Wyniki wyszukiwania - Biblioteka Nauki

1

Autotroficzny pikoplankton /APP/ - najdrobniejszy skladnik fitoplanktonu.

100%

Jasser I.

Działalność Naukowa PAN. Wybrane Zagadnienia

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2002

|

tom 13

46-49

2

The relationship between autotrophic picoplankton [APP] - the smallest autotrophic component of food web and the trophic status and the depth of lakes

100%

Jasser I.

International Journal of Ecohydrology and Hydrobiology

|

2006

|

tom 06

|

nr 1-4

69-77

3

Autotrophic picoplankton (APP) in four lakes of different trophic status : composition, dynamics and relation to phytoplankton

100%

Jasser I.

Polish Journal of Ecology

|

2002

|

tom Vol. 50, nr 3

341-355

EN

Abundance and dynamics of autotrophic picoplankton (APP) were studied in four temperate lakes: oligo-, meso- and eutrophic, as well as dystrophic lake. Orange fluorescing cyanobacteria prevailed in APP community in all four lakes, but in spring and autumn eukaryotic contribution increased. The densities of APP ranged between 2 x 10^4 ml^-1 and 9.5 x 10^5 ml^-1. There was a trend of increase of APP numbers along classical trophic gradient, but its share in total phytoplankton biomass was decreasing importance of picoplankton with eutrophication. Two types of APP seasonal patterns were described. One characterised by only one, spring-early summer peak, was found in mesotrophic and eutrophic lake. The second pattern described for humic lake was characterised by two peaks, in spring and Autumn.

4

Autotrophic picoplankton [APP] in four lakes of different trophic status: composition, dynamics and relation to phytoplankton

100%

Jasser I.

Polish Journal of Ecology

|

2002

|

tom 50

|

nr 3

5

Pikoplankton, najdrobniejszy skladnik fitoplanktonu: wystepowanie, struktura, funkcja

88%

Jasser I.

Wiadomości Ekologiczne

|

1993

|

tom 39

|

nr 1

3-19

6

XXVI Kongres Miedzynarodowego Towarzystwa Limnologicznego - SIL [Sao Paulo, 23-29 VII 1995r.]

75%

Jasser I.

Wiadomości Ekologiczne

|

1996

|

tom 42

|

nr 1

53-56

7

Fading out of the trophic cascade at the base of the microbial food web caused by changes in the grazing community in mesocosm experiments

63%

Jasser I. , Kostrzewska-Szlakowska I.

Oceanological and Hydrobiological Studies

|

2012

|

tom 41

|

nr 1

8

Black box: what do we know about humic lakes?

63%

Kostrzewska-Szlakowska I. , Jasser I.

Polish Journal of Ecology

|

2011

|

tom 59

|

nr 4

EN

The classic description of a coloured lake implies low productivity (Nauman 1921; cited in Jones 1922). Wetzel (1975) initially classified dystrophic lakes as oligotrophic, but later stated that dystrophy represents a subset of trophic continuum, from oligotrophy to eutrophy, rather than a parallel concept (Wetzel 2001). Other more recent studies have demonstrated that many dystrophic lakes are mesotrophic or even eutrophic (Jones 1992, Keskitalo and Eloranta 1999). Furthermore, the pH of their water can range between 4.1 and 8.0 (Keskitalo and Eloranta 1999), and it is clear that this property should be treated as an additional factor affecting their trophic state. Our own findings from humic acidic lakes of different trophic states and from one posthumic lake (originally humic, now eutrophic with pH = 7), together with data from the literature describing about 40 brown-water lakes, can be used to verify general statements concerning microbial ecology paradigms for humic waters: 1) the bacterial to phytoplankton biomass ratio is generally high and increases with lake water colour; 2) there is a positive relationship between bacterial biomass and the concentration of organic matter expressed in dissolved organic carbon units and as water colour; 3) bacterial production is generally higher than primary production; 4) there is a good correlation between bacterial production and humic matter content; 5) the pH of the water/sediments can modify these relationships by accelerating the rates between the variables mentioned above in neutral pH and/or limiting them in low pH. In this review we show that these statements are not always confirmed by detailed analyses of the available data, suggesting that in addition to the concentration of humic matter, the lake productivity, expressed as chlorophyll a and primary production, also influences the ratios between the compared variables. We also demonstrate that despite being weaker, the relationships between phytoplankton-related variables and bacterial abundance and production in low pH lakes are similar to those in circum-neutral humic waters. In addition, we show that the conversion factors and the proportion of active bacterial cells greatly influence all of the aforementioned relationships.

9

Black box : what do we know about Humic lakes?

63%

Kostrzewska-Szlakowska I. , Jasser I.

Polish Journal of Ecology

|

2011

|

tom Vol. 59, nr 4

647-664

EN

The classic description of a coloured lake implies low productivity (Nauman 1921; cited in Jones 1922). Wetzel (1975) initially classified dystrophic lakes as oligotrophic, but later stated that dystrophy represents a subset of trophic continuum, from oligotrophy to eutrophy, rather than a parallel concept (Wetzel 2001). Other more recent studies have demonstrated that many dystrophic lakes are mesotrophic or even eutrophic (Jones 1992, Keskitalo and Eloranta 1999). Furthermore, the pH of their water can range between 4.1 and 8.0 (Keskitalo and Eloranta 1999), and it is clear that this property should be treated as an additional factor affecting their trophic state. Our own findings from humic acidic lakes of different trophic states and from one posthumic lake (originally humic, now eutrophic with pH = 7), together with data from the literature describing about 40 brown-water lakes, can be used to verify general statements concerning microbial ecology paradigms for humic waters: 1) the bacterial to phytoplankton biomass ratio is generally high and increases with lake water colour; 2) there is a positive relationship between bacterial biomass and the concentration of organic matter expressed in dissolved organic carbon units and as water colour; 3) bacterial production is generally higher than primary production; 4) there is a good correlation between bacterial production and humic matter content; 5) the pH of the water/sediments can modify these relationships by accelerating the rates between the variables mentioned above in neutral pH and/or limiting them in low pH. In this review we show that these statements are not always confirmed by detailed analyses of the available data, suggesting that in addition to the concentration of humic matter, the lake productivity, expressed as chlorophyll a and primary production, also influences the ratios between the compared variables. We also demonstrate that despite being weaker, the relationships between phytoplankton-related variables and bacterial abundance and production in low pH lakes are similar to those in circum-neutral humic waters. In addition, we show that the conversion factors and the proportion of active bacterial cells greatly influence all of the aforementioned relationships.

10

Fading out of the trophic cascade at the base of the microbial food web caused by changes in the grazing community in mesocosm experiments

63%

Jasser I. , Kostrzewska-Szlakowska I.

Oceanological and Hydrobiological Studies

|

2012

|

tom Vol. 41, No. 1

1-11

EN

Biomanipulation of consumer populations can have strong top-down impacts on the composition and biomass of lower trophic levels. In this paper, we assess how changes in crustaceans' biomass influence classical grazing and the microbial food web in an oligo-mesohumic, low-pH lake (Mazurian Lake District, Poland). Removal of mesozooplankton from the experimental mesocosms created a gradient of crustacean biomass resulting in the biomass increase of rotifers, phytoplankton and protozooplankton, while autotrophic eukaryotic picoplankton (eu-APP) and bacteria were not affected. The strongest modifications concerned the rotifer biomass and phytoplankton community structure. Our results imply that the trophic cascade generated in the experiment did not extend to bacteria and eu-APP.

11

Male sympozjum na temat 'Ekologiczne konsekwencje globalnych zmian klimatu w naszej strefie geograficznej' [Dziekanow Lesny, 18 XII 1992 r.]

63%

Jasser I. , Rutkowski D. H.

Wiadomości Ekologiczne

|

1993

|

tom 39

|

nr 2

127-129

12

XXIX Kongres Miedzynarodowego Towarzystwa Limnologicznego - SIL [Lahti, Finlandia, 8-14 VIII 2004 r.]

63%

Jasser I. , Kostrzewska-Szlakowska I.

Wiadomości Ekologiczne

|

2004

|

tom 50

|

nr 4

303-308

13

Wloski Instytut Hydrobiologii w Pallanzy

63%

Jasser I.

Wiadomości Ekologiczne

|

1994

|

tom 40

|

nr 4

241-243

14

Konkurs fotograficzny ' W strone... wody'

63%

Jasser I.

Wiadomości Ekologiczne

|

2006

|

tom 52

|

nr 2

112-115

15

Enzymatic fingerprints used for comparison of physiological diversity of microbial communities in clear-water and humic lakes

51%

Siuda W. , Jasser I. , Kiersztyn B.

Polish Journal of Ecology

|

2013

|

tom Vol. 61, nr 4

715--728

EN

Extracellular enzymes occurring in aquatic environment are heterogeneous in respect to their origin and function, place, where they are located and their activity. They can be divided into mainly ‘bacterial-origin’ enzymes produced by heterotrophic organisms in order to obtain organic carbon, and mostly ‘phytoplankton-bacterial-origin’ enzymes, which are produced by autotrophic and heterotrophic organisms, and are responsible mainly for obtaining inorganic compounds. Enzymes activity provides information about microorganisms present in given environment and about their physiological state. We hypothesize that the patterns (‘fingerprints’) calculated on the basis of activity of several enzymes both mainly ‘bacterial-origin’ and mainly ‘phytoplankton-bacterial-origin’ may be used to characterise lake ecosystems in terms of the physiological structure of aquatic microorganisms present in these lakes. For the study we selected four lakes from Mazurian Lakes District in north-eastern Poland. Three of them were clear-water (lakes: Kuc, Mikołajskie, Tałtowisko) and ranged from oligotrophy to eutrophy, the fourth (Lake Smolak Duży) was slightly acidic (pH 5.2), highly productive and polyhumic. Activity of phosphatase (PA), L-leucine-aminopeptidase (AMP), β-glucosidase (B-Glu), esterase (EST), glucosaminidase (Glu-ami), glucuronidase (Glu-uro) and cellobiohydrolase (Cellob) were measured fluorometrically. The results were normalised and analysis of agglomerative clustering was performed to create an enzyme activity patterns characteristic for lakes. We found out that the enzymatic pattern reflected trophic differences between studied lakes. The patterns (‘fingerprints’) of enzymes were similar for three clear-water lakes, with urease (U–ase), AMP and EST dominating the overall enzymatic activity, but differed substantially for polyhumic lake, in which considerably high PA and saccharolytic enzyme activities were observed. We conclude that the analysis of enzymatic ‘fingerprints’ can be a useful tool to characterise lakes with respect to their trophic status and physiological diversity of microbial assemblages associated with each particular lake.

16

Enzymatic "fingerprinting" of physiological diversity of microbial communities in clear-water and humic lakes

51%

Siuda W. , Jasser I. , Kiersztyn B.

Polish Journal of Ecology

|

2013

|

tom 61

|

nr 4

EN

Extracellular enzymes occurring in aquatic environment are heterogeneous in respect to their origin and function, place, where they are located and their activity. They can be divided into mainly ‘bacterial-origin’ enzymes produced by heterotrophic organisms in order to obtain organic carbon, and mostly ‘phytoplankton-bacterial-origin’ enzymes, which are produced by autotrophic and heterotrophic organisms, and are responsible mainly for obtaining inorganic compounds. Enzymes activity provides information about microorganisms present in given environment and about their physiological state. We hypothesize that the patterns (‘fingerprints’) calculated on the basis of activity of several enzymes both mainly ‘bacterial-origin’ and mainly ‘phytoplankton-bacterial-origin’ may be used to characterise lake ecosystems in terms of the physiological structure of aquatic microorganisms present in these lakes. For the study we selected four lakes from Mazurian Lakes District in north-eastern Poland. Three of them were clear-water (lakes: Kuc, Mikołajskie, Tałtowisko) and ranged from oligotrophy to eutrophy, the fourth (Lake Smolak Duży) was slightly acidic (pH 5.2), highly productive and polyhumic. Activity of phosphatase (PA), L-leucine-aminopeptidase (AMP), β-glucosidase (B-Glu), esterase (EST), glucosaminidase (Glu-ami), glucuronidase (Glu-uro) and cellobiohydrolase (Cellob) were measured fluorometrically. The results were normalised and analysis of agglomerative clustering was performed to create an enzyme activity patterns characteristic for lakes. We found out that the enzymatic pattern reflected trophic differences between studied lakes. The patterns (‘fingerprints’) of enzymes were similar for three clear-water lakes, with urease (U–ase), AMP and EST dominating the overall enzymatic activity, but differed substantially for polyhumic lake, in which considerably high PA and saccharolytic enzyme activities were observed. We conclude that the analysis of enzymatic ‘fingerprints’ can be a useful tool to characterise lakes with respect to their trophic status and physiological diversity of microbial assemblages associated with each particular lake.

17

Autotrophic versus heterotrophic production and components of trophic chain in humic lakes: the role of microbial communities

45%

Jasser I. , Kostrzewska-Szlakowska I. , Ejsmont-Karabin J. , Kalinowska K. , Weglenska T.

Polish Journal of Ecology

|

2009

|

tom 57

|

nr 3

423-439

EN

The ratio and rates of autotrophic and heterotrophic pathways of organic matter cycles constitute the basic functions of aquatic ecosystem and humic lakes are unique in this respect. The autotrophic and heterotrophic production, the food web structure and the role of microbial communities in three humic lakes (area 1.3–9.2 ha) were studied. The abundance of bacteria, autotrophic picoplankton (APP), nanoflagellates (NF), ciliates, phytoplankton, rotifer and crustacean zooplankton as well as chlorophyll a and primary (¹⁴C method) and bacterial production (³H–thymidine method) were measured. The lakes differed in humic matter content, water colour, pH and hydrology. Two lakes were acidic (pH 5.2–4.9) with different dissolved organic carbon (DOC) content: oligo/mesohumic – 7.1 mg C L⁻¹ , and polyhumic lake – 21 mg C L⁻¹. Due to draining of surrounding meadows, the third lake – formerly humic – experienced changes in the hydrological regime together with liming and fertilisation. Despite low DOC, the oligohumic lake resembled a low productive, typically humic, acidic lake with dominating bacterial production. The lake was characterised by the highest crustaceans biomass and very variable chlorophyll a concentration (between 1.5 and 71 mg Chl a m⁻³). The polyhumic lake had the highest mean and maximal chlorophyll a content but the lowest crustacean biomass, and functioned more like a eutrophic lake. The formerly humic lake had lost probably most of its humic features and experienced a eutrophication process that resulted in a food web structure typical of a shallow eutrophic pond-like environment. The mean chlorophyll a concentration there was at the same level as in an oligohumic lake, but the variability was much lower. This lake can be considered as an example of the posthumic lakes abundant in the managed wetland regions. Microbial communities were numerous in both humic lakes, with bacteria prevailing in microbial biomass in the oligo-humic and APP in the polyhumic lake. In the former humic lake the microbial communities, especially APP, seemed to play a lesser role, while the whole planktonic food web was more balanced. The results demonstrated that uncontrolled drainage and reclamation of wetland can be detrimental to biodiversity of small, mid-forest lakes. Although biodiversity in almost all plankton groups was the highest in the posthumic lake but this lake lacked rare species typical of humic acidic lakes like: Gonyostomum semen, Dictyosphaerium sphagnale from phytoplankton or Holopedium gibberum from crustacean zooplankton. Instead eurytopic species, common in eutrophic waters, were present.

18

Autotrophic versus heterotrophic production and components of trophic chain in humic lakes : The role of microbial communities

45%

Jasser I. , Kostrzewska-Szlakowska I. , Ejsmont-Karabin J. , Kalinowska K. , Węgleńska T.

Polish Journal of Ecology

|

2009

|

tom Vol. 57, nr 3

423-439

EN

The ratio and rates of autotrophic and heterotrophic pathways of organic matter cycles constitute the basic functions of aquatic ecosystem and humic lakes are unique in this respect. The autotrophic and heterotrophic production, the food web structure and the role of microbial communities in three humic lakes (area 1.3-9.2 ha) were studied. The abundance of bacteria, autotrophic picoplankton (APP), nanoflagellates (NF), ciliates, phytoplankton, rotifer and crustacean zooplankton as well as chlorophyll a and primary ([^14]C method) and bacterial production ([^3]H-thymidine method) were measured. The lakes differed in humic matter content, water colour, pH and hydrology. Two lakes were acidic (pH 5.2-4.9) with different dissolved organic carbon (DOC) content: oligo/mesohumic - 7.1 mg C L[^-1] , and polyhumic lake - 21 mg C L[^-1]. Due to draining of surrounding meadows, the third lake - formerly humic - experienced changes in the hydrological regime together with liming and fertilisation. Despite low DOC, the oligohumic lake resembled a low productive, typically humic, acidic lake with dominating bacterial production. The lake was characterised by the highest crustaceans biomass and very variable chlorophyll a concentration (between 1.5 and 71 mg Chl a m[^-3]). The polyhumic lake had the highest mean and maximal chlorophyll a content but the lowest crustacean biomass, and functioned more like a eutrophic lake. The formerly humic lake had lost probably most of its humic features and experienced a eutrophication process that resulted in a food web structure typical of a shallow eutrophic pond-like environment. The mean chlorophyll a concentration there was at the same level as in an oligohumic lake, but the variability was much lower. This lake can be considered as an example of the posthumic lakes abundant in the managed wetland regions. Microbial communities were numerous in both humic lakes, with bacteria prevailing in microbial biomass in the oligo-humic and APP in the polyhumic lake. In the former humic lake the microbial communities, especially APP, seemed to play a lesser role, while the whole planktonic food web was more balanced. The results demonstrated that uncontrolled drainage and reclamation of wetland can be detrimental to biodiversity of small, mid-forest lakes. Although biodiversity in almost all plankton groups was the highest in the posthumic lake but this lake lacked rare species typical of humic acidic lakes like: Gonyostomum semen, Dictyosphaerium sphagnale from phytoplankton or Holopedium gibberum from crustacean zooplankton. Instead eurytopic species, common in eutrophic waters, were present.

19

Composition of picocyanobacteria community in the Great Mazurian Lakes: isolation of phycoerythrin-rich and phycocyanin-rich ecotypes from the system - comparison of two methods

45%

Jasser I. , Karnkowska-Ishikawa A. , Kozlowska E. , Krolicka A. , Lukomska-Kowalczyk M.

Polish Journal of Microbiology

|

2010

|

tom 59

|

nr 1

21-31

EN

The study showed that the picocyanobacteria community of the Great Mazurian Lakes system (GML) was dominated by phycoerythrin-rich (PE) ecotypes and demonstrated a gradual decrease of the ratio between PE and phycocyanin-rich (PC) ecotypes. The Great Mazurian Lakes offer better conditions for the PE ecotype than for the PC one, despite the considerably high trophic status, probably thanks to low turbidity and attenuation of light in the water column. The successful isolation of PE and PC picocyanobacteria was achieved by two methods: the classic plate method and a modified flow-cytometry method. The modified flow-cytometry method proved to be superior: being more selective for PE picocyanobacteria as well as less time consuming and less laborious. The modifications introduced to the method, such us concentration of cyanobacterial cells by centrifugation to the density required by the flow cytometer, did not hinder the isolation while allowing to skip an intermediate phase of enrichment cultures that had been formerly proposed. The first phylogenetic analyses based on cpcBA operon and 16S rRNA gene demonstrated that picocyanobacteria isolates from GML could, with a high bootstrap support, be grouped into five and four clusters, respectively. Based on a cpcBA-IGS analysis and IGS length the study suggests that at least one of the clusters is new and has not been previously described.

20

Life in extreme habitats: diversity of endolithic microorganisms from cold desert ecosystems of Eastern Pamir

38%

Khomutovska N. , Jerzak M. , Kostrzewska-Szlakowska I. , Kwiatkowski J. , Suska-Malawska M. , Syczewski M. , Jasser I.

Polish Journal of Ecology

|

2017

|

tom 65

|

nr 4

EN

The aim of this study was to identify cyanobacteria diversity in rock communities from the cold desert ecosystem in Eastern Pamir Mountains (Tajikistan) and assess if the rock type and rock`s porosity can be indicators of microbial diversity in this extreme environment. Seven samples were collected in July 2015 from hillsides (ca 4000–4500 m a.s.l.) of the Eastern Pamir Mountains. Petrographic and scanning microscopy (SEM) allowed for the characterization of the rocks inhabited by endolithic communities as granite, gneiss and limestone with variable porosity. Based on next-generation sequencing (NGS) of amplicon of V3–V4 hypervariable region of 16S rRNA gene, we established that Actinobacteria,Proteobacteria and Cyanobacteria dominated the endolithic communities of microorganisms in the rocks studied, which distinguishes these communities from those described for other cold arid regions. Chroococcidiopsis and Leptolyngbya were dominant genera in the cyanobacterial communities according to culture-dependent analysis, as well as microscopic analyses of endoliths scraps from the rocks. Culture-independent metagenomic analyses revealed that Microcoleus, Acaryochloris, Chroococcidiopsis and Thermosynechococcus reads were the most abundant from all reads and dominated interchangeably in the samples. Endolithic communities of microorganisms in the rocks from the cold desert shrubland of Eastern Pamir Mts. appear to be diverse and different from communities described for other cold deserts.