Biodegradation of Terephthalic Acid by Isolated Active Sludge Microorganisms and Monitoring of Bacteria in a Continuous Stirred Tank Reactor

Abstract Terephthalic acid is extensively used as an important raw material in polyester fibers, as well as the production of polyethylene terephthalate bottles and textile industries. Especially, in the petrochemical industry, toxic chemicals are released to the atmosphere during the production of polyethylene terephthalate, unless the wastewater treatment is carried out. It's a well-known fact that chemicals have serious side effects on human health, so manufacturing companies should not dispose of such harmful chemicals without treatment. Biodegradation is an effective option for eco-friendly degradation of hydrocarbons. Hydrocarbon-degrading bacteria are everywhere in environment and can utilize these chemicals as sources of carbon and energy. In the present study, aerobic bacterial strains T1, T4, T5, and TK were isolated from activated sludge and crude oil deposits of a petrochemical company in Turkey. The strains were identified to be Pseudomonas sp., Chryseobacterium sp., Burkholderia sp., and Arthrobacter sp. according to morphological, physiological and biochemical characteristics. The strains were able to degrade about 100% of 100 mg/L terephthalic acid within, respectively, 8, 67, 52, 24 hour as sole carbon and energy source. Therefore, these isolates can be effectively used for degradation of terephthalic acid contaminated sites. In addition to this, a Continuous Stirred Tank Reactor (CSTR) was used to test the biodegradation capabilities of the isolates in the activated sludge system. Throughout the biodegradation, bacterial existence and numbers were monitored using designed primer-probe sets in real-time polymerase chain reaction (PCR).

CHEMical KINetics SimuLATOR (Chemkinlator): A friendly user interface for chemical kinetics simulations / CHEMical KINetics SimuLATOR (Chemkinlator): Una herramienta amigable para realizar simulaciones de cinética química / CHEMical KINetics SimuLATOR (Chemkinlator): Uma ferramenta amigável para realizar simulações de cinética química

Abstract CHEMicalKINetics SimuLATOR (Chemkinlator) is a Graphical User Interface for the simulation of reaction mechanisms. The interface allows the user to see and change the parameters of a reaction network within a single window. Chemkinlator comes with built-in support for three types of kinetic simulations: Time Series, which computes the concentration of all species in an interval of time for the defined model; Bifurcation diagrams, which are the result of running several Time Series simulations over gradually different kinetic rate constants; and Flow/Temperature time series, which takes into account the effect of flow in the Continuous-flow well-Stirred Tank Reactor, and the effect of temperature on the rates constants according to the Arrhenius equation. In our research group, Chemkinlator has been the primary tool used to test the predictions made by algorithms that analyze homochirality phenomena. Chemkinlator is written in C++14 and Qt, and it uses the Fortran subroutine DLSODE to solve the differential equations associated with the reaction networks. Chemkinlator is open source software under the Apache 2.0 license and can be downloaded freely from https://gitlab.com/homochirality/chemkinlator.

Resumen CHEMical KINetics SimuLATOR (Chemkinlator) es una interfaz gráfica para realizar simulaciones de mecanismos de reacción. La interfaz le permite al usuario ver y cambiar los parámetros de una red de reacciones en una única ventana. Chemkinlator puede realizar tres tipos de simulaciones cinéticas: Time Series, calcula la concentración de cada especie en un intervalo de tiempo del modelo estudiado; Bifurcation, es el resultado de ejecutar varias veces las simulaciones del modo Time Series, cambiando gradualmente diferentes constantes de velocidad; y Flow/ Temperature es una serie de tiempo en la que se tiene en cuenta el efecto del flujo considerando un Reactor de Flujo Continuo bien Agitado y el efecto de la temperatura sobre las constantes de velocidad según la ecuación de Arrhenius. En nuestro grupo de investigación, Chemkinlator ha sido la herramienta principal para verificar las predicciones hechas por los algoritmos que analizan el fenómeno de homochiralidad. Chemkinlator está escrito en C++14 y Qt, y usa la subrutina de Fortran DLSODE para resolver las ecuaciones diferenciales relacionadas con los mecanismos de reacción. Chemkinlator es software de código abierto bajo la licencia Apache 2.0 y se puede descargar libremente de https://gitlab.com/homochirality/chemkinlator.

Resumo O CHEMical KINetics SimuLATOR (Chemkinlator) é uma interface gráfica para realizar simulações de mecanismos de reação. A interface permite ao usuário visualizar e alterar os parâmetros de uma rede de reação em uma única janela. O Chemkinlator pode realizar três tipos de simulações cinéticas: Time Series, calcula a concentração de cada espécie em um intervalo de tempo do modelo estudado; Bifurcation, é o resultado de executar várias vezes as simulações do modo Time Series, modificando gradualmente diferentes constantes de velocidade; e Flow/Temperature é uma serie de tempo que se considera o efeito do fluxo considerando um Reator de Fluxo Continuo bem Agitado e o efeito da temperatura sobre as constantes de velocidade pela equação de Arrhenius. No nosso grupo de investigação, o Chemkinlator tem sido a principal ferramenta para verificar as predições realizadas pelos algoritmos que analisam o fenómeno de homoquiralidade. O Chemkinlator está escrito em C++14 e Qt, e usa a sub-rotina de Fortran DLSODE para resolver as equações diferenciais relacionadas com os mecanismos de reação. O Chemkinlator é um software de código aberto baixo a licença Apache 2.0 e pode ser descarregado livremente em https://gitlab.com/homochirality/chemkinlator.

Efeito da variação da carga orgânica volumétrica natural na produção de biogás a partir de dejeto suíno em diferentes tempos de retenção hidráulica / The effect of organic loading rate's natural variation on the biogas yields from swine manure digestion at different hydraulic retention time

RESUMO O estudo sobre reatores anaeróbios em laboratório prioriza o controle de determinados parâmetros que são de difícil controle em campo, o que dificulta o processo de scale-up. Entre os parâmetros está a carga orgânica volumétrica (COV). No caso do dejeto suíno, esse parâmetro pode sofrer alterações diárias em função das condições climáticas, das mudanças no manejo, da alimentação dos animais, entre outros. A fim de verificar o impacto dessa variação na produtividade de biogás, foi analisado o comportamento de um reator anaeróbio de mistura completa (CSTR) em dois diferentes tempos de retenção hidráulica (TRHs) - 20 e 30 dias - durante um período total de 180 dias. Os resultados demonstraram que a elevação da COV resulta em piora da eficiência de tratamento, bem como na produção de biogás. O ensaio com TRH de 20 dias obteve uma melhor resposta às alterações de carga orgânica.

ABSTRACT The study of anaerobic digesters at laboratory focuses on the control of certain parameters that are not so easy to control in the field, which makes it difficult to process scale-up. One example is the Organic Loading Rate. To swine manure, this parameter can change daily due to weather conditions, management practices, feeding and others. In order to verify the impact of this fluctuation on biogas yield, the behavior of a CSTR reactor was analyzed in two different Hydraulic Retention Times (20 and 30 days) for a total period of 180 days. The result demonstrated that the increase of OLR result in a decrease of treatment efficiency as well as biogas yields. The study with HRT of 20 days had a better response to changes in organic load.

Scaling-up batch conditions for efficient sucrose hydrolysis catalyzed by an immobilized recombinant Pichia pastoris cells in a stirrer tank reactor

Background: Invert sugar is used greatly in food and pharmaceutical industries. This paper describes scaling-up batch conditions for sucrose inversion catalyzed by the recombinant Pichia pastoris BfrA4X whole cells expressing Thermotoga maritima invertase entrapped in calcium alginate beads. For the first time, we describe the application of a kinetic model to predict the fractional conversion expected during sucrose hydrolysis reaction in both, a model and a prototype bioreactor with 0.5- and 5-L working volume, respectively. Results: Different scaled-up criteria used to operate the 0.5-L bioreactor were analyzed to explore the invert sugar large scale production. After model inversion studies, a 5-L scaled-up reaction system was performed in a 7-L stirred reactor. Both scaled-up criteria, immobilized biocatalyst dosage and stirring speed, were analyzed in each type of bioreactors and the collected data were used to ensure an efficient scale-up of this biocatalyst. Conclusions: To date, there is not enough information to describe the large-scale production of invert sugar using different scaled-up criteria such as dose of immobilized biocatalyst and stirring speed effect on mass transfer. The present study results constitute a valuable tool to successfully carry out this type of high-scale operation for industrial purposes.

Isolation of the intracellular and extracellular polysaccharides of Ganoderma neojaponicum (Imazeki) and characterization of their immunomodulatory properties

Background The role of polysaccharides isolated from the Ganoderma species of fungi in innate immunity has recently become a topic of research. Although some work has been conducted concerning Ganoderma lucidum, the characteristics of polysaccharides isolated from Ganoderma neojaponicum (Imazeki) as immunomodulatory agents are largely unknown. The aims for this study were to isolate and characterize the intracellular polysaccharides (IPSs) and extracellular polysaccharides (EPSs) of G. neojaponicum from STR reactor. Results The production of EPS and IPS was optimized on day 4 of the cultivation time in 2 L STR reactor based on the amount of biomass yield, total carbohydrate, β-glucan and a-glucan content. Further analysis, both the EPSs and IPSs showed the enhancement on proliferation and increment of phagocytosis activities of macrophage (RAW264.7) cell lines. Using an oral toxicity test, we also observed that 2000 mg/kg body weight/day dosage of dried G. neojaponicum mycelium does not cause any significant toxic effects on Sprague-Dawley rats in 14 d of administration. Conclusion The findings of this study indicate that the IPSs and EPSs of G. neojaponicum have the potential to be used as immunomodulating agents to stimulate the innate immune system for fighting infectious diseases. The polysaccharides from G. neojaponicum have to be further commercially explored as an alternative for medicinal Ganoderma variety of G. lucidum production.