The research presented in this paper have been taken due to the limited and fragmentary data on: the presence of fungi in dairy sewage sludge; selected properties of fungi isolated from this sludge, essential in assessing the possibility of using these microorganisms in the degradation of wastes; and evaluation of metabolic profile of soil fertilized with dairy sewage sludge compared to other traditional indicators of soil microbial activity.

The paper included two parts. First part included the research concerning the presence of fungi in dairy sewage sludge and characterization of taxonomic position of dominant fungi isolated from dairy sewage sludge and their phylogenetic relationships with other species. In this study the physiological properties and catabolic profiles of fungi and their hydrolytic potential were evaluated. In the second part the results concerning the evaluation of dairy sewage sludge on soil community level physiological profiles were presented. The inhibition or stimulation of soil microorganisms capabilities to utilization the following carbon sources groups: carbohydrates, amino acids, amines and amides, carboxylic and ketonic acids and polymers were assessed.

Fungi isolated from dairy sewage sludge were identified based on morphological and genetic criteria as: S1 – Penicillium spinulosum, S2 – Geotrichum fragrans, S3 – Hypocrea jecorina, S4 – Coprinus cinereus, S5 – Fusarium sporotrichioides, S6 – Mucor hiemalis, S7 – Penicillium camembertii, S8 – Trichoderma atroviride, S9 – Mucor circinelloides, S10 – Aspergillus flavus oryzae, S11 – Trichoderma fertile, S12 – Trichoderma koningii, S13 – Geotrichum citri-aurantii, S14 – Trichoderma aureoviride, S15 – Rhizopus stolonifer stolonifer, S16 – Alternaria alternata, S17 – Candida tropicalis, S18 – Acremonium murorum felina, S19 –  Beauveria felina. The results showed that the saprotpophic fungi, safety for human health were most isolated from dairy sewage sludge. The results indicated that only one species Candida tropicalis, geophilic dermatophyte was danger for human health. However, due to the fact that the fungi of the genus Candida are a natural component of the microbial communities of many habitats, where they are actively involved in the degradation of organic substrates, they can not be equated with other pathogens, like Salmonella bacteria or parasites like Ascaris and Trichuris. The conducted study and literature data indicate that the dairy sewage sludge environment is not conducive to the development of zoophilic and anthropophilic dermatophytes. Therefore, the risk of these dermatophytes infection in the case of human contact with dairy sewage sludge or the soil amended with this wastes can be considered as minimal.

The results showed that some fungal strains isolated from dairy sewage sludge had potential for application (T. fertile, T. koningii, T. aureoviride, T. atroviride, A. flavus oryzae, M. circinelloides) in the degradation of complex organic compounds (polysaccharides, proteins and fats).  These fungi utilize also simple organic compounds from the following carbohydrates, carboxylic and ketonic acids, as a source of C and energy and are able to degrade organic nitrogen compounds, like: amino acids, amines and amides. Conducted preliminary studies indicated the potential usefulness of the test strains in the degradation of complex organic compounds, but further, more detailed studies on their practical use in the development of biopreparation for agricultural biotechnology and environmental technologies, especially in the disposal and recycling of organic wastes are necessary.

The study showed that the dairy sewage sludge and the soil depth had a significant influence on the tested microbiological parameters. Analysis of the soil metabolic profile (CLPP), expressed as indicators AWCD, R and H was a sensitive indicator of changes in soil microbial activity due to dairy sewage sludge application. The study showed that the dairy sewage sludge stimulated soil microbial communities, thus increasing the soil functional diversity and thus increase the catabolic potential of soil microorganisms. This effect, however, were noted only in the surface layer of soil. It was found that the catabolic potential of microorganisms in soil fertilized with dairy sewage sludge was close to the metabolic profile of the natural ecosystem, which is advantageous, because of the lack of an imbalance in the soil environment and stability after the sludge application.