Bacterial decontamination of
on-grown Artemia
A. Tolomei, Ch. Burke, B. Crear, J. Carson-2004
Aquaculture, 232(1-4): 357-371
Abstract:
The bacterial load of on-grown Artemia was
manipulated using a variety of commercially available enrichment DHA
boosters, selected algal species (Skeletonema costatum; Nannochloropsis
oculata; Tetraselmis suecica; Chaetoceros muelleri), and
ozone to decontaminate enteric and external surfaces, respectively.
Enrichment in C. muelleri over a 6-h period, with an additional algal
exchange mid-enrichment, provided the most efficient method for enteric
decontamination as measured by total viable counts. Direct exposure to ozone
at 4 ppm for 5 min provided further bacterial reduction, resulting in a
combined bacterial load reduction of 99.5% without compromising Artemia
viability. The commercial enrichment A1 DHA Selco™, containing
antibacterial compounds, provides an alternative to algal-based enrichments,
however, its decontaminating properties were inferior. Fluorescence in situ
hybridisation (FISH) was used on occasions to verify total bacterial
abundance estimates obtained by standard plating procedures. In all except
one case, Johnson's Marine Agar (JMA) provided results comparable to direct
counts by FISH. This indicates that the bacterial community present in
on-grown Artemia cultures is dominated by several fast-growing
r-strategists amenable to culture on conventional plates. Underestimation of
bacterial abundance using marine agar was therefore unlikely.