P. Makridis et al., Control of the bacterial flora of Brachionus plicatilis and Artemia franciscana by incubation in bacterial suspensions, AQUACULTURE, 185(3-4), 2000, pp. 207-218
The accumulation of bacteria in Brachionus plicatilis and Artemia francisca
na during a short-term incubation was quantified using immunocolony blot (I
CB) and an enzyme-linked immunosorbent assay (ELISA). Four bacterial strain
s, isolated from turbot and halibut, were grazed effectively by both specie
s when given at high concentrations (greater than or equal to 5 X 10(7) bac
teria ml(-1)). B. plicatilis accumulated 21-63 X 10(3) bacteria per rotifer
and A. franciscana up to 45 X 10(3) bacteria per metanauplius after 20-60
min of grazing. The composition of the bacterial microflora of the live foo
d organisms changed drastically, as the bioencapsulated strains comprised u
p to 100% of the total count of colony-forming units. After incubation in t
he bacterial suspensions, B. plicatilis and A. franciscana were transferred
to seawater with added microalgae (Tetraselmis sp., 2 mg C 1(-1)), to eval
uate the persistence of the changed bacterial composition in conditions sim
ilar to those present in a first feeding tank. The bioencapsulated bacteria
decreased in numbers, but in most cases remained present in both live food
organisms after 24 h. It is possible, after a short-term incubation, to re
place opportunistic (r-selected) bacteria present in the live food cultures
with other bacteria, which persist as a dominant part of the bacterial flo
ra of the live food for a relatively long period of time (4-24 h). (C) 2000
Elsevier Science B.V. All rights reserved.