Probiotic culture of the rotifer Brachionus plicatilis

Abstract

We adapted a probiotic culture system originally developed for domestic animals and fish for the intensive culture of rotifers. In this modification, a crude starter fluid was made by incubating a mixture of some 40 species of bacteria (so-called Uchishiro Microorganisms) with the by-products of other food-related materials. The probiotic culture medium (PCM) was then completed by incubation of 50 g of starter fluid (25 °C) for 3–4 days in 1 L of 50% sea water with strong aeration. After processing, the medium may be used as food for the rotifer Brachionus plicatilis. We determined the optimal levels for feeding B. plicatilis cultures by providing a starter culture of 100 rotifers different concentrations of PCM and monitoring their population growth over five days. The highest population density of B. plicatilis (351 ind ml-1) was achieved from a mixture of 20 ml PCM per 1 L rotifer water. From these experiments, we conclude that PCM is useful as food for rotifer culture if it is supplied at a satisfactory concentration.