Fungal extracellular enzymes may play a role in biodeterioration of dried materials of medicinal plants and in propagation of toxigenic and pathogenic fungal strains. However, no data on enzymatic activities of xerophilic fungi contaminating these materials have been found in the literature. The objective of the study was to determine extracellular enzyme profiles of slow-growing fungi, i.e. Eurotium amstelodami, E. chevalieri, E. herbariorum and Aspergillus versicolor isolated from dried materials of medicinal plants from herbal shops of Szczecin, Poland. Solid media and API ZYM® test were used to determine enzymatic activities. The highest colony diameters were observed in A. versicolor on gelatin, cellulose, tributyrin, rapeseed oil, biodiesel oil and diesel oil agars, and in E. herbariorum on milk and starch agars. A. versicolor also showed the highest hydrolytic activity on milk, gelatin, starch and tributyrin agars. No hydrolysis zones were formed on cellulose, rapeseed oil and biodiesel oil agars, but the stimulation effect of the oils on fungal growth was clearly observed. The effect was the highest in E. amstelodami, and considerably increased during a 21-day incubation period. In addition, E. amstelodami and A. versicolor showed high catalase, urease and DNA-se activities. A. versicolor had higher pectate lyase activity compared to E. amstelodami. Of the fungi examined, E. amstelodami showed the highest hydrolase activity in the API ZYM® test. A. versicolor and E. amstelodami were found to be the two species with the highest biodeterioration potential for dried materials of medicinal plants. Xerophilic fungi isolated from this environment could also be used in bioremediation.
The majority of mycotoxins produced by Aspergillus fungi are immunosuppressive agents, and their cytotoxicity may impair defense mechanisms in humans. The objective of the study was evaluation of the cytotoxicity of fungi isolated from an environment where inpatients with impaired immunity were present. The materials comprised 57 fungal strains: Aspergillus fumigatus, Aspergillus niger. Aspergillus ochraceus, Aspergillus flavus, Aspergillus versicolor and Aspergillus ustus isolated from hospital rooms in Cracow. The cytotoxicity of all the strains was evaluated using the MTT test (3-(4,5-dimethylthiazol-2-yl) 2,5 diphenyltetrazolium bromide). To emphasize the differences in cytotoxicity among the particular strains, variance analysis (ANOVA) and Tukey's difference test were used. Out of 57 Aspergillus strains tested, 48 (84%) turned out to be cytotoxic. The cytyotoxicity was high (+++) in 21 strains, mainly in A. fumigatus. The least cytotoxic were A. niger fungi, this being statistically significant (p<0,05). To protect a patient from the adverse effects of mycotoxins, not only his or her immunity status should be evaluated but also the presence of fungi in hospital environment and their cytotoxicity should be monitored (possible exposure).
Fast and sensitive techniques are needed to determine microorganism presence in liquid samples. In this research, the feasibility of using light scattering spectrometry for enumerating the biological particles in liquid samples was investigated. A particle size spectrometer was used to count six commonly found microbial species suspended in liquid with and without microbiological stains applied: Pseudomonas fluorescens, Micrococcus spp. vegetative cells and Bacillus subtilis var. niger endospores were stained with Acridine Orange and Crystal Violet, while Cladosporium cladosporioides, Penicillium melinii and Aspergillus versicolor fungi were stained with Acridine Orange and Lactophenol Cotton Blue. The counts obtained with the spectrometer were compared with those obtained with a phase-contrast microscope. It was found that the spectrometer counted about 32% of non-stained B. subtilis endospores and this percentage increased to almost 90% for stained endospores. Among the investigated species of fungi, the counting efficiency of P. melinii was the only one significantly affected by the application of the stain Lactophenol Cotton Blue: the fraction of counted fungal spores increased from 64% (non-stained spores) to about 100% (stained spores). The observed difference in counting efficiency may serve as a basis for differentiating biological from non-biological particles in liquid samples.
Mycological investigations were carried out in areas of intensive vehicle traffic (intersections) in Cracow. The results indicated considerable concentrations of fungi spores in the air at sites with heavy traffic (highest at 7007.0 spores/m3). At the control site, two hundred meters from an intersection, the number of fungi spores was several times lower (2802.8 spores/m3). Cladosporium herbarum, Penicillium viridicatum and P. lanosum, Aspergillus versicolor and A. fumigatus, and Alternaría alternata were noted at all sites examined.