The biofiltration process in the biologically activated carbon filters (BAC) is one of advanced methods of water treatment. It enables efficient elimination of dissolved organic matter and some inorganic pollutants. The production of high-quality drinking water requires an appropriate method of filter work control based on biofilm growth assessment. The first aim of the study was to assess the microbial development in beds of two BAC filters with the use of various methods. The second aim was to compare the obtained results and indicate the method which could support filter operators during routine control of biofiltration process. The study was carried out in a pilot scale on models of BAC filters during two filter runs. The analysis of Microorganisms was performed in water samples collected from different depths of the filter beds with the use of culture method (HPC), metabolica ctivity assay (with the FDA), epifluorescence microscopy – total cell count method (TCC) and biochemical method (system Vitek 2 Compact). No statistical correlation between HPC and metabolic activity assay was noted. Total bacteria number determined with the use of TCC was approx. 100–900 times higher than in the HPC method. The biochemical tests revealed the presence of several Gram-negative species. The comparison of the applied methods shows that microbial activity assay is the most useful, fast and low-cost method which may be applied additionally to the HPC method at standard water treatment plant laboratory.

Microbiological and chemical analysis of air was carried out on the area of landfill of wastes other than inert or hazardous. The landfill covers 20 ha and 40 000 Mg of wastes is deposited annually. Municipal waste is not segregated at the landfill. The research was conducted in April, May and November 2012. Number of the psychrophilic and mesophilic bacteria and fungi was estimated by a culture-based method. Quantitative determination of sulfur compounds and meteorological and olfactrometric examinations were also carried out. Chemical analysis was conducted with a Photovac Voyager portable gas chromatograph. Air samples were collected at 5 points. The largest group of microbes were psychrophilic bacteria, especially in summer. The highest concentration of hydrogen sulfide and other odorants was found at leachate tank and landfill body. According to the Polish Standard for the assessment of atmospheric air pollution the air in the area of the landfill is classified as not contaminated and sporadically moderately contaminated. In spring and summer the number of microscopic fungi was increased also in control samples.

Over the two-year study (2008–2009) we monitored the influence of integrated and conventional

production systems on microbiological activity in soil and strawberry yield. The experiment also involved

fertilizers applied in three variants of treatment. The studied parameters were monitored over 2008 and 2009 by

determining the total number of soil microorganisms, the number of ammonifying bacteria and the strawberry

yield. The results of the study suggest the pronounced inhibitory effect of insecticides on number of studied

microorganism groups in all three conventionally treated variants, over the both years of study, which further

infers negligible stimulative influence of strawberry plants on yield.

Przedmiotem dwuletnich badań było poznanie dynamiki rozwoju wybranych grup drobnoustrojów (mikroorganizmy oligotroficzne, kopiotroficznc, proteolityczne, celulolityczne, rozpuszczające fosforany) w glebie nawożonej komunalnymi osadami ściekowymi. Celem przeprowadzonego doświadczenia było wyjaśnienie możliwości zachwiania równowagi biologicznej gleby, przejawiającej się wzmożonym i długotrwałym rozwojem analizowanych grup drobnoustrojów w glebie, po wprowadzeniu do niej materii organicznej w formic osadów ściekowych, w różnych dawkach. W doświadczeniu zastosowano cztery obiekty badawcze: kontrola-gleba + NPK, 2 Mg s.m. osaduha+rok' + NPK, 4 Mg s.m. osadu-hal-rok' + NPK oraz 8 Mg s.m. osaduhatrok' + NPK). Fosfor i potas stosowano przedsiewnie pod orkę, natomiast azot: część przedsiewnie i drugą część pogłównie. Osady ściekowe stosowano przedsiewnie. Poletka glebowe, na których przeprowadzono badania obsiano żytem odmiany Wibro (2003 r.) oraz obsadzono ziemniakami odmiany Bila (2004 r.). Wykazano, że zastosowane dawki osadów ściekowych nic wpływały istotnie statystycznie na namnażanie się mikroorganizmów glebowych. Na podstawie przeprowadzonych analiz mikrobiologicznych stwierdzono, że w badanym okresie (2003-2004) liczebność oznaczonych grup drobnoustrojów ulegała wahaniom, zależnym od terminu pobierania próbek glebowych. Próbki glebowe, niezbędne do przeprowadzenie analiz, pobierane były w lenninach związanych z kolejnymi fazami rozwojowymi roślin. Kolejnym czynnikiem wpływającym na dynamikę rozwoju mikroorganizmów glebowych był gatunek rośliny użytej w doświadczeniu. Żyto uprawiane w 2003 r. stymulowało rozwój większości grup drobnoustrojów (mikroorganizmów oligotroficznych, kopiotroficznych, proteolitycznych, rozpuszczających fosforany). Z kolei ziemniaki w okresie rozwoju generatywnego ( 16.07- 28.08.2004) spowodowały silniejszy rozwój mikroorganizmów celulolitycznych.

The paper presents the results of the studies on a degree of pollution and sanitary-bacteriological stale of bottom sediments of Wigry Lake in I 998 and 1999. Total Viable Count at 20°C (TYC 20°C) and Total Viable Count at 37°C (TYC 37°C) were used as indicators of pollution, while Total Coli (TC), Faecal Coli (FC), Faecal Streptococcus - Enterococcus (FS) and Clostridium perfringens - as indicators of the sanitary stale. Bottom sediment samples wen: collected from 3 sites situated in the centre of the lake and from 6 sites in the vicinity of the lake shore. Sanely and gravel offshore bottom sediments showed less degree or pollution than muddy bottom sediments collected from the centre or the lake. Higher numbers of anaerobic spore-forming and sulphite reducing bacteria (Clostridium pcrfringens) found at sites 1 and 2 in the vicinity of the mouth of Czarna Hańcza River lo Lake Wigry. At those places a higher bacteriological pol lution of bottom sediments samples was found.

The paper presents microbiological characteristic of sewage sludge composted in controlled conditions together with biowastes (wheat, maize and rapeseed straw, sawdust and refined glycerol). An experiment was carried out in which the material was mixed at appropriate weight proportions and then placed in bioreactor chambers of constant air flow (4 lźmin-1). The performed composting process aimed at determining the developmental dynamics of heterotrophic bacteria, molds, actinomycetes as well as bacteria from Salmonella genus and Enterobacteriaceae family. Microbiological analyses were performed on selective substrates using Koch's plate method. Moreover, using the floatation method, the presence of live eggs of ATT (Ascaris spp., Trichuris spp., Toxocara spp.) intestinal parasites was assessed and levels of dehydrogenase activity were determined using 1% triphenylotetrazole chloride as a substrate. It was concluded, on the basis of the obtained research results, that the composting process reduced bacterial counts of heterotrophic bacteria, molds and the activity of dehydrogenases activity in all experimental treatments. On the other hand, no reduction was observed in quantities of actinomycetes in the composted materials whose changes in numbers were found to correlate positively most strongly with levels of dehydrogenases activity. In addition, it was found that changes in numbers of the analysed groups of microorganisms depended, primarily, on the pH value and concentrations of ammonia released from the composted materials. Furthermore, the obtained research results also revealed that the sewage sludge used in the experiment did not contain Salmonella spp. bacteria and live eggs of ATT intestinal parasites, and that the composting process reduced completely numbers of bacteria from the Enterobacteriaceae family in all compost treatments. The obtained composts fulfilled all sanitary standards complying with the requirements issued by the Minister of Agriculture and Rural Development (2008) as well as with the EU regulation (EC) No. 185/2007 from February 2007 changing EEC regulations No. 809/2003 and No. 810/2003 connected with the extension of the period of transitional requirements for composting and biogas plants as provided by the EU regulation No. 1774/2002 of the European Parliament and Council.

The aim of this study was to determine the effect of carfentrazone-ethyl (CE) doses of 0.265, 5.280, 10.560, 21.180, 42.240 μg kg-1 soil DM on fungi, Acnomycetes, organotrophic bacteria, total oligotrophic bacteria and spore-forming oligotrophic bacteria, and on the activity of dehydrogenases, catalase, urease, alkaline phosphatase, acid phosphatase, arylsulfatase and β-glucosidase. Carfentrazone-ethyl had a stimulating effect on total oligotrophic bacteria and organotrophic bacteria, but it inhibited the growth of Azotobacter, fungi, spore-forming oligotrophic bacteria and Actinomycetes. The analyzed substance modified the structure of soil microbial communities, and it induced the most profound changes in fungi. The highest values of the colony development (CD) index and the eco-physiological (EP) index were observed in organotrophic bacteria. The optimal dose of carfentrazone-ethyl stimulated the activity of dehydrogenases, catalase, urease, alkaline phosphatase, acid phosphatase and β-glucosidase, but it had no effect on arylsulfatase. The highest doses of the analyzed substance inhibited the activity of dehydrogenases (reduction from 11.835 to 11.381 μmol TPF), urease (reduction from 0.545 to 0.500 mmol N-NH4) and arylosulfatase (reduction from 0.210 to 0.168 mmol PNP). Dehydrogenases were most resistant to CE, whereas acid phosphatase and arylsulfatase were least resistant to the analyzed compound

The paper presents the results of studies of sanitary microorganisms' vertical distribution in pelagial and profundal waters of Lake Wigry against the background of thermal-oxygen relations and the presence of a chosen chemical compound in the annual cycle. Total Viable Count at 20°C (TYC 20°C) and Total Viable Count at 37°C (TYC 37°C) were used as indicators of pollution, while Total Coli (TC), Faecal Coli (FC) and Faecal Streptococcus-Enterococcus (FS) - as indicators of the sanitary state. Water samples were collected from 3 sites situated in the centre of the lake. Pelagial and profundal waters showed a little degree of pollution. Higher bacteriological pollution was found in some of waters samples from Lake Wigry at site I in the vicinity of the mouth of the Czarna Hańcza River. The most numerous sanitary microorganisms were detected at the deep from I to 5 meters and above the bottom sediments. Number of FC bacteria was only higher at the depth of 5 meters and deeper. An important positive correlation was noted between temperature and TYC 20°C as well as TYC 37°C, while negative between TC also FC during the whole study period. The oxygen content was correlated negative with TYC 20°C, TYC 37°C and FS. The depth was correlated negatively with TYC 20°C only.

The aim of the presented investigations was to examine changes in the intensity of dehydrogenase and acid phosphatase activities as well as of the dynamics of selected groups of microorganisms in the soil under the cultivation of winter triticale following the application of the following seed dressings: (a.s.) flutriafol 2.5% + fludioxonil 2.5% in two doses and (a.s.) carboxin and tiuram. The experiment had a field character. The number of microorganisms (total bacteria, fungi, oligotrophic, copiotrophic and Azotobacter) was determined by the plate method on adequate agar substrates. Activity levels of the selected enzymes were defined using the spectrometrical method.

The obtained results indicate a change in the dehydrogenase and phoshatase activity in soil depending on the seed dressing applied in the experiment as well as at the date of investigations. The number of microorganisms in the soil underwent fluctuations depending on the developmental stage of triticale and the applied fungicide. The performed experiment demonstrated that counts of microorganisms in the soil underwent fluctuations depending on the developmental stage of triticale and the applied fungicide.

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 %.

The paper contains a micobiological characteristic of sewage sludge composted in controlled conditions together with bio-wastes (straw, sawdust, bark). An experiment was carried out in which the composted material was mixed up in adequate weight proportion and placed in biorcactor chambers with a constant air flow. The composting process aimed at defining the development dynamics and the survival of pathogenic microorganisms in the sewage sludge composted with different additions in a cybernetic bioreactor. Samples of compost necessary for microbiological analyses were taken at the same time, in reference to the actual temperature value. Bacteriological studies were carried out on selected substrates by plate method determining the number of pathogenic bacteria from the species: Salmonella, Clostridium perfringens, as well as from Enterobacteriaccac family. In the experiments, the presence of living eggs or intestinal ATT pathogens was determined by floatation method, as well. Il was found that the sewage sludge used in composting process did not contain any Salmonella spp. bacteria or any living eggs of intestinal ATT pathogens. Composting process completely eliminated the number or bacteria from Enterobactcriaccae family, bul it did not contribute lo the elimination of Clostridium perfringens bacteria. On the basis of the obtained results, it was found that the elimination of the studied groups of microorganisms, in all studied composts took place with the increase of temperature. In the case or Enterobacteriaceae, it was found that their complete removal from the composted material took place in chamber K3, while in the remaining chambers, it followed 48 hours later. Elimination ofthe vegetative forms ofC!oslridium perfringens bacteria followed after 96 hours of composting, in all composts at the same time. The obtained composts met the sanitary norms according lo the regulations of the EC Commission No. I 85/2007 of February 20, 2007 which changed the regulation of WE No. 809/2003 and WE No. 810/2003 referring to the extension of the validity period of transitional means for composting plants and biogas producing plants according to the instruction orWE No. 1774/2002 of European Parliament and Council and according to the instruction of the Minister for Agriculture and Country Development (2004).

Field research was conducted at Siedlce University of Natural Sciences and Humanities in 2019–2021. The objective was to determine the effects of bacterial formulations and cover crops on the biomass, number and species composition of dominating weeds prior to spring barley harvest. The field trial involved two factors: A – bacterial formulations: I – control, II – nitrogen-fixing bacteria ( Azospirillum lipoferum Br17, Azotobacter chroococcum), III – nitrogen-fixing bacteria ( Azospirillum lipoferum Br17, Azotobacter chroococcum) + phosphorus-solubilizing bacteria ( Bacillus megaterium var, phosphaticum, Arthrobacter agilis), IV – nitrogen-fixing bacteria ( Azotobacter chroococcum) + plant growth-promoting rhizobacteria (PGPR) ( Bacillus subtilis, Bacillus amyloliquefaciens, Pseudomonas fluorescens); B – cover crops: control without a cover crop, red clover, red clover + Italian ryegrass, Italian ryegrass. Spring barley was harvested in late July. Weed samples were collected just before harvest to determine the fresh and dry matter of weeds as well as their number and species composition. The research demonstrated conclusively that an application of bacterial products combined with cover crops contributed to a significant reduction in the weight and number of weeds including dominating species such as Chenopodium album, Sinapis arvensis, Tripleurospermum inodorum and Elymus repens. Superior weed control was achieved in spring barley grown in combination with Azotobacter chroococcum + PGPR and a mixture of red clover and Italian ryegrass as a cover crop.

Agricultural utilization of appropriately stabilized sewage sludge appears to be the most rational method of its utilization, even though there is no agreement among scientists as to the impact that these wastes can exert on the maintenance of the soil biological balance. That is why the objective of the performed field-laboratory experiments was to determine the developmental dynamics of selected groups of microorganisms in a grey-brown podzolic soil fertilized with acceptable and unacceptable doses of sewage sludge and farmyard manure. Numbers of six groups of microorganisms were determined at various dates associated with the development of spring barley (total bacterial number, number of actinomycetes, fungi, bacteria from the Azotobacter genus and Pseudomonas j/uorescens) as well as pathogenic bacteria from the Sa/111011ella genus. The selected groups of microorganisms were determined on selective media by the plate method. The obtained research results showed that, in the majority of cases, the applied levels of organic fertilization did not have a significant impact on the numbers of microorganisms in the soil. Therefore, it can be said that the application of both acceptable and unacceptable doses of sewage sludge in the form of fertilizers failed to disturb the biological balance of the examined soil. In addition, the results of the performed experiments indicated that the agricultural utilization of sewage sludge should be forestalled by a sanitation process (e.g. composting) in order to get rid of' pathogenic bacteria, especially bacteria from the Salmonella genus.

The paper presents microbiological characteristics of sewage sludge derived from the mechanicalbiological sewage treatment plant and farmyard manure as well as composts manufactured from them. In the performed experiment, four types of composts were analyzed. The first of them comprised the sewage sludge alone, the second one - was made up only of farmyard manure, while the remaining composts were prepared by mixing the above-mentioned bio-wastcs in the following proportions: 75% sewage sludge+ 25% farmyard manure and 50% sewage sludge + 50% farmyard manure. The next stage of experiments involved analyses of the composts incubated with soil. The following assays were carried out in the experimental composts and mixtures of soil and composts: counts of Salmonella sp., E. coli, Clostridium perfringens, total counts of bacteria, fungi and actinomycetes on selective media employing the plate method. The performed investigations revealed that the composting process resulted in complete riddance of the Salmonella sp. and reduction in the numbers of the remaining groups of microorganisms. Therefore, it can be said that the composted sewage sludge was suitable for the utilization for agricultural purposes in accordance with the Directive of the Minister of Agriculture and Rural Development of October 2004. Moreover, it was found that, as early as 60 days after the introduction of composts into the soil, counts of the majority of the analyzed groups of microorganisms (with the exception of actinornycctcs and E. coli), including pathogenic bacteria from the C. perfringens genus, were found reduced. The obtained research results proved that the introduction of bi o-wastes into the soil may decrease survivability in the natural environment of certain pathogens; hence it is a good method of utilization of this organic material.

The main aim of the below presented work was to investigate the possibility of using impedance spectroscopy in the unpasteurized beer microbial contamination degree assessment. Advantages of the impedance spectroscopy method, a negligible number of similar published results as well as their practical aspect make the research important. Four different types of beerswere investigated whichwere unfit for consumption due to improper storage and were heavily microbiologically contaminated. Their impedance was measured in the frequency range from 0.1 Hz to 1 kHz before and after centrifugation. Based on the measured values, an innovative electrical equivalent circuit was proposed and the parameters of the circuit elements were fitted. The obtained results show significant differences (23 up to 35%) in the values of resistance modelling the diffusion phenomenon. Such large changes, resulting from the removal of biomass from the samples, prove the validity of impedance spectroscopy in the study of the properties of unpasteurized beer. According to the authors, it would be possible to use the proposed methodology during the production of beer.With some limitations, it should aid in the early detection of microbial contamination.

The results of studies on the disintegration kinetics of the yeast Saccharomyces cerevisiae are presented. The process was carried out in a 500 W ultrasonic homogenizer equipped with a spherical working chamber with a volume of 100 cm ³. The concentration of the suspension of microorganisms was 0.05 g d.m./cm ³. The continuous phase was water solution containing 0.15 M NaCl and 4 mM K ₂HPO ₄. The kinetics of cell disruption were studied by the direct method. The theory of random transformation of dispersed matter was used to analyze the process. There was significant variation in the size of yeast cells. The range of changes in the values of parameters describing the size of microorganisms was divided into size classes. The kinetics of cell disruption in individual classes was described by a first-order linear differential equation. During the implosion of cavitation bubbles, the transformation volume of individual microorganisms is generated. It has been shown that as the volume of cells in subsequent size classes increases, their transformation volumes do not increase significantly. The safe volume for cells remains unchanged. As the size of the microorganisms increased, there was no increase in the constant rate of cell disruption.

In many wastewater treatment plants (WWTPs) inconveniences resulting from foam formation on the surface of activated sludge wastewater treatment devices appear. Foaming phenomenon is related to the characteristics of raw sewage and applied technological parameters of activated sludge process which promote the development of specific foam-forming filamentous microorganisms. In bulking activated sludges there are about 30 species of filamentous microorganisms and in the foam not more than about 1 O species. Basic method of identification of filamentous microorganisms present in foam are microscopic investigations which can be performed both in vivo by direct observation of no stained, so called living smears, with contrast - phase device and in stained smears alter different stain methods in direct light or dark field.

The aim of the research was to assess the microbiological (number of heterotrophic bacteria, actinobacteria and moulds) and biochemical (urease and acid phosphatase activity) state of peat with the admixture of composts produced from sewage sludge. An additional aim of the research was to demonstrate the influence of those substrates on the morphological traits of scarlet sage (height, number and length of shoots, number of buds and inflorescences, greenness index (SPAD)). Composts produced from sewage sludge, wheat, maize and lupine straw were mixed with peat, where their percentage varied from 25% to 75%.

The substrate which included the composts applied in the experiment had a higher number of heterotrophic bacteria and a higher acid phosphatase activity level than the control substrate (peat). The multiplication of moulds and actinobacteria was more intensive than in the peat only in the combinations with K3 (sewage sludge 50%+sawdust 20%+ lupine straw 30%) and K4 (sewage sludge 50%+sawdust 20%+fresh maize straw 30%) composts, whereas the highest urease activity level was observed in the soils produced from K1 (sewage sludge 50%+sawdust 20%+white straw 30%) compost.

The most optimal development of plants was observed in the substrate with compost produced from wheat straw. Composts produced from municipal sewage sludge were found to be suitable for growing scarlet sage. However, their effect depends on the percentage of high peat in the substrate.

One of the methods of sewage sludge disposal, which is based on its fertilizing properties, is its use in nature, e.g. in farming (if all the permissible standards are met). However, the sludge used for soil fertilization might also contain heavy metals, pathogenic microorganisms, thus causing contamination in soil foundation and deterioration of the conditions for development of indigenous organisms. Particular threat is posed by the existence of drug-resistant microorganisms in sewage sludge. This problem has not been researched in detail yet.

The authors of the present study aimed to determine qualitative changes in drug-resistant microorganisms in sandy soil fertilized with selected sewage sludge. Sewage sludge after different types of drying process (natural and solar) was added to the degraded sandy soil. The effect of the methods of sewage sludge drying on concentration of drug-resistant microorganisms in soil fertilized with the sludge was analysed.

The study demonstrated that sewage sludge dried naturally in drying beds pose threat to soil environment and, potentially, to people and animals which have contact with fertilized soils. In sandy soils fertilized with these types of sewage sludge, pathogenic forms which exhibit resistance to first-line antibiotics can be found.

Activated sludge systems designed for enhanced nutrients removal are based on the principle of altering anaerobic and aerobic conditions for growth ofmicroorganisms with a high capacity of phosphorous accumulation. To avoid return of large parts of accumulated phosphorous in the processes of sludge conditioning chemical precipitation is often applied. This can be not be the case, at least for a part, if prior to other processes of sludge handling, the sludge will be disintegrated. It was demonstrated that disintegration of surplus activated sludge permits removal of a substantial part of nutrients in the form of struvite. The effects of sludge disintegration on metals ions release and poly-P destruction were elucidated. Appropriated handling of disintegrated sludge allows for removal of at least 25% of the inflowing phosphorous load without addition of chemicals.

The study discusses an experimental method for treatment of high strength domestic sewage on biofilters filled with polyurethane (PUR) waste in the form of trims of upholstery foam. We determined effectiveness of two biological preparations containing effective microorganisms in elimination of organic and biogenic compounds, indicator bacteria and total suspended solids from the sewage pretreated in a septic tank. After four months of work under a hydraulic loading of 76.4 mm∙d ^-1 we found the filter with 60 cm foam layer to be the most efficient in the elimination of BOD ₅, COD _Cr, NH ₄ ⁺-N and coliform bacteria. An average reduction in these pollutants reached 79.4%, 67.8%, 58.0% and 88.0%, respectively. Vertical filters filled with trims of upholstery foam and supplied with effective microorganisms ensured favorable conditions for development of heterotrophic and nitrifying bacteria without any need for additional aeration.

The pot experiment was conducted to access the soil microorganisms biomass (physiological method – Substrate Induced Respiration) and emissions of N2O, CO2 and CH4 (photoacoustic infrared detection method), and grasses biomass (weight method). The obtained results of analysed gases were converted to CO2 equivalent. There was no effect of the microorganisms biomass on the N2O emissions. The increase in CO2 emissions was accompanied by an increase in the microorganisms biomass (r = 0.48) under the conditions of the I swath and acid soil reaction, as well as the II swath and neutral reaction ( r = 0.94). On the other hand, in the case of CH4 emission, such a relationship was noted both swaths under the conditions of neutral reaction ( r = 0.51), but a negative correlation ( r = –0.71) was noted for the acid reaction only at the II swath. The increase in the grasses biomass with the increase in the microorganisms biomass was recorded only at the II swath in neutral reaction ( r = 0.91). In a short period of time, with the neutral soil reaction with the increase in the soil microorganisms biomass, an increase in CO2 sequestration and biomass of cultivated grasses was noted. Information on the determination of the microorganisms groups responsible mainly for the transformation of carbon compounds and CO2 and CH4 emissions from the soils of grasslands would be valuable scientifically.

The aggregate of various taxonomic groups of microorganisms colonising living organisms is known as the microbiome. The plant microbiome encompasses a wide network of biological, chemical and metabolic interactions between the plant and microorganisms (mainly algae, bacteria and protozoa). The relationships between microbes and peatland plants, particularly carnivorous plants, are a very interesting subject that is still little understood. Microbes colonising carnivorous peatland plants may be present in their traps or on the surface of the plant. Previous research on the relationships between the microbiome composition of carnivorous plants and the external factors influencing it directly and indirectly is still inadequate. There is a lack of review articles analysing the current state of knowledge regarding carnivorous plant–microbiome interactions. This review of the literature is a collection of data on the functioning of the microbiome of carnivorous plants growing in peatland ecosystems. In addition, it summarises the available information on host–microorganism relationships.

Petroleum products are complex mixture of compounds of varied biological properties. They can

cause harmful changes in contaminated ecosystems and threaten humans and living organisms as well. Bioremediation (including bioremediation stimulated by biogenic substances and inoculation with biopreparations

from autochthonous bacteria and fungi) can result in creation of metabolites of a varied structure and biological

activeness, which has been partly recognised. Some of them are more toxic than an initial substrate. Besides,

they might have mutagenic features and be responsible for cancer. Estimation of bioremediation effectiveness in

waste pits was completed with toxicological monitoring. It was led with the use of living organisms as biomarkers representing all trophic levels of a chosen ecosystem: producers, consumers and reducers. This process enables total estimation of natural environment conditions. The aim of the research was to determine the influence

of petroleum contaminants and indirect metabolites (produced during bioremediation) on soil biocenose. The

results of biotests (toxicity, phytotoxicity and genotoxity) have been taken into account. The following biotests,

prepared and produced by Microbiotest, have been applied: PhytotoxkitTM, Ostracodtoxkit FTM, acute toxicity

tests Microtox® Solid Phase and Ames mutagenicity tests. The obtained results enabled observation of changes

in toxic properties during purification of the soil taken from waste pits. In addition, it can be claimed whether

the areas are suitable for forest usage.