Alexandra Šimonovičová

Investigation of microbial community isolated from indoor artworks and air environment: identification, biodegradative abilities, and DNA typing

This study deals with establishing the characteristics of a microbial community isolated from indoor artworks and the surrounding air environment. It is one of the few studies on microbial degradation of indoor artworks. It shows the potential biodegradative risk that can occur if artworks are not exhibited and conserved in an appropriate environment. The microbial community isolated from the indoor artworks and air environment was examined by cultural and molecular methods. Different plate assays were used to screen the biodegradative activity of the isolated microflora: Remazol Brilliant Blue R, phenol red, and Azure B for the ligninolytic properties; Ostazin brilliant red H-3B for cellulose degradation; CaCO3 glucose agar for solubilization activity; and B4 agar for biomineralization. To type the bacterial and fungal isolates, 2 PCR methods, repetitive extragenic palindromes (REP) and random amplified microsatellite polymorphisms (RAMP) were used. The art objects were principally colonized by fungi. The most commonly isolated strains were represented by hyphomycetes of the genera Penicillium, Aspergillus, Cladosporium, and Chaetomium. Members of these genera showed intensive biodegradation activity, both on wood and on stone. Bacteria were predominant in the air, exhibiting complex communities, both in the air and on the artworks. The most frequently isolated genera were Bacillus and Staphylococcus with extensive biodegradation abilities. REP-PCR revealed high variability within strains belonging to the same genus. RAMP is a new PCR-based method, used in this research for the first time to cluster the microfilamentous fungi and to characterize and select especially Penicillium and Aspergillus strains, which were isolated in a large number.

Wooden art objects and the museum environment: identification and biodegradative characteristics of isolated microflora

Aims:  The identification of culturable microbial communities on wooden art objects and from indoor air, and the analysis of their biodegradative properties.

Disclosing a crypt: Microbial diversity and degradation activity of the microflora isolated from funeral clothes of Cardinal Peter Pázmány

A crypt can be considered as a particular environment where different microbial communities contribute to decomposition of organic materials present inside during a long interval of time. The textile remains of the funeral clothes (biretta and tunic) of Cardinal Pázmány, an important historic figure dead in Bratislava the 19th March 1637, conserved in this kind of environment were subjected to microbial investigation. The sampling comprised three different approaches and the use of various kinds of cultivation media. Two different PCR-based clustering methods, f-ITS and f-CBH, were employed in order to select the bacterial and fungal microfloras which were identified in a second step by the 16S rRNA and ITS sequencing respectively. The isolated microflora was tested for its proteolytic, keratinolytic and cellulolytic activities and for its ability to grow on Fibroin agar medium. The combination of cultural, molecular and biodegradative assays was able to isolate and characterize a bacterial community composed mainly by members of the phyla Firmicutes and Actinobacteria. The fungal community appeared more diversified, together with several Penicillium and Aspergillus strains, members belonging to the species Beauveria bassiana, Eurotium cristatum, Xenochalara juniperi, Phialosimplex caninus and Myriodontium keratinophilum were isolated. Bacteria, especially the Bacillus members, showed their strong ability to degrade keratin and gelatin and a large portion of them was able to growth on Fibroin agar. The fungal isolates displayed a widespread cellulolytic activity and fibroin utilization, although they possessed a weaker and slower proteolytic and keratinolytic properties respect to bacterial counterpart. The present study can be considered perhaps as the first or among the few microbial investigations which treated the textile biodegradation from such unusual environment.

Sorption, desorption, and degradation of (4-chloro-2-methylphenoxy)acetic acid in representative soils of the Danubian Lowland, Slovakia.

Herbicide leaching through soil into groundwater greatly depends upon sorption-desorption and degradation phenomena. Batch adsorption, desorption and degradation experiments were performed with acidic herbicide MCPA and three soil types collected from their respective soil horizons. MCPA was found to be weakly sorbed by the soils with Freundlich coefficient values ranging from 0.37 to 1.03 mg(1-1/)(n) kg(-1) L(1/)(n). It was shown that MCPA sorption positively correlated with soil organic carbon content, humic and fulvic acid carbon contents, and negatively with soil pH. The importance of soil organic matter in MCPA sorption by soils was also confirmed by performing sorption experiments after soil organic matter removal. MCPA sorption in these treated soils decreased by 37-100% compared to the original soils. A relatively large part of the sorbed MCPA was released from soils into aqueous solution after four successive desorption steps, although some hysteresis occurred during desorption of MCPA from all soils. Both sorption and desorption were depth-dependent, the A soil horizons exhibited higher retention capacity of the herbicide than B or C soil horizons. Generally, MCPA sorption decreased in the presence of phosphate and low molecular weight organic acids. Degradation of MCPA was faster in the A soil horizons than the corresponding B or C soil horizons with half-life values ranging from 4.9 to 9.6 d in topsoils and from 11.6 to 23.4 d in subsoils.

Production of catalases by Aspergillus niger isolates as a response to pollutant stress by heavy metals.

Isolates of Aspergillus niger, selected from the coal dust of a mine containing arsenic (As; 400 mg/kg) and from the river sediment of mine surroundings (As, 1651 mg/kg, Sb, 362 mg/kg), growing in minimal nitrate medium in the phase of hyphal development and spore formation, exhibited much higher levels of total catalase activity than the same species from the culture collection or a culture adapted to soil contaminated with As (5 mg/L). Electrophoretic resolution of catalases in cell-free extracts revealed three isozymes of catalases and production of individual isozymes was not significantly affected by stress environments. Exogenously added stressors (As5+, Cd2+, Cu2+) at final concentrations of 25 and 50 mg/L and H2O2 (20 or 40 mM) mostly stimulated production of catalases only in isolates from mines surroundings, and H2O2 and Hg2+ caused the disappearance of the smallest catalase I. Isolates exhibited a higher tolerance of the toxic effects of heavy metals and H2O2, as monitored by growth, than did the strain from the culture collection.

Analysis and comparison of the microflora isolated from fresco surface and from surrounding air environment through molecular and biodegradative assays

The aim of this study was to find a correlation among the environmental isolated microflora and the fresco colonizators through the investigation of their biodegradative abilities and DNA characteristics. A molecular technique named RAMP (Random Amplified Microsatellite Polymorphisms) was utilized in order to analyze the DNA diversity of bacterial and fungal species isolated from fresco as well as from air samples. The RAMP-PCR results were combined with the screening of some biodegradative properties obtained through the use of specific agar plate assays detecting the proteolytic, solubilization and biomineralization abilities of the isolated microflora. This comparative analysis showed that only in few cases a direct link among the fresco and airborne isolates of specific microbial group existed. The investigation clearly evidenced that colonization of surface of Ladislav’s fresco occurred in different time and by different strains than those observed at the moment of sampling campaign. Furthermore, the microflora investigation permitted the identification of taxonomically interesting bacteria with particular biodegradative properties, which had been less studied until now.

Bio-accumulation of As(III) and As(V) species from water samples by two strains of Aspergillus niger using hydride generation atomic absorption spectrometry.

The bio-accumulation ability of two strains of Aspergillus niger was studied in various synthetic media containing inorganic single-species As(III) and As(V) solutions and their admixtures and mining water with high As content in order to study the extent of bio-accumulation of the As species by the fungi. The AN1 A. niger strain, which served as a reference, was isolated from the Eutric Fluvisol soil (pH H2O/KCl 7.7/7.4) originating from an uncontaminated area near Gabčíkovo (Southwest Slovakia). The AN3 A. niger strain was isolated from the bottom sediment with a natural content of As 363 mg kg−1 (pH H2O/KCl 5.27/4.8) collected from the Blatina stream running from abandoned antimony mines near Pezinok (West Slovakia). Samples of fungi biomass following bio-accumulation experiments were acid-decomposed in an autoclave under elevated temperature and pressure and used for total inorganic arsenic (As) determination. After 24 h of bio-accumulation in a solution containing 10 µg L−1 As(III), the AN1 strain showed to be more efficient transforming 73% of As(III), in comparison with the AN3 strain by which 38% of As(III) was bio-transformed. On the other hand, the AN3 strain demonstrated greater capacity to retain in its mycelia 17% of As from a solution containing 10 µg L−1 As(V) as compared with less than 10% of As(V) accumulated in the mycelia of the AN1 strain. Continuous hydride generation atomic absorption spectrometry (HG-AAS) was used for simple, rapid, sensitive and accurate determinations of total inorganic As and As(III). The accuracy of the method for the determination of As(III) was evaluated by analysing spiked synthetic and natural river waters. Recoveries of 96–102% of spikes were obtained. Limits of detection (3σ-criterion) for total inorganic As determination and As(III) determination were 0.22 and 0.28 µg L−1, respectively.

Bioaccumulation and biovolatilization of various elements using filamentous fungus Scopulariopsis brevicaulis.

Biovolatilization and bioaccumulation capabilities of different elements by microscopic filamentous fungus Scopulariopsis brevicaulis were observed. Accumulation of As(III), As(V), Se(IV), Se(VI), Sb(III), Sb(V), Te(IV), Te(VI), Hg(II), Tl(I) and Bi(III) by S. brevicaulis was quantified by analysing the amount of elements in biomass of the fungus using ICP AAS. The highest amounts of bioaccumulated metal(loid)s were obtained as follows: Bi(III) > Te(IV) > Hg(II) > Se(IV) > Te(VI) > Sb(III) at different initial contents, with Bi(III) accumulation approximately 87%. The highest percentages of volatilization were found using Hg(II) (50%) and Se(IV) (46·5%); it was also demonstrated with all studied elements. This proved the biovolatilization ability of microscopic fungi under aerobic conditions. The highest removed amount was observed using Hg(II) (95·30%), and more than 80% of Se(IV), Te(IV), Bi(III) and Hg(II) was removed by bioaccumulation and biovolatilization, which implies the possibilities of use of these processes for bioremediations. There were reported significant differences between bioaccumulation and biovolatilization of almost all applied metal(loid)s if valence is mentioned.

The occurrence of heat-resistant species of Trichophaea abundans in different types of soil in Slovakia and Czech Republic

Strains of Trichophaea abundans (Ascomycota, Pezizales, Pyrenomycetaceae) were isolated from Haplic Cambisol, Haplic Cambisol (Eutric), Litic Leptosol (Sceletic), Haplic Umbrisol, and Fulvic Andosol soils in Slovakia and from Rendzic Leptosol, Chernozem, Cambisol, drilosphere, and feacal pelets of the earthworm Allolobophora hrabei collected in southern Moravia. The Slovak soils markedly differ in pH, from extremely acidic (pHH2O 3.9) to weakly alkaline (pHH2O 7.4). T. abundans appeared as a post-burn species on Haplic Cambisol, which experienced a wildfire after a windthrow event (November 2004). In Moravia T. abundans was also isolated from sites situated in southern slopes, from time and time they affected by fires. We also note the growth of T. abundans on the surface of Fulvic Andosol after gradual heating in the lab to temperatures reaching 105°C. These findings confirmed by a review of the literature, indicate that T. abundans belongs to the group of heat-resistant fungi appearing in soils regularly influenced by the fire or grass calcining.

Alkaline Technosol contaminated by former mining activity and its culturable autochthonous microbiota

Technosols or technogenic substrates contaminated by potentially toxic elements as a result of iron mining causes not only contamination of the surrounding ecosystem but may also lead to changes of the extent, abundance, structure and activity of soil microbial community. Microbial biomass were significantly inhibited mainly by exceeding limits of potentially toxic metals as arsenic (in the range of 343–511 mg/kg), copper (in the range of 7980–9227 mg/kg), manganese (in the range of 2417–2670 mg/kg), alkaline and strong alkaline pH conditions and minimal contents of organic nutrients. All of the 14 bacterial isolates, belonged to 4 bacterial phyla, Actinobacteria, Firmicutes; β- and γ-Proteobacteria. Thirteen genera and 20 species of microscopic filamentous fungi were recovered. The most frequently found species belonged to genera Aspergillus (A. clavatus, A. niger, A. flavus, A. versicolor, Aspergillus sp.) with the dominating A. niger in all samples, and Penicillium (P. canescens, P. chrysogenum, P. spinulosum, Penicillium sp.). Fungal plant pathogens occurred in all surface samples. These included Bjerkandera adustata, Bionectria ochloleuca with anamorph state Clonostachys pseudochloleuca, Lewia infectoria, Phoma macrostoma and Rhizoctonia sp.