Improved
performance of an intensive rotifer culture system by using a nitrifying
inoculum (ABIL)
G. Rombaut, R. Grommen, Q. Zizhong, V. Vanhoof, G. Suantika, P. Dhert, P.
Sorgeloos, W. Verstraete-2003
Aquaculture
Research, 34(2):
165-174
Abstract:
A dense nitrifying culture (ABIL) has been
examined for its capacity to stimulate rotifer growth in a labscale culture
system. The nitrifiers were applied in different ways. When ABIL was added
directly to rotifer batch cultures, it gave rise to significantly higher
population densities (factor 1.5-2.5 higher, P < 0.05).
The nitrifiers were subsequently examined for their capacity to enhance the
start-up of bioreactors, commonly installed in aquaculture rearing tanks. Of
the different carrier materials used in these bioreactors, i.e. CaCO3,
gravel and a PVC matrix (Bionet), CaCO3 gave by far the best
results. In a third set of experiments, effectively nitrifying bioreactor
systems were connected to rotifer culture tanks and operated over a period
of up to 10 days. It was demonstrated that the ABIL inoculated CaCO3-based
bioreactor allowed excellent rotifer growth reaching rotifer densities up to
5500 rotifers per mL. Moreover, a new system in which the ABIL culture was
recirculated through hollow fibres was developed and demonstrated to be
effective for supporting rotifer growth up to 3500 rotifers per mL. Overall,
the use of the dense nitrifying culture either in seed batch cultures,
conventional bioreactors or hollow fibre bioreactor systems in support of
rotifer cultures was demonstrated to be effective for improving the water
quality and the rotifer growth.
(Laboratory of Microbial Ecology and
Technology (LabMET), Ghent University, B-9000 Ghent, Belgium. E-mail of W.
Verstraete: Willy.Verstraete@rug.ac.be)