DBPapers
DOI: 10.5593/sgem2012/s14.v3010

THE DYNAMICS OF MARINE BACTERIONEUSTON IN LABORATORY MICROCOSMS: 1. THE INFLUENCE OF SALINITY AND TEMPERATURE

A. M. MOLDOVEANU, I. I. ARDELEAN
Wednesday 1 August 2012 by Libadmin2012

References: 12th International Multidisciplinary Scientific GeoConference, www.sgem.org, SGEM2012 Conference Proceedings/ ISSN 1314-2704, June 17-23, 2012, Vol. 3, 1001 - 1008 pp

ABSTRACT

The bacterial cells from the air-liquid interface (with implication in bacterioneuston
formation) from Romanian coast waters were studied in laboratory microcosms. The
aim of this study was to determine bacterioneuston dynamics from 2 to 120 hours after
formation under the influences of salinity and temperature, environmental factors with
implications in bacterial cells growth and multiplication. The surfaces with collected
marine bacterioneuston were analyzed with epifluorescence microscopy, using SYBR
Green I for total cell count and Propidium Iodide (used for visualising dead cells with
damaged membranes). The dynamics of cell densities in bacterioneuston formed under
different salinities were: at 5g/l (0.82 – 5.23 ·102 cells/mm2), 10g/l (1.22– 6.24 ·103
cells/mm2), 15g/l (1.21– 12.91 ·103 cells/mm2) and at 25g/l (0.92– 12.11 ·103
cells/mm2). The dynamics of cell densities in bacterioneuston formed under the
influence of different temperatures were: at 6ºC (0.67– 3.25 ·103 cells/mm2), 18ºC
(1.17– 6.98 ·102 cells/mm2) and at 23ºC (1.20– 12.11 ·103 cells/mm2). The proportion of
cells with damaged membranes was higher toward the end of our measurements (72 and
120 hours) than at the beginning of bacterioneuston formation in microcosms.

Keywords: biofilm, interface, bacterioneuston, adherence, organic matter.