Advances in electrochemically active biofilm of Shewanella oneidensis MR-1 / 生物工程学报

Facing the increasingly severe energy shortage and environmental pollution, electrocatalytic processes using electroactive microorganisms provide a new alternative for achieving environmental-friendly production. Because of its unique respiratory mode and electron transfer ability, Shewanella oneidensis MR-1 has been widely used in the fields of microbial fuel cell, bioelectrosynthesis of value-added chemicals, metal waste treatment and environmental remediation system. The electrochemically active biofilm of S. oneidensis MR-1 is an excellent carrier for transferring the electrons of the electroactive microorganisms. The formation of electrochemically active biofilm is a dynamic and complex process, which is affected by many factors, such as electrode materials, culture conditions, strains and their metabolism. The electrochemically active biofilm plays a very important role in enhancing bacterial environmental stress resistance, improving nutrient uptake and electron transfer efficiency. This paper reviewed the formation process, influencing factors and applications of S. oneidensis MR-1 biofilm in bio-energy, bioremediation and biosensing, with the aim to facilitate and expand its further application.

Construction and performance analysis of a microbial electrochemical sensor for monitoring heavy metals in water environment / 生物工程学报

A microbial fuel cell (MFC)-based microbial electrochemical sensor was developed for real-time on-line monitoring of heavy metals in water environment. The microbial electrochemical sensor was constructed with staggered flow distribution method to optimize the parameters such as external resistance value and external circulation rate. The inhibition of concentration of simulated heavy metal wastewater on voltage under optimal parameters was analyzed. The results showed that the best performance of MFC electrochemical sensor was achieved when the external resistance value was 130 Ω and the external circulation rate was 1.0 mL/min. In this case, the microbial electrochemical sensors were responsive to 1-10 mg/L Cu2+, 0.25-1.25 mg/L Cd2+, 0.25-1.25 mg/L Cr6+ and 0.25-1.00 mg/L Hg2+ within 60 minutes. The maximum rejection rates of the output voltage were 92.95%, 73.11%, 82.76% and 75.80%, respectively, and the linear correlation coefficients were all greater than 0.95. In addition, the microbial electrochemical sensor showed a good biological reproducibility. The good performance for detecting heavy metals by the newly developed microbial electrochemical sensor may facilitate the real-time on-line monitoring of heavy metals in water environment.

Fuentes de energía en apendicectomía laparoscópica en un programa académico de Cirugía general en Colombia / Energy sources in laparoscopic appendectomy in an academic program of General Surgery in Colombia

Introducción. La apendicectomía por laparoscopia se considera el patrón de oro en el tratamiento de la apendicitis aguda. Sin embargo, su disponibilidad es limitada en nuestro sistema de salud, principalmente por los costos asociados. El objetivo de este estudio fue evaluar la relación entre el uso de los diferentes tipos de energía y los métodos de ligadura de la base apendicular, con las complicaciones postoperatorias, al igual que describir los costos asociados. Métodos. Estudio observacional analítico de una cohorte retrospectiva de pacientes mayores de 15 años a quienes se les realizó apendicectomía por laparoscopia, en un hospital universitario entre los años 2014 y 2018. Se utilizaron modelos de regresión logística y lineal para evaluar la relación entre métodos de ligadura del meso y base apendicular, desenlaces operatorios y costos. Resultados. Se realizaron 2074 apendicectomías por laparoscopia, 58,2 % (n=1207) en mujeres, la edad mediana fue de 32 años. En el 71,5 % (n=1483) la apendicitis aguda no fue complicada. La energía monopolar para la liga-dura del meso apendicular fue la utilizada más frecuentemente en 57,2 % (n=1187) y el Hemolok® el más utilizado para la ligadura de la base apendicular en el 84,8 % (n=1759) de los pacientes. No se observaron diferencias estadísticamente significativas en la tasa de infección del sitio operatorio, reintervención o íleo. El uso de energía simple redujo los costos del procedimiento de manera significativa durante el período evaluado. Discusión. El uso de energía monopolar demostró ser una técnica segura, reproducible y de menor costo en comparación con el uso de energía bipolar, independientemente de la fase de la apendicitis aguda. Lo anterior ha permitido que se realicen más apendicectomías por laparoscopia y que los médicos residentes de cirugía general puedan realizar procedimientos laparoscópicos de forma más temprana

Introduction. Laparoscopic appendectomy is considered the gold standard in the treatment of acute appendicitis. However, its availability is limited in our health system mainly due to the associated costs. The objective of this study is to evaluate the relationship between the use of different types of energy and the methods of ligation of the appendicular base with postoperative complications, as well as to describe the associated costs. Methods. Retrospective observational study of a cohort of patients older than 15 years old who underwent laparoscopic appendectomy in a university hospital between 2014 and 2018. Logistic and linear regression models were used to evaluate the relationship between methods of ligation of the meso and appendicular base, operative outcomes and costs. Results: 2074 laparoscopic appendectomies were performed. Of those, 58.2% (n=1207) were women, median age was 32 years. In 71.5% (n=1483), acute appendicitis was uncomplicated. Monopolar energy for ligation was the most frequently used for ligation of the appendicular meso in 57.2% (n=1187) and Hem-o-lok® the most used for ligation of the appendicular base in 84.8% (n=1759) of the patients. There were no statistically significant differences in the rate of surgical site infection, reoperation, or ileus. The use of simple energy reduced the costs of the procedure significantly during the study period. Discussion. The use of monopolar energy proved to be a safe, reproducible and a lower cost technique compared to the use of bipolar energy, regardless of the phase of acute appendicitis. This has allowed more laparoscopic appendectomies to be performed and the general surgery residents to perform laparoscopic procedures earlier

Progress in enhancing electron transfer rate between exoelectrogenic microorganisms and electrode interface / 生物工程学报

Exoelectrogenic microorganisms are the research basis of microbial electrochemical technologies such as microbial fuel cells, electrolytic cells and electrosynthesis. However, their applications are restricted in organic degradation, power generation, seawater desalination, bioremediation, and biosensors due to the weak ability of biofilm formation and the low extracellular electron transfer (EET) efficiency between exoelectrogenic microorganisms and electrode. Therefore, engineering optimization of interaction between exoelectrogenic microorganisms and electrode interface recently has been the research focus. In this article, we review the updated progress in strategies for enhancing microbe-electrode interactions based on microbial engineering modifications, with a focus on the applicability and limitations of these strategies. In addition, we also address research prospects of enhancing the interaction between electroactive cells and electrodes.

Construction of conjugated polymer-exoelectrogen hybrid bioelectrodes and applications in microbial fuel cells / 生物工程学报

Microbial fuel cell (MFC) is a bioelectrochemical device, that enables simultaneous wastewater treatment and energy generation. However, a few issues such as low output power, high ohmic internal resistance, and long start-up time greatly limit MFCs' applications. MFC anode is the carrier of microbial attachment, and plays a key role in the generation and transmission of electrons. High-quality bioelectrodes have developed into an effective way to improve MFC performance. Conjugated polymers have advantages of low cost, high conductivity, chemical stability and good biocompatibility. The use of conjugated polymers to modify bioelectrodes can achieve a large specific surface area and shorten the charge transfer path, thereby achieving efficient biological electrochemical performance. In addition, bacteria can be coated with nano-scale conjugated polymer and effectively transfer the electrons generated by cells to electrodes. This article reviews the recently reported applications of conjugated polymers in microbial fuel cells, focusing on the MFC anode materials modified by conjugated polymers. This review also systematically analyzes the advantages and limitations of conjugated polymers, and how these composite hybrid bioelectrodes solve practical issues such as low energy output, high inner resistance, and long starting time.

Research progress in screening method of exoelectrogens / 生物工程学报

Exoelectrogens are promising for a wide variety of potential applications in the areas of environment and energy, which convert chemical energy from organic matter into electrical energy by extracellular electrons transfer (EET). Microorganisms with different mechanisms and EET efficiencies have been elucidated. However, the practical applications of exoelectrogens are limited by their fundamental features. At present, it is difficult to realize the extensive application of exoelectrogens in complex and diverse environments by means of traditional engineering strategies such as rational design and directed evolution. The exoelectrogens with excellent performance in environments can be screened with efficient strain identification technologies, which promote the widespread applications of exoelectrogens. The aims of this review are to summarize the methods of screening based on different types of exoelectrogens, and to outline future research directions of strain screening.

Bioelectrogenesis with microbial fuel cells (MFCs) using the microalga Chlorella vulgaris and bacterial communities

Background: Microbial Fuel Cell (MFC) technology is used in various applications such as wastewater treatment with the production of electrical energy. The objective of this study was to estimate the biodepuration of oils and fats, the elimination of blue dye brl and bioelectro-characterization in MFCs with Chlorella vulgaris and bacterial community. Results: The operation of MFCs at 32 d showed an increase in bioelectrogenic activity (from 23.17 to 327.67 mW/m2 ) and in the potential (from 200 to 954 mV), with biodepuration of fats and oils (95%) in the microalgal cathode, and a removal of the chemical oxygen demand COD (anode, 71%, cathode, 78.6%) and the blue dye brl (73%) at the anode, here biofilms were formed by the bacterial community consisting of Actinobacteria and Deltaproteobacteria. Conclusions: These findings suggest that MFCs with C. vulgaris and bacterial community have a simultaneous efficiency in the production of bioelectricity and bioremediation processes, becoming an important source of bioenergy in the future.

Advances in enzyme bioelectrochemistry

ABSTRACT Bioelectrochemistry can be defined as a branch of Chemical Science concerned with electron-proton transfer and transport involving biomolecules, as well as electrode reactions of redox enzymes. The bioelectrochemical reactions and system have direct impact in biotechnological development, in medical devices designing, in the behavior of DNA-protein complexes, in green-energy and bioenergy concepts, and make it possible an understanding of metabolism of all living organisms (e.g. humans) where biomolecules are integral to health and proper functioning. In the last years, many researchers have dedicated itself to study different redox enzymes by using electrochemistry, aiming to understand their mechanisms and to develop promising bioanodes and biocathodes for biofuel cells as well as to develop biosensors and implantable bioelectronics devices. Inside this scope, this review try to introduce and contemplate some relevant topics for enzyme bioelectrochemistry, such as the immobilization of the enzymes at electrode surfaces, the electron transfer, the bioelectrocatalysis, and new techniques conjugated with electrochemistry vising understand the kinetics and thermodynamics of redox proteins. Furthermore, examples of recent approaches in designing biosensors and biofuel developed are presented.

Progress in nanomaterials modified anodes of microbial fuel cell / 生物工程学报

Anode is an important part of microbial fuel cell, its performance significantly affects the electricity generation of microbial fuel cells (MFCs). Nanomaterials have excellent properties, such as good conductivity and large surface area. Therefore, nanomaterials modified anode can effectively reduce the electrode resistance, increase the amount of microbial adhesion and improve the electricity generation of MFCs. In this paper, we introduced various nanomaterials modified anodes and summarized their effects on the output performance of MFCs. Finally, the prospect of modifying nanomaterials and technologies were discussed.

Surgical Ablation of Atrial Fibrillation Using Energy Sources

ABSTRACT Surgical ablation, concomitant with other operations, is an option for treatment in patients with chronic atrial fibrillation. The aim of this study is to present a literature review on surgical ablation of atrial fibrillation in patients undergoing cardiac surgery, considering energy sources and return to sinus rhythm. A comprehensive survey was performed in the literature on surgical ablation of atrial fibrillation considering energy sources, sample size, study type, outcome (early and late), and return to sinus rhythm. Analyzing studies with immediate results (n=5), the percentage of return to sinus rhythm ranged from 73% to 96%, while those with long-term results (n=20) (from 12 months on) ranged from 62% to 97.7%. In both of them, there was subsequent clinical improvement of patients who underwent ablation, regardless of the energy source used. Surgical ablation of atrial fibrillation is essential for the treatment of this arrhythmia. With current technology, it may be minimally invasive, making it mandatory to perform a procedure in an attempt to revert to sinus rhythm in patients requiring heart surgery.

Eficacia del tratamiento segmentario con corriente Trabert en pacientes con epicondilitis humeral externa / Effectiveness of the segmental treatment with Trabert current in patients with external humeral epicondylitis

Se realizó un estudio experimental, de tipo intervención terapéutica, en 60 pacientes de ambos sexos, con epicondilitis humeral externa, atendidos en la Sala de Rehabilitación del Policlínico Comunitario Docente "Eduardo Mesa Llull", del municipio de II Frente, de la provincia Santiago de Cuba, desde noviembre de 2013 hasta igual mes de 2014, con vistas a evaluar la eficacia del tratamiento segmentario con corriente Trabert según variables de interés para la investigación. La muestra fue dividida en 2 grupos de 30 integrantes cada uno. Los del primero recibieron tratamiento segmentario; los del segundo, tratamiento a puntos de gatillo doloroso. Con la terapia aplicada se logró una recuperación total de 27 pacientes del grupo de estudio y 26 del control, de manera que la eficacia del tratamiento segmentario en la epicondilitis humeral externa es similar a la de gatillo doloroso.

An experimental study, of therapeutic intervention type was carried out in 60 patients of both sexes, with humeral, external epicondylitis assisted in the Rehabilitation Room of "Eduardo Mesa Llull" Teaching Community Polyclinic, from II Front municipality, of Santiago de Cuba province, from November, 2013 to same month of 2014, with the objective of evaluating the effectiveness of the segmental treatment with Trabert current according to variables of interest for the investigation. The sample was divided into 2 groups of 30 members each. Those of the first group received segmental treatment; those of the second group, were treated with painful trigger points. With the applied therapy a total recovery of 27 patients of the study group and 26 of the control was achieved, so that the effectiveness of the segmental treatment in the humeral external epicondylitis is similar to that of painful trigger.

Design of a microbial fuel cell and its transition to microbial electrolytic cell for hydrogen production by electrohydrogenesis.

Anaerobic bacteria were isolated from industrial wastewater and soil samples and tested for exoelectrogenic activity by current production in double chambered microbial fuel cell (MFC), which was further transitioned into a single chambered microbial electrolytic cell to test hydrogen production by electrohydrogenesis. Of all the cultures, the isolate from industrial water sample showed the maximum values for current = 0.161 mA, current density = 108.57 mA/m2 and power density = 48.85 mW/m2 with graphite electrode. Maximum voltage across the cell, however, was reported by the isolate from sewage water sample (506 mv) with copper as electrode. Tap water with KMnO4 was the best cathodic electrolyte as the highest values for all the measured MFC parameters were reported with it. Once the exoelectrogenic activity of the isolates was confirmed by current production, these were tested for hydrogen production in a single chambered microbial electrolytic cell (MEC) modified from the MFC. Hydrogen production was reported positive from co-culture of isolates of both the water samples and co-culture of one soil and one water sample. The maximum rate and yield of hydrogen production was 0.18 m3H2/m3/d and 3.2 mol H2/mol glucose respectively with total hydrogen production of 42.4 mL and energy recovery of 57.4%. Cumulative hydrogen production for a five day cycle of MEC operation was 0.16 m3H2/m3/d.

Preparation and physical properties of [PVA][0.7] [NaBr][0.3] [H[3]PO[4]][xM] solid acid membrane for phosphoric acid - Fuel cells

A solid acid membranes based on poly [vinyl alcohol] [PVA], sodium bromide [NaBr] and phosphoric acid [H[3]PO[4]] were prepared by a solution casting method. The morphological, IR, electrical and optical properties of the [PVA][0.7][NaBr][0.3][H[3]PO[4]][xM] solid acid membranes where x =0.00, 0.85, 1.7, 3.4, 5.1 M were investigated. The variation of film morphology was examined by scanning electron microscopy [SEM] studies. FTIR spectroscopy has been used to characterize the structure of polymer and confirms the complexation of phosphoric acid with host polymeric matrix. The temperature dependent nature of ionic conductivity and the impedance of the polymer electrolytes were determined along with the associated activation energy. The ionic conductivity at room temperature was found to be strongly depends on the H[3]PO[4] concentration which it has been achieved to be of the order 4.3 x 10[-3] S/cm at ambient temperature. Optical measurements showed a decrease in optical band gap and an increase in band tail width with the increase of phosphoric acid. The data shows that the [PVA][0.7][NaBr][0.3][H[3]PO[4]][xM] solid acid membrane is promising for intermediate temperature phosphoric acid fuel cell applications

[Electricity generation from synthetic wastewater treatment in microbial fuel cell]

Microbial fuel cell [MFC] used for electricity generation and wastewater treatment, simultaneously. In MFC, microorganisms act as a catalyst to convert chemical energy stored in organic materials into electrical energy. This study was performed with the aim of electricity generation from synthetic wastewater treatment in microbial fuel cell. A dual chambered microbial fuel cell was operated in continuous flow for 720 hours at temperature 20 +/- 4 °C at different organic loading rates and hydraulic retention times. Organic loading rate and hydraulic retention time were effective factors for the power production and removal of organic loading rate. Maximum COD removal efficiency was observed as 49% for a period of 1.5 to 2.5 hours that this range of time can be used as optimum retention time for operation of microbial fuel cell reactor. Maximum voltage and power production were obtained 700 mV and 1700 mW/m[2], respectively. Considering the advantages such as direct electricity generation from wastewater and considerable removal efficiency of organic loading rate, wastewater treatment in a microbial fuel cell, application of industrial scale microbial fuel cell for wastewater treatment is recommended after complementary studies and economic assessment

Preface for special issue on bioenergy (2013) / 生物工程学报

Bioenergy, as a renewable energy, is one of the best solutions to substitute part of fossil fuels. Based on the 6th World Bioenergy Symposium, this special issue includes latest reports and articles on the fields of bioethanol, biodiesel, microbial lipid, biofuel standard and aviation biofuels.

[Electricity production through treatment of simulated wastewater of food industries using dual chamber microbial fuel cell [MFC] with nafions membrane]

Microbial fuel cells are the electrochemical exchangers that convert the microbial reduced power, generated via the metabolism of organic substrate, to electrical energy. The aim of this study is to find out the rate of produced electricity and also treatment rate of simulated wastewater of food industries using dual chamber microbial fuel cell [MFC] without mediator and catalyst. MFC used in this study was consisted of two compartments including anaerobic anode chamber containing simulated food industries wastewater as synthetic substrate and aerobic cathode chamber containing phosphate buffer, respectively. These two chambers were separated by proton exchange membrane made of Nafion. Produced voltage and current intensity were measured using a digital ohm meter and the amount of electricity was calculated by Ohm's law. Effluent from the anode compartment was tested for COD, BOD5, NH3, P, TSS, VSS, SO42- and alkalinity in accordance with the Standard Methods. In this study, maximum current intensity and power production at anode surface in the OLR of 0.79 Kg/m3.d were measured as 1.71 mA and 140 mW/m2, respectively. The maximum voltage of 0.422 V was obtained in the OLR of 0.36 Kg/m3.d. The greatest columbic efficiency of the system was 15% in the OLR of 0.18 Kg/m3.d. Maximum removal efficiency of COD, BOD5, NH3, P, TSS, VSS, SO42- and alkalinity, were obtained 78, 72, 66, 7, 56, 49, 26 and 40%, respectively. The findings showed that the MFC can be used as a new technology to produce electricity from renewable organic materials and for the treatment of different municipal and industrial wastewaters such as food industries

Application of microbial fuel cell (MFC) in solid waste composting / 生物工程学报

Microbial fuel cell (MFC) is a new technology that can recover energy from biomass with simultaneous waste treatment. This technique has been developed fast in recent years in combining with environmental techniques such as wastewater treatment, degradation of toxic pollutants and desalination. With the increase of solid waste, applying MFC in composting is promising due to its property of waste disposal with simultaneous energy generation. In this paper, the microbial community of MFCs during composting was summarized. Four major influencing factors including electrodes, separators, oxygen supplement and configurations on the performance of composting MFCs were discussed. The characteristics of composting MFC as a new technique for reducing solid waste were as follows: high microbial biomass resulted in the high current density; adaptable to different environmental conditions; self-adjustable temperature with high energy efficiency; the transportation of proton from anode to cathode were limited by different solid substrates.

Preface for special issue on bioenergy / 生物工程学报

More and more attentions have been being paid to seeking alternatives for fossil fuels. Bioenergy, as a renewable energy, is one of the best solutions. Bioenergy has been developed rapidly in China, which became the third largest producer and consumer of fuel ethanol. In order to promote the research of bioenergy technology in China, this special issue includes latest reports and articles on the fields of bioethanol, biodiesel, microbial lipid and biofuel system analysis.

Preface for special issue on biofuels and bioenergy / 生物工程学报

Biofuels and bioenergy not only benefit independence of energy supply, but also mitigate CO2 emissions. This special issue includes review reports and research articles involving various biofuels and bioenergy products and systems such as fuel ethanol, biodiesel, biogas, biohydrogen, microbial fuel cells and microbial electrolysis cells. Both fundamental research and technology development are highlighted. And in the meantime, challenges for large scale production and application of biofuels and bioenergy are discussed. Taking advantages of modern biotechnology advances, solutions to address these challenges are envisioned.

Progress on biogas technology and engineering / 生物工程学报

Dwindling supplies of conventional energy sources and the demand to increase the share of renewable energy for sustainability have increased the significance of biogas, the product of synergistic fermentation of biodegrable organic wastes from municipal, agricultural and industrial activities by microbial populations under anaerobic conditions. With extensive research and engineering practice, many technologies and modes have been developed for biogas production and application. Currently, the most widely used mode is the complete-mixing mesophilic fermentation. Europe, especially Germany, is leading the world in the combined heat and power production (CHP) from biogas. In this paper, updated progress in biogas technologies is reviewed, with focuses on anaerobic microorganisms, bioreactor configurations and process development, biogas production and applications, in which perspectives of biogas as a clean and renewable energy are projected.