Interactions between microfungi and Eisenia andrei (Oligochaeta) during cattle manure vermicomposting

Microscopic fungi, associated with fresh and processed substrates and with the intestines of Eisenia andrei, were studied in three vermiculture systems differing in their productivity. To assess the possible effects of fungi on the rates of growth of E. andrei, laboratory-based feeding trials were carried out on substrates amended with selected fungal species. In total, 151 species and 7 forms of microscopic fungi were isolated during the study. Of those, 132 taxa were recorded from three vermiculture substrates and 123 taxa from worm intestines. In vermiculture substrates, Aspergillus fumigatus, A. flavus, Geotrichum candidum, Penicillium expansum and P roquefortii were most frequently isolated by dilution plate method and Rhizopus stolonifer by soil washing technique. Fusarium ventricosum dominated among the cellulolytic fungi. A. fumigatus, Mucor circinelloides f. circinelloides and P expansum were dominant in the intestines of earthworms. Processed vermiculture substrates regularly yielded higher numbers of culturable micromycetes (CFU) and the CFU values of fungi in earthworm intestines were close to or higher than those of processed substrates. Mycelial biomass was lower in fresh than in processed substrates in two vermiculture systems, but higher in the less effective third system. The results of earthworm feeding experiments showed that the amendment of vermiculture substrates resulted in an increase of growth rates; the earthworm growth rate was greatest in treatment with Aspergillus flavus.