Zbigniew Gorski

Microwave-Assisted Extraction Combined with HPLC-MS/MS for Diagnosis of Fungal Contamination in Building Materials

Ergosterol was used as indicator of fungal contamination to assess mould presence on the building materials. Microwave-assisted saponification followed by pentane extraction was used in the sample preparation step. Samples of brick, plaster, concrete and granite were analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Ergosterol concentrations in laboratory infected samples ranged from 6 to 16 ng g-1, while in samples of naturally occurring materials ranged from 66 to 3020 ng g-1. Limits of detection and of quantitation were 1.7 and 5.5 ng g-1, respectively. Recovery and matrix effect were tested using samples spiked at 100 ng g-1. Mean recovery and mean matrix effect were 65.9 and 111.6%, respectively. Microscopic observations and bioluminescence measurements were carried out for the infected samples to make additional confirmation of fungi presence. The ergosterol concentration determined by HPLC-MS/MS in building materials proved to be a suitable indicator to estimate fungal contamination. The developed method was considerably faster for this aim than bioluminescence measurements and traditionally used culture methods.

Conidia of Trichoderma virens as a phosphorus source for mycorrhizal Pinus sylvestris seedlings

In this study, the mobilization and further translocation of phosphorus from conidia of saprotrophic fungus Trichoderma virens into Pinus sylvestris seedlings by nondestructive measuring of 32P was assessed. The radioactive phosphorus flux from the conidia to the Scots pine seedlings forming mycorrhiza with Laccaria laccata and Suillus bovinus amounted up to 27.82% and 7.42%, respectively, on the 28th day of the experiment, while at the same time in nonmycorrhizal pine seedlings, the detected radioactivity reached only 0.56%. Our studies revealed that both ectomycorrhizal fungi: L. laccata and S. bovinus, mobilized the phosphorus from radioactive conidia of T. virens. On this basis, we conclude that activities of the mycosymbionts may facilitate absorption and further translocation of phosphorus from organic matter into the host plants.

Use of a CCD-monitored chemiluminescence imaging for sensing of the UV-and ozone-induced degradation of humus substances

The single photoelectron counting imaging technique of ultraweak chemiluminescence accompanying oxidative degradation reactions of humus substances under the influence of detrimental environmental physical and chemical factors is described. A new type of a slow scan charge coupled device camera Molecular Light Imager was applied to quantify the spatial distribution of the ultraweak chemiluminescence from natural and model humic acids and mineral soil components (silica gel) exposed to UV-C, UV+VIS radiation, ozone and acid rains. The transformation algorithm was elaborated to obtain the state of the art. pseudocolored images and quantification of the intensity and kinetics and to elucidate mechanisms of the studied processes as well as their environmental significance.

A comprehensive study on the risk of biocorrosion of building materials

The fungal genera are known for their high ability to biodeteriorate construction materials. Weight loss and release of calcium are observed when materials, especially concrete, are exposed to fungi. The paper presents the procedures enabling to assess the risk of biocorrosion of buildings at various stages of its development. The presented results lead to selection of effective analytical methodology for this propose. The study was conducted on materials commonly used as construction materials such as granite, ceramic, concrete and plaster. Surfaces of the tested samples were fouled by three selected fungal genera. Changes in properties of the materials due to interaction of fungi have been studied with the use of ergosterol content measurements, microscopic picturing, bioluminescence imaging, measurements of pH and X-ray spectroscopy analysis. Particular attention was paid to propose an appropriate method of estimating the effect of fungi on the surface of building materials using advanced analytical techniques.

Chemiluminescence methods for the evaluation of degradative processes in soil organic matter

Application of chemiluminescent methods for monitoring and quantification of degradation processes of humus substances (HS) in soil organic matter under detrimental environment conditions is described. Single photoelectron counting and imaging techniques of chemiluminescence accompanying degradation reactions of HS as well as quenching of electrochemiluminescence and lucigenin chemiluminescence by degraded HS are applied.

Degradation of humic acids by UV-radiation and ozone

Model research was performed on the influence of UV- radiation and ozone on humus substances (HS) - dark ubiquitous biopolymers, the most important component of soil and aquatic organic matter. Aqueous aerated solutions of natural and synthetic model HS (0.001-0.08%) were irradiated with UV - and visible radiation in a flow-circulation system or exposed to the atmosphere containing 0.027 ppm ozone. Control and tested samples were analyzed using the chemiluminescence (CL) method, UV and Vis spectrophotometry and EPR spectroscopy. The results obtained indicate that dry HS are resistant to the UV- and visible radiation and low concentrations of ozone. However, HS is aerated solutions undergo degradative oxidation. These exergonic reactions are accompanied by the generation of electronically excited states and free radicals that manifest as a CL and changes in EPR signals. Prolonged irradiation or exposure to ozone causes a gradual degradation of the aromatic core of HS to hydrophilic, low molecular carboxylic products. Mechanisms of the degradation reactions, CL, changes in EPR signals and optical density of HS are proposed and possible ecological consequences of these processes are considered.