Are prokaryotic cell shape and size suitable to ec

Authors: R La Ferla G Maimone G Caruso F Azzaro M Azzaro F Decembrini A Cosenza M Leonardi R Paranhos

Publish Date: 2013/11/24

Volume: 726, Issue: 1, Pages: 65-80

PDF Link

Abstract

Estimation of microbial biomass depends on cell shape and size determinations and thus there is a wide biovolume variability among morphotypes Nevertheless data on morphology and morphometry of prokaryotic cells under different trophic status are seldom published due to the methodological difficulties of cell measurements The main question addressed in this paper concerns the suitability of prokaryotic size and shape for environmental characterization Microbial biovolumes were compared among different ecosystems located in temperate and tropical regions Samples were taken from fresh brackish mixohaline and estuarine waters that were classified as oligo meso eu and hypertrophic by comparing synoptically different trophic indices Prokaryotic cell abundance and volume were quantified by Image Analysis used to calculate biomass and correlated to environmental variables Some samples were analyzed by flow cytometry also and data from subpopulations with a different apparent DNA content were available Prokaryotic abundances generally increased from oligo to hypertrophic waters while cell volumes increased from oligotrophic to eutrophic waters Although significant correlations between cell volumes and environmental variables were detected positive with salinity and negative with Chlorophylla different morphotypes dominated each studied regions Our results sustain the hypothesis that prokaryotic cell size and shape could be useful to ecosystem characterizationThe authors wish to thank the editor and two anonymous reviewers for their useful comments They also thank two colleagues of IAMC—Mr Francesco Soraci for his help in the laboratory and Mr Enrico Minicante Armeli for data processing—as well as the Municipality of Regalbuto Enna Italy for its endorsement This study was supported by funds by CNPq and FAPERJ in the frame of project “Microbial Observatory of Rio de Janeiro” CNR in the frame of the program of Short Term Mobility 2009 AMMCNT—CNR n 0051228 “Confronto tra popolamenti procariotici dell’Oceano Atlantico e del Mediterraneo attraverso l’uso congiunto di tecniche citofluorimetriche e di analisi d’immagine Analisi di campioni epi meso e batipelagici ed interpretazione di dati pregressi per la progettazione di studi futuri sui cambiamenti globali” Joint project CNRCAS AMMCNT—CNR n 0038575 “Understanding expression and regulation of microbial enzymes involved in organic matter decomposition at different trophic levels and the interrelationship between alkaline phosphatase and eutrophication in Italian and Chinese water bodies” Marine Strategy Framework Directive MFSD of European Commission

Keywords: