Agnieszka Kalwasińska

Municipal landfill sites as sources of microorganisms potentially pathogenic to humans

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 <LOD-1604 CFU g(-1) of dry mass of soil. The results question the strategy of municipal landfill sites in densely populated areas, and emphasize the need for regular monitoring of microbiological tests in their vicinity as well as for control strategies in order to protect workers at landfill sites. The results of the study should be used for future decisions on the location of municipal landfill sites and suggest the need for better environmental control technologies in the sites that are already functioning.

Physiology and Molecular Phylogeny of Bacteria Isolated from Alkaline Distillery Lime

This paper presents the results of the research on the number, taxonomic composition, and biochemical properties of bacterial strains isolated from the alkaline Solvay distillery lime, deposited at the repository in Janikowo (central Poland). Fifteen strains out of 17 were facultative alkaliphiles and moderate halophiles, and two were alkalitolerants and moderate halophiles. The number of aerobic bacteria cultured in alkaline lime was approximately 10(5) CFU ml(-1), and the total number of bacteria was 10(7) cells g(-1). According to 16S rRNA gene sequence analysis, nine strains belonged to the genus Bacillus, six to the genus Halomonas, one to the genus Planococcus, and one to the genus Microcella. Strains that hydrolyse starch and protein were the most numerous. Esterase (C4) and esterase lipase (C8) were detected in the majority of bacterial strains. Twelve strains exhibited α-glucosidase activity and nine, naphtol-AS-BI-phosphohydrolase activity. The present study proves that alkaliphilic bacteria of this type may constitute a source of potentially useful extremozymes.

Extracellular enzymatic activities in subsurface water of eutrophic Lake Chełmżyńskie, Poland

Variations in hydrolytic activity of six extracellular enzymes were measured in subsurface waters in eutrophic Lake Chełmżyńskie. The ranking of potential activity rates of the assayed enzymes was: lipase > aminopeptidase > phosphatase > α-D-glucosidase > chitinase > β-D-glucosidase. The selected extracellular enzymatic activities were all characterized by a distinct seasonal variability and depended on the location of the research site. In spring and in autumn, the waters of Lake Chełmżyńskie were more eutrophic than in summer. Significant differences in enzyme activity between different parts of the studied lake were demonstrated. In autumn, stations near the town of Chełmża (I–II) were more eutrophic than the stations far from the town; this was supported by the activity of aminopeptidase being higher in the urban area of the lake than in the zone away from town. On the other hand, in spring the activity of aminopeptidase near town (stations II–IV) was lower than far from town (stations VI, VII, X and XI). The enzyme chitinase exhibited higher activity far from town both in summer and autumn.

Bacterial growth and biofilm formation in household-stored groundwater collected from public wells

The research was aimed at assessing changes in the number of bacteria and evaluating biofilm formation in groundwater collected from public wells, both aspects directly related to the methods of household storage. In the research, water collected from Cretaceous aquifer wells in Toruń (Poland) was stored in a refrigerator and at room temperature. Microbiological parameters of the water were measured immediately after the water collection, and then after 3 and 7 days of storage under specified conditions. The microbiological examination involved determining the number of heterotrophic bacteria capable of growth at 22 and 37 °C, the number of spore-forming bacteria, and the total number of bacteria on membrane filters. The storage may affect water quality to such an extent that the water, which initially met the microbiological criteria for water intended for human consumption, may pose a health risk. The repeated use of the same containers for water storage results in biofilm formation containing live and metabolically active bacterial cells.

The role of open-air inhalatoria in the air quality improvement in spa towns

ObjectivesThe present study was aimed at evaluating microbiological contamination of air in Ciechocinek and Inowrocław — Polish lowland spa towns. Additionally, the impact of open-air inhalatoria on the quality of air was evaluated.Material and MethodsAir samples were collected seasonally in the urban areas, in the recreation areas and in the vicinity of inhalatoria in both towns using impaction. The numbers of mesophilic bacteria, staphylococci, hemolytic bacteria and actinomycetes were determined on media according to the Polish Standard PN-86/Z-04111/02. The number of moulds was determined on media according to the Polish Standard PN-86/Z-04111/03.ResultsWhile the highest numbers of microorganisms were noted at the sites located in the urban areas, the lowest numbers were noted in the vicinity of the open-air inhalatoria. In all the investigated air samples the values of bioaerosol concentrations were below the recommended TLVs (≤ 5000 CFU×m−3 for both bacteria and fungi in outdoor environments). Location of the sampling site was invariably a decisive factor in determining the number of microorganisms in the air.ConclusionsThe aerosol which is formed in the open-air inhalatoria has a positive influence on microbiological air quality. Owing to a unique microclimate and low air contamination, Ciechocinek and Inowrocław comply with all necessary requirements set for health resorts specializing in treating upper respiratory tract infections.

Alkaline and Halophilic Protease Production by Bacillus luteus H11 and its Potential Industrial Applications

SUMMARY This paper presents the results of the study on the production of protease by Bacillus luteus H11 isolated from an alkaline soda lime. B. luteus H11 was identified as an alkalohalophilic bacterium, and its extracellular serine endoprotease also showed an extreme alkali- and halotolerance. It was remarkably stable in the presence of NaCl up to 5 M. The enzyme was active in a broad range of pH values and temperatures, with an optimum pH of 10.5 and a temperature of 45 °C. It had a molecular mass of about 37 kDa and showed activity against azocasein and a synthetic substrate for the subtilisin-like protease, N-succinyl-l-phenylalanine-p-nitroanilide. The halo-alkaline protease produced by B. luteus H11 seems to be significant from an industrial perspective because of its tolerance towards high salinity and alkalinity as well as its stability against some organic solvents, surfactants and oxidants. These properties make the protease suitable for applications in food, detergent and pharmaceutical industries, and also in environmental bioremediation.

Changes in bacterial and archaeal communities during the concentration of brine at the graduation towers in Ciechocinek spa (Poland)

This study evaluates the changes in bacterial and archaeal community structure during the gradual evaporation of water from the brine (extracted from subsurface Jurassic deposits) in the system of graduation towers located in Ciechocinek spa, Poland. The communities were assessed with 16S rRNA gene sequencing (MiSeq, Illumina) and microscopic methods. The microbial cell density determined by direct cell count was at the order of magnitude of 107 cells/mL. It was found that increasing salt concentration was positively correlated with both the cell counts, and species-level diversity of bacterial and archaeal communities. The archaeal community was mostly constituted by members of the phylum Euryarchaeota, class Halobacteria and was dominated by Halorubrum-related sequences. The bacterial community was more diverse, with representatives of the phyla Proteobacteria and Bacteroidetes as the most abundant. The proportion of Proteobacteria decreased with increasing salt concentration, while the proportion of Bacteroidetes increased significantly in the more concentrated samples. Representatives of the genera Idiomarina, Psychroflexus, Roseovarius, and Marinobacter appeared to be tolerant to changes of salinity. During the brine concentration, the relative abundances of Sphingobium and Sphingomonas were significantly decreased and the raised contributions of genera Fabibacter and Fodinibius were observed. The high proportion of novel (not identified at 97% similarity level) bacterial reads (up to 42%) in the 16S rRNA gene sequences indicated that potentially new bacterial taxa inhabit this unique environment.

The influence of polyhexamethylene guanidine derivatives introduced into polyhydroxybutyrate on biofilm formation and the activity of bacterial enzymes

Escherichia coli and Staphylococcus aureus were able to produce biofilm on the surface of polyhydroxybutyrate (PHB), but their abundance depended on type and the concentrations of the polyhexamethylene guanidine (PHMG) derivatives introduced in PHB. Different types of PHMG derivatives inhibited S. aureus ATCC 6538P biofilm formation, but PHB with PHMG salt of sulfanilic acid stimulated E. coli ATCC 8739 biofilm formation. The presence of all PHMG derivatives decreased significantly the number of viable cells of the test bacteria directly proportional to the concentration of the biocidal agent. PHMG derivatives affected the activity of microbiological hydrolases with different degrees. Some of them (PHB with PHMG stearate) stimulated activity of E. coli ATCC 8739 hydrolases, other (PHB with the PHMG salt of sulfanilic acid) inhibited activity of the S. aureus ATCC 6538P hydrolases. The PHMG derivatives introduced in PHB also inhibited the activity of bacterial dehydrogenases.