This paper provides a review of the latest research findings on the applications of microbial chitinases to biological control. Microorganisms producing these enzymes can inhibit the growth of many fungal diseases that pose a serious threat to global crop production. Currently, efforts are being made to discover producers of chitinolytic enzymes. The potential exists that natural biofungicides will replace chemical fungicides or will be used to supplement currently used fungicides, which would reduce the negative impact of chemicals on the environment and support the sustainable development of agriculture and forestry.

The present research was aimed at assessing the quality of air in work environment of the municipal landfill site in Toru n. Air samples were collected in the outdoor space (operating landfill cell, technological square), and in indoor space (sorting station, weighing station, social room) using the impaction method. The microbiological air testing included determining the number of airborne mesophilic bacteria and molds. Bacterial strains were identified with appropriate API tests; molds were identified according to their macro and micro characteristics. In outdoor air, the highest average concentration of mesophilic bacteria were recorded at the operating landfill cell (1361 colony forming unit (CFU)/m 3 ). The highest average concentrations of molds were recorded at the technological square (1179 CFU/m 3 ). In indoor air, the highest average concentration of investigated microorganisms (bacteria: 10 707 CFU/m 3 , molds:12 471 CFU/m 3 ) were recorded in the sorting facility. The concentration of microorganisms in the outdoor air depended on the season (p < 0.05), but did not depend on the sampling site, while in the indoor air depended on the sampling site (p < 0.05) but did not depend on the season. Bioaerosol emitted in municipal facility was the source of bacterial (Bacillus subtilis, Pseudomonas aeruginosa) and fungal species (Aspergillus fumigatus, Madurella grisea, Penicillium manfferei, Scedosporium apiospermium, Cryptococcus neoformans), posing a health risk for humans. However Gram-negative bacteria constituted only a small fraction of the isolated microorganisms. The highest risk of exposure to biological agents was determined in the sorting station. The majority of the outdoor air samples were classified as uncontaminated. The results emphasize the need for regular monitoring of microbiological tests in indoor and outdoor air of municipal landfill sites as well as for control strategies in order to protect workers at landfill.

The present research was aimed at assessing the quality of air and soil on the premises and in the vicinity of the municipal landfill sites in Toruń with regard to the presence of pathogenic bacteria, potentially dangerous to humans. Air samples (the impaction method using a MAS-100 impactor) and soil samples were collected from seven sampling sites including the operating and closed landfill cells, sampling sites located near leachate ponds, and sampling sites located outside the above premises. The research also involved assessing microbial air contamination in three indoor spaces on the premises of the landfill sites. Microbial tests involved the determination of the number of culturable mesophilic, mannitol-positive, and α- and β-hemolytic bacteria in the air, determination of the number of coliform bacteria, spore-forming Clostridium perfringens in soil, and the presence of Salmonella in soil. The results indicate that bioaerosol emitted by this municipal facility is the source of hemolytic bacteria (≤ 300 CFU m(-3) of air), as well as of pathogenic bacteria (Pseudomonas aeruginosa and Bacillus subtilis). The highest risk of exposure to biological agents was determined in the sorting facility. Over sixty percent of air samples in this sampling site presented high pollution degree with mesophilic bacteria (500-2000 CFU m(-3) of air) and over one fourth of air samples presented very high pollution degree (>2000 CFU m(-3) of air). Indoor air in other rooms was considered highly/moderately contaminated (100-2000 CFU m(-3) of air). The highest risk related to the presence of Salmonella, Clostridium perfringens, and coliform bacteria in soil was determined at the operating landfill cell and near the leachate pond of the closed landfill cell. At the operating landfill cell the total coli ranged from 4-1226 MPN g(-1) of dry mass of soil and Clostridium perfringens ranged from

Three homopolymers containing hydantoin substituents were obtained by chemical modification of reactive p-chloromethylated polystyrene. The prepared polymers were chlorinated to yield N-halamine materials with biocidal properties. The chemical structure of polymers was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. All of the hydantoin polymers are insoluble in water and common organic solvents. Microbiological investigations prove the high biocidal activity of the obtained chlorinated polystyrene derivatives containing spirohydantoin moieties. The obtained polymers will be useful in designing and constructing medical and pharmaceutical equipment. The ability to crosslink allows to expect easy grafting of these biocidal macrochains, for example, on textiles.

The study was aimed at determining whether potentially pathogenic free-living amoebae (FLA) and Legionella pneumophila can be found in lakes serving as a natural cooling system of a power plant. Water samples were collected from five lakes forming the cooling system of the power plants Pątnów and Konin (Poland). The numbers of investigated organisms were determined with the use of a very sensitive molecular method—fluorescence in situ hybridization (FISH). The result of the present study shows that thermally altered aquatic environments provide perfect conditions for the growth of L. pneumophila and amoebae. The bacteria were identified in the biofilm throughout the entire research period and in the subsurface water layer in July and August. Hartmanella sp. and/or Naegleria fowleri were identified in the biofilm throughout the entire research period.

Chitinolytic strain Streptomyces albidoflavus was isolated from soil of the central region of Poland. Its identification was based on analysis of 16S rRNA gene sequence. The colloidal chitin was revealed as the finest substrate for the production of chitinases by S. albidoflavus. The enzyme catalyzed the hydrolysis of the disaccharide 4 methylumbelliferyl β D N,N',N'' triacetylchitotriose most efficiently and was, therefore, classified as an endochitinase. The chitinase of S. albidoflavus was purified by applying the two step proce dure: fractionation with ammonium sulphate and chitin affinity chromatography. The molecular weight of the purified enzyme determined by SDS PAGE was approximately 50 kDa. The enzyme was characterised as thermostable during 180 min of preincubation at the temperature of 35°C and 40°C. The activity of the enzyme was strongly inhibited in the presence of Hg 2+ and Mn 2+ ions, SDS but stabilized by Ca 2+ and Mg 2+ ions. Both purified and crude chitinases from S. albidoflavus inhibited the development of fungal phytopatho gens. Purified chitinase inhibited the growth of Alternaria alternata, Fusarium culmorum, Fusarium oxysporum and Botrytis cinerea. Additionally, the crude chitinase inhibited the growth of Fusarium solani.

This study was aimed at determining whether Legionella pneumophila can be found in lakes serving as a natural cooling system of a power plant. Water samples were collected from five lakes forming the cooling system of the power plants Pątnów and Konin (Poland). The numbers of bacteria belonging to different phylogenetic groups (bacteria, Legionella sp. and L. pneumophila) were determined with the use of a molecular FISH method. The results of the present study show that thermally altered aquatic environments provide perfect conditions for the growth of L. pneumophila. These microorganisms were identified in the biofilm throughout the entire research period, and in the subsurface water layer in July and August. The percentage of L. pneumophila species in the Legionella genus was 11.55-12.42%.

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