Evaluation of different
yeast cell wall mutants and microalgae strains as feed for gnotobiotically
grown brine shrimp Artemia franciscana
A. Marques, J. Dhont, P. Sorgeloos, P. Bossier-2004
Journal of Experimental Marine Biology and Ecology, 312(1): 115-136
Abstract:
The nutritional value of isogenic yeast strains and
two microalgal species for gnotobiotically grown Artemia was
examined. Yeast cell wall mutants were always better feed for Artemia
than their respective wild type. Yeast cells harbouring null mutants for
enzymes involved early in the biochemical pathway for cell wall
mannoproteins synthesis performed best as feed for Artemia. Yeast
cells defective in chitin or β-glucan production were scored in second
order. The mnn6 isogenic yeast mutant, harbouring a null mutation for
mannoprotein phosphorylation, performed poorly as feed for Artemia,
although with good growth. These results suggest that any mutation affecting
the yeast cell wall scaffolding by reducing the amount of covalent links
between the major components of yeast cell wall, namely mannoproteins,
β-glucans and chitin, is sufficient to improve the digestibility for Artemia.
The results with microalgae indicated that within one species, strains can
have different nutritional value under gnotobiotic conditions. The growth
phase was another parameter influencing feed quality, although here it was
not possible to reveal the exact cause. It is anticipated that the standard Artemia
gnotobiotic growth test is an excellent tool to study the mode of action of
bacteria, with a probiotic as well as with a pathogenic character.
(Laboratory of Aquaculture and Artemia Reference
Center, Ghent University, Rozier 44, 9000 Ghent, Belgium, e-mail: Antonio.marques@ugent.be)