Preprint volume - SIBM

Pre-print Volume – Oral presentations
Topic 3: INTEGRATED COASTAL ZONE MANAGEMENT
see Biandolino et al., 2007); 3) in vitro antimicrobial activity of lipidic extracts against
several pathogens for fish and humans recording the diameter of bacterial growth
inhibition (Tab. 1) (for methods see Stabili et al., 2007, 2008).
Results – 1) Ammonium uptake: all the examined species showed a high capability in
removing N-NH4 + even when cultivated in N-replete status. In this last condition
Gracilaria dura removed about 6 µmol g -1 fw h -1 (Alabiso et al., 2007); C. linum, G.
gracilis and C. rupestris removed from 4 to 4.5 µmol g -1 fw h -1 ; finally, Gracilariopsis
longissima (Alabiso et al., 2008) and C. barbata removed about 3 µmol g -1 fw h -1 . After
one hour, the absorption capability of G. gracilis and C. barbata remained almost
constant; on the contrary, the other four species still showed a slight increasing trend
(Fig. 1).
2) Lipidic and fatty acids composition: palmitic acid was the most abundant among
saturated fatty acids in all the studied species, even though with different percentages;
among the polyunsaturated fatty acids, the arachidonic acid (ARA) was the most
abundant in G. gracilis and C. linum; the eicosapentaenoic acid (EPA) and the
docosahexaenoic acid (DHA) were the most abundant in C. linum and G. dura (Fig. 2).
The best values of ω3/ω6 ratio were found in G. dura (Biandolino et al., 2007) and
Gracilariopsis longissima (Biandolino, unpublished data).
3) Antimicrobial activity: Gracilariopsis longissima extract proved to be active against
the highest number of the tested bacterial strains, probably due to the palmitic acid
present in its lipidic extract with the highest percentage (Fig. 2) (see also Stabili et al.,
2010); however, all the species showed a good antimicrobial activity mainly against
several Vibrio species (Tab. 1) (see also Stabili et al., 2007, 2008).
µmol/g
6
5
4
3
2
1
0
Cystoseira barbata Gracilariopsis longissima
Gracilaria gracilis Cladophora rupestris
Chaetomorpha linum Gracilaria dura
0 20 40 60 80 100 120 140 160
time (minutes)
Fig. 1 – Variation vs. time of N-NH 4 + removed by each species in N-replete status.
Variazione nel tempo del N-NH 4 + rimosso da ciascuna specie.
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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