Biomonitoring of Indoor Air Fungal or Chemical Toxins with nematodes.

Bad indoor air quality due to toxins and other impurities can have a negative impact on human well-being, working capacity and health. Therefore, reliable methods to monitor the health risks associated with exposure to hazardous indoor air agents are needed. Here, we have used transgenic nematode strains carrying stress-responsive fluorescent reporters and evaluated their ability to sense fungal or chemical toxins, especially those that are present in moisture-damaged buildings.

Toxic Indoor Air Is a Potential Risk of Causing Immuno Suppression and Morbidity-A Pilot Study.

We aimed to establish an etiology-based connection between the symptoms experienced by the occupants of a workplace and the presence in the building of toxic dampness microbiota. The occupants (5/6) underwent a medical examination and urine samples (2/6) were analyzed by LC-MS/MS for mycotoxins at two time-points. The magnitude of inhaled water was estimated.

Fungal enzyme production and biodegradation of polychlorinated dibenzo-p-dioxins and dibenzofurans in contaminated sawmill soil.

The current treatment method for PCDD/F-contaminated soil, which fulfils the requirements for POP soils, is incineration at high temperature. In this study, we investigated if bioaugmentation with fungal inoculum or treatment with manganese peroxidase (MnP) enzyme preparation could be used instead. The main source of PCDD/F contamination in Finland has been the national production and use of a chlorophenol containing wood preservative, which contained PCDD/Fs as impurities.

Mycoremediation of wood and soil from an old sawmill area contaminated for decades.

We investigated the potential of white-rot and litter-decomposing fungi for the treatment of soil and wood from a sawmill area contaminated with aged chlorinated phenols, dibenzo-p-dioxins and furans (PCDD/F). Eight screening assays with emphasis on application of non-sterile conditions were carried out in order to select the strains with capability to withstand indigenous microbes and contamination. Nine fungi were then selected for degrading pentachlorophenol (PCP), and 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) and mineralizing radiolabelled pentachlorophenol ((14)C-PCP) in non-sterile soil or wood during 15 weeks of incubation.

Bioluminescent yeast assay for detection of organotin compounds.

Organotin compounds are toxic and endocrine disrupting compounds, which have been intensively used as antifouling paints for ship hulls and thus are widely spread in the environment. They are suspected to cause imposex, the formation of male characteristics in female gastropods, because of the activation of retinoid X receptor (RXR) at very low environmental concentrations. Here we report the development and optimization of a bioluminescent yeast assay for the detection of organotin compounds based on the interaction with a hybrid RXR and subsequent expression of a reporter luciferase gene.

Fate of bisphenol A during treatment with the litter-decomposing fungi Stropharia rugosoannulata and Stropharia coronilla.

Bisphenol A is an endocrine disrupting compound, which is ubiquitous in the environment due to its wide use in plastic and resin production. Seven day old cultures of the litter-decomposing fungus Stropharia coronilla removed the estrogenic activity of bisphenol A (BPA) rapidly and enduringly. Treatment of BPA with purified neutral manganese peroxidase (MnP) from this fungus also resulted in 100% reduction of estrogenic activity, as analyzed using a bioluminescent yeast assay, and in the formation of polymeric compounds.

Scots pine (Pinus sylvestris) bark composition and degradation by fungi: potential substrate for bioremediation.

The composition of Scots pine bark, its degradation, and the production of hydrolytic and ligninolytic enzymes were evaluated during 90 days of incubation with Phanerochaete velutina and Stropharia rugosoannulata. The aim was to evaluate if pine bark can be a suitable fungal substrate for bioremediation applications. The original pine bark contained 45% lignin, 25% cellulose, and 15% hemicellulose.

Microbial activities in soils of a former sawmill area.

To find out microbial metabolic functioning and toxicity in a former sawmill area, carbon dioxide evolution, methane oxidation potential, 10 hydrolytic enzyme activities, Vibrio fischeri test, fluorescein diacetate hydrolysis activity (FDA), soil pH, carbon, nitrogen and pentachlorophenol (PCP) content were measured at four sites. The area is contaminated with aged chlorophenols. Chlorophenol content of soil was analyzed with a novel HPLC-MS technique, which allowed to measure chlorophenols without derivatization.

Enhancement of bioconversion of high-molecular mass polycyclic aromatic hydrocarbons in contaminated non-sterile soil by litter-decomposing fungi.

With the focus on alternative microbes for soil-bioremediation, 18 species of litter-decomposing basidiomycetous fungi were screened for their ability to grow on different lignocellulosic substrates including straw, flax and pine bark as well as to produce ligninolytic enzymes, namely laccase and manganese peroxidase. Following characteristics have been chosen as criteria for the strain selection: (i) the ability to grow at least on one of the mentioned materials, (ii) production of either of the ligninolytic enzymes and (iii) the ability to invade non-sterile soil. As the result, eight species were selected for a bioremediation experiment with an artificially contaminated soil (total polycyclic aromatic hydrocarbon (PAH) concentration 250 mg/kg soil).

Influence of Pb contamination in boreal forest soil on the growth and ligninolytic activity of litter-decomposing fungi.

Lignin mineralization activity of three basidiomycetous litter-decomposing fungi (LDF) was studied with humus layer samples taken from a boreal forest soil. The total Pb concentration in the samples was 32,000 mg kg(-1) and water soluble Pb 67 mg kg(-1). Synthetic lignin mineralization by Collybia dryophila and Clitocybe (Lepista) nebularis was strongly inhibited, whereas Stropharia coronilla was more tolerant to Pb stress in soil and liquid cultures.

Modification of humic acids by the compost-dwelling deuteromycete Paecilomyces inflatus.

The soil mold Paecilomyces inflatus is capable of modifying and partially mineralizing synthetic and natural humic acids (HAs) in compost environments. HA degradation studies using a synthetic HA (14C-HA) in autoclaved compost microcosms showed that, after 12 weeks of cultivation, P. inflatus mineralized approximately 5% of the 14C-labeled HA to 14CO2, while 6% of the 14C-HA was converted into 14C-labeled water-soluble fragments (fulvic-acid-like fraction).

Priming effect as determined by adding 14C-glucose to modified controlled composting test.

The development of new biodegradable packaging materials, especially biodegradable plastics, has created a need for biodegradability testing. The European standard for controlled composting test was used in this study for assessing if the addition of a test material results in excess CO2 production in compost. This effect, designated as the priming effect, would give an erroneous result for biodegradation, which is based on CO2 formation from the test material.