English
 
User Manual Privacy Policy Disclaimer Contact us
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Journal Article

A new in vivo fluorimetric technique to measure growth of adhering phototrophic microorganisms

MPS-Authors

Karsten,  U
Permanent Research Group Microsensor, Max Planck Institute for Marine Microbiology, Max Planck Society;

Klimant,  I
Permanent Research Group Microsensor, Max Planck Institute for Marine Microbiology, Max Planck Society;

/persons/resource/persons210461

Holst,  Gerhard A.
Department of Biogeochemistry, Max Planck Institute for Marine Microbiology, Max Planck Society;

Locator
There are no locators available
Fulltext (public)
There are no public fulltexts available
Supplementary Material (public)
There is no public supplementary material available
Citation

Karsten, U., Klimant, I., & Holst, G. A. (1996). A new in vivo fluorimetric technique to measure growth of adhering phototrophic microorganisms. Applied and Environmental Microbiology, 62(1), 237-243.


Cite as: http://hdl.handle.net/21.11116/0000-0004-B449-F
Abstract
We developed a noninvasive rapid fluorimetric method for the investigation of growth of adhering (benthic) phototrophic microorganisms; The technique is based on the sensitive detection of the in vivo fluorescence of chlorophylls chlorophyll a and bacteriochlorophyll a and monitors increases in signal over time as an indicator for growth, The growth fluorimeter uses modulated excitation light of blue-light-emitting diodes and a photodiode as the detector. The light-emitting diodes are mounted geometrically in an aluminum housing for efficient and uniform illumination of the bottoms of the growth containers, The fluorimeter was characterized with respect to detection limit and dynamic range. This system is capable of resolving in vivo chlorophyll a concentrations of 0.5 mu g liter(-1) in cyanobacteria and 0.03 mu g liter(-1) in diatoms as well as in vivo bacteriochlorophyll a concentrations in phototrophic bacteria of 0.3 mu g liter(-1), which points to an extremely high sensitivity compared with that of similar available techniques. Thus, the new fluorimeter allows the determination of growth at extremely low cell densities, The instrument was used successfully to measure the growth of several adhering isolates of the filamentous cyanobacterium Microcoleus chthonoplastes from benthic microbial mats in seawater of different salinities. The data obtained demonstrate broad growth responses for all strains, which thus can be characterized as euryhaline organisms.