Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 8

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Occurrence and activity of the chitinolytic bacteria of Aeromonas genus

100%
Swiontek B. M., Donderski W.
Polish Journal of Environmental Studies
|
2001
|
tom 10
|
nr 1
A study was carried out on the occurrence and activity of chitinolytic planktonic bacteria of Aeromonas sp., Aeromonas hydrophila and Aeromonas salmonicida species, isolated from lake Jeziorak. Among the identified strains decomposing chitin the most abundant were Aeromonas sp.. All the investigated strains showed maximum chitinolytic activity at pH 6.0. An increase in chitinolytic activity was observed that occurred along with temperature growth (10° - 40°C) and colloidal chitin concentration in the medium (0.5 - 2.5%). Their decomposing activity was most intense after a 192 h incubation time. No strain displayed activity after a 48 h incubation time.
2

Chitinolytic bacteria in two lakes of different trophic status

100%
Swiontek B. M., Donderski W.
Polish Journal of Ecology
|
2006
|
tom 54
|
nr 2
This paper presents the results of research on the number of chitinolytic bacteria and chitinolytic activity of strains in the oligomesotrophic and the eutrophic lakes. Two lakes of soft and hard water and of different trophic status (in terms of nutrients contents) from Iławskie Lake District (North Poland) were choosen. The numbers of chitinolytic bacteria were higher in eutrophic lake (average 1.0 × 10³ cells cm⁻³) than in oligo-mesotrophic lake (average 0.5 × 10³ cells cm⁻³) as well as in littoral versus pelagic zone. However, a higher percentage of chitinolytic bacteria (average 13%) among the total numbers of heterotrophic bacteria was found in oligo-mesotrophic lake as well as higher rate of the chitinolytic activity of bacteria (7.0 versus 4.5 nmol GlcNAc mg⁻¹ protein h⁻¹ after 6 days of incubation). The possible shortage of dissolved organic compounds in mesotrophic lake was pointed up as the reason for using the dissolved chitin as the source of carbon and nitrogen. Enterobacter aerogenes (28%), Aeromonas sp. (25%) and Chromobacterium sp. (16%) dominated in oligo – mesotrophic lake. In eutrophic lake, the most numerous species were Aeromonas hydrophila (46%) and Aeromonas sp. (15%).
3

Degradation of chitin in natural environment: role of actinomycetes

81%
Swiontek B. M., Lalke-Porczyk E., Donderski W., Walczak M.
Polish Journal of Ecology
|
2009
|
tom 57
|
nr 2
229-238
The actinomycetes in water samples and bottom sediments of lowland, eutrophic lake as well as in soil (farmland, sandy) of the lake basin were studied. Chitin-degrading actinomycetes were isolated (with a plate technique) from each habitat; subsequently, their chitinolytic activity (with the fluorometric method) was determined in relation to temperature (10–50°C) and the physical type of chitinous substance (colloidal chitin, chitin powder, and shrimp shells). This study demonstrated that actinomycetes were the most abundant in soil samples (average of 18 × 10³ CFU g⁻¹ in farmland soil, 9 × 10³ CFU g⁻¹ in sandy soil), and the least abundant in water samples (average of 2.7 × 10¹ CFU mL⁻¹ in lake water at neutral pH, 0.6 × 10¹ CFU mL⁻¹ in lake water with alkaline pH). The highest percentage of chitinolytic actinomycetes was observed in soil (average of 80% in sandy soil and 85% in farmland soil). Chitinolytic actinomycetes also made up a large fraction of total actinomycetes in water samples (average of 73%). In silt and sandy sediments, percentages of chitinolytic actinomycetes equaled 23 and 15%, respectively. Actinomycetes collected in soil were characterized by the highest activity (average of 14 nmol MUF mg⁻¹ of protein h⁻¹ in farmland soil, 8.5 nmol MUF mg⁻¹ protein h⁻¹ in sandy soil). The lowest activity was observed among benthic actinomycetes (average of 5.4 nmol MUF mg⁻¹ of protein h⁻¹ in silt, 0.65 nmol MUF mg⁻¹ protein h⁻¹ in sandy sediments). The impact of temperature and the type of chitinous substrate on the activity of chitinases produced by actinomycetes demonstrated that their activity peaked at 40°C and in the presence of colloidal chitin. Observed differences in actinomycetales number and activity in the lake and the soil may be explained by higher accumulation of chitin substances in the soil. This polymer allows microorganisms to continually synthesize chitinolytic enzymes and take active part in that compound decomposition.
4

The role of chitinolytic bacteria and fungi in biodegradation of crustacean remains in lacustrine habitats

81%
Swiontek B. M., Lalke-Porczyk E., Donderski W.
Polish Journal of Ecology
|
2008
|
tom 56
|
nr 2
335-342
This study presents results of research on occurrence of chitinolytic bacteria and fungi in water, bottom sediments, and watershed soil of an eutrophic lake and on their ability to use the crustacean skeletons (shrimp waste) as a respiration substrate. It was found that the respiration rate of bacteria and fungi during decomposition of chitin varied in different environments. The participation of chitinolytic microorganisms in water (13%) and soil (18%) was greater than in bottom sediments (5%). The respiration activity in the presence of all parts of shrimp waste and shrimp exoskeletons observed in chitinolytic bacteria was higher than that of fungi. But fungi demonstrated the highest metabolic activity in the presence of the shrimp head sections. The highest respiration activity was observed in planktonic and soil bacteria, while the lowest, in benthic strains. The chitinolytic bacteria used well all examined respiration substrates (all parts of shrimp waste – 671 mg O₂ r⁻¹ protein in 5 days, the shrimp head sections – 851 mg O₂ r⁻¹ protein in 5 days and shrimp exoskeletons – 490 mg O₂ r⁻¹ protein in 5 days). No significant differences in respiration activity were observed in chitinolytic fungi isolated from water, bottom sediments and soil. All of fungal strains demonstrated the highest metabolic activity in the presence of the shrimp head sections (average 1083 mg O₂ r⁻¹ protein in 5 days). Shrimp exoskeletons were oxidized the least efficiently (average 160 mg O₂ r⁻¹ protein in 5 days). Certain strains were not using them at all.
5

Utilization of shrimp waste as a respiration substrate by planktonic and benthic microorganisms

81%
Swiontek B. M., Lalke-Porczyk E., Donderski W.
Polish Journal of Environmental Studies
|
2008
|
tom 17
|
nr 2
273-282
This study presents results of research on the number of heterotrophic bacteria and fungi in water and bottom sediments of Lake Chełmżyńskie and their role in the decomposition of chitin. The authors also examined the level of respiration activity of water and sediment microorganisms in the presence of shrimp waste. Results demonstrate that the number of heterotrophic bacteria and fungi in water and bottom sediments were variable. The analyzed groups of microorganisms predominated in bottom sediments with the number of heterotrophic bacteria significantly exceeding that of fungi. The proportion of microorganisms capable of decomposing chitin was greater among fungi than among heterotrophic bacteria. In water chitinolytic bacteria constituted 11–19% of the total number of heterotrophic bacteria and in bottom sediments only 3–8%. Chitinolytic fungi constituted 17–67% and dominated in water. In the presence of shrimp waste, the level of respiration activity of microorganisms in water and bottom sediments of Lake Chełmżyńskie clearly depended on examined factors. The temperature, incubation time, and type of respiration substrate had a statistically significant impact on this activity. The highest respiration activity (2.4–90.3 mg O₂ · dm⁻³) of aquatic microorganisms was recorded in the summer, when the water temperature equaled 24°C. In bottom sediments the highest values of respiration activity also were observed in summer (13.4–447.4 mg O₂ g⁻¹ dry mass) but alkaline sediments were characterized by higher activity levels. Benthic and planktonic microorganisms were utilizing shrimp heads most effectively and the exoskeletons least effectively.
6

Utilization of shrimp-shell waste as a substrate for the activity of chitinases produced by microorganisms

81%
Swiontek B. M., Walczak M., Lalke-Porczyk E., Donderski W.
Polish Journal of Environmental Studies
|
2010
|
tom 19
|
nr 1
177-182
Chitinolytic microorganisms such as bacteria, fungi, and actinomycetes, were isolated from the water and bottom sediments of Lake Chełmżyńskie and the soil of its watershed. The impact of various forms of chitin on the chitinolytic activity of these microorganisms was investigated. Bacteria isolated from the analyzed environments exhibited the highest chitinolytic activity in the presence of colloidal chitin. High activity was also observed in a culture medium containing shrimp shells. The analysis of chitinolytic activity of actinomycetes demonstrated that strains isolated from the soil had considerably higher activity levels than those isolated from lacustrine water and bottom sediments. All soil actinomycetes exhibited the highest activity in a culture medium containing colloidal chitin and shrimp shells. Actinomycetes collected in water and bottom sediments were characterized by similar activity levels. Chitinolytic fungi exhibited the maximum activity also in a medium containing colloidal chitin. The presence of shrimp shells in a culture medium had the lowest impact on chitinolytic activity. Among the analyzed forms of chitin, the impact of chitin powder on the activity of chitinases was the least stimulating.
7

The bacteriological and sanitary state of sewage in an on-site willow wastewater treatment facility

81%
Swiontek B. M., Lalke-Porczyk E., Donderski W.
Polish Journal of Natural Sciences
|
2007
|
tom 22
|
nr 2
284-293
The numbers of heterotrophic bacteria, capable of growing at 22℃ and 37℃, as well as the following indicator bacteria used to determine the sanitary and bacteriological conditions, were determined in an on-site willow wastewater treatment facility in the Czarne Błoto, Zławieś Wielka district: coliforms bacteria (TC), fecal coliforms bacteria (FC), and fecal streptococci (FS). The study demonstrated that the number of heterotrophic bacteria, capable of growing at 22℃ and 37℃, as well as indicator bacteria was greatly reduced after wastewater passed through all stages of treatment in the soil – willow filter. The greatest reduction in the bacterial abundance was observed between the raw sewage that flows into the soil-willow filter and the treated sewage (even in winter). Reduction of coliform and fecal coliform bacteria was the greatest following all stages of sewage treatment (on average 95.2% and 94.6%). The reduction of fecal streptococcus equaled 90.4% on average. The lowest reduction in abundance (on average 82.2%) was observed for heterotrophic bacteria capable of growth at 22℃.
8

Shrimp waste as a respiration substrate for soil microflora of the Chelmzynskie Lake watershed

81%
Swiontek B. M., Lalke-Porczyk E., Donderski W.
Polish Journal of Natural Sciences
|
2008
|
tom 23
|
nr 1
164-177
This study presents results of research on number of heterotrophic bacteria and fungi in soil of the Chełmżyńskie Lake watershed and their role in decomposition of chitin. The authors also examined the level of respiration activity of soil microorganisms in the presence of shrimp waste. Results demonstrate that the number of heterotrophic bacteria and fungi in soil were variable. During the entire research period, the analyzed groups of microorganisms predominated in neutral soils with the number of heterotrophic bacteria significantly exceeding that of fungi. The proportion of microorganisms capable of decomposing chitin was greater among fungi than among heterotrophic bacteria. Chitinolytic bacteria constituted 14-38% of the total number of heterotrophic bacteria and their proportion was higher in alkaline soil. Chitinolytic fungi constituted 31-50% and also dominated in alkaline soil. The conducted analyses demonstrated that chitinolytic activity was higher among heterotrophic bacteria than among fungi. In the presence of shrimp waste, the level of respiration activity of microorganisms of the Chełmżyńskie Lake watershed soil clearly depended on examined factors. The temperature and time of incubation, the soil reaction, and the type of the respiration substrate had a statistically significant impact on this activity. Microorganism respiration activity ranged from 0 to 550 mg O₂ g⁻¹ dry soil mass with the highest values recorded in the summer and lowest, in spring. During the entire research period, the microorganisms inhabiting alkaline soil were more readily able to take advantage of shrimp waste and found shrimp heads the most useful, while shells, the least.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.