocula selection and improve the system's performance. Results: Successive batch anaerobic digestion of phenol and p-cresol was performed using granular or suspended sludge. Granular sludge in comparison to suspended sludge showed higher degradation rates both for phenol (11.3 ± 0.7 vs 8.1 ± 1.1 mg l-1 d-1) and p-cresol (7.8 ± 0.4 vs 3.7 ± 1.0 mg l-1 d-1). After three and four re-feedings of phenol and p-cresol, respectively, the microbial structure from both sludges was clearly different from the original sludges. Anaerobic digestion of phenol and p-cresol generated an abundance increase in Syntrophorhabdus genus and bamA gene, together with hydrogenotrophic and aceticlastic archaea. Analysis of results indicates that differences in methanogenic pathways and levels of Syntrophorhabdus and bamA gene in the inocula, could be the causes of dissimilar degradation rates between each sludge. Conclusions: Syntrophorhabdus and bamA gene play relevant roles in anaerobic degradation of phenolics. Estimation of these components could serve as a fast screening tool to find the most acclimatized sludge to efficiently degrade mono-aromatic compounds.

Evaluation of biogas and syngas as energy vectors for heat and power generation using lignocellulosic biomass as raw material

The use of nonrenewable energy sources to provide the worldwide energy needs has caused different problems such as global warming, water pollution, and smog production. In this sense, lignocellulosic biomass has been postulated as a renewable energy source able to produce energy carriers that can cover this energy demand. Biogas and syngas are two energy vectors that have been suggested to generate heat and power through their use in cogeneration systems. Therefore, the aim of this review is to develop a comparison between these energy vectors considering their main features based on literature reports. In addition, a techno-economic and energy assessment of the heat and power generation using these vectors as energy sources is performed. If lignocellulosic biomass is used as raw material, biogas is more commonly used for cogeneration purposes than syngas. However, syngas from biomass gasification has a great potential to be employed as a chemical platform in the production of value-added products. Moreover, the investment costs to generate heat and power from lignocellulosic materials using the anaerobic digestion technology are higher than those using the gasification technology. As a conclusion, it was evidenced that upgraded biogas has a higher potential to produce heat and power than syngas. Nevertheless, the implementation of both energy vectors into the energy market is important to cover the increasing worldwide energy demand.

Insects of forensic importance associated to cadaveric decomposition in a rural area of the Andean Amazon, Caquetá, Colombia / Insetos de importância forense associados à decomposição cadavérica em uma área rural na Amazônia Andina, Caquetá, Colômbia

ABSTRACT Forensic entomology is a frequently used tool to estimate the time interval between death and the discovery of the corpse. Succession of arthropods associated with cadaveric decomposition was monitored in a rural area of the Municipality of Florencia, Department of Caquetá, Colombia. Three pigs (Sus scrofa) were used as study models. Insect sampling, and monitoring of carcasses and environmental conditions were carried out every five hours. The total time from death to skeletonization was of 545 hours (22.7 days). A total of 30833 insect individuals were collected. Specimens were distributed in nine orders, 46 families, 95 genera and 106 species. Diptera was the most abundant, with 23215 individuals (75.3%), followed by Coleoptera, with 3711 individuals (12%), and Hymenoptera, with 3154 individuals (10.2%). Immature stages of Cochliomyia macellaria, Chrysomya albiceps, Hemilucilia semidiaphana and Ophyra aenescens were the main species involved in tissue consumption and acceleration of the decomposition process. Due to the presence of ants Cheliomyrmex sp., Camponotus sp. and Dinoponera sp., and coleopterans Hister sp., Acylophorus sp. and Philonthus spp., it was not possible to obtain sufficient Diptera egg masses for rearing the colonizing species. These results can be used as a standard to determine the postmortem interval in criminal investigations in the rural area of the Andean Amazon, Caquetá, Colombia.

RESUMO A entomologia forense é uma ferramenta frequentemente utilizada para estimar o intervalo de tempo entre a morte e a descoberta do corpo. Na área rural do município de Florencia, Caquetá, foi monitorada a sucessão de artrópodes associados à decomposição cadavérica, utilizando como modelo de estudo os cadáveres de três porcos (Sus scrofa). A amostragem de insetos e coleta de dados ambientais foram realizadas a cada cinco horas. A duração total do processo desde a morte até a esqueletização foi de 545 horas (22,7 dias). Foram coletados 30833 espécimes de insetos, distribuídos em nove ordens, 46 famílias, 95 gêneros e 106 espécies. Diptera foi o grupo mais representativo, com 23215 indivíduos (75,3%), seguido de Coleoptera, com 3711 indivíduos (12%) e Hymenoptera, com 3154 indivíduos (10,2%). Os estágios imaturos de Cochliomyia macellaria, Chrysomya albiceps, Hemilucilia semidiaphana e Ophyra aenescens foram as principais espécies envolvidas no consumo de tecidos e na aceleração do processo de decomposição. Devido à presença de formigas Cheliomyrmex sp., Camponotus sp. e Dinoponera sp. e de besouros Hister sp., Acylophorus sp. e Philonthus spp., não foi possível obter massas de ovos de Diptera suficientes para a criação de espécies colonizadoras. Nosso estudo fornece subsídios para determinar o intervalo post-mortem em investigações policiais e promover a entomologia forense em uma área rural da Amazônia Andina na Colômbia.

Green conversion of municipal solid wastes into fuels and chemicals

Presently, the society is facing a serious challenge for the effective management of the increasing amount of produced municipal solid wastes. The accumulated waste has caused a series of environmental problems such as uncontrolled release of greenhouse gases. Moreover, the increasing amount of wastes has resulted in a shortage of areas available for waste disposal, resulting in a nonsustainable waste management. These problems led to serious public concerns, which in turn resulted in political actions aiming to reduce the amount of wastes reaching the environment. These actions aim to promote sustainable waste management solutions. The main objective of these policies is to promote the recycling of municipal solid waste and the conversion of waste to energy and valuable chemicals. These conversions can be performed using either biological (e.g., anaerobic digestion) or thermochemical processes (e.g., pyrolysis). Research efforts during the last years have been fruitful, and many publications demonstrated the effective conversation of municipal solid waste to energy and chemicals. These processes are discussed in the current review article together with the change of the waste policy that was implemented in the EU during the last years.

Methanogenic toxicity evaluation of chlortetracycline hydrochloride

Background Anaerobic digestion is a technology applied successfully to converting organic matter into biogas. However, the presence of inhibitory compounds such as antibiotics can adversely affect methane production. The aim of this study is to evaluate the toxic effect of chlortetracycline hydrochloride (CLOR) on the methanogenic bacteria. In order to study the methanogenic toxicity of CLOR, different concentrations of CLOR (10, 50, 100, 200 mg L- 1) were evaluated by methanogenic toxicity assays using three feedings. Results Maximum methane production was obtained for the assays with 10 mg CLOR L- 1, the values obtained were 277 ± 4.07; 193 ± 11.31 and 166 ± 7.07 mL for the first, second and third feedings, respectively. The average values for acetic, propionic and butyric acid at start of the experiments were 2104 ± 139; 632 ± 7.6; 544 ± 26 mg L- 1, respectively. The VFA values obtained finally of the experiment were dependent on the evaluated antibiotic concentrations, indicating that the efficiency of methanogenesis is directly affected by the CLOR concentration. Conclusions CLOR is an effective methanogenic bacteria inhibitor. Moreover, the results show that CLOR has a bactericidal effect on methanogenic activity given that methane production did not recover during the third feeding. This study shows that the 50% inhibitory concentration (IC50) for methanogenic bacteria in 10 mg L- 1.

Residuos agroindustriales con potencial para la producción de metano mediante la digestión anaerobia / Agroindustrial wastes methanization and bacterial composition in anaerobic digestion

Las toneladas de residuos orgánicos que se generan anualmente en la agroindustria pueden aprovecharse como materia prima para la producción de metano. Para que los residuos orgánicos se puedan convertir a metano a gran escala, es importante que previamente se realicen sobre ellos pruebas de biodegradabilidad; un parámetro importante que conviene establecer es su potencial bioquímico de metano. En el presente trabajo se estudió la biodegradabilidad, la producción de metano y el comportamiento de poblaciones de eubacterias y arqueobacterias durante la digestión anaerobia de residuos de plátano, mango y papaya provenientes de la agroindustria, adicionando un inóculo microbiano. Los residuos de mango y plátano tenían mayor contenido de materia orgánica (94 y 75 %, respectivamente) que el residuo de papaya con base en su relación sólidos volátiles/sólidos totales. Después de 63 días de tratamiento, la mayor producción de metano se observó en la digestión anaerobia del residuo de plátano: 63,89 ml de metano por g de demanda química de oxígeno del residuo. Los resultados del potencial bioquímico de metano demostraron que el residuo de plátano tiene el mejor potencial para ser usado como materia prima en la producción de metano. A través de un análisis por PCR-DGGE con oligonucleótidos específicos se logró evaluar el tamaño y la composición de las poblaciones de eubacterias y arqueobacterias presentes en la digestión anaerobia de residuos agroindustriales a lo largo del proceso.

The tons of organic waste that are annually generated by agro-industry, can be used as raw material for methane production. For this reason, it is important to previously perform biodegradability tests to organic wastes for their full scale methanization. This paper addresses biodegradability, methane production and the behavior of populations of eubacteria and archaeabacteria during anaerobic digestion of banana, mango and papaya agroindustrial wastes. Mango and banana wastes had higher organic matter content than papaya in terms of their volatile solids and total solid rate (94 and 75 % respectively). After 63 days of treatment, the highest methane production was observed in banana waste anaerobic digestion: 63.89 ml CH4/per gram of chemical oxygen demand of the waste. In the PCR-DGGE molecular analysis, different genomic footprints with oligonucleotides for eubacteria and archeobacteria were found. Biochemical methane potential results proved that banana wastes have the best potential to be used as raw material for methane production. The result of a PCR- DGGE analysis using specific oligonucleotides enabled to identify the behavior of populations of eubacteria and archaeabacteria present during the anaerobic digestion of agroindustrial wastes throughout the process.

Communities of anamorphic fungi on green leaves and leaf litter of native forests of Scutia buxifolia and Celtis tala: Composition, diversity, seasonality and substrate specificity / Comunidades de hongos anamórficos en hojas verdes y hojarasca de bosques nativos deScutia buxifolia y Celtis tala: composición, diversidad, estacionalidad y especificidad del sustrato

Background: Xeric forests dominated by two tree species, Scutia buxifolia (Rhamnaceae) and Celtis tala (Ulmacea), are temperate, semi-deciduous wooded communities that represent the most abundant woodlands on the eastern plains of Buenos Aires Province, Argentina. The district of Magdalena has one of the most well-preserved native-forest areas, with an environmental heterogeneity that gives rise to the wide variability in the vegetation present. Aims: The aim of this study was to analyze the species composition, diversity, seasonal variations, and substrate specificity of anamorphic fungi (Ascomycota) on the green leaves and in the leaf litter of native forests dominated by Scutia buxifolia and Celtis tala from Magdalena, Buenos Aires, Argentina. Methods: In order to obtain the mycobiota of decomposition, seasonal samples of green leaves and leaf litter from both types of trees were collected over a two-year period. In the laboratory, the leaves were placed in a moist chamber and incubated at room temperature. Results: A total of 100 species of anamorphic Ascomycota were identified in both forests. No significant variations were observed in the richness, diversity, or evenness of the fungal communities of the green leaves and leaf litter of both forests between seasons. Conclusions: The species that characterized the fungal communities in the leaves of each of the trees were found to be different. The type of substrate had a stronger influence in determining the composition of the fungal community in both types of forests (AU)

Antecedentes: Los bosques xerófilos dominados por las especies arbóreas Scutia buxifolia (Rhamnaceae) y Celtis tala (Ulmaceae) conforman comunidades boscosas semicaducas y templadas que constituyen los bosques nativos más abundantes de la provincia de Buenos Aires, Argentina. En el distrito de Magdalena constituyen una de las comunidades naturales de este tipo mejor conservada, con una heterogeneidad ambiental que da lugar a la gran variabilidad en la composición de la vegetación presente. Objetivos: El objetivo del presente trabajo fue analizar las distribución de especies, la diversidad, las variaciones estacionales y la especificidad por el sustrato de hongos anamórficos (Ascomycota) presentes en las hojas verdes y en la hojarasca de los bosques nativos xerófilos dominados por las especies arbóreas Scutia buxifolia y Celtis tala en el partido de Magdalena, provincia de Buenos Aires, Argentina. Métodos: Para obtener la micobiota descomponedora se tomaron muestras estacionales de hojas verdes y hojarasca de los 2 tipos de árboles durante un período de 2 años. En el laboratorio, las hojas se colocaron en cámara húmeda y se incubaron a temperatura ambiente. Resultados: Se identificaron 100 especies de anamorfos de la división Ascomycota en las hojas de ambos tipos de árboles. No se observaron diferencias en cuanto a la diversidad, equidad y riqueza de especies entre ambos tipos de hojas. Conclusiones: Las especies que componen la comunidad fúngica de las hojas de Scutia buxifolia y Celtis tala es diferente. El tipo de sustrato que representan las hojas de cada especie arbórea condiciona la composición de la comunidad de anamorfos de Ascomycota presentes en ambos tipos de hoja (AU)

Crecimiento rápido autotrófico de microorganismos anaerobios oxidadores de amonio en presencia de nitrito, usando inóculos de Colombia / Faster autotrophic growth of anaerobic ammonium-oxidizing microorganisms in presence of nitrite, using inocula from Colombia

Anammox is a nitrite dependent process, catalyzed by bacteria of the order Brocadiales. Anammox bacteria oxidize ammonia under anoxic conditions, with nitrite as electron acceptor producing dinitrogen gas. Here, we demonstrated the presence of anammox bacteria by enriched them in a SBR reactor, with anaerobic samples taken from de bottom of a pond used in primary wastewater treatment. The enrichment reached nitrogen (N) removal rates of nearly 1.92kg N/m3/day. (The stoichiometry of the reaction matched previous anammox studies). The enriched bacterial communities were analyzed by Fluorescence In situ Hybridization (FISH), and showed a nearly 90% enrichment at the end of the experiment (day 90). As far as we know this is the first time that the anammox bacteria were enriched using Colombian inocula. The enrichment was achieved in relatively short time with high yields and have an excellent potential for application in wastewater treatment opening the opportunity to treat nitrogen-rich effluents by partial nitritation and anammox, thereby decreasing operational costs with respect to aeration (nitrification) and addition of organic electron donor (heterotrophic denitrification). This more sustainable treatment is a good alternative to control nutrient pollution in water bodies in tropical countries.

La oxidación anaerobia del amonio (anammox), es un proceso nitrito dependiente, catalizado por bacterias del filo planctomicetes. Estas bacterias oxidan el amonio en ausencia de oxígeno, con nitrito como aceptor de electrones produciendo nitrógeno molecular. En Colombia, demostramos la presencia de estas bacterias mediante el enriquecimiento de cultivos en reactores por lotes, con inóculos nativos, provenientes de muestras anaeróbias tomadas del fondo de una laguna para el tratamiento primario de aguas residuales. El enriquecimiento logrado alcanzó remociones de nitrógeno (N), en el orden de 1.92kg - N /m3/día (la estequiometria de la reacción estuvo acorde con estudios previos de anammox). La comunidad bacteriana enriquecida, se analizó mediante hibridación en sitio con fluorescencia (FISH), y mostró que el enriquecimiento contenía aprox. 90 % de bacterias anammox al final del experimento (Día 90). Esta es la primera vez que en Colombia se logra el enriquecimiento de estas bacterias con inóculos locales, hasta nuestro conocimiento. El enriquecimiento fue alcanzado en relativamente corto tiempo con altos rendimientos y tiene un excelente potencial de aplicación en el tratamiento de aguas residuales, abriendo oportunidades para el tratamiento de efluentes ricos en nitrógeno mediante nitritación parcial y anammox, disminuyendo los costos en los procesos de aireación (nitrificación) y en la de adición de donadores orgánicos (denitrificación heterótrofa). El uso de estos tratamientos más sostenibles es una buena alternativa para el control de contaminación por nutrientes en los cuerpos de agua, en países tropicales.

Degradación del colorante Rojo Punzó por medio de lodos anaerobios / Ponceau Red dye degradation by anaerobic sludge

La presencia de vertimientos líquidos con contenidos de colorantes ha generado deterioro en la calidad del agua de las fuentes que reciben estas descarga, desfavoreciendo sus características estéticas, organolépticas y la presencia de fauna íctica debido a las interferencias que provocan con el ingreso luz natural para que se de la productividad primaria en estos ecosistemas, de esta forma se deterioran los eslabones en la cadena trófica y la pérdida de biodiversidad; es por ello, que es importante las iniciativas para disminuir la demanda de bienes y servicios ambientales, además, de los pasivos ambientales entorno a los vertimientos coloreados, de esta forma, mediante este estudio de degradación del colorante rojo Punzó se pretende dar solución e incrementar la capacidad técnica y científica entorno al tratamiento de efluentes con presencia de colorantes azoicos como es el caso del rojo Punzó. El presente trabajo determinó la biodegradabilidad anaerobia del colorante Rojo Punzó empleando recuentos microbianos.

Fungos anaeróbios do rúmen de bovinos e caprinos de corte criados em pastagens tropicais / Ruminal anaerobic fungi of beef cattle and beef goats raised on tropical pastures

The presence of anaerobic fungi structures was evaluated in ruminal juice of beef goats and beef cattle raised in the North of Minas Gerais, Brazil. The strains were collected from 18 Anglo-Nubian crossbred male goats and 23 Nellore crossbred steers during the dry period of the year. Physical-chemical characteristics of the juice were evaluated and direct examination with KOH digestion was performed for anaerobic fungi detection. Structures of these fungi were detected in samples of 14 (77.8 percent) goats and 17 (73.9 percent) steers. The monocentric fungi frequency (56.5 percent) was significantly higher in cattle than polycentric fungi frequency (26.1 percent). This study is the first report of anaerobic ruminal fungi in these ruminants in Brazil and showed high prevalence of theses microorganisms in the ruminal ecosystem of both animals.

Simultaneous effects of pH and substrate concentration on hydrogen production by acidogenic fermentation / Efectos simultáneos del pH y la concentración de sustrato en la producción de hidrógeno mediante fermentación acidogénica

The present research examined the effects of initial substrate concentration and pH on the yield and productivity of hydrogen production by acidogenic fermentation. Assays were carried out at three different initial pH levels (5.5, 6.5 and 7.5) and three initial substrate concentrations (3, 5 and 10 g COD/L). Glucose was used as carbon source and the experiments were conducted at 37°C in batch tests, after a thermal pretreatment to eliminate methanogenic microorganisms. Conversions of glucose into hydrogen were between 16.75 and 27.25 percent of theoretical maximum, and high values of hydrogen productivity were obtained. An optimum value for the yield of glucose between initial pH of 6.3 and 3.7 g COD/L and productivity of the 5.95 H2/gVSS h and initial pH of 6.7 and 10 g COD/L were obtained from the response surface.

Aislamiento y evaluación de la actividad enzimática de hongos descomponedores de madera (Quindío, Colombia) / Isolation of wood-decaying fungi and evaluation of their enzymatic activity (Quindío, Colombia)

Se realizó la colecta de hongos (rdas.) en troncos caídos con diferentes estados de descomposición en un bosque subandino (la reserva natural La Montaña del Ocaso) y se evaluó su actividad ligninolítica. Se cultivaron en Agar extracto de malta y se realizaron pruebas semicuantitativas de actividad lacasa utilizando como inductor enzimático el ácido 2,2’azino-bis-[3-etilbenzotiazolin-6-sulfónico] y el 2,6-diclorofenolindofenol para la celobiosa deshidrogenasa (CDH). Se seleccionaron los hongos con mayor actividad enzimática de troncos con diferente grado de descomposición: Cookeina sulcipes (de estado 1), un hongo de la familia Corticiaceae (de estado 2), Xylaria polymorpha (de estado 3) y Earliella sp. (de estado 4). La fermentación se realizó a 28°C durante 11 días, a 150r.p.m., con mediciones diarias para biomasa, glucosa, actividad lacasa, actividad CDH y proteínas. Los hongos de los troncos con estados de descomposición 1 a 3 presentaron mayor actividad lacasa, a medida que aumentaba el estado de descomposición. Hubo un aumento en la actividad CDH a medida que se incrementó el estado de descomposición de los troncos. Hubo una relación positiva entre la producción de las 2 enzimas. Earliella sp. fue el hongo con mayor producción de biomasa (1.140,19g/l), actividad lacasa (157Ul−1) y CDH (43,50Ul−1). Este trabajo es el primer reporte de actividad lacasa y CDH en C. sulcipes y Earliella sp. Además, sienta las bases para la utilización de estos hongos nativos en aplicaciones biotecnológicas y se adentra en el conocimiento de su función dentro del proceso de descomposición de la madera en bosques(AU)

White rotfungi(AscomycotaandBasidiomycota)werecollectedonfallentrunkswithdifferentdecaystages, inasubandeanforest(LaMontan˜a delOcasonaturereserve),anditwasevaluatedtheirligninoliticactivity.Theywereculturedonmaltextractagar.Thenitwasperformedsemiquantitativetestsforlaccaseand cellobiosedehydrogenase(CDH)activityusingABTSandDCPIPasenzymaticinducers.Basedontheresults ofthesetests,thefungiwithhigheractivitiesfromtrunkswithdifferentdecaystageswereselected:Cookeina sulcipes (for stage1),afungusfromthefamilyCorticiaceae(forstage2), Xylariapolymorpha (forstage 3)and Earliella sp. (forstage4).Afermentationwasperformedat28 1C, during11days,inarotatoryshaker at150rpm.Biomass,glucose,proteinsandenzymeactivitiesmeasurementswereperformeddaily.The fungithatwereinthetrunkswithdecaystatesfrom1to3,showedhigherlaccaseactivityasthestateof decayincreased.AhigherDCHactivitywasalsoassociatedwithahigher.Also,therewasapositiverelationship betweenbothenzymes’activities.Erliellawasthefunguswhichpresentedthehighestbiomass production(1140,19g/l),laccaseactivity(157UL 1) andCDHactivity(43,50UL 1). Thisworkisthefirst reportoflaccaseandCDHactivityfor Cookeina sulcipes and Earliella sp. Moreover,itgivesbasisforthe useofthesenativefungiinbiotechnologicalapplicationsandtheacknowledgmentoftheirfunctioninthe wooddecayprocessinnativeforest

PCR-based DGGE and FISH analysis of methanogens in an anaerobic closed digester tank for treating palm oil mill effluent

16S ribosomal RNA (rRNA)-targeted fluorescent in situ hybridization combined with polymerase chain reaction (PCR)-cloning, light microscopy using Gram stains, scanning electron microscopy and denatured gradient gel electrophoresis were used to reveal the distribution of methanogens within an anaerobic closed digester tank fed with palm oil mill effluent. For specific detection of methanogens, 16S rRNA-cloning analysis was conducted followed by restriction fragment length polymorphism (RFLP) for presumptive identification of methanogens. To cover the drawbacks of the PCR-cloning study, the organization of the microorganisms was visualized in the activated sludge sample by using fluorescent oligonucleotide probes specific to several different methanogens, and a probe for bacteria. In situ hybridization with methanogens and bacterial probes and denatured gradient gel electrophoresis within activated sludge clearly confirmed the presence of Methanosaeta sp. and Methanosarcina sp. cells. Methanosaeta concilii was found to be the dominant species in the bioreactor. These results revealed the presence of possibly new strain of Methanosaeta in the bioreactor for treating palm oil mill effluent called Methanosaeta concilii SamaliEB (Gene bank accession number: EU580025). In addition, fluorescent hybridization pictured the close association between the methanogens and bacteria and that the number of methanogens was greater than the number of bacteria.

Treatment of low strength sewage with high suspended organic matter content in an anaerobic sequencing batch reactor and modeling application

In this work, an anaerobic sequencing batch reactor (ASBR) was operated for 8 months to treat low strength sewage with high suspended organic matter content. Three phases of operation with increasing organic loading rates (OLR) were performed: 0.4 kg COD/m³ x d (phase I), 0 .8 kg COD/m³ x d (phase II) and 1.2 kg COD/m³ x d (phase III). Adequate stability parameters (pH, total alkalinity) were obtained through all three experimental phases. During phases I and II, the removal efficiencies of organic matter (expressed as total chemical oxygen demand (COD) and total suspended solids ranged between 50-60 percent. However, these values decreased to 15-25 percent in phase III. In addition, a non-complex model, including hydrolysis, acidogenesis and methanogenesis, was applied to predict the reactor behavior.

Performance of an Anaerobic Baffled Reactor (ABR) in treatment of cassava wastewater / Desempenho de um Reator Anaeróbio Compartimentado (RAC) no tratamento da manipueira

The performance of an anaerobic baffled reactor (ABR) was evaluated in the treatment of cassava wastewater, a pollutant residue. An ABR divided in four equal volume compartments (total volume 4L) and operated at 35ºC was used in cassava wastewater treatment. Feed tank chemical oxygen demand (COD) was varied from 2000 to 7000 mg L-1 and it was evaluated the most appropriated hydraulic retention time (HRT) for the best performance on COD removal. The ABR was evaluated by analysis of COD (colorimetric method), pH, turbidity, total and volatile solids, alkalinity and acidity. Principal component analysis (PCA) was carried to better understand data obtained. The system showed buffering ability as acidity decreased along compartments while alkalinity and pH values were increased. There was particulate material retention and COD removal varied from 83 to 92% for HRT of 3.5 days.

O desempenho de um reator anaeróbio compartimentado (RAC) foi avaliado para o tratamento da manipueira, resíduo tóxico. Um RAC dividido em quatro compartimentos de mesmo volume (volume total 4L) e operado a 35ºC foi utilizado no tratamento da manipueira. A demanda química de oxigênio (DQO) do tanque de alimentação variou de 2000 a 7000 mg L-1 e avaliou-se o tempo de residência hidráulica (TRH) mais apropriado ao melhor desempenho do reator. O RAC foi avaliado pelas análises de DQO (método colorimétrico), pH, turbidez, sólidos totais e voláteis, alcalinidade e acidez. A Análise das Componentes Principais (PCA) foi conduzida para melhor compreensão dos dados obtidos. O sistema apresentou capacidade tamponante conforme a acidez decresceu ao longo dos compartimentos ao passo que a alcalinidade e o pH aumentaram. Houve retenção do material particulado e a remoção da DQO variou de 83 a 92% para TRH de 3,5 dias.