Bioremediation is based on microorganisms able to use pollutants either as a source of carbon or in co-metabolism, and is a promising strategy in cleaning the environment. Using soil contaminated with petroleum products from an industrial area in Saudi Arabia (Jubail), and after enrichment with the polycyclic aromatic hydrocarbon (PAH) naphthalene, a Methylobacterium radiotolerans strain (N7A0) was isolated that can grow in the presence of naphthalene as the sole source of carbon. M. radiotolerans is known to be resistant to gamma radiation, and this is the first documented report of a strain of this bacterium using a PAH as the sole source of carbon. The commonly reported Pseudomonas aeruginosa (strain N7B1) that biodegrades naphthalene was also identified, and gas chromatography analyses have shown that the biodegradation of naphthalene by M. radiotolerans and P. aeruginosa did follow both the salicylate and phthalate pathways.
Diclofenac (2-[(2,6-Dichlorophenyl)amino]benzeneacetic acid) is a non-steroidal anti-infl ammatory
drug. Due to excessive use of diclofenac, this drug has been detected in surface water, ground water and drinking
water. In our study, four fungal strain Trametes trogii, Aspergillus niger, Yarrowia lipolytica and Phanerochaete
chrysosporium were investigated in terms of diclofenac degradation potential. Trametes trogii was found to be
the most effi cient strain with 100% diclofenac degradation rate. Two hydroxylated diclofenac metabolites have
been identifi ed in culture medium. Crude laccase from T. trogii almost completely removed diclofenac with 97%
removal in 48 h. We suggest that the degradation of diclofenac depends on the cytochrome P450 enzyme system
and laccase activity. After 24 h incubation decrease in toxicity of diclofenac was confi rmed by Microtox test.
The aim of the study was to determine the impact of various methods of oil mixing with wastewater on
properties of synthetic municipal wastewater containing edible oil (SMW+0.02% m/v rapeseed oil). The study was
carried out in 3L glass, cylindrical reactors to which SMW+0.02% were introduced. Various methods of its mixing
with water were applied: mechanical mixing (SMW+0.02%+mixing) and sonication (SMW+0.02%+ultrasounds).
The wastewater was sonicated at 35 kHz for 30 min. The constant temperature conditions were maintained during
the experiment for each mixing method (15°C, 20°C and 30°C). The analysis of parameters (pH, COD, BOD5
and
long chain free fatty acids concentration) of raw wastewater and after 2, 4, 6, 24, 48 and 72 hours of inoculation
was performed to determine the effect of mixing method.
The most signifi cant changes in wastewater chemical parameters after the introduction of the oil were observed
in the case of COD. For SMW+0.02%+ mixing a slow increase in COD within 24 hours of the process was observed.
In the case of SMW+0.02%+ultrasounds the increase and the decrease of COD value were observed in reference
to the initial value. The changes in acids concentrations observed in reactors with SMW+0.02%+ultrasounds were
referred to the ones observed in reactors with SMW+0.02%+mixing but changes were more intense in the fi rst
reactor. The use of ultrasounds in pre-treatment of wastewater resulted in the intense appearance of palmitic acid
for 6 hours. Regardless of the emulsion formation method (mixing or ultrasounds), the concentration of oleic acid
and linoleic acid was reduced. The biggest changes in free fatty acids concentration were observed for palmitic,
oleic and linoleic acids after 24 hours.
Recent studies in the area of biological air treatment in filters have addressed fundamental key issues, such as a biofilter bed of different origin composed of natural zeolite granules, foam cubes and wood chips. When foam and zeolite are mixed with wood chips to remove volatile organic compounds from the air, not only biological but also adsorption air purification methods are accomplished. The use of complex purification technologies helps to improve the efficiency of a filter as well as the bed service life of the filter bed. Investigations revealed that microorganisms prevailing in biological purification, can also reproduce themselves in biofilter beds of inorganic and synthetic origin composed of natural zeolite and foam. By cultivating associations of spontaneous microorganisms in the filter bed the dependencies of the purification efficiency of filter on the origin, concentration and filtration time of injected pollutants were determined. The highest purification efficiency was obtained when air polluted with acetone vapour was supplied to the equipment at 0.1 m/s of superficial gas velocity. When cleaning air from volatile organic compounds (acetone, toluene and butanol), under the initial pollutant concentration of ~100 mg/m3, the filter efficiency reached 95 %.
In environmental matrices there are mixtures of parent drug and its metabolites. The majority of research is focused on the biological activity and toxic effect of diclofenac (DCF), there is little research on the biological activity of DCF metabolites and their mixtures. The study focused on the assessment of the biological impact of DCF, its metabolites 4’-hydroxydiclofenac (4’-OHDCF) and 5-hydroxydiclofenac (5-OHDCF) and their mixtures on E. coli strains. The biological effects of tested chemicals were evaluated using the following: E. coli K-12 cells viability assay, the inhibition of bacteria culture growth, ROS (reactive oxygene species) generation and glutathione (GSH) content estimation. Moreover, we examined the influence of the mixture of DCF with caffeic acid (CA) on E. coli cells viability. Our results showed the strongest impact of the mixtures of DCF with 4’-OHDCF and 5-OHDCF on E. coli SM biosensor strains in comparison to parent chemicals. Similar results were obtained in viability test, where we noticed the highest reduction in E. coli cell viability after bacteria incubation with the mixtures of DCF with 4’-OHDCF and 5-OHDCF. Similarly, these mixtures strongly inhibited the growth of E. coli culture. We also found synergistic effect of caffeic acid in combination with DCF on E. coli cells viability. After bacteria treatment with the mixture of DCF and its metabolites we also noted the strongest amount of ROS generation and GSH depletion in E. coli culture. It suggests that oxidative stress is the most important mechanism underlying the activity of DCF and its metabolites.
In the present study, the enrichment and isolation of textile effluent decolorizing bacteria were carried out in wheat bran (WB) medium. The isolated bacterium Providencia rettgeri strain HSL1 was then tested for decolorization of textile effluent in consortium with a dyestuff degrading fungus Aspergillus ochraceus NCIM 1146. Decolorization study suggests that A. ochraceus NCIM 1146 and P. rettgeri strain HSL1 alone re moves only 6 and 32% of textile effluent American Dye Manufacturing Institute respectively in 30 h at 30 ±0.2°C of microaerophilic incubation, while the fungal-bacterial consortium does 92% ADMI removal within the same time period. The fungal-bacterial consortium exhibited enhanced decolorization rate due to the induction in activities of catalytic enzymes laccase (196%), lignin peroxidase (77%), azoreductase (80%) and NADH-DCIP reductase (84%). The HPLC analysis confirmed the biodegradation of textile effluent into various metabolites. Detoxification studies of textile effluent before and after treatment with fungal-bacterial consortium revealed reduced toxicity of degradation metabolites. The efficient degradation and detoxification by fungal-bacterial consortium pre-grown in agricultural based medium thus suggest a promising approach in designing low-cost treatment technologies for textile effluent.
Studies were conducted using a 10-chamber Micro-Oxymax (Columbus, OH, USA) respirometer to determine the effect of bioaugmentation, biostimulation and combination of them on enhancing intrinsic biodegradation of oil hydrocarbons in soil. Contaminated soil was collected from a former military airport in Kluczewo, Poland. Bioaugmentation was realized by addition of indigenous or exogenous bacteria to soil. Biostimulation was done by aerated water supply and surfactant addition. Bioaugmentation + addition of a surfactant was applied as the combined treatment. The intrinsic and enhanced hydrocarbons biodegradation rates were estimated from the slopes of linear regressions of cumulative curves of O2 uptake. Pertinent biodegradation rates were recalculated on the basis of the stoichiometric reaction (mass balance equation) and conversion equation. The results showed that combined treatment (indigenous bacteria bioaugmentation + addition of a surfactant) was the most effective method of biodegradation enhancement as the 20-fold increase of biodegradation rate was observed.
Since fluoroquinolone (FQ) antibiotics are extensively used both in human and veterinary medicine their accumulation in the environment is causing increasing concern. The aim of the study was to isolate a microbial consortium resistant to ofl oxacin and norfl oxacin and able to biodegrade both antibiotics. Green compost was used as a source of microorganisms. The biodegradation effi ciency was monitored by changes of antibiotics concentrations and toxicity. The microbial consortium was composed of two bacterial isolates: Klebsiella pneumoniae (K2) and Achromobacter sp. (K3) and two fungi Candida manassasensis (K1) and Trichosporon asahii (K4). All the isolates were characterized as highly resistant to both antibiotics – ofl oxacin and norfl oxacin. FQs were supplied individually into the culture medium in the presence of an easily degradable carbon source – glucose. Biodegradation of norfl oxacin was much faster than ofl oxacin biodegradation. During 20 days of the experiment, the norfl oxacin level decreased by more than 80%. Ofl oxacin was generally biodegraded thereafter at relatively slow biodegradation rate. After 28 days the ofl oxacin level decreased by 60%. Similarly, the toxicity of biodegraded antibiotics decreased 4-fold and 3.5-fold for norfl oxacin and ofl oxacin, respectively. The ability of the bacterial-fungal consortium to degrade antibiotics and reduce toxicity could help to reduce environmental pollution with these pharmaceutical.
High intake of over-the-counter, non-steroidal anti-inflammatory drugs, such as ibuprofen, has resulted in their presence in wastewaters and surface waters. The potentially harmful effect of ibuprofen present in the waters has led to a search for new methods of drugs’ removal from the environment. One of the most important technological and economical solutions comprises microbiological degradation of these resistant pollutants. Searching for new strains able to degrade ibuprofen could be one of the answers for increasing the detection of pharmaceuticals in the waters. In this study, the ability of bacterial strain Bacillus thuringiensis B1(2015b) to remove ibuprofen is described. Bacteria were cultured in both monosubstrate and cometabolic systems with 1, 3, 5, 7 and 9 mg L-1 ibuprofen and 1 g L-1 glucose as a carbon source. Bacillus thuringiensis B1(2015b) removed ibuprofen up to 9 mg L-1 in 232 hours in the monosubstrate culture, whereas in the cometabolic culture the removal of the drug was over 6 times faster. That is why the examined strain could be used to enhance the bioremediation of ibuprofen.