Quantification of pelagic filamentous microorganisms in aquatic environments using the line-intercept method

Nedoma, J

doi:10.1016/s0168-6496(01)00172-6

Cited by 12 publications

(18 citation statements)

References 11 publications

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“…Bacterioplankton were counted and sized after DAPI staining on black polycarbonate filters (0.2-lm pore size, Osmonics), using an epifluorescence microscope (Olympus BX-60 or AX-70) and an image analysis system (Lucia G/F 4.11 or NIS-Elements 3.0, Laboratory Imaging, Prague). We quantified single unicellular bacteria separately, and used the line intercept method for quantification of the total length of bacterial filaments (Nedoma et al 2001). After a pre-sedimentation of samples (59), phytoplankton were counted in Utermöhl's sedimentation chambers on an inverted microscope (Nikon Diaphot).…”

Section: Analysesmentioning

confidence: 99%

“…After a pre-sedimentation of samples (59), phytoplankton were counted in Utermöhl's sedimentation chambers on an inverted microscope (Nikon Diaphot). Total biovolume of filamentous cyanobacteria was estimated in sedimentation chambers using the line intercept method (Nedoma et al 2001). Cell volumes were estimated by shape assimilation to simple geometric forms and converted to carbon using a factor of 200 fg C lm -3 (Straškrabová et al 1999).…”

Section: Analysesmentioning

confidence: 99%

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Forest Die-Back Modified Plankton Recovery from Acidic Stress

Vrba

Kopáček

Fott

et al. 2013

AMBIO

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We examined long-term data on water chemistry of Lake Rachelsee (Germany) following the changes in acidic depositions in central Europe since 1980s. Despite gradual chemical recovery of Rachelsee, its biological recovery was delayed. In 1999, lake recovery was abruptly reversed by a coincident forest die-back, which resulted in elevated terrestrial export of nitrate and ionic aluminum lasting *5 years. This re-acidification episode provided unique opportunity to study plankton recovery in the rapidly recovering lake water after the abrupt decline in nitrate leaching from the catchment. There were sudden changes both in lake water chemistry and in plankton biomass structure, such as decreased bacterial filaments, increased phytoplankton biomass, and rotifer abundance. The shift from dominance of heterotrophic to autotrophic organisms suggested their substantial release from severe phosphorus stress. Such a rapid change in plankton structure in a lake recovering from acidity has, to the best of our knowledge, not been previously documented.

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Section: Analysesmentioning

confidence: 99%

Section: Analysesmentioning

confidence: 99%

Forest Die-Back Modified Plankton Recovery from Acidic Stress

Vrba

Kopáček

Fott

et al. 2013

AMBIO

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“…In aquatic microbiology, image analysis has been applied, e.g., for the shape recognition (6,22,27), sizing, and biomass quantification of the total bacterioplankton community (4,38) or the respiratory active fraction (31), for motion tracking (5,41), for densitometric or fluorescence intensity measurement on single cells (21,25,32), or to determine cell orientation in complex communities (33). The major advantages of computer-assisted image analysis in microbiology are the potential for highthroughput evaluation, the objectivation of image-derived data (e.g., object size distributions, fluorescence intensities), and the extraction of object features that cannot be detected intutitively (e.g., complex dimensions describing object shape).…”

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confidence: 99%

Automated Enumeration of Groups of Marine Picoplankton after Fluorescence In Situ Hybridization

Pernthaler

Amann

2003

Appl Environ Microbiol

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We describe here an automated system for the counting of multiple samples of double-stained microbial cells on sections of membrane filters. The application integrates an epifluorescence microscope equipped with motorized z-axis drive, shutters, and filter wheels with a scanning stage, a digital camera, and image analysis software. The relative abundances of specific microbial taxa are quantified in samples of marine picoplankton, as detected by fluorescence in situ hybridization (FISH) and catalyzed reporter deposition. Pairs of microscopic images are automatically acquired from numerous positions at two wavelengths, and microbial cells with both general DNA and FISH staining are counted after object edge detection and signal-to-background ratio thresholding. Microscopic fields that are inappropriate for cell counting are automatically excluded prior to measurements. Two nested walk paths guide the device across a series of triangular preparations until a user-defined number of total cells has been analyzed per sample. A backup autofocusing routine at incident light allows automated refocusing between individual samples and can reestablish the focal plane after fatal focusing errors at epifluorescence illumination. The system was calibrated to produce relative abundances of FISH-stained cells in North Sea samples that were comparable to results obtained by manual evaluation. Up to 28 preparations could be analyzed within 4 h without operator interference. The device was subsequently applied for the counting of different microbial populations in incubation series of North Sea waters. Automated digital microscopy greatly facilitates the processing of numerous FISH-stained samples and might thus open new perspectives for bacterioplankton population ecology.During the last decade digital imaging devices have developed at an unsurpassed pace. Inexpensive digital cameras for hobby photographers have evolved to quality levels that reach or even exceed the typical instrumentation of professional microscopists in many respects, e.g., in pixel resolution of chargecoupled device chips. It is likely that there will soon be major changes in the use of digital imaging as a tool in microbial ecology. Digital cameras have already almost completely replaced traditional microphotography for documentation and publication purposes. Digital images are, moreover, the primary data of some modern microscopic techniques, such as confocal laser-scanning microscopy.The analysis of such images by edge-enhancing and background-reducing mathematical algorithms is a well-established strategy for object morphometry, feature classification, or particle counting and sizing in disciplines as unrelated as histology, landscape ecology, or the material sciences (35). In aquatic microbiology, image analysis has been applied, e.g., for the shape recognition (6, 22, 27), sizing, and biomass quantification of the total bacterioplankton community (4, 38) or the respiratory active fraction (31), for motion tracking (5, 41), for densitometric or fluoresce...

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“…Cell dimensions were measured using an electronic calliper connected to a PC (LEGNER & SPRULES, 1993); about 30 cells of each taxon were measured, for more details see NEDBALOVÁ & VRTIŠKA (2000). Filamentous cyanobacteria were quantified using the lineintercept method as described in NEDOMA et al (2001). As manual phytoplankton biomass determination in parallel with chlorophyll measurement was performed only once in 2003 (a vertical profile on 10 Sept. 2003), the whole season data for 1998 are published here for comparison.…”

Section: Methodsmentioning

confidence: 99%

Chlorophyll content of Plešné Lake phytoplankton cells studied with image analysis

Nedoma

Nedbalová

2006

Biologia

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Using image analysis, chlorophyll autofluorescence was measured in single cells of green alga Monoraphidium dybowskii and in filaments of cyanobacteria (Pseudanabaena sp. and Limnothrix sp.) in the vertical profile of small acidified mountain lake Plešné jezero (Plešné Lake) from May to November of 2003. Cell chlorophyll autofluorescence was converted to cell chlorophyll content using a conversion factor determined by comparing the total autofluorescence of phytoplankton in a microscope field with spectrophotometrically determined total chlorophyll concentration; the conversion factor did not differ between epilimnion (0.5 m depth) and hypolimnion (9 m depth). Vertical patterns of chlorophyll concentration and of cellular chlorophyll content depended on water column mixing: during the period of stable thermal stratification, a metalimnetic peak in total chlorophyll concentration was present and cellular chlorophyll contents in the metalimnion and hypolimnion were notably elevated compared to the surface. Monotonous vertical profiles of both total chlorophyll concentration and cell chlorophyll content were typical for the period of water column overturn. During the stratification period, hypolimnetic Monoraphidium cell chlorophyll content was on average twice as high (maximum difference 2.7-fold) compared to surface values (of 3.2-12.9 fg µm −3 ), while in filamentous cyanobacteria (surface cell chlorophyll content of 2.2-13.3 fg µm −3 ), the difference was much higher -six-fold on average, with an 11.6-fold maximum value. The values measured with image analysis in 2003 were compared to unpublished values of total phytoplankton biomass-specific chlorophyll concentrations obtained using manual phytoplankton biomass determination and spectrophotometric chlorophyll measurement in 1998 at the same locality. Good agreement was found in seasonal patterns and vertical profiles of chlorophyll between both seasons.

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Quantification of pelagic filamentous microorganisms in aquatic environments using the line-intercept method

Cited by 12 publications

References 11 publications

Forest Die-Back Modified Plankton Recovery from Acidic Stress

Forest Die-Back Modified Plankton Recovery from Acidic Stress

Automated Enumeration of Groups of Marine Picoplankton after Fluorescence In Situ Hybridization

Chlorophyll content of Plešné Lake phytoplankton cells studied with image analysis

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