Katalin Bélafi-Bakó

University of Pannonia, Veszprém · Research Institute on Bioengineering, Membrane Technology and Energetics

Keywords: Agrobacterium 1; Xenorhabdus 2; NR-AMP 3 T-DNA keyword 4; TI-plasmid 5; Intact/Cured/T-DNA Deleted 6 Sensitive/Resistant 7; EMA_PF2 8; HPLC 9

Itaconic acid is an important bio-based chemical. The present study aims to evaluate the applicability of semi-continuous fermentation technique for itaconic acid production by Aspergillus terreus. The fermentation is planned to be connected with bipolar membrane electrodialysis unit for acid recovery. This process allows the reuse of residual gluc...

Urine is a widely available renewable source of nitrogen and phosphorous. The nitrogen in urine is present in the form of urea, which is rapidly hydrolyzed to ammonia and carbonic acid by the urease enzymes occurring in nature. In order to efficiently recover urea, the inhibition of urease must be done, usually by increasing the pH value above 11....

Itaconic acid is a promising biobased organic acid that can be industrially produced in an eco-friendly way by aerobic fungal fermentation. It has many applications, e.g. in biopolymers, and has the potential to help replace or facilitate the green production of other similar but fossil-based chemicals. Nowadays, its production costs are still rela...

Microbial electrosynthesis cells (MES) are devices with demonstrated capability to treat CO2-containing gaseous streams and alongside, generate certain valuable chemical products, particularly methane gas, carboxylic acids, alcohols, etc. Although there are many varieties of MES with their own individual characteristics, all systems have a lot in c...

Biohydrogen production based on agro-industrial wastes might be an attractive and effective technology for providing an energy source in the future. Dark fermentation is considered to be one of the most suitable biohydrogen formation processes. In this paper, various agro-industrial wastes as well as microorganisms applied for biohydrogen formation...

This study aimed to evaluate a gas-liquid membrane contactor for recovering the dissolved gases of methane (CH4) and carbon dioxide (CO2) from model aqueous anaerobic effluents. For this purpose, synthetic effluents were prepared by using the gas mixtures of SE-1: 100/0, SE-2: 0/100 and SE-3: 50/50 CH4/CO2 vol.% as well as DI water. The units in wh...

In this research, the recovery of dissolved biogas (CO2/CH4) from synthetic anaerobic effluents was studied using non-porous, polydimethylsiloxane (PDMS), hollow-fibre gas-liquid membrane contactors towards the design of a reduced carbon-footprint integrated bioprocess. As a key parameter, the gas-to-liquid (G/L) ratio (employing argon as sweep gas...

In this study, microbial fuel cells deploying heterogeneous ion exchange membranes were assessed. The behavior of the cells as a function of the membrane applied was evaluated in terms of maximal current density, electron recovery efficiency and energy production rate (up to 427.5 mA, 47.7 % and 660 J m-2 h-1 , respectively) at different substrate...

Microbial secondary metabolites are widely applied in many fields as medicines, pesticides, food additives, etc. To produce these compounds, several fermentation methods exist from lab-scale to industrial manufacturing, all of them having different advantages and drawbacks. In this comprehensive review, four types of cultivation techniques - conven...

Anaerobic bioprocesses, such as anaerobic digestion and dark fermentation, provide energy carriers in the form of methane and hydrogen gases, respectively. However, their wastewater-type residues, that is, the fermentation effluents, must be treated carefully due to the incomplete and non-selective conversion of organic matter fed to the actual sys...

The scientific interest towards itaconic acid (IA) recovery (produced industrially from biomass by fermentation) significantly increased from around the last decade. IA is a value-added chemical with key-role in the production of versatile polymers and is potentially able to replace certain petrochemical-based materials. Typically, multi-step cryst...

Anaerobic degradation processes: anaerobic digestion (biogasification), biohydrogen fermentation (dark) and microbial fuel cells were applied to treat the organic fraction of a municipal solid waste. The processes were compared based on their ability of energy recovery and Chemical Oxygen Demand reduction.

Organic acids, e.g, citric acid, fumaric acid, lactic acid, malic acid, pyruvic acid and succinic acid, have important role in the food industry and are potential raw materials for the sustainable chemical industry. Their fermentative production based on renewable raw materials requires innovatively designed downstream processing to maintain low en...

This study investigated microalgal CO2 fixation at the CO2 concentration ranging from 5 to 40% and the CO2 loading rate of 14.4 to 57.6 L/L-d. Chlorella sp. (AG10133) was selected as the optimal strain for CO2 fixation among examined algal strains. The microalgal CO2 fixation was highly dependent on the CO2 loading rate as well as CO2 concentration...

Hydrophobic ionic liquids (IL) may offer a special electrolyte in the form of supported ionic liquid membranes (SILM) for microbial fuel cells (MFC) due to their advantageous mass transfer characteristics. In this work, the proton and ion transfer properties of SILMs made with IL containing imidazolium cation and [PF6]− and [NTf2]− anions were stud...

In this work, the potential of utilizing a polyetherimide (PEI) hollow‐fiber membrane to separate synthetic biohydrogen mixture (H2/CO2) was studied. From the gas separation experiments, where the effects of feed to permeate pressure ratio (Pfeed/Ppermeate) and stage‐cut as key factors were evaluated, it was found that the PEI membrane had the capa...

In this work, a novel cation exchange membrane, PSEBS SU22 was deployed in microbial fuel cells (MFCs) to examine system efficacy in line with membrane characteristics and inoculum source. It turned out that compared to a reference membrane (Nafion), employing PSEBS SU22 resulted in higher current density and electricity generation kinetics, while...

The scope of the current review is to discuss and evaluate the role of the external electrical load/resistor (EEL) on the overall behavior and functional properties of microbial fuel cells (MFCs). In this work, a comprehensive analysis is made by considering various levels of MFC architecture, such as electric and energy harvesting efficiency, anod...

Deriving biohydrogen from dark fermentation is a practically suitable pathway for scaling-up and envisaged mass production. However, a common issue with these systems is the incomplete conversion of feedstock as a result of which, a process effluent with notable organic strength is left behind. The main components of dark fermentation effluents are...

In this study, hollow fibers of commercial polyimide were arranged into membrane modules to test their capacity and performance towards natural gas processing. Particularly, the membranes were characterized for CO2/CH4 separation with and without exposure to some naturally occurring contaminants of natural gases, namely hydrogen sulfide, dodecane,...

To increase the efficiency of microbial fuel cells (MFCs), the separator (which is mostly a membrane) placed between the electrodes or their compartments is considered of high importance besides several other biotic and abiotic factors (e.g. configuration, mode of operation, types of inoculum and substrate). Nafion-based proton exchange membranes (...

Effluents of anaerobic processes still contain valuable components, among which volatile fatty acids (VFAs) can be regarded and should be recovered and/or used further in applications such as microbial electrochemical technology to generate energy/energy carriers. To accomplish the separation of VFAs from waste liquors, various membrane-based solut...

Nowadays, the merging of membrane and fermentation technologies is receiving significant attention such as in the case of itaconic acid (IA) production, which is considered as a value-added chemical. Its biotechnological production is already industrially established; however, the improvements of its fermentative and recovery steps remain topics of...

The performance and behavior of microbial fuel cells (MFCs) are influenced by among others the external load (Rext). In this study, the anode-surface biofilm formation in MFCs operated under different Rext selection/tracking-strategies was assessed. MFCs were characterized by electrochemical (voltage/current generation, polarization tests, EIS), mo...

Itaconic acid (IA) is a well-known, unsaturated, dicarboxylic acid. It is widely used in plastic industry as a co-polymer. Nowadays the itaconic acid is mainly produced by fermentation. Due to the product inhibition effect during the batch operation, the continuous/semi-continuous separation of itaconic acid from the fermentation broth is highly de...

The purpose of downstream processing in a fermentation technology is the isolation, purification and concentration of the final product. Membrane processes are generally used in these steps. In this paper, the application possibilities of polymer membranes in pressure-driven membrane techniques (microfiltration, ultrafiltration, nanofiltration), pe...

In this work, two polymeric membrane separators (a proton exchange membrane (PEM), Nafion, and an anion-exchange membrane (AEM), 1,4-diazabicyclo[2.2.2]octane (DABCO)-functionalized PSEBS) deployed in microbial fuel cells (MFCs) are comparatively assessed. The performances of MFCs according to membrane type were evaluated by biological and electroc...

Biohydrogen production via dark fermentation is currently the most developed method considering its practical readiness for scale-up. However, technological issues to be resolved are still identifiable and should be of concern, particularly in terms of internal mass transfer. If sufficient liquid-to-gas H2 mass transfer rates are not ensured, serio...

In this work, itaconic acid (IA) was produced biotechnologically by Aspergillus terreus fungal strain from glucose. The performance of the batch fermentation was kinetically assessed and the maximal IA production potential, maximal production rate and lag-phase time were determined as 28.1 g/L, 3.83 g/L day and 1.52 days, respectively. In addition,...

In the course of dark fermentative hydrogen production, a complex gaseous mixture with significant quantity of CO2 is formed. Hence, proper separation of H2 and CO2 is required for adequate utilization of hydrogen gas in fuel cell applications. Technological solutions for the removal of CO2 can be designed by using gas separation membranes. Neverth...

Membrane separators are key elements of microbial fuel cells (MFCs), especially of those constructed in a dual-chamber configuration. Until now, membranes made of Nafion have been applied the most widely to setup MFCs. However, there is a broader agreement in the literature that Nafion is expensive and in many cases, does not meet the actual (mainl...

The effects of the bioreactor conditions, in particular the mode and intensity of aeration and mixing were studied on itaconic acid (IA) fermentation efficiency by Aspergillus terreus strain from glucose substrate. IA was produced in batch system by systematically varying the oxygen content of the aeration gas (from 21 to 31.5 vol% O2) and the stir...

In this review, the conversion (thermochemical, biological and hybrid) of chemical energy chiefly enclosed in biomass structures i.e. as 30–50 % cellulose, 15– 35 % hemicellulose and 10–20 % lignin into various forms of fuels/energy products is comparatively analyzed. Cellulose and hemicelluloses formulate almost ~ 70 % of the biomass and are defin...

Biological itaconic acid production can by catalyzed by Aspergillus terreus (a filamentous fungi) where the fermentation medium pH is of prominent importance. Therefore, in this work, we investigated what benefits the different pH regulation options might offer in enhancing the process. The batch itaconic acid fermentation data underwent a kinetic...

In this study, microbial fuel cells(MFCs)–operated withnovel cation-and anion-exchange membranes, in particular AN-VPA 60 (CEM) and PSEBS DABCO (AEM)–were assessed comparatively with Nafion proton exchange membrane (PEM). The process characterization involved versatileelectrochemical (polarization, electrochemical impedance spectroscopy –EIS, cycli...

Leachate generated in landfills is considered as a hazardous waste stream due to its composition and needs adequate treatment for environmental protection purposes. Nonetheless, a contemporary technology should not only be able to deal with its degradation, but at the same time, recover energy in various forms. Such valorization approaches with pri...

The scope of the review is to discuss the current state of knowledge and lessons learned on biofouling of membrane separators being used for microbial electrochemical technologies (MET). It is illustrated what crucial membrane features have to be considered and how these affect the MET performance, paying particular attention to membrane biofouling...

In this study, mixed culture bioelectrochemical systems were operated with various membrane separators: one prepared with 1-Butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]) ionic liquid and another one called Nafion, used as reference for comparative evaluation. In the course of experiments, the primary objective was to reveal the influe...

This review article focuses on an assessment of the innovative Gas Separation Membrane Bioreactor (GS-MBR), which is an emerging technology because of its potential for in-situ biohydrogen production and separation. The GS-MBR, as a special membrane bioreactor, enriches CO2 directly from the headspace of the anaerobic H2 fermentation process. CO2 c...

The possible replacement of lubricants with fossil-fuel sources and the manufacture of biolubricants with more beneficial features were studied. Oleic acid and isoamyl alcohol were reacted with an enzyme in an ionic liquid. During the reaction conventional as well as microwave heating was applied. After the experimental determination of the optimal...

Itaconic acid is an organic acid produced mainly for non-food purposes. It can be manufactured by biotechnological synthesis using various strains which results in the salt form of the acid. In this work, the separation of sodium itaconate by electrodialysis was studied. Homopolar cation- and anion-selective membranes were applied and the module wa...

Significant advances in the design of bioelectrochemical systems (BES) have promoted these applications to be seen as contemporary biotechnological platforms. However, notable issues in system architecture are still to be addressed and overcome, in particular concerning the membrane separators, which rely widely on polymers. These architectural com...

This study investigated mixed microalgae consortia cultivation in a fed batch reactor using textile wastewater. The results showed 95% of total phosphorus (TP) and 70% of total nitrogen (TN) depletion during the operational period. Algal biomass growth, pollutant removal, and biomass constituents were examined for five cycles of the fed batch opera...

In this work, bioaugmentation strategy was tested to enhance electricity production efficiency from municipal waste liquor feedstock in microbial fuel cells (MFC). During the experiments, MFCs inocu-lated with a mixed anaerobic consortium were enriched by several pure, electro-active bacterial cultures (such as Propionibacterium freudenreichii, Cup...

Lignocellulosic biofuel, in particular hydrogen gas production is governed by successful feedstock pretreatment, hydrolysis and fermentation. In these days, remarkable attention is paid to the use of ionic liquids to make the fermentable regions of lignocellulose biomass more accessible to the biocatalysts. Although these compounds have great poten...

The purpose of this research was to improve microbial fuel cell (MFC) performance - treating landfill-derived waste liquor - by applying effluents of various biogas fermenters as inocula. It turned out that the differences of initial microbial community profiles notably influenced the efficiency of MFCs. In fact, the adaptation time (during 3 weeks...

In this paper, the enrichment of methane by membrane technology was studied by employing (i) a model as well as (ii) a real biogas mixture produced on a laboratory-scale. Thereafter, the endurance of the process was tested at an existing biogas plant. The commercial gas separation module under investigation contained hollow fiber membranes with a p...

Background Antimicrobial compounds released by the entomopathogenic nematode-symbiont bacterium Xenorhabdus budapestensis (EMA) are oligopeptides and the "trump" is fabclavine. They kill antibiotic multi-resistant Escherichia coli, Salmonella ; mastitis-isolate Staphylococcus aureus, E. coli and Klebisella pneumoniae ; S. aureu s MRSA strain; plant...

Background Antimicrobial compounds released by the entomopathogenic nematode-symbiont bacterium Xenorhabdus budapestensis (EMA) are oligopeptides and the "trump" is fabclavine. They kill antibiotic multi-resistant Escherichia coli, Salmonella ; mastitis-isolate Staphylococcus aureus, E. coli and Klebisella pneumoniae ; S. aureu s MRSA strain; plant...

In this paper, pectin-reinforced, supported liquid membranes (SLMs) prepared with carbonic anhydrase (CA) were investigated for CO ⁠ 2 /N ⁠ 2 separation. In the first part of the study, the effect of [Bmim][NTf ⁠ 2 ] ionic liquid (IL)-as possible solvent to fill the pores of cellulose acetate support during SLM fabrication-on enzyme activity was te...

In this study, a novel miniature terrestrial microbial fuel cells (TMFCs) inoculated with commercial garden soil was developed to generate bioelectricity. The startup and stabilization were evaluated as open circuit voltage (OCV). The effect of an enrichment procedure with 12 mM, 37 mM, and 61 mM Na-acetate under anaerobic conditions was assessed....

Esters of short chain acids and alcohols are found in nature as compounds of flavors. Lately the method for their manufacture has been the enzymatic esterification in non-conventional media. Although several reactions have been studied in various media (organic solvents, ionic liquids, supercritical fluids, solvent-free systems), there has been no...

(Red, green and brown) macroalgal biomass is a propitious candidate towards covenant alternative energy resources to be converted into biofuels i.e. hydrogen. The application of macroalgae for hydrogen fermentation (promising route in advancing the biohydrogen generation process) could be accomplished by the transformation of carbohydrates, which i...

Ammonia recovery from industrial wastewater is gaining more and more attention. Due to the environmental impact the regulations for ammonia emissions are becoming stricter, and the need for improved processes is growing. An alternative to conventional technology is TransMembraneChemiSorption, using hydrophobic membranes for controlled mass transfer...

The composition of wastewater produced in industrial processes can vary dynamically and often ran­domly. Immediate intervention is necessary to preserve the water quality before any parameter of the wastewater exceeds the threshold limit; therefore, the parameters of the wastewater must be deter­mined in real time. Direct laboratory methods have lo...

Environmental protection is one of the today’s most important concerns, therefore, firms are expected to reduce their environmental loads continuously whilst enhancing their productivity. In our study, a procedure was developed to manage the wastewater of a pharmaceutical process. The parameters of the wastewater, which flows into the sewerage syst...

Fresh juices of colourful wild berries: cornelian cherry, blackthorn, white beam and elderberry are considered as valuable, highly nutritive beverages and characterized by the high level of vitamins and antioxidant capacity. The concentration process of these juices by membrane osmotic distillation was studied, where only water vapour is eliminated...

Fermentative hydrogen production research grows rapidly around the globe to harness "clean energy" by the utilization of renewable feedstock, which can reduce climate change impacts as well as able to resolve concerns related to fossil fuel consumption. Biohydrogen production technologies have been carried out in various modes of operation among wh...

Erwinia amylovora is one of the most frequently occurred plant pathogenic bacterium. It causes necrosis and blight symptoms on host plants and it lead to considerable yield losses throughout the world on apple trees. There is no effective chemical treatment is currently available against fire blight. The purpose of the present study was to search a...

This work reports on the separation of biohydrogen using a hollow-fiber PDMS membrane. The performance of the module was evaluated using binary CO2/H2 (35-65vol.% H2 content) and ternary CO2/H2/H2S mixtures (50vol.% H2, 50vol% CO2, 25-175ppm H2S) and the effect of recovery and gas composition (with special focus on hydrogen sulfide content) was rev...

Esterification of glucose and palmitic acid catalyzed by Novozyme 435 was carried out in three ionic liquids (IL): Cyphos 104, Cyphos 109 and [bmim][PF6]. To our knowledge this product has not been obtained in these ILs from these substrates up to now. The equilibrium conversion, as well as the amount of produced ester, were the highest in [bmim][P...

A novel substrate (obtained from biofraction of municipal solid waste by pressing and called LPW) rich in organic substances was used in three anaerobic degradation processes (biogas, biohydrogen fermentation and microbial fuel cells) to comparatively assess their feasibility for energy recovery. It has turned out that all the processes have succes...

The organic matter consumption and hydrogen production rate were evaluated in a two-chamber microbial electrolysis cell (MEC). Three chemical oxygen demand (COD) concentration levels (400, 600 and 1200 mg/L) were tested. The COD was composed of a mixture of volatile fatty acids (VFAs) present in the effluent of a dark fermentation process. The two...

In this study various pretreatment methods of sewage sludge inoculum and the statistical process optimization of de-oiled jatropha waste have been reported. Peak hydrogen production rate (HPR) and hydrogen yield (HY) of 0.36 L H2/L-d and 20 mL H2/g Volatile Solid (VS) were obtained when heat shock pretreatment (95 oC, 30 min) was employed. Afterwar...

In this work biohydrogen generation and its improvement possibilities from beverage industrial wastewater were sought. Firstly, mesophilic hydrogen fermentations were conducted in batch vials by applying heat-treated (80°C, 30 min) sludge and liquid (LB-grown) cultures of Escherichia coli XL1-Blue/Enterobacter cloacae DSM 16657 strains for bioaugme...

In this work the establishment of a double-membrane bioreactor was aimed. Initially, a continuous hydrogen fermenter was coupled with a commercial Kubota® microfiltration membrane module and the production performance of the cell-retentive design was evaluated under various hydraulic retention times. As a result, it has been observed that altering...

The cheap, renewable lignocellulosic materials are relevant to the future of the biofuel production. The wood and agricultural wastes (e.g.: straw, corn stover) provide a raw material source that could not be used for human consumption whereof a part of biofuels provided does not threat the food supply. The aim of the work was to carry out the pre-...

Integration of bioconversion and product separation process, as well as process intensification, have been a focus of the scientific community for some time now because of the necessity of developing processes that are environmentally friendly, spend fewer chemicals and less energy, have higher yields, and generate more profit. In this chapter the...

In this project, the production of biohydrogen, as a renewable and sustainable energy source was studied. Biohydrogen was manufactured by using E. coli strain in a batch dark fermentative process integrated with membrane gas separation. Two different methods were applied: Firstly, the amount of the produced gas and component concentrations were mea...

Gas separation by membranes is one of the most intensively studied fields of separation processes. Among them, supported liquid membranes (SLMs) are considered to be highly selective and promising techniques. Using ionic liquids in preparing SLMs has numerous advantages in this particular area. This chapter summarizes the benefits of SLMs, the feat...

In this study, the preconditioning of anaerobic culture by aging was carried out followed by testing various pretreatments (heat shock and alkali) to improve H2 production. It has turned out that aging could enhance the hydrogen generation meanwhile heat- and alkali curing led to comparable H2 formation activity with a slight advantage of the forme...

Microbial fuel cells are bioelectrochemical devices converting chemical energy of organic compounds (i.e. biomass) into electrical energy by catalytic reactions of microbes under anaerobic conditions. The operation of two-chamber microbial fuel cells by Shewanella putrefaciens and mesophilic anaerobic sludge was studied comparatively, using xylose...

In this study, the effects of pretreatment temperature and time during conventional and unconventional, microwave-assisted heat shock on the hydrogen producing capability of anaerobic seed sludge from soluble starch was focused. It was found that the different heat transfer techniques resulted in seed cultures with comparable hydrogen production po...

In this work the purification of biohydrogen was attempted in mixed gas measurements using a commercial polyimide membrane module. The impact of several process variables (gas composition, temperature, ratio of retentate and feed flows) on the real separation efficiency was statistically studied applying a 3-level full-factorial experimental design...

The ability of (dimethyl siloxane) (PDMS) and SAPO 34 membrane modules to separate a H2/CO2 gas mixture was investigated in a continuous permeation system in order to decide if they were suitable to be coupled to a biological hydrogen production process. Permeation studies were carried out at relatively low feed pressures ranging from 110 to 180 kP...

Many types of membranes are available to enrich hydrogen. Nevertheless, there are some with special potential for biohydrogen purification such as the non-porous, polymeric and ionic liquid based membranes. The attractiveness of these membranes comes from the fact that they can be employed nearly under the conditions where biohydrogen formation tak...

Jute has been used as a raw material to chemically modified cellulose microfibres. For this purpose three chemical treatments were used: mercerization with NaOH, acetylating with nitric acid and acetic acid and finally hydrolysis with sulphuric acid. The isolated microfibrils were characterized by Fourier transform infrared spectroscopy (FTIR) and...