Miroslav Matucha

Degradation of 3,3',4,4'-tetrachlorobiphenyl by selected white rot fungi

Abstract N-limited stationary cultures of the white rot fungi Phanerochaete chrysosporium, Trametes versicolor, and Coriolopsis polysona mineralized 1.393 ± 0.353 (0.301 ± 0.023) and 0.398 ± 0.061 (0.112 ± 0.010), and 0.015 ± 0.004 (0.002 ± 0.0008) % of the originally supplied 30.14 nmol (513.7 nmol) of 3,3′,4,4′-tetrachloro[U-14C]biphenyl (PCB 77) during 4 weeks. The extent of PCB 77 degradation was followed by 14C-radioactivity partitioning into aqueous, organic soluble, biomass associated, aqueous (intracellular) and organic soluble (intracellular) fractions. After four weeks incubation the pattern of distribution of radioactivity was similar in P. chrysosporium and C. polysona at higher dose but not at the lower dose of PCB 77. T. versicolor differed in the distribution pattern of radiolabel.

Trichloroacetic acid in Norway spruce/soil-system I. Biodegradation in soil

Trichloroacetic acid (TCA) as a phytotoxic substance affects health status of coniferous trees. It is known as a secondary air pollutant (formed by photooxidation of tetrachloroethene and 1,1,1-trichloroethane) and as a product of chlorination of humic substances in soil. Its break-down in soil, however, influences considerably the TCA level, i.e. the extent of TCA uptake by spruce roots. In connection with our investigations of TCA effects on Norway spruce, microbial processes in soil were studied using 14C-labeling. It was shown that TCA degradation in soil is a fast process depending on TCA concentration, soil properties, humidity and temperature. As a result, the TCA level in soil is determined by a steady state between uptake from the atmosphere, formation in soil, leaching and degradation. The process of TCA degradation in soil thus participates significantly in the chlorine cycle in forest ecosystems.

The formation and fate of chlorinated organic substances in temperate and boreal forest soils.

Background, aim and scopeChlorine is an abundant element, commonly occurring in nature either as chloride ions or as chlorinated organic compounds (OCls). Chlorinated organic substances were long considered purely anthropogenic products; however, they are, in addition, a commonly occurring and important part of natural ecosystems. Formation of OCls may affect the degradation of soil organic matter (SOM) and thus the carbon cycle with implications for the ability of forest soils to sequester carbon, whilst the occurrence of potentially toxic OCls in groundwater aquifers is of concern with regard to water quality. It is thus important to understand the biogeochemical cycle of chlorine, both inorganic and organic, to get information about the relevant processes in the forest ecosystem and the effects on these from human activities, including forestry practices. A survey is given of processes in the soil of temperate and boreal forests, predominantly in Europe, including the participation of chlorine, and gaps in knowledge and the need for further work are discussed.ResultsChlorine is present as chloride ion and/or OCls in all compartments of temperate and boreal forest ecosystems. It contributes to the degradation of SOM, thus also affecting carbon sequestration in the forest soil. The most important source of chloride to coastal forest ecosystems is sea salt deposition, and volcanoes and coal burning can also be important sources. Locally, de-icing salt can be an important chloride input near major roads. In addition, anthropogenic sources of OCls are manifold. However, results also indicate the formation of chlorinated organics by microorganisms as an important source, together with natural abiotic formation. In fact, the soil pool of OCls seems to be a result of the balance between chlorination and degradation processes. Ecologically, organochlorines may function as antibiotics, signal substances and energy equivalents, in descending order of significance. Forest management practices can affect the chlorine cycle, although little is at present known about how.DiscussionThe present data on the apparently considerable size of the pool of OCls indicate its importance for the functioning of the forest soil system and its stability, but factors controlling their formation, degradation and transport are not clearly understood. It would be useful to estimate the significance and rates of key processes to be able to judge the importance of OCls in SOM and litter degradation. Effects of forest management processes affecting SOM and chloride deposition are likely to affect OCls as well. Further standardisation and harmonisation of sampling and analytical procedures is necessary.Conclusions and perspectivesMore work is necessary in order to understand and, if necessary, develop strategies for mitigating the environmental impact of OCls in temperate and boreal forest soils. This includes both intensified research, especially to understand the key processes of formation and degradation of chlorinated compounds, and monitoring of the substances in question in forest ecosystems. It is also important to understand the effect of various forest management techniques on OCls, as management can be used to produce desired effects.

Gas chromatography of 3H- and 14C-labelled compounds.

Abstract GC methods of analysis of 3H- and 14C-labelled compounds that have been published in the period from 1955 to mid-1976, together with important applications, are reviewed. In addition to its obvious use for identification purposes, RGC is mostly used for the determination of the distribution of radioactivity among the components of mixture under analysis and for the determination of their contents and specific activities. It can be also combined with chemical reactions (reaction gas chromatography). Applications that require derivatization have some limitations connected with the derivatization reaction and the stability of the derivatives. The separation of isotopic molecules by GC is also possible. For the measurement of radioactivity, a discontinuous method involving the collection of fractions and subsequent counting is often used, while for continuous monitoring of effluent activity flow-through radiation detectors (Geiger-Muller and proportional counters, ionization chambers and scintillation methods) are used, mainly after conversion of the effluent. The possibilities of various recording techniques with respect to quantitative evaluation are surveyed and applications of RGC in the production of labelled compounds,“hot-atom” chemistry, organic chemistry, chemical processing, biochemistry and clinical chemistry are discussed.

Biodegradation of Trichloroacetic Acid in Norway Spruce/Soil System

Trichloroacetic acid (TCA) belongs to secondary atmospheric pollutants affecting the forest health. Distribution of [1,2-14C]TCA-residues and TCA biodegradation were investigated in 4-year-old nursery-grown trees of Norway spruce [Picea abies (L.) Karst.] in the whole plant/soil system. Radioactivity was monitored in needles, wood, roots and soil as well as in the air. During two weeks of exposure TCA was continuously degraded, especially in the soil. Estimates of radioactivity balance showed loss of radioactivity into the atmosphere in the form of 14CO2; unincorporated [1,2-14C]TCA, chloroform, carbon monoxide and methane were not detected at all. TCA degradation to CO2 was indicated also in the spruce needles. Moreover, it was found that soil litter contained [1,2-14C]TCA unavailable to microorganisms.

Single-column gas chromatographic analysis of amino acid oxazolidinones

Abstract A study was made of single-column analysis of cyclic oxazolidinone derivatives of protein amino acids. Employment of Chromosorb 750 as the most inert chromatographic support and hydrogen as the carrier gas in a packed column improved only slightly the elution of the most polar (histidine, arginine) and the heaviest (tryptophan, cystine) amino acid derivatives. Similar results were obtained with a support-coated (OV-17) open tubular column. The best analytical performance was afforded by wide-bore open tubular columns either with methylphenylsilicone liquid coated on the glass walls or with methylsilicone gum chemically bonded to fused silica. The total analysis time for all protein members was approximately 10 min.

N‐acyl‐homoserine lactone uptake and systemic transport in barley rest upon active parts of the plant

Bacteria communicate with each other in a population density-dependent process known as quorum sensing. N-acyl-homoserine lactones (HSLs) are the autoinducers of Gram-negative bacteria and the best-studied quorum sensing signals so far. HSLs induce various responses in plants, including systemic resistance and root development. Here, we used different methods, including tritium labelling, sensor strain assays and monoclonal antibodies (mAbs), to analyse the uptake and translocation of C8- and C10- homoserine lactones into barley (Hordeum vulgare cv Barke). Both HSLs were already systemically transported into the shoot at 2 h after application. HSL uptake could be inhibited by orthovanadate, demonstrating that ABC transporters are involved in the uptake. Root transport occurs predominantly via the central cylinder, which was shown by transport inhibition via KCl application and autoradiography of root cross-sections. Furthermore, a newly established detection method with mAbs allowed the first detection of a systemic transport of long-chain HSLs in plants. The coupled use of different HSL detection methods demonstrated that the uptake and transport of HSLs into barley does not occur passively, but relies, at least partially, on active processes in the plant.

Uptake, translocation and fate of trichloroacetic acid in a Norway spruce/soil system

Trichloroacetic acid (TCA) is a secondary atmospheric pollutant formed by photooxidation of chlorinated solvents in the troposphere--it has, however, recently been ranked among natural organohalogens. Its herbicidal properties might be one of the factors adversely affecting forest health. TCA accumulates rapidly in conifer needles and influences the detoxification capacity in the trees. The aim of the investigations--a survey of which is briefly given here--was to elucidate the uptake, distribution and fate of TCA in Norway spruce. For this purpose young nursery-grown plants of Norway spruce (Picea abies (L.) Karst.) were exposed to [1,2-14C]TCA and the fate of the compound was followed in needles, wood, roots, soil and air with appropriate radio-indicator methods. As shown by radioactivity monitoring, the uptake of TCA from soil by roots proceeded most rapidly into current needles at the beginning of the TCA treatment and was redistributed at later dates so that TCA content in older needles increased. The only product of TCA metabolism/biodegradation found in the plant/soil-system was CO(2) (and corresponding assimilates). TCA biodegradation in soil depends on TCA concentration, soil humidity and other factors.

Aufnahme und Verteilung von Trichloressigsäure in Trieben Norwegischer Fichte

ZusammenfassungZur Untersuchung der Aufnahme von Trichloressigsäure (TCA) durch die Wurzeln und der Verteilung von TCA in Fichtenzweigen wurden Experimente mit [14C]TCA in Verbindung mit der Verbrennungsanalyse und Radioaktivitätsmessung sowie mit autoradiographischen Detektionsmethoden durchgeführt.Es konnte nachgewiesen werden, daß die Aufnahme von TCA durch die Nadeln rasch erfolgt. Die Aufnahmegeschwindigkeit ist während der Hauptwachstumsperiode im Juni höher als im September.Eine hohe Anreicherung von radioaktiver Substanz wurde in den Nadeln des Neuwuchses (des laufenden Jahres), insbesondere in den Nadelspitzen und ebenso im Korkkambium der einjährigen Holzbestandteile der Zweige gefunden. Unsere Versuchsergebnisse unterstützen die Ansicht, daß die Aufnahme von TCA in Fichtennadeln über das Bodenwasser mit dem Transpirationsstrom erfolgt.AbstractTo elucidate the uptake of TCA by roots and its distribution in Norway spruce shoots, experiments with [14C]TCA were carried out in combination with radioactivity measurements after combustion, and with autoradiographic detection methods.It was shown that the uptake of TCA by spruce shoots is faster during the growth period in June than in the post-growth period in September.A high uptake of radioactivity was observed in the current-year needles, especially in the top of them, and in the corc cambium of the one-year-old wooden parts of the spruce shoots.The results of our experiments suggest uptake of TCA into spruce needles from the soil water with the transpiration stream.

Chloride concentration affects soil microbial community

We studied the effect of increased inorganic chloride concentration on forest soil microflora in a laboratory experiment. Microbial DNA extracted from experimental soil samples was amplified with PCR using primer pairs specifically amplifying bacterial, eukaryotic and fungal DNA fragments. The resulting amplified DNA was further used for terminal restriction fragment length polymorphism (TRFLP) analysis. Our work revealed that chloride concentration affects the indigenous microbial community in experimental soil. This was documented on an unidentified microorganism whose DNA was detectable in soil high in chloride but was not found in soil with low chloride concentration. The presence of the organism responsive to increased chloride concentration was associated with the highest observed value of chlorination of humic acid, suggesting possible role of this organism in soil chlorine turnover. High chloride concentration in the soil tended to decrease the rate of degradation of trichloroacetic acid. The problems connected with measurement of chlorination rates in soil are discussed.