**2.1 Parasitological methods**

To determine helminth eggs count in slurry (input and output samples from bioreactor and in lagoon samples – supernatant and sediment), 50 ml from each of the 1 l sample was taken and examined by a sedimentation-flotation mathod (Cherepanov, 1982).

*A. suum* eggs were isolated by dissection of a distal uterine part of female pig ascaris. The distal uterine ends were then removed to a glass homogenizer and processed. The water suspension of eggs was stored in an Erlenmayer flask in a refrigerator at 4°C.

We used the ''artificial contamination of lagoon and organic wastes'' approach to make sure that there is s sufficient number of positive samples in our observations.

Model eggs were inoculated by a micropipette into polyurethane carriers, prepared according to Plachý and Juriš (1995), at a dose of 1 000 eggs per one carrier. A porous cellular plastic - soft expanded polyurethane, commercially known as a plastic foam, was used as a material for the carriers. It is an additive product of polyisocyanates and compounds with a high content of hydroxylic groups. It consists of a network of interconnected cells, resembling a honeycomb. Its polyurethane structure allows for a sufficient contact of helminth eggs with the environment, preventing them from release and consequently improving their recovery (Picture 1). For mechanical protection the carriers were placed to perforated plastic net (Picture 2) before introducing them into the organic wastes. Three samples were taken and analysed at each sampling interval. The eggs were re-isolated from the inoculated carriers as follows: the carriers were cut into small pieces and washed in a mortar with 3 · 5 ml portions of saline, thoroughly stirred and filtered through a sieve into test tubes. After centrifugation, sediments were transferred to Petri dishes.

The viability of exposed unembryonated *A. suum* eggs was determined by incubation up to the embryonated stage (Picture 6) in a thermostat at 26°C for 21 days. Petri dishes with *A. suum* eggs were aerated daily with micropipette. The developmental ability of *A. suum* eggs was compared with that of the control eggs which were kept in distilled water under aerobic conditions.
