Colloids and surfaces. B, Biointerfaces, Jan 25, 2015
The research was aimed at determining the abundance and viability of biofilm formed on the surfac... more The research was aimed at determining the abundance and viability of biofilm formed on the surface of polylactide (PLA) during its biodegradation in different environments. It was also aimed at isolating biofilm forming bacteria, determining their hydrolytic activity and taxonomic status. The first step was to evaluate PLA biodegradability in lake water, compost and soil, using OxiTop Control. The next step was to assess the ability of isolated bacteria to form biofilm in the investigated environments and to evaluate the biofilm structure. The results indicate that PLA is sensitive to biodegradation in any environment, particularly in compost. During this process biofilm of high viability was observed on the surface of PLA. Based on the 16S rRNA gene sequence, the biofilm-forming bacteria were classified as the following species: Acidovorax sp. LW9, Chryseobacterium sp. LW2, Aeromonas veronii LW8, Arthrobacter aurescens LG2, Arthrobacter sp. LG12, A. aurescens LG9, Elizabethkingia m...
The research was aimed at determining the abundance and viability of biofilm formed on the surfac... more The research was aimed at determining the abundance and viability of biofilm formed on the surface of polylactide (PLA) during its biodegradation in different environments. It was also aimed at isolating biofilm forming bacteria, determining their hydrolytic activity and taxonomic status. The first step was to evaluate PLA biodegradability in lake water, compost and soil, using OxiTop Control. The next step was to assess the ability of isolated bacteria to form biofilm in the investigated environments and to evaluate the biofilm structure. The results indicate that PLA is sensitive to biodegradation in any environment, particularly in compost. During this process biofilm of high viability was observed on the surface of PLA. Based on the 16S rRNA gene sequence, the biofilm-forming bacteria were classified as the following species: Acidovorax sp. LW9, Chryseobacterium sp. LW2, Aeromonas veronii LW8, Arthrobacter aurescens LG2, Arthrobacter sp. LG12, A. aurescens LG9, Elizabethkingia meningoseptica LK3, A. aurescens LK9, A. aurescens and LK7. The results show that different bacterial species formed biofilm of different abundance and hydrolytic activitiy levels.
The range of solar radiation reaching the air-water inter-phase, medium wave UV radiation, i.e. U... more The range of solar radiation reaching the air-water inter-phase, medium wave UV radiation, i.e. UVB 290–320 nm and UVA 320–400 nm, is of the highest biological impor-tance due to its harmful effects. Radiation within this range causes DNA damage (lethal effect) or limits the growth of organisms by inhibiting en-zyme synthesis, reducing active transport, or by inducing mutations. The studies were carried out in 2007 based on samples water collected from surface microlayer (SM) (up to 150 μm) and subsurface water (SSW) (25 cm) of pelagic zone of eutrophic lake. The representative collection of bacterial strains was isolated from collected samples. The following are measured: the DNA and cellular protein synthe-sis activity, respiration activity of the bacteria and activity of hydrolytic enzymes in control cultures, subjected to UVB radiation (applied dose 100 mW cm -2) and with and without humic substances (HS) (final concentration 100 mg L -1) playing role of compounds potentially pr...
Annals of agricultural and environmental medicine : AAEM, 2013
The aim of this study was determination of the level of water contamination in fountains in Toruń... more The aim of this study was determination of the level of water contamination in fountains in Toruń, Poland. The studies were conducted at monthly intervals from May - September 2009, and consisted in the determination of the number of heterotrophic bacteria capable of growing at a temperature of 22 and 37°C (PN-ISO 6222), as well as the number of coliform bacteria (PN-75/C-04615/05), E. coli (ISO 9308-1) and faecal streptococci (PN-EN ISO 7899-2). The 'Rafter' fountain in the Old Town Market Square, continuously supplied with municipal water, had the cleanest water. The highest number of heterotrophic bacteria capable of development at 22 and 37°C was found in the fountain located in the City Park of Bydgoskie suburb. Throughout the entire research period, water from the fountain in the Old Town Moat had the worst sanitary (health) indices. The recorded results indicate that water from the 3 out of 4 examined fountains, with inappropriate exploitation--bathing, water drinking...
This study was aimed at determining whether Legionella pneumophila can be found in lakes serving ... more 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%.
The present paper provides an account of a study on benzene, toluene and xylene degradation by ne... more The present paper provides an account of a study on benzene, toluene and xylene degradation by neustonic and planktonic bacteria in lake Jeziorak Maty. Aromatic hydrocarbons were better decomposed by neustonic bacteria than planktonic bacteria. Moreover, the obtained data point to the total number of bacteria and heterotrophic bacteria number being greater in surface microlayer than in subsurface water.
The efficiency of utilization of low molecular weight organic molecules by neustonic and plankton... more The efficiency of utilization of low molecular weight organic molecules by neustonic and planktonic bacteria inhabiting the waters of the Gdansk Deep region has been determined. The most intensive growth was observed in the presence of amino acids, while carbohydrates and organic acids were utilized less actively. Glutamic acid, asparatic acid, histidine, glycine, cysteine and calcium lactate were the most suitable sources of carbon and energy for the bacteria. Significant differences in the level of intensity of assimilation of low molecular weight organic molecules by bacteria inhabiting various water layers occurred.
This paper showed, that the samples recovered from the subsurface water always contained much few... more This paper showed, that the samples recovered from the subsurface water always contained much fewer bacteria than those sampled from the surface microlayer. The neustonic bacteria are more resistant to the heavy metals ions than bacteria collected from subsurface water. The mean data obtained allow a statement that copper ions provoked the least response, while lead and cadmium ions -the greatest ones.
Research was conducted for the present paper on microbiological contamination of the air within t... more Research was conducted for the present paper on microbiological contamination of the air within the City of Toruń. It follows from the studies conducted that microorganisms occurred in greater numbers in the air within the area of the Old Town than in the Rubinkowo residential district. The number of microorgan-isms in the air was subject to seasonal changes. The highest numbers of heterotrophic mesophylic bacteria (CFU 37°C) were found in the summer season and the lowest in the winter season. The majority of isolated bacteria belonged to Gram positive forms -bacilli or cocci. A significant proportion of the isolated bacteria displayed antibiotic resistance to commonly used antibiotics.
This paper presents results of research concerning bacteria inhabiting the surface microlayer and... more This paper presents results of research concerning bacteria inhabiting the surface microlayer and subsurface water of the eutrophic lake Jeziorak Maty. Total number, biomass and share of heterotrophic bacteria was higher in surface microlayer than in subsurface water. Identification shows significant differences between genera of bacteria inhabiting surface biofilm and subsurface water.
We have attempted to evaluate the level of the earliest human hematopoietic cell marker expressio... more We have attempted to evaluate the level of the earliest human hematopoietic cell marker expression (CD34, CD117, CD133, CD184) on cells obtained from heparinized cadaveric organ donors before and after disconnection from the respirator. Moreover, we compared various cell populations: (1) coexpressing CD34/CD117; (2) CD34/CD133; (3) highly enriched hematopoietic stem cells (CD34+CXCR4+CD45+); and (4) highly enriched tissue-committed stem cells (CD34+CXCR4+CD45-). Finally, we analyzed whether the level of hematopoietic stem cell marker expression depended on the age of the donor. The expression of the membrane receptors (CD34, CD45, CD117, CD133, CD184) was studied by flow cytometry. We observed that the proportion of mononuclear cells expressing these markers slightly decreased in bone marrow harvested after disconnection from the respirator compared with the samples obtained before disconnection. Moreover, the proportion of cells expressing CD117 antigen depended on age of the donor.
Colloids and surfaces. B, Biointerfaces, Jan 25, 2015
The research was aimed at determining the abundance and viability of biofilm formed on the surfac... more The research was aimed at determining the abundance and viability of biofilm formed on the surface of polylactide (PLA) during its biodegradation in different environments. It was also aimed at isolating biofilm forming bacteria, determining their hydrolytic activity and taxonomic status. The first step was to evaluate PLA biodegradability in lake water, compost and soil, using OxiTop Control. The next step was to assess the ability of isolated bacteria to form biofilm in the investigated environments and to evaluate the biofilm structure. The results indicate that PLA is sensitive to biodegradation in any environment, particularly in compost. During this process biofilm of high viability was observed on the surface of PLA. Based on the 16S rRNA gene sequence, the biofilm-forming bacteria were classified as the following species: Acidovorax sp. LW9, Chryseobacterium sp. LW2, Aeromonas veronii LW8, Arthrobacter aurescens LG2, Arthrobacter sp. LG12, A. aurescens LG9, Elizabethkingia m...
The research was aimed at determining the abundance and viability of biofilm formed on the surfac... more The research was aimed at determining the abundance and viability of biofilm formed on the surface of polylactide (PLA) during its biodegradation in different environments. It was also aimed at isolating biofilm forming bacteria, determining their hydrolytic activity and taxonomic status. The first step was to evaluate PLA biodegradability in lake water, compost and soil, using OxiTop Control. The next step was to assess the ability of isolated bacteria to form biofilm in the investigated environments and to evaluate the biofilm structure. The results indicate that PLA is sensitive to biodegradation in any environment, particularly in compost. During this process biofilm of high viability was observed on the surface of PLA. Based on the 16S rRNA gene sequence, the biofilm-forming bacteria were classified as the following species: Acidovorax sp. LW9, Chryseobacterium sp. LW2, Aeromonas veronii LW8, Arthrobacter aurescens LG2, Arthrobacter sp. LG12, A. aurescens LG9, Elizabethkingia meningoseptica LK3, A. aurescens LK9, A. aurescens and LK7. The results show that different bacterial species formed biofilm of different abundance and hydrolytic activitiy levels.
The range of solar radiation reaching the air-water inter-phase, medium wave UV radiation, i.e. U... more The range of solar radiation reaching the air-water inter-phase, medium wave UV radiation, i.e. UVB 290–320 nm and UVA 320–400 nm, is of the highest biological impor-tance due to its harmful effects. Radiation within this range causes DNA damage (lethal effect) or limits the growth of organisms by inhibiting en-zyme synthesis, reducing active transport, or by inducing mutations. The studies were carried out in 2007 based on samples water collected from surface microlayer (SM) (up to 150 μm) and subsurface water (SSW) (25 cm) of pelagic zone of eutrophic lake. The representative collection of bacterial strains was isolated from collected samples. The following are measured: the DNA and cellular protein synthe-sis activity, respiration activity of the bacteria and activity of hydrolytic enzymes in control cultures, subjected to UVB radiation (applied dose 100 mW cm -2) and with and without humic substances (HS) (final concentration 100 mg L -1) playing role of compounds potentially pr...
Annals of agricultural and environmental medicine : AAEM, 2013
The aim of this study was determination of the level of water contamination in fountains in Toruń... more The aim of this study was determination of the level of water contamination in fountains in Toruń, Poland. The studies were conducted at monthly intervals from May - September 2009, and consisted in the determination of the number of heterotrophic bacteria capable of growing at a temperature of 22 and 37°C (PN-ISO 6222), as well as the number of coliform bacteria (PN-75/C-04615/05), E. coli (ISO 9308-1) and faecal streptococci (PN-EN ISO 7899-2). The 'Rafter' fountain in the Old Town Market Square, continuously supplied with municipal water, had the cleanest water. The highest number of heterotrophic bacteria capable of development at 22 and 37°C was found in the fountain located in the City Park of Bydgoskie suburb. Throughout the entire research period, water from the fountain in the Old Town Moat had the worst sanitary (health) indices. The recorded results indicate that water from the 3 out of 4 examined fountains, with inappropriate exploitation--bathing, water drinking...
This study was aimed at determining whether Legionella pneumophila can be found in lakes serving ... more 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%.
The present paper provides an account of a study on benzene, toluene and xylene degradation by ne... more The present paper provides an account of a study on benzene, toluene and xylene degradation by neustonic and planktonic bacteria in lake Jeziorak Maty. Aromatic hydrocarbons were better decomposed by neustonic bacteria than planktonic bacteria. Moreover, the obtained data point to the total number of bacteria and heterotrophic bacteria number being greater in surface microlayer than in subsurface water.
The efficiency of utilization of low molecular weight organic molecules by neustonic and plankton... more The efficiency of utilization of low molecular weight organic molecules by neustonic and planktonic bacteria inhabiting the waters of the Gdansk Deep region has been determined. The most intensive growth was observed in the presence of amino acids, while carbohydrates and organic acids were utilized less actively. Glutamic acid, asparatic acid, histidine, glycine, cysteine and calcium lactate were the most suitable sources of carbon and energy for the bacteria. Significant differences in the level of intensity of assimilation of low molecular weight organic molecules by bacteria inhabiting various water layers occurred.
This paper showed, that the samples recovered from the subsurface water always contained much few... more This paper showed, that the samples recovered from the subsurface water always contained much fewer bacteria than those sampled from the surface microlayer. The neustonic bacteria are more resistant to the heavy metals ions than bacteria collected from subsurface water. The mean data obtained allow a statement that copper ions provoked the least response, while lead and cadmium ions -the greatest ones.
Research was conducted for the present paper on microbiological contamination of the air within t... more Research was conducted for the present paper on microbiological contamination of the air within the City of Toruń. It follows from the studies conducted that microorganisms occurred in greater numbers in the air within the area of the Old Town than in the Rubinkowo residential district. The number of microorgan-isms in the air was subject to seasonal changes. The highest numbers of heterotrophic mesophylic bacteria (CFU 37°C) were found in the summer season and the lowest in the winter season. The majority of isolated bacteria belonged to Gram positive forms -bacilli or cocci. A significant proportion of the isolated bacteria displayed antibiotic resistance to commonly used antibiotics.
This paper presents results of research concerning bacteria inhabiting the surface microlayer and... more This paper presents results of research concerning bacteria inhabiting the surface microlayer and subsurface water of the eutrophic lake Jeziorak Maty. Total number, biomass and share of heterotrophic bacteria was higher in surface microlayer than in subsurface water. Identification shows significant differences between genera of bacteria inhabiting surface biofilm and subsurface water.
We have attempted to evaluate the level of the earliest human hematopoietic cell marker expressio... more We have attempted to evaluate the level of the earliest human hematopoietic cell marker expression (CD34, CD117, CD133, CD184) on cells obtained from heparinized cadaveric organ donors before and after disconnection from the respirator. Moreover, we compared various cell populations: (1) coexpressing CD34/CD117; (2) CD34/CD133; (3) highly enriched hematopoietic stem cells (CD34+CXCR4+CD45+); and (4) highly enriched tissue-committed stem cells (CD34+CXCR4+CD45-). Finally, we analyzed whether the level of hematopoietic stem cell marker expression depended on the age of the donor. The expression of the membrane receptors (CD34, CD45, CD117, CD133, CD184) was studied by flow cytometry. We observed that the proportion of mononuclear cells expressing these markers slightly decreased in bone marrow harvested after disconnection from the respirator compared with the samples obtained before disconnection. Moreover, the proportion of cells expressing CD117 antigen depended on age of the donor.
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Papers by Maciej Walczak