Psychrotrophic bacteria from a coastal station in the Ross sea (Terra Nova Bay, Antarctica)
Bruni, V.; Gugliandolo, C.; Maugeri, T.; Allegra, A.
New Microbiologica 22(4): 357-363
1999
ISSN/ISBN: 1121-7138 PMID: 10555207 Document Number: 511552
Seawater samples were collected from a fixed, coastal station in the Terra Nova Bay at different depths during the Xth Oceanographic Cruise in the 1994-95 Antarctic summer. Picoplanktonic abundance, estimated by direct counts in epifluorescence microscopy, ranged from 2.2X107 to 1.6X108cellscntdotl-1. The heterotrophic bacterial densities, evaluated on Marine Agar 2216 (Difco) after incubation at +4degreeC for 21 days, ranged from 2X103 to 4.5X106 CFUcntdotl-1. The qualitative composition of the heterotrophic bacterial community was studied on 64 morphological and biochemical characters of the 125 strains isolated. Heterotrophic, psychrotrophic isolates were tentatively identified at genus level as Pseudomonas, Vibrio, Acinetobacter, and Flavobacterium/Cytophaga. In order to compare the characteristics of the isolates with those previously studied during 1989/90, the synthetical indices of the structure and the metabolic potentiality of the heterotrophic bacterial community were processed. Results showed that the bacterial community was metabolically more active and more homogenous than that previously studied