Search

Freeze storage and pasteurization of human milk are common treatments in milk banks. However, thermal treatment changes milk quality for preterm infants’ nutrition. Therefore, this paper aimed to examine preterm human milk's nutritional profile and antioxidant potential after storage, pasteurization, and after supplementation with a fortifier. The effects of storage processes were estimated on the mature preterm milk of 30 breastfeeding women. Total proteins, lipids, and lactose were determined after thermal processing and supplementing mature preterm milk with a fortifier. The ferric-reducing antioxidant potential method and lipid peroxidation inhibition assay determined the antioxidant capacity. Protein concentration decreased after frozen storage and pasteurization (p

Persistent organic pollutants (POPs) are lipophilic, constant and bioaccumulative toxic compounds. In general, they are considered resistant to biological, photolytic, and chemical degradation with polychlorinated biphenyls (PCBs) belonging to these chemicals. PCBs were never produced in Serbia, but they were imported and mainly used in electrical equipment, transformers, and capacitors. Our study aimed to analyse sequential multi-stage aerobic/anaerobic microbial biodegradation of PCBs present in the river sediment from the area known for long-term pollution with these chemicals. The study with an autochthonous natural microbial community (NMC model system) and NMC augmented with allochthonous hydrocarbon-degrading (AHD) microorganisms (isolated from location contaminated with petroleum products) (NMC-AHD model system) was performed in order to estimate the potential of these microorganisms for possible use in future bioremediation treatment of these sites. The laboratory biodegradation study lasted 70 days, after which an overall >33 % reduction in the concentration of total PCBs was observed. This study confirmed the strong potential of the NMC for the reduction of the level of PCBs in the river sediment under alternating multi-stage aerobic/anaerobic conditions.

Water contaminated with diesel oil represents one of the greatest challenges in waste water management. Water soluble fraction (WSF) is of particular interest because of its toxicity to aquatic organisms and discharge regulations set by environmental authorities. Biochar sorbents have attracted great attention, due to their low cost origin and advantageous properties as well as high sorption capacities in sorption processes. In this study, we have reported the synthesis and characteristics of novel biochar sorbent made from waste lignocellulosic biomass (peach stones (PS)) and evaluated its possible application in removal of diesel WSF from synthetic water. Physiochemical characteristics of the biochar sample were analysed by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) method, and Fourier-transform infrared spectroscopy (FTIR), along with the elemental analysis. Characterisation of PS biochar (PS-B) indicated high multi porous surface area (159.1 m2 g-1) with the average pore diameter 2.7 nm. FTIR results indicated higher presence of aromatic compounds in PS-B as compared to PS. The sorption experiments performed in a batch system using PS-B resulted in more than 95 % removal of diesel WSF, reaching equilibrium after 5 h. Equilibrium data were well fitted by Freundlich isotherm, while the pseudo-second order equation fitted well the kinetic data, indicating chemisorption involving valency forces through the sharing/exchange of electrons between the sorbent and PS-B. Applications of ecotoxicology tests based on a microbial biosensor (Aliivibrio fischeri) have shown a significant toxicity reduction of water sample after the treatment with biochar.

Environmental pollution is a global problem, while bioremediation technology removes pollutants from the environment using microorganisms. This study was aimed at investigating how a bioremediation process affected soil humification. In soil polluted with petroleum and its derivatives that was submitted to bioremediation, besides the total petroleum hydrocarbons and the number of microorganisms, quantitative and qualitative changes of isolated humic acids were determined during the process. The bioremediation of 150 m3 of polluted soil lasted 150 days. The level of total petroleum hydrocarbons decreased by 86.6 %, while the level of humic acids increased by 26.5 %. The elemental analysis showed the reduction of C and the H/C ratio and the increase of O and the O/C ratio of isolated humic acids during the process. The ratio of absorbencies at 465 and 665 nm also increased. Based on this and the Fourier-transform infrared spectra, it was shown that the humic acids isolated at the end of bioremediation were enriched with oxygen functional groups and aromatic structures. This study provides one of the first insights into the relationship between bioremediation and humification, as well as evidence of how hydrocarbon-degrading microorganisms have a significant influence on changes to humic acid structure during bioremediation. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43004]

Humic acids isolated from the soil of heat power plant (HA-E) contaminated with oil were analyzed by the Fourier Transform Infrared spectra (FTIR). In comparison with humic acids standard (HA-S) luck of intense broad band of stretching vibrations of hydrogen-bonded hydroxyl groups (3600-3200 cm-1) is evident. HA-E have a pick at 1649 cm-1 which could belong to carbonyl groups. HA-E are heavily oxidized and among isolated microorganisms Achromobacter denitrificans may be responsible for such intensive oxidation of HA-E. To phylogenetically diverse nitrate-reducing microorganisms that have the capacity to utilize reduced HA as electron donors in soils, we can ad A. denitrificans. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43004]

Due to their extensive use, petroleum hydrocarbons are among the most common groundwater contaminants. Compared to the traditional methods of physical pumping of contamination from the aquifer and subsequent treatment (i.e., pump and treat), bioremediation is an economically cost-effective technology. The aim of this remediation approach is to transform biologically contaminants, most often by microbiological activity, into non-toxic compounds. More precisely, it is an active remediation process that involves biostimulation (increase of aquifer oxygenation, addition of nutrients) and/or bioaugmentation (injection of a concentrated and specialized population of microorganisms). Using both biostimulation and bioaugmentation, enhanced in situ groundwater bioremediation was applied at a hydrocarbon-contaminated site in Belgrade. The bioremediation treatment, applied over twelve months, was highly efficient in reducing the concentrations of total petroleum hydrocarbon (TPH) to acceptable levels. The concentration of TPH in the piezometer P-5 was reduced by 98.55 %, in the piezometer P-6 by 98.30 % and in the piezometer P-7 by 98.09 %. These results provided strong evidence on the potential of this remediation approach to overcome site-limiting factors and enhance microbiological activity in order to reduce groundwater contamination. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43004]

The group of polycyclic aromatic hydrocarbons (PAHs) are very hazardous environmental pollutants because of their mutagenic, carcinogenic and toxic effects on living systems. The aim of this study was to examine and compare the ability and efficiency of selected bacterial isolates obtained from oil-contaminated areas to biodegrade PAHs. The potential of the bacteria to biodegrade various aromatic hydrocarbons was assessed using the 2,6-dichlorophenol-indophenol assay. Further biodegradation of PAHs was monitored by gravimetric and gas-chromatographic analysis. Among the eight bacterial isolates, identified on the basis of 16S rDNA sequences, two isolates, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, had the ability to grow on and utilize almost all examined hydrocarbons. Those isolates were further examined for biodegradation of phenanthrene and pyrene, as single substrates, and as a mixture, in vitro for ten days. After three days, both isolates degraded a significant amount phenanthrene, which has a simpler chemical structure than pyrene. Planomicrobium sp.RNP01 commenced biodegradation of pyrene in the PAH mixture only after it had almost completly degraded phenanthrene. The isolated and characterized bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05, have shown high bioremediation potential and are likely candidates to be used for degradation of highly toxic PAHs in contaminated areas. [Projekat Ministarstva nauke Republike Srbije, br. III43004]

In this paper an overview of data collected during monitoring of lead content in atmospheric precipitation on GAW/EMEP (Global Atmosphere Watch/European Monitoring and Evaluation Programme) station “Kamenicki Vis”, Serbia from 2000 to 2010 is given. Annual arithmetic mean concentrations, weighted arithmetic mean concentrations, and median of week samples are presented. Obtained data was compared with results of analysis of atmospheric precipitation collected on experimental EMEP station “Zeleno brdo“, Serbia and discussed in scope of European average levels of lead content in precipitation and air. Significant increase of average annual lead content in precipitation was observed in 2003 and 2007. Observed peaks can not be seen on average European trends thus lead to conclusion that recorded increases are characteristic for local region. In order to further discuss nature and direction of possible sources of detected lead pollution short analysis of lead emission data was performed. An effort was made to gather data from the counties that lay in directions from which dominant winds blow as well as for Serbia. For this purpose total national emissions from LRTAP (Long-range transboudary air pollution) Convention emission inventory report and EMEP emission inventory were used as well as data published by relevant national authorities. According to these emission levels, majority of surrounding countries couldn’t have contributed much to the recorded increases of lead content in precipitation. However, several possible sources were revealed. In all studied countries emission levels steadily dropped during the analyzed period, whereas only for Serbia different trend was observed. Presented data leads to conclusion that recorded increase of lead content in precipitation in 2003 probably originates from trans-boundary contributions, while increases in 2007 and onwards may come from Serbia’s own emissions. [Projekat Ministarstva nauke Republike Srbije, br. TR 34023]

Sustainable development is a concept that is based on the development of the human society without compromising the natural resources, which should improve human lives and protect the environment for future generations. The UN Agenda 2030 has set 17 goals aimed to transform the development of humanity in accordance with the environment, and with the social and economic rights. This concept is recognized as one of the most important concepts for the future international development. One of the four main pillars of the Agenda 2030 is a pillar Planet, which consists of five sustainability development goals (SDGs) aiming to clean the pollution on the Earth and set the sustainable use of the Earth's resources. The aim of paper is to demonstrate the role of oil pollution bioremediation in achieving SDGs by assessing the importance of this technology and using microorganisms as natural capacity of the Earth for self-cleaning. This review article highlights the applicability of bioremediation as an oil pollution cleaning technique and reviews the compliance of bioremediation with the SDGs. According to this review, bioremediation techniques are an important element which can help in integrated approach to achieve several goals set by the Agenda 2030. Due to the incomplete biodegradation and co-contamination by other chemicals, further research is needed in order to make bioremediation a more effective biotechnological strategy. It is necessary to integrate the Agenda 2030 to university curricula and stream SDGs into scientific funding by opening dedicated calls that contribute to selected SDGs of the Agenda 2030. [ABSTRACT FROM AUTHOR]

Diesel contamination in water bodies poses a significant environmental challenge due to the toxic effects of its water-soluble fraction (WSF) on aquatic ecosystems and human health. The aim of this work was the design of a new technological procedure for the purification of water contaminated with the WSF of diesel. The procedure is based on the adsorption of organic pollution on an organozeolite, after which the biodegradation of the adsorbed pollutant takes place. The material for obtaining organozeolite was a natural zeolite from the Zlatokop deposit (Vranje, Serbia). The zeolitic surface was modified with hexadecyltrimethylammonium bromide (HDTMA-Br), a cationic quaternary ammonium salt. The adsorption experiments, with initial WSF concentrations of 2.5–25 mg/L, at pH 6 and at 20 °C, were performed in a batch system using organozeolite, and the results showed that more than 90% of the WSF of diesel was removed, reaching equilibrium after 1 h. The maximum adsorbed capacity of organozeolite for the removal of the WSF of diesel fuel from water under the tested conditions was 22.2 mg/g. Equilibrium data were well fitted by a linear isotherm model, while a pseudo-second-order equation well fitted the kinetic data. After adsorption, a 15-day biodegradation experiment was carried out under batch conditions. The results showed that the examined consortium of microorganisms degraded 80% of the adsorbed contaminant. Additional respirometric analyses showed that, in parallel with the degradation of the contaminant, the degradation of the long-chain HDTMA ions at the surface of the organozeolite also occurred. To the best of our knowledge, this is the first study combining adsorption and biodegradation to remove the WSF of diesel from water. [ABSTRACT FROM AUTHOR]

The use of fossil fuels leads to environmental contamination during their extraction, processing and distribution. Microbial biodegradation provides a sustainable method for cleaning contaminated areas which follows the principles of sustainability. This paper presents the dynamics of biodegradation of hydrocarbon fractions of diesel oil, using Planomicrobium sp. and Rhodococcus sp. isolated from petroleum-contaminated sites. GC–MS analysis was employed to analyse abundances of the specific compounds such as n-alkanes, isoprenoids, sesquitepranes, hopanes, steranes and aromatic compounds (naphthalene and its methylated homologues, phenanthrene and anthracene and their methylated homologues, and dibenzothiophene and its methylated homologues). The obtained results showed that after 30 days of biodegradation of diesel, a significant degradation was achieved, with almost complete degradation of n-alkanes and a decrease in the amount of sesquiterapanes. Rhodococcus sp. had a higher efficiency in degradation of n-alkanes, while Planomicrobium sp. had a higher efficiency in the degradation of branched hydrocarbons. Both strains showed high activity in the biodegradation of sesquitepranes and demonstrate ability to degrade methylated phenanthrenes. Additionally, dimethyl-dibenzothiophenes were almost completely degraded and removed from the system. This study presents the first comprehensive report on the GC–MS analysis of the diesel biodegradation pattern of the Planomicrobium sp., compared with the well-established Rhodococcus sp. [ABSTRACT FROM AUTHOR]

Environmental context: Mitigating the environmental fallout of industrial accidents is crucial. In a recent study, researchers conducted tests on model substrates to explore the effectiveness of bioremediation in treating complex refinery contaminants resulting from both accidental and deliberate facility damage. The research reveals that bioremediation can be a promising, eco-friendly solution for cleaning up such pollutants, aligning with broader efforts to combat environmental harm resulting from industrial incidents. Rationale: Bioremediation harnesses microorganisms' diverse metabolic abilities to detoxify and eliminate pollutants, particularly hydrocarbon-based ones such as oil. This natural biodegradation process performed by microorganisms is a cost-effective method for environmental cleanup compared to other remediation technologies. Methodology: In this study, we examined the fate of heavy metals, cobalt and molybdenum, by the analysis of the basic chemical parameters of other sample components, such as n -hexane extractable substances and total petroleum hydrocarbons. The metal content was determined using inductively coupled plasma–optical emission spectrometry (ICP-OES). Exchangeable (loosely bound to the surface of particles and due to its high mobility and availability is crucial for understanding the potential immediate impact of metal contamination) and more stable fractions of the metal and the metal forms were determined using a sequential extraction method. The phase composition of the samples was determined by X-ray diffraction. Results: In our microbiological analysis, we isolated various cultures from a consortium of microorganisms. Basic chemical analysis indicators, such as n -hexane extractable substances, total petroleum hydrocarbons and humic acids, reflected robust microbiological activity. During the study, metals in exchangeable form decreased and those in more stable forms increased. Discussion: The sequential extraction of cobalt and molybdenum revealed shifts in various metal fractions within the bioaugmented substrate post-bioremediation, differing from the initial substrate. These alterations in metal fractions are likely attributable to microbial actions, leading to the formation of more stable metal fractions throughout the bioremediation process. Environmental context. Mitigating the environmental fallout of industrial accidents is crucial. In a recent study, researchers conducted tests on model substrates to explore the effectiveness of bioremediation in treating complex refinery contaminants resulting from both accidental and deliberate facility damage. The research reveals that bioremediation can be a promising, eco-friendly solution for cleaning up such pollutants, aligning with broader efforts to combat environmental harm resulting from industrial incidents. [ABSTRACT FROM AUTHOR]

The contamination of the water bodies by diesel oil (DO) and its water-soluble fraction (WSF) represents one of the most challenging tasks in the management of polluted water streams. This paper contains data related to the synthesis and characteristics of the plum stone biochar material (PmS-B), which was made from waste plum stones (PmS), along with its possible application in the sorption of the WSF of DO from contaminated water. Techniques applied in sample characterisation and comparisons were: Elemental Organic Analysis (EOA), Scanning Electron Microscopy−Energy Dispersive X-ray Spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), pH (pHsus) and point of zero charge (pHpzc). In order to increase the overall efficiency of the removal process, sorption and bioremediation were subsequently combined. Firstly, PmS-B was used as a sorbent of WSF, and then the remaining solution was additionally treated with a specific consortium of microorganisms. After the first treatment phase, the initial concentration of diesel WSF was reduced by more than 90%, where most of the aromatic components of DO were removed by sorption. The sorption equilibrium results were best fitted by the Sips isotherm model, where the maximum sorption capacity was found to be 40.72 mg/g. The rest of the hydrocarbon components that remained in the solution were further subjected to the biodegradation process by a consortium of microorganisms. Microbial degradation lasted 19 days and reduced the total diesel WSF concentration to 0.46 mg/L. In order to confirm the non-toxicity of the water sample after this two-stage treatment, eco-toxicity tests based on a microbial biosensor (Aliivibrio fischeri) were applied, confirming the high efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

The characterization and cleanup of groundwater contamination in hazardous-waste sites are of significant engineering and scientific importance. This study analyzes biodegradation fingerprints in groundwater, 25 years after the accidental leakage of kerosene (jet fuel) at the site in central Serbia. The long-term existence of hydrocarbon contamination and the presence of indigenous microbiological populations capable of biodegradation have been confirmed by the results of GCxGC-MS chromatography and microbiological characterization. Total petroleum hydrocarbons (TPH), geochemical indicators, and other parameters were spatially analyzed to provide insight into biodegradation occurrence. The lowest concentrations of electron acceptors (O2, NO3-, and SO42-) and the highest concentrations of microbial metabolic products (Mn and Fe) overlap in the piezometers closest to the source of contamination, due to the occurrence of different biodegradation mechanisms. Based on the analysis of redox-sensitive compounds, the mixed oxic-anoxic processes in groundwater also correspond to the aforementioned zone, as confirmed by the redox potential (Eh) measurements. The results of cross-study analysis reveal further reduction of hydrocarbon contamination, the occurrence of less anoxic redox processes, and the increase of oxic conditions in groundwater. Overall, the results provide clear evidence of the biodegradation effects in groundwater and insight into their evolution under natural attenuation processes. [ABSTRACT FROM AUTHOR]

Concentrations of 10 potentially toxic trace elements were measured in soil samples collected from 18 sites in urban areas of Belgrade, the capital and the largest city in Serbia. Samples were analysed in order to assess the extent of soil contamination and to distinguish natural and anthropogenic input. The results demonstrated a general Zn, Pb, and Cd enrichment in surface samples, hence, after comparison with guidelines, it has been determined that there is a potential risk for human health. In the surface and buried samples, traces of cooper were detected. The highest concentrations of Cr (121 ± 12.3 mg/kg) and Ni (94.9 ± 12.6 mg/kg) were found at a sediment depth of 2 m and should be ascribed to geogenic sources. The results of HCA and PCA analysis supported a natural origin of Co, Cu, Mn, Cr, and Ni, while Cd, Zn, and Pb originated from anthropogenic inputs. Based on the pollution indices, Cd made the most dominant contribution, posing a high contamination risk in the studied area. Results of Nemerow pollution index (PIN) and potential ecological risk index (PER) demonstrated that pollution by heavy metals in sediments on several sites is moderately intense. [ABSTRACT FROM AUTHOR]

Project "Boosting Institute of Chemistry, Technology and Metallurgy in Water Biomonitoring" (BIOLAWEB) aims to strengthen the research and innovation capacity of the Institute of Chemistry, Technology and Metallurgy, National Institute of the Republic of Serbia, University of Belgrade (UB-ICTM) in biodiversity assessment and biomonitoring. UBICTM researchers made a noticeable contribution to the study of biodiversity, community ecology, and conservation of water bodies in South-Eastern Europe. However, a knowledge on index development and intercalibration following the EU standards for lakes and watercourse monitoring is still lacking in this geographic region. Similarly, there is a knowledge gap in DNA-based ecological status assessment in SEE. Overcoming these gaps and achieving the objectives of the BIOLAWEB isrealized through networking with international institutions with a strong expertise in metabarcoding approach and in biological indices development: the French National Research Institute for Agriculture, Food and Environment (INRAE) and the Norwegian Institute for Water Research (NIVA). Staff exchange, common field, and laboratory work, and a variety of courses are used for an effective knowledge transfer from the partnering institutions to UB-ICTM. In order to strengthen research and innovation capacity, through BIOLAWEB project the International Cooperation and Project Office was established at UB-ICTM to support project application, management, and reporting at the international level. The implementation of the BIOLAWEB results will raise the research profile of the coordinator and partner institutions and contribute to UB-ICTM's vision of becoming a lighthouse for attracting the best talents and tackling the burning issues of environmental assessment. [ABSTRACT FROM AUTHOR]

This paper focuses on lignocellulosic waste biomass originating from food industry, which should find its further application in order to fulfill demands of circular economy. Therefore, here are presented some of the chemical and physical properties that affect combustion process, as well as thermochemical reaction kinetics for lignocellulosic biomass wastes. The biomass investigated was peach stone particles originating from food industry. The results have showed that peach stones can be characterized as good energy alternative renewable material, with properties that allow its safe thermochemical conversion. Kinetic analysis of this biomass was performed using Thermogravimetric Analysis (TGA) with a simple reaction model applied, namely n-th order reaction model. The obtained results have confirmed the complex nature of this material and the need for further modelling. [ABSTRACT FROM AUTHOR]

The mud generated from oil and natural gas drilling, presents a considerable ecological problem. There are still insufficient remedies for the removal and minimization of these very stable emulsions. Existing technologies that are in use, more or less successfully, treat about 20% of generated waste drilling mud, while the rest is temporarily deposited in so-called mud pits. This study investigated in situ bioremediation of a mud pit. The bioremediation technology used in this case was based on the use of naturally occurring microorganisms, isolated from the contaminated site, which were capable of using the contaminating substances as nutrients. The bioremediation was stimulated through repeated inoculation with a zymogenous microbial consortium, along with mixing, watering and biostimulation. Application of these bioremediation techniques reduced the concentration of total petroleum hydrocarbons from 32.2 to 1.5 g kg−1 (95% degradation) during six months of treatment. [ABSTRACT FROM AUTHOR]

Within a 30-day incubation laboratory study, the polycyclic aromatic hydrocarbon (PAH) degradation profile of two bacteria, Planomicrobium sp. RNP01 and Rhodococcus sp. RNP05 were studied by three microtiter plate assays to reveal the combination of certain biological and biochemical characteristics which are reliable indicators in evaluation of bacterial biodegradation abilities. The three assays, which are hydrocarbon growth assay, 2,6-DCPIP assay and dehydrogenase activity assay revealed that Rhodococcus sp. RNP05 exhibited better potential for PAH degradation than Planomicrobium sp. RNP01. Differences between initial and final optical density and specific growth rate constants were significantly higher (r = 0.995, P < 0.05) in case of Rhodococcus sp. RNP05 on all tested substrates, as compared to Planomicrobium sp. RNP01. This was confirmed by GC-FID analyses. Dehydrogenase activity of Rhodococcus sp. RNP05 was higher (r = 0.9995, P < 0.05) than Planomicrobium sp. RNP01 and correlated positively with the hydrocarbon growth assay (r = 0.999, P < 0.05, for Rhodococcus sp. RNP05, r = 0.986, P < 0.05 for Planomicrobium sp. RNP01). This study has shown that the combination of these assays could be used for determining the bioremediation potential of PAHs in petroleum contaminated soil with the ability of screening a large number of bacterial strains. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III43004]

This paper describes experiments with standard humic acids (HA-S) and humic acids (HA) isolated from soil that was contaminated with mazut and treated with a consortium of microorganisms for the process of bioremediation (HA-E). Both acids inhibited the toxicity of ferric chloride and increased the growth of a zymogenous microbial consortia compared with controls. Electron paramagnetic resonance spectroscopy showed that HA-S and HA-E exhibit high anti-oxidative activity involving free radical scavenging and iron sequestration. HA additionally promote microbial consortium growth by providing protection from oxidative stress. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Industry / Hemijska Industrija is the property of Association of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Acidithiobacillus ferrooxidans is lithotrophic microorganism involved in many transformation and cyclic reactions of elements in nature, with an important role in biochemical cycles of sulfur and iron. Natural ability of this microorganism has been widely used by man in processes of metal exploitation. More precisely, to convert low-soluble metal compounds, mostly sulfides, into solutions. Practically, naturally occurring reactions have been directed and enhanced, in such a way to get useful metals, mostly from low-grade metal ores and waste materials. By the means of microbial leaching solution, in the case when the type of ore and the geological characteristics of the soil are suitable, it is possible to recover certain metals with minimum investment and threats to environment. In order to extract copper from ore dumps, microbial leaching has been conducted in laboratory using the culture of Acidithiobacillus ferrooxidans. Samples were taken from twelve different locations on Bor ore dumps. Leaching experiments were performed by the shake flask testing technique at 28°C, during two-week period. Parameters, like solid-liquid ratio, number of bacteria, rate of leaching, physical and chemical characteristics of ore, were determined. Obtained results show 7.5-fold higher copper leaching efficiency in the suspension with Acidithiobacillus ferrooxidans, then in control suspension. Microbial leaching of low-grade ores and ore dumps plays very important role in the concept of environmental protection, because it allows use of relatively simple technology to control and redirect uncontrolled loss of metals into the soil and water-streams. [ABSTRACT FROM AUTHOR]

One of the main global focuses of mankind today is the required switch to new energy sources. Generating energy from waste is one of the potential solutions that can be achieved using microbial fuel cells (MFCs). Microorganisms, thanks to their ability to degrade organic substrates in contaminated environments, could contribute to solving our pollution challenge. The aim of this study was to investigate the potential of sediment with its natural microbiota from the River Danube to optimize electricity generation using MFCs. 16S rRNA gene analysis identified the main bacterial genera in the river sediment, Clostridium , Bacillus and Tepidibacter , which were isolated and cultured in the laboratory. Addition of these cultured microorganisms to the MFC resulted in current density of 192 mA/m3, while the power density was about 8.80 mW/m3. Our study confirms proper selection and enrichment of the microbial community can optimize the amount of current obtainable from river sediment by MFCs. Image 1 • Sampling sediment from the Danube River. • Characterization of microbial communities of composite sediment. • Construction and electrical characterization of 4 different MFCs. • Investigation of impact of microbial communities on MFCs power production. • The high power density (10.6 mW/m3) was obtained. [ABSTRACT FROM AUTHOR]