Relative real refractive index of marine microorganisms: a technique for flow cytometric estimation

Spinrad, Richard W.; Brown, Jeffrey F.

doi:10.1364/ao.25.001930

Cited by 64 publications

(26 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Chlorella cultures, light absorption is well represented by the Beer-Lambert law at a variety of cellular densities, without the necessity for consideration of reflectance (Lee, 1999). The difference in reflective properties between a leaf and an algal culture could be the result of both the decreased differences in refractive indices between the algal cell (1.047 to 1.092; Spinrad and Brown, 1986) and the aqueous culture medium (1.33) compared to leaves and the less cell-dense culture conditions, which minimize cell-tomedium light scattering. For example, in the experiments of Kirst et al (2012), that reported improved growth of Chlamydomonas reinhardtii with reduced antenna complexes, cells were cultured at densities 1-3 3 10 6 cells mL 21 .…”

Section: Tradeoffs Between Leaf Reflectance and Transmittance Limit Tmentioning

confidence: 99%

Chlorophyll Can Be Reduced in Crop Canopies with Little Penalty to Photosynthesis

et al. 2017

View full text Add to dashboard Cite

The hypothesis that reducing chlorophyll content (Chl) can increase canopy photosynthesis in soybeans was tested using an advanced model of canopy photosynthesis. The relationship among leaf Chl, leaf optical properties, and photosynthetic biochemical capacity was measured in 67 soybean (Glycine max) accessions showing large variation in leaf Chl. These relationships were integrated into a biophysical model of canopy-scale photosynthesis to simulate the intercanopy light environment and carbon assimilation capacity of canopies with wild type, a Chl-deficient mutant (Y11y11), and 67 other mutants spanning the extremes of Chl to quantify the impact of variation in leaf-level Chl on canopy-scale photosynthetic assimilation and identify possible opportunities for improving canopy photosynthesis through Chl reduction. These simulations demonstrate that canopy photosynthesis should not increase with Chl reduction due to increases in leaf reflectance and nonoptimal distribution of canopy nitrogen. However, similar rates of canopy photosynthesis can be maintained with a 9% savings in leaf nitrogen resulting from decreased Chl. Additionally, analysis of these simulations indicate that the inability of Chl reductions to increase photosynthesis arises primarily from the connection between Chl and leaf reflectance and secondarily from the mismatch between the vertical distribution of leaf nitrogen and the light absorption profile. These simulations suggest that future work should explore the possibility of using reduced Chl to improve canopy performance by adapting the distribution of the "saved" nitrogen within the canopy to take greater advantage of the more deeply penetrating light.

show abstract

Section: Tradeoffs Between Leaf Reflectance and Transmittance Limit Tmentioning

confidence: 99%

Chlorophyll Can Be Reduced in Crop Canopies with Little Penalty to Photosynthesis

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Eukaryotic phototrophs were first distinguished from eukaryotic heterotrophs on a cytogram of chlorophyll fluorescence (FL3) versus forward scatter (FSC), based on the high relative chlorophyll fluorescence of the phototrophs (Olson et al 1983, Yentsch et al 1983. Detritus was then separated from cellular material on a cytogram of side scatter (SSC) versus green fluorescence (FL1), based on the high refractive index of the detritus (Spinrad & Brown 1986, Ackleson & Spinrad 1988. Green fluorescent polystyrene beads (2.5 µm) were then used to establish a size reference on a cytogram of green fluorescence (FL1) versus FSC.…”

Section: Cultures the Lysotracker Greenmentioning

confidence: 99%

“…Detrital particles emitted a low level of green fluorescence, most probably due to the accumulation of LysoTracker Green ® in microzones of low pH associated with bacteria. Conveniently, most detritus can be identified by its high side-scatter properties and relatively low green fluorescence (Spinrad & Brown 1986, Ackleson & Spinrad 1988. Based on these characters, detritus could be identified in cytograms of green fluorescence (FL1) versus side-scatter (SSC) (Fig.…”

Section: Application Of Lysotracker Green ® To Natural Water Samplesmentioning

confidence: 99%

Counting heterotrophic nanoplanktonic protists in cultures and aquatic communities by flow cytometry

Rose¹,

Caron²,

Sieracki³

et al. 2004

Aquat. Microb. Ecol.

View full text Add to dashboard Cite

®can only be used with live samples because preservation destroys membrane potential, resulting in loss of fluorescence. However, the flow cytometric method employing LysoTracker Green ® is highly applicable for monitoring the growth of many heterotrophic protists in cultures and has the potential to be extremely useful for field samples, providing comparable counts to microscopical methods while allowing much faster sample processing. KEY WORDS: Heterotrophic protists · Flow cytometry · Nanoplankton · Fluorescent stainingResale or republication not permitted without written consent of the publisher Aquat Microb Ecol 34: 263-277, 2004 trophs, and human error. Nanoplanktonic protists have occasionally been counted live (Dale & Burkill 1982), but it is difficult to differentiate small phototrophs from heterotrophs using this method. To address these issues, we sought to develop a faster and more precise method of quantification, based on flow cytometry.Flow cytometry has been employed in aquatic microbiology to quantify autotrophic prokaryotes, small autotrophic eukaryotes, heterotrophic bacteria and viruses (Olson et al. 1983, Yentsch et al. 1983, del Giorgio et al. 1996, Marie et al. 1997, 1999. Prokaryotic and eukaryotic phototrophs can be detected and quantified based on the autofluorescence of their photosynthetic pigments. Also, heterotrophic bacteria and viruses can be detected and quantified using a variety of nucleic acid stains to distinguish them from detrital particles. The speed and accuracy with which these populations can be counted by this method has made the flow cytometer a valuable tool for ecological studies in aquatic sciences (Olson et al. 1991, Porter 1999, Campbell 2001.Unfortunately, an effective, accurate technique for the enumeration of heterotrophic unicellular eukaryotes in natural water samples using flow cytometry has not yet emerged. Most heterotrophic eukaryotes have little or no autofluorescence, except some heterotrophic dinoflagellates which fluoresce apple-green with blue light excitation (Carpenter et al. 1991). Therefore, detection of most heterotrophic nanoplanktonic protists is not possible by cytometry without staining. Common fluorescent compounds used to stain prokaryotes and eukaryotes do not differentiate these populations on a flow cytometer. For example, one technique published recently by Rifa et al. (2002) used the nucleic acid stain ® to quantify heterotrophic eukaryotes in cultures and in field samples. However, both the prokaryotic and eukaryotic assemblages were stained, and eukaryotes were indistinguishable from prokaryotes on cytograms when the abundance of bacteria greatly exceeded the abundance of protists. This drawback makes SYTO-13 ® problematic for use in growth experiments, because starting bacterial concentrations are often several orders of magnitude greater than the protistan populations. This complication may also preclude the use of SYTO-13 ® for many natural samples, where the ratio of bacteria to heterotrophic protists may exceed 1000 (Sand...

show abstract

“…In the EC MAST project AIMS (developing flow cytometry technology for identification of microbial cell populations and determination of their cellular characteristics -Geider et al, 1998;Jonker et al, 2000), algorithms are being developed to translate flow cytometric light scatter signals to size spectra. Under conditions, size and refractive index of marine particles can be measured Spinrad, 1988, Spinrad andBrown, 1986). Dilution (osmosis), chemical fixation and/or staining as well as cell damage cause changes in forward light scatter signatures (Ackleson et al, 1988;Navaluna et al, 1989).…”

Section: Light Scattermentioning

confidence: 99%

Flow cytometry as a tool for the study of phytoplankton

Dubelaar¹,

Jonker²

2000

Sci. Mar.

View full text Add to dashboard Cite

SUMMARY: An overview is presented on flow cytometry as a tool for counting, analysis and identification of phytoplankton species and groups. The paper covers basics on the analysis technique and instrumentation such as the measuring principle, the type of instrument, limitations and pitfalls with phytoplankton samples and sample handling and preprocessing. Possibilities of the measured entities are discussed, roughly divided in light scatter and related parameters, the endogenous fluorescence and exogenous fluorescence, followed by a discussion on the actual applications such as phytoplankton abundance analysis, ecology and physiology research and monitoring of particle size and biomass. In addition to a limited literature review, we tried to assess how flow cytometry is used in routine laboratory practice and monitoring operations. Therefore, a questionnaire was sent out via email to 47 scientists at 43 institutes known to us as involved in flow cytometric analysis of phytoplankton. In total, 19 scientists responded. Specific survey results are included in italic print whereas some more general answers were integrated in the overview.

show abstract

Relative real refractive index of marine microorganisms: a technique for flow cytometric estimation

Cited by 64 publications

References 14 publications

Chlorophyll Can Be Reduced in Crop Canopies with Little Penalty to Photosynthesis

Chlorophyll Can Be Reduced in Crop Canopies with Little Penalty to Photosynthesis

Counting heterotrophic nanoplanktonic protists in cultures and aquatic communities by flow cytometry

Flow cytometry as a tool for the study of phytoplankton

Contact Info

Product

Resources

About