Scheda di dettaglio – i prodotti della ricerca

DatoValore
TitleRECOVERY AND QUANTIFICATION OF BACTERIAL CELLS ASSOCIATED WITH STREAMBED SEDIMENTS
AbstractEfficient detachment and purification of bacterial cells associated with streambed sediments are required in order to quantify cell abundance and to assess community composition through the application of epifluorescence microscopy techniques. We applied chemical (i.e., sodium pyrophosphate and polysorbate) and physical treatments (i.e., shaking and sonication), followed by Nycodenz density gradient centrifugation to efficiently recover benthic bacteria. This procedure resulted in a highly purified cell suspension allowing for a precise cell quantification through the application of fluorescent dyes. About 93% of total cells were recovered from the original sediment, with higher recovery from the finer grain-size class (90%) in comparison to the coarse fraction (69%). The potential damaging effects of the applied procedures on cell integrity were assessed on planktonic bacteria in a pre-filtered water control. As a consequence of the high purity of the extracted bacteria, flow cytometry was successfully applied as counting method for sediment cell suspension. However, a significant decrease of protein synthesis in purified samples was measured by estimating the 3H-Leucine incorporation rates, rising uncertainties on the possibility to apply potential metabolic assays after Nycodenz purification.
SourceJournal of microbiological methods 75 (6), pp. 237–243
JournalJournal of microbiological methods
EditorElsevier Science Ireland, Shannon, Paesi Bassi
Year2008
TypeArticolo in rivista
DOI10.1016/j.mimet.2008.06.004
AuthorsAMALFITANO S., FAZI S.
Text42257 2008 10.1016/j.mimet.2008.06.004 ISI Web of Science WOS 000259942500014 RECOVERY AND QUANTIFICATION OF BACTERIAL CELLS ASSOCIATED WITH STREAMBED SEDIMENTS AMALFITANO S., FAZI S. Water Research Institute IRSA CNR , via Reno 1, 00198 Roma, Italy Efficient detachment and purification of bacterial cells associated with streambed sediments are required in order to quantify cell abundance and to assess community composition through the application of epifluorescence microscopy techniques. We applied chemical i.e., sodium pyrophosphate and polysorbate and physical treatments i.e., shaking and sonication , followed by Nycodenz density gradient centrifugation to efficiently recover benthic bacteria. This procedure resulted in a highly purified cell suspension allowing for a precise cell quantification through the application of fluorescent dyes. About 93% of total cells were recovered from the original sediment, with higher recovery from the finer grain size class 90% in comparison to the coarse fraction 69% . The potential damaging effects of the applied procedures on cell integrity were assessed on planktonic bacteria in a pre filtered water control. As a consequence of the high purity of the extracted bacteria, flow cytometry was successfully applied as counting method for sediment cell suspension. However, a significant decrease of protein synthesis in purified samples was measured by estimating the 3H Leucine incorporation rates, rising uncertainties on the possibility to apply potential metabolic assays after Nycodenz purification. 75 RECOVERY AND QUANTIFICATION OF BACTERIAL CELLS ASSOCIATED WITH STREAMBED SEDIMENTS Amalfitano_2008_JMM_Nycodenz.pdf Articolo in rivista Elsevier Science Ireland 0167 7012 Journal of microbiological methods Journal of microbiological methods J. microbiol. methods Journal of microbiological methods. stefano.fazi FAZI STEFANO stefano.amalfitano AMALFITANO STEFANO TA.P02.002.003 Ruolo di comunita microbiche nella degradazione della sostanza organica e nella circolazione del carbonio nei sistemi acquatici