Pyrolysis-field Ionization Mass Spectrometry Research Articles

Acanthocephalan fish parasites (Rhadinorhynchidae Lühe, 1912) as potential biomarkers: Molecular–chemical screening by pyrolysis-field ionization mass spectrometry

The present study represents the first molecular–chemical screening by pyrolysis-field ionization mass spectrometry applied on fish parasites. A total of 71 fishes from Balinese fish markets, 36 Auxis rochei (Risso, 1810) and 35 A. thazard (Lacepède, 1800), were studied for their acanthocephalan parasites. This is the first record of Rhadinorhynchus zhukovi in Balinese waters, Indonesia, and we describe for the first time A. rochei and A. thazard as R. zhukovi hosts. Using this method, small scale variations within the chemical compounds of acanthocephalans could be detected. Using this methodology it will be possible to generate additional, pollutant specific information from aquatic habitats in future with the potential of a new bioindicator application for parasite/host origin and/or environmental pollution.

Analyzing organic matter composition at intact biopore and crack surfaces by combining DRIFT spectroscopy and Pyrolysis‐Field Ionization Mass Spectrometry#

AbstractIn the clay‐illuvial horizons (Bt) of Luvisols, surfaces of biopores and aggregates can be enriched in clay and organic matter (OM), relative to the bulk of the soil matrix. The OM composition of these coatings determines their bio‐physico‐chemical properties and is relevant for transport and transformation processes but is largely unknown at the molecular scale. The objective of this study was to improve the interpretation of spectra from Fourier transform infrared spectroscopy in diffuse reflectance mode (DRIFT) by using thermograms and released ion intensities obtained with pyrolysis‐field ionization mass spectrometry (Py‐FIMS) for a more detailed analysis of the mm‐scale spatial distribution of OM components at intact structural surfaces. Samples were separated from earthworm burrow walls, crack coatings, uncoated cracks, root channels, and pinhole fillings of the Bt‐horizons of Luvisols. The information from Py‐FI mass spectra enabled the assignment of OM functional groups also from spectral regions of overlapping DRIFT signal intensities to specific OM compound classes. In particular, bands from C=O and C=C bonds in the infrared range of wave numbers between 1,641 and 1,605 cm−1 were related to heterocyclic N‐compounds, benzonitrile, and naphthalene. The OM at earthworm burrow walls was composed of chemically labile aliphatic C‐rich and rather stable lignin and alkylaromatic compounds whereas the OM of thick crack coatings and pinholes was dominated by heterocyclic N and nitriles and high‐molecular compounds, likely originating from combustion residues. In combination with Py‐FIMS, DRIFT applications to intact samples seem promising for generating a more detailed mm‐scale spatial distribution of OM‐related sorption and wettability properties of crack and biopore surfaces that may serve as preferential flow paths in structured soils.

English

The identification of medicinal plants and derived natural products for development as anti-cancer agents is of long standing interest. We have investigated the anti-proliferative properties of Lupinus angustifolius on breast cancer and, in particular, whether the extracts of roots and shoots of L. angustifolius can be considered as candidates for primary and secondary cancer prevention. Ethanolic extracts of roots and shoots of L. angustifolius were analysed for their substance classes by pyrolysis-field ionization mass spectrometry. Various concentrations of these extracts (0.1, 1, 10, 25, 50, 100 and 200 µg/ml, incubation period: 24 h) were studied with respect to their effects on cell proliferation and cytotoxicity against the breast cancer cell lines MCF-7 (ER-α+, ER-β+) and BT20 (ER-α-, ER-β-). L. angustifolius ethanolic root and shoot extracts inhibited cell proliferation in the MCF-7 and BT20 cells; root extract: strongest inhibition MCF-7 (200 μg/ml 71.03 ± 12.62%); BT20 (200 μg/ml 99.72 ± 6.48%), IC50-values: MCF-7 (52.3 ± 9.39 μg/ml); BT20 (66.86 ± 7.02 μg/ml); shoot extract: strongest inhibition MCF-7 (200 μg/ml 64.7 ± 10.07 %); BT20 (200 μg/ml 86.32 ± 9.19%), IC50-values: MCF-7 (18.06 ±4.49 μg/ml); BT20 (70.27 ± 0.76 μg/ml). Thus, extracts of L. angustifolius roots and shoots have anti-tumour activity against receptor-positive and receptor-negative breast cancer cell lines.   Key words: Anti-tumour activity, Lupinus angustifolius, breast cancer, MCF-7, BT20

Origin and alteration of organic matter in termite mounds from different feeding guilds of the Amazon rainforests.

The impact of termites on nutrient cycling and tropical soil formation depends on their feeding habits and related material transformation. The identification of food sources, however, is difficult, because they are variable and changed by termite activity and nest construction. Here, we related the sources and alteration of organic matter in nests from seven different termite genera and feeding habits in the Terra Firme rainforests to the properties of potential food sources soil, wood, and microepiphytes. Chemical analyses comprised isotopic composition of C and N, cellulosic (CPS), non-cellulosic (NCPS), and N-containing saccharides, and molecular composition screening using pyrolysis-field ionization mass spectrometry (Py-FIMS). The isotopic analysis revealed higher soil δ13C (-27.4‰) and δ15N (6.6‰) values in nests of wood feeding Nasutitermes and Cornitermes than in wood samples (δ13C = -29.1‰, δ15N = 3.4‰), reflecting stable-isotope enrichment with organic matter alterations during or after nest construction. This result was confirmed by elevated NCPS:CPS ratios, indicating a preferential cellulose decomposition in the nests. High portions of muramic acid (MurAc) pointed to the participation of bacteria in the transformation processes. Non-metric multidimensional scaling (NMDS) revealed increasing geophagy in the sequence Termes < Embiratermes < Anoplotermes and increasing xylophagy for Cornitermes < Nasutitermes, and that the nest material of Constrictotermes was similar to the microepiphytes sample, confirming the report that Constrictotermes belongs to the microepiphyte-feeders. We therewith document that nest chemistry of rainforest termites shows variations and evidence of modification by microbial processes, but nevertheless it primarily reflects the trophic niches of the constructors.

Will changes in climate and land use affect soil organic matter composition? Evidence from an ecotonal climosequence

As the largest actively cycling pool of terrestrial C, the response of soil organic matter (SOM) to climate change may greatly affect global C cycling and climate change feedbacks. Despite the influence of SOM chemistry—here defined as soil organic C (SOC) and soil organic N (SON) functional groups and compounds—on decomposition, uncertainty exists regarding the response of SOM chemistry to climate change and associated land use shifts. Here, we adopt a climosequence approach, using latitude along a uniform glacial till deposit at the grassland–forest ecotone in central Canada as a surrogate for the effects of climate change on SOM chemistry. Additionally, we evaluate differences in SOM chemistry from paired native grassland, native trembling aspen (Populus tremuloides) forest, and arable soil profiles to investigate the effects of likely climate-induced land use alterations.The combination of C and N K-edge X-ray absorption near edge structure (XANES) with pyrolysis-field ionization mass spectrometry (Py-FIMS) techniques was used to examine SOM chemistry at atomic and molecular scales, respectively. These techniques revealed only modest differences in surface SOM chemistry related to land use and latitude. Greater variation was apparent in the vertical stratification of SOM constituents from soil depth profiles. These findings indicate that pedon-scale processes have greater control over SOM chemistry than do processes operating on landscape (e.g. land use) and regional (e.g. climate) scales. Additionally they imply that SOM chemistry is largely unresponsive to climatic change on the magnitude of the mean annual temperature (MAT) gradient under study (~0.7°C), despite its location at the grassland–forest boundary highlighting its sensitivity, and is similarly unresponsive to associated land use shifts.

Indicators for soil organic matter quality in no-till soils under perennial crops in Central Sweden

Assessing the organic C (Corg) sequestration in no-till soils under perennial crops requires molecular-level quality indicators. Therefore, we investigated the quality of soil organic matter (SOM) in the topsoil under Salix viminalis L. and Lolium perenne L. at two test sites in Central Sweden. The willow S. viminalis (clone 78021) was grown in short rotation coppice, and the grass L. perenne in an adjacent meadow for 17 (site Ultuna) and 15 years (site Enköping), respectively. The concentrations of aliphatic lipids, determined by gas chromatography/mass spectrometry (GC/MS), as well as the molecular composition and thermal stability of the bulk SOM, determined by pyrolysis-field ionization mass spectrometry (Py-FIMS), were tested as indicators for the crop-specific SOM quality. Larger Corg concentrations (factor 1.4) in the topsoil (site Ultuna) under S. viminalis than under L.perenne corresponded to higher concentrations of summed aliphatic lipids (factor 1.6), mainly saturated n-alkanoic acids (factor 2.1) and n-alkanols (factor 1.5) in the GC/MS-analyses. Moreover, in the willow stand (site Ultuna) at soil depth of 0–10cm disproportionally higher concentrations of saturated n-alkanoic acids (C17–C36) (factor 2.4) and n-alkanes (C21–C36) (factor 2.6) indicated a preferential sequestration of aliphatic C because the bulk Corg concentrations were only larger by factor 1.4. This crop-specific impact on SOM at soil depth of 0–10cm was proven for both test sites. Furthermore, the Py-FIMS showed larger abundances of thermally stabile alkylaromatics (factor 1.4), and non-peptidic N-containing compounds (factor 1.3) in the S. viminalis plot (site Enköping), which supported a crop-specific Corg-sequestration of these compounds. Thus, in summary, accumulations in extracted long C-chain aliphatic lipids and the thermal stability of some substance classes indicated that the Corg sequestration by no-till may be more distinct in soils under S. viminalis than under L. perenne.

Microbial contribution to SOM quantity and quality in density fractions of temperate arable soils

The formation of soil organic matter (SOM) very much depends on microbial activity. Even more, latest studies identified microbial necromass itself being a significant source of SOM and found microbial products to initiate and enhance the formation of long-term stabilized SOM. The objectives of this study were to investigate the microbial contribution to SOM in pools of different stability and its impact on SOM quality. Hence, four arable soils of widely differing properties were density-fractionated into free and occluded particulate organic matter (fPOM, oPOM < 1.6 g cm−3 and oPOM < 2.0 g cm−3) and mineral associated organic matter (MOM > 2.0 g cm−3) by using sodium polytungstate. These fractions were characterized by in-source pyrolysis-field ionization mass spectrometry (Py-FIMS). Main SOM compound classes of the fractions were determined and further SOM properties were derived (polydispersity, thermostability). The contribution of microbial derived input to arable soil OM was estimated from the hexose to pentose ratio of the carbohydrates and the ratio of C4–C26 to C26–C36 fatty acids. Additionally, selected samples were investigated by scanning electron microscopy (SEM) for visualizing structures as indicators for the origin of OM. Results showed that, although the samples differed significantly regarding soil properties, SOM composition was comparable and almost 50% of identifiable SOM compounds of all soils types and all density fractions were assigned to phenols, lignin monomers and alkylaromatics. Most distinguishing were the high contents of carbohydrates for the MOM and of lipids for the POM fractions. Qualitative features such as polydispersity or thermostability were not in general assignable to specific compounds, density fractions or different mean residence times. Only the microbial derived part of the soil carbohydrates could be shown to be correlated with high SOM thermostability (r2 = 0.63**, n=39). Microbial derived carbohydrates and fatty acids were both enriched in the MOM, showing that the relative contribution of microbial versus plant-derived input to arable SOM increased with density and therefore especially increased MOM thermostability. Nevertheless, the general microbial contribution to arable SOM is suggested to be high for all density fractions; a mean proportion of about 1:1 was estimated for carbohydrates. Despite biomolecules released from living microorganisms, SEM revealed that microbial mass (biomass and necromass) is a considerable source for stable SOM which is also increasing with density.

Manipulation of rhizosphere organisms to enhance glomalin production and C sequestration: Pitfalls and promises

Walley, F. L., Gillespie, A. W., Adetona, A. B., Germida, J. J. and Farrell, R. E. 2014. Manipulation of rhizosphere organisms to enhance glomalin production and C-sequestration: Pitfalls and promises. Can. J. Plant Sci. 94: 1025–1032. Arbuscular mycorrhizal fungi (AMF) reportedly produce glomalin, a glycoprotein that has the potential to increase soil carbon (C) and nitrogen (N) storage. We hypothesized that interactions between rhizosphere microorganisms, such as plant growth-promoting rhizobacteria (PGPR), and AMF, would influence glomalin production. Our objectives were to determine the effects of AMF/PGPR interactions on plant growth and glomalin production in the rhizosphere of pea (Pisum sativum L.) with the goal of enhancing C and N storage in the rhizosphere. One component of the study focussed on the molecular characterization of glomalin and glomalin-related soil protein (GRSP) using complementary synchrotron-based N and C X-ray absorption near-edge structure (XANES) spectroscopy, pyrolysis field ionization mass spectrometry (Py-FIMS), and proteomics techniques to characterize specific organic C and N fractions associated with glomalin production. Our research ultimately led us to conclude that the proteinaceous material extracted, and characterized in the literature, as GRSP is not exclusively of AMF origin. Our research supports the established concept that GRSP is important to soil quality, and C and N storage, irrespective of origin. However, efforts to manipulate this important soil C pool will remain compromised until we more clearly elucidate the chemical nature and origin of this resource.

English

The seeds of flax (binomial name: Linum usitatissimum L.) are well known for their high content of phytoestrogens. In the present study, extracts from roots, leaves and stems of flax were analysed for their content of compounds, which might have phytoestrogen-like properties, by pyrolysis field ionisation mass spectrometry. All extracts were tested on the human breast cancer cell lines MCF7 (estrogen receptor positive) and BT20 (estrogen receptor negative). Specific tests were applied for cell vitality ((3-(4,5)-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric assay (MTT) test), proliferation (BrdU test) and cytotoxicity (lactate dehydrogenase (LDH) test). In the flax root extract, the amounts of monolignols and polyphenols were three times higher than in the stem and leaf extracts. Even at higher concentrations, the root extract also was the least cytotoxic one of all extracts in MCF7 cells, while it showed a dose-dependent and much higher cytotoxicity in BT20 cells. Furthermore, at higher concentrations (&gt; 100 &micro;g/ml), the root extract reduced cell vitality in MCF7 significantly less than in BT20 cells and inhibited proliferation in MCF7 by up to 85%. Since flax root extracts induce significant inhibition of cell vitality and proliferation without performing strong cytotoxicity in the human mamma carcinoma cell lines MCF7, the potential phytoestrogens in flax root extracts could have beneficial effects in hormone-dependent tumours. Key words: Flax, Linum usitatissimum, phytoestrogens, MCF7, cell proliferation, breast cancer.

Secondary Metabolites in Flax Root Extracts at Various Stages of Maturity and Effects on Proliferation and Cytotoxicity in Oestrogen-Receptor-Positive Breast Cancer Cells

Flax contains large amounts of hormone-like compounds, especially lignans. These socalled phytoestrogens are thought to inhibit the cell growth of hormone-sensitive cancers. Hence, we analysed the influence of flax root extracts at various stages of maturity on the proliferation and cytotoxicity in oestrogen-receptor-positive breast cancer cells (MCF7) in vitro. Flax root extracts were prepared by using lignan extraction. The extracted compounds were analysed by Pyrolysis-Field Ionisation Mass Spectrometry. Various extract concentrations were applied to the cells to test for proliferation (BrdU test) and cytotoxicity (LDH test). A significantly higher inhibition of cell proliferation was observed with an extract made from 9-week-old flax roots in comparison with that of 3- and 6-week-old roots. Older roots contained more lignans and other phenolic substances than younger roots. The maturity grade of plants or their various parts is thus important for the production and concentration of secondary metabolites and leads to different biological effects on breast cancer cell growth.

Impact of Populus trees on the composition of organic matter and the soil microbial community in Orthic Gray Luvisols in Saskatchewan (Canada)

The conversion of agriculture land to short rotation coppice (SRC) systems with hybrid poplar (Populus spp.) is becoming an important practice to store carbon and produce biomass for the fiber industry. This land-use change is likely to affect the microbial community structure, in part through the introduction of an ectomycorrhizal host, but also by changing organic matter inputs, ultimately shifting the molecular composition of soil organic matter (SOM) because these properties are crop-specific. The objective of this study was to examine the effect of different aged poplar stands growing on Orthic Gray Luvisols on these soil properties compared to an adjacent perennial crop. The site consisted of four treatments: hybrid poplar (Populus deltoides × Populus petroskyana) in SRC of 7 and 14 years age (Pop7 and Pop14), a 40-year-old aspen (Populus tremuloides) forest (Aspen), and an adjacent arable site with alfalfa (Medicago sativa). The molecular composition of SOM was determined using pyrolysis-field ionization mass spectrometry (Py-FIMS) and synchrotron-based X-ray absorption near edge spectroscopy at the nitrogen (N) K-edge (N-XANES). Phospholipid fatty acid (PLFA) profiles revealed higher concentrations of fungal but not bacterial biomarkers in poplar plantations than under alfalfa. Fungal:bacterial ratio was lower under alfalfa than under poplar trees. Overall microbial community structure also changed in response to vegetation type and the duration of woody biomass. Along the chronosequence of poplar, Py-FIMS revealed significant increases in the proportions of carbohydrates with pentose and hexose subunits, phenols and lignin monomers, alkylaromatics and peptides and significant decreases in lipids, alkanes, alkenes, bound fatty acids and alkylmonoesters and free fatty acids with increasing poplar stand age. Thermal stability of sterols decreased along the chronosequence, suggesting that poplar plantations are not involved in the build-up of these substances. Differences in the ordination were well reflected by N K-edge XANES spectra. Increased carbohydrate portions indicated a significant impact of the ectomycorrhizal host poplar on the molecular composition of SOM in arable soils. Our results demonstrate that a change in land-use from agricultural cropping to woody biomass caused shifts in microbial community structure that were lagged by a shift in SOM chemistry. These shifts impact soil functioning and should be considered in future land management strategies when SRC are harvested.

Wheat straw biomass: A resource for high-value chemicals

Two methods are proposed for increasing the commercial value of wheat straw based on its chemical constituents. The first method involves the determination and extraction of the major organic components of wheat straw, and the second involves those found and extracted in the aqueous and viscous biooils derived from the straw by fast pyrolysis. We used pyrolysis-field ionization mass spectrometry to identify the fine chemicals, which have high commercial values. The most abundant organic compounds in the wheat straw and biooil used as precursors for green chemicals are N-heterocycles (16 to 29% of the Total Ion Intensities, TII) and fatty acids (19 to 26% of TIIs), followed by phenols and lignins (12 to 23% of TIIs). Other important precursors were carbohydrates and amino acids (1 to 8% TIIs), n-alkyl benzenes (3 to 5% of TIIs), and diols (4 to 9% TIIs). Steroids and flavonoids represented 1 to 5% of TIIs in the three materials. Examples of valuable chemical compounds that can be extracted from the wheat straw and biooils are m/z 256, 270, 278, 280, 282 and 284, which are the n-C16 and n-C17 fatty acids respectively, and the C18:3, C18:2 and C18:1 unsaturated fatty acids. In particular, the C18:2 (linoleic acid) is present at a concentration of 1.7% of TIIs. Pyrazole, pyrazine, pyridine, indoles, quinolines, carbazoles, and their identified derivatives are found in relatively high concentrations (1 to 8% of TIIs). Other useful compounds are sterols such as m/z 412 (stigmasterol), m/z 414 (β-sitosterol), and steroids such m/z 394 (stigmastatriene), m/z 398 (stigmastene) and m/z 410 (stigmastadienone). Relative to the wheat straw, the relative concentration of all flavonoids such as m/z 222 (flavone) and m/z 224 (flavonone) doubled in the biooils. The conversion of wheat straw by fast pyrolysis, followed by chemical characterization with mass spectrometry, and extraction of fine chemicals, opens up new possibilities for increasing the monetary value of crop residues.

Chernozem properties of Black Soils in the Baltic region of Germany as revealed by mass-spectrometric fingerprinting of organic matter

Black Soils with dark-coloured, mollic horizons occur in the Baltic region of Germany and their classification as Chernozems was previously discussed. Mollic topsoil horizons are diagnostic for steppe soils. We therefore hypothesized that the molecular characterization of soil organic matter (SOM) by pyrolysis-field ionization-mass spectrometry (Py-FIMS) is suitable to identify similarities between the Black Soils and Chernozems as well as soils from other major soil groups with mollic horizons or otherwise high SOM content. Data were collected from a set of 341 topsoil samples and analysed based on 139 Py-FI mass spectra and thermograms. The OC content in Black Soils reached high values matching those of Haplic Chernozems from Germany and typical steppe climate ecosystems. Arable soil use converted Ah horizons to lighter-coloured Ap horizons that nonetheless had a similar or higher OC content than underlying Ah horizons. Arable soil use led to less stable SOM as indicated by a higher percentage of volatilized organic matter (VM) upon pyrolysis. Furthermore, VM was especially high (21–52%) for redoximorphic soils, whereas it ranged between 5.1 and 15% in the Black Soils, Chernozems and other steppe soils such as Phaeozems or Kastanozems. Assignment of marker signals from Py-FI mass spectra to the compound classes revealed that Black Soils, all Chernozems and other steppe soils had more phenols and N-containing compounds but less sterols and suberin than most of the other soil groups investigated. The percentage of volatilized organic matter (VM) – with low values hinting at SOM stabilization in soil – ranged from 5 to 52%. It was especially high for redoximorphic (21%) and organic soils (52%), whereas it ranged between 5.1 and 15% in the Black Soils, Chernozems and other steppe soils. Principal component analysis unravelled the SOM composition patterns of different soils and showed that the Black Soils clustered together with typical Chernozems, while soils of other units differed. This indicates that sources and especially humification pathways of SOM were different in these soils compared to Black Soils and Chernozems. Notably, this was the case for Colluvic soils (=Colluvic Regosols), redoximorphic soils (e.g. Gleysols, Stagnosols), Luvisols and Phaeozems, although colluviation, influence of ground- or stagnant water, and clay migration were found in several Black Soils as well. Our findings do not support a strong, direct influence of colluviation and perched water on the SOM composition in the mollic horizons of Black Soils. The data also show that the Chernozem-specific SOM formation and clay migration, as in Luvisols and Phaeozems, are temporally discrete processes. The results underline that Chernozem formation in Central Europe is a relic process and is not only due to steppe ecosystem conditions. Rather, it depends on parent substrate properties, especially clay and carbonate content, secondary carbonate input and anthropogenic soil use. These factors preserved or even regraded the relic Chernozems since the Atlantic stage.

Spatial carbon and nitrogen distribution and organic matter characteristics of biological soil crusts in the Negev desert (Israel) along a rainfall gradient

In arid and semi-arid areas biological soil crusts are main contributors to C and N-cycles and the origin of organic matter. Nevertheless systematic studies on the spatial distribution of total organic carbon (TOC) and nitrogen (N) and a characterization of crust organic matter composition are missing. To describe the spatial distribution of TOC and N we examined three soil depths and three relief positions along a steep rainfall gradient. In addition the molecular composition of organic matter was characterized by Pyrolysis-field ionization mass spectrometry.TOC and N concentrations decreased with increasing depth, the effects of the relief followed no clear trend. Surprisingly the amount of TOC and N decreased with increasing rainfall. Stable organic matter compounds were reduced with increasing rainfall. Topcrusts (0–2 mm) showed a relative enrichment in bacteria, as indicated by proportionally larger contents in N-acetylmuramic acid (m/z 167 + 276) than the subcrusts (2–40 mm). These were enrichment in cyanobacteria, as indicated by proportionally larger contents of hexadecadienoic acid (m/z 252).We conclude that the spatial distribution of TOC and N is related to sampling depth and annual precipitation. Organic matter composition and the main biomass contributors in crusts are successfully identified by pyrolysis-field ionization mass spectrometry.

Impact of poplar on soil organic matter quality and microbial communities in arable soils

Poplars grown in short rotation coppice on agricultural land are a promising bioenergy crop. This study aimed to evaluate the soil organic matter (SOM) quality and viable microbial consortium under six-years-old poplar (Populus maximowiczii) and under wheat (Triticum aestivum) at a test site in central Germany. The SOM molecular composition and stability was determined by pyrolysis-field ionization mass spectrometry (Py-FIMS). The microbial consortium was assessed in terms of microbial phospholipid fatty acid (PLFA) profiles. Py-FIMS and the PLFAs agreed in showing crop-specific differences in the SOM quality and in the associated microbial communities. Higher proportions of carbohydrates, long-chained fatty acids, sterols and suberins at the expense of N-containing compounds under poplar than under wheat were associated with lower concentrations of microbial PLFAs in the organic matter. A higher ratio of total fungal to bacterial (f/b) PLFAs, a lower ratio of Gram-positive to Gram-negative bacterial PLFAs and lower biomass of arbuscular mycorrhizal fungi in the organic matter were revealed under poplar than under wheat. Lower N- and increased C-availability in the SOM promoted fungal vs. bacterial colonization, increased the SOM stability by a lower decomposability and caused SOM accumulation under poplar.

An ethanolic extract of Linum usitatissimum caused cell lethality and inhibition of cell vitality/ - proliferation of MCF-7 and BT20 mamma carcinoma cells in vitro

Flaxseeds were shown to have anticancerogenic properties on breast cancer. In this work, an extract of roots of Linum usitatissimum was tested on MCF-7 and BT20 mamma carcinoma cells in vitro. The extract was produced by an ethanolic extraction method and its chemical composition was afterwards analysed by pyrolysis field ionization mass spectrometry. The extract was tested in concentrations from 0.01 to 1,000 μg/mL. Its effects were detected by measuring the influence on cell lethality, viability and proliferation. The extract was shown to contain mainly sterols and triterpenes (21.4 %), free fatty acids (17.8 %), lignin dimers (12.2 %) and lipids (7.7 %). High concentrations of the extract caused significant cell lethality and suppression of cell vitality and proliferation. In this study, it was shown for the first time that an extract made of flaxroots caused different anticancerogenic effects on MCF-7 and BT20 cells in vitro. The extract supposably acts as a plantal multicomponent mixture, whereas the main active agents are not yet indentified and can only be suggested. Summarized, roots of flax may contain potential agents in the therapy of mamma carcinomas. Further investigations have to be carried out.

Compost of Different Stability Affects the Molecular Composition and Mineralization of Soil Organic Matter

This study investigated the C mineralization and chemical modification of a typical tropical soil amended with regional compost of different stability. Compost samples were produced from coffee pulp and fruit and vegetable waste in a method of small heap composting and the samples were collected in three different phases of composting. Both the fresh waste and compost samples were analyzed for their phytotoxicity. These samples were added to a tropical Nitisol at the rate of 48 t ha?1 and a control was set up without amendment. The CO2-C respired was determined during 98 days of incubation and the incubated samples were taken at the start and end of incubation for molecular-chemical analysis by Pyrolysis-Field Ionization Mass Spectrometry (Py-FIMS). The fresh waste yielded a germination index (GI) 100%). The CO2-C respired was best explained by a first order plus linear model. A soil amended with a compost taken at the thermophilic phase attained the lowest overall organic C loss. In general, the Py-FIMS revealed a significant enrichment of stable N-compounds during the incubation in all amended soils compared to the control. Furthermore, among the compost-soil mixtures Py-FIMS indicated significantly higher increases in the proportions of carbohydrates, peptides and phenols/lignin monomers at the expense of fatty acids and sterols in soil amended with composts from the thermophilic phase. Thermal volatilization curves of Py-FIMS indicated enrichments of stable N-compounds and peptides in compost amended soil. This was a result of enhanced decomposition and stabilization of decomposition products by physical protection through association with clay and soil aggregates. In summary, application of compost shortly after reaching the high temperature phase was shown to be more efficient in organic C sequestration in a clay-rich tropical agricultural soil than mature composts.

Hydrothermal Carbonization of Biomass Residues: Mass Spectrometric Characterization for Ecological Effects in the Soil-Plant System

Hydrochars, technically manufactured by hydrothermal carbonization (HTC) of biomass residues, are recently tested in high numbers for their suitability as feedstock for bioenergy production, the bioproduct industry, and as long-term carbon storage in soil, but ecological effects in the soil-plant system are not sufficiently known. Therefore, we investigated the influence of different biomass residues and process duration on the molecular composition of hydrochars, and how hydrochar addition to soils affected the germination of spring barley ( L.) seeds. Samples from biomass residues and the corresponding hydrochars were analyzed by pyrolysis-field ionization mass spectrometry (Py-FIMS) and gaseous emissions from the germination experiments with different soil-hydrochar mixtures by gas chromatography/mass spectrometry (GC/MS). The molecular-level characterization of various hydrochars by Py-FIMS clearly showed that the kind of biomass residue influenced the chemical composition of the corresponding hydrochars more strongly than the process duration. In addition to various detected possible toxic substances, two independent mass spectrometric methods (Py-FIMS and GC/MS) indicated long C-chain aliphatic compounds which are typically degraded to the C-unit ethylene that can evoke phytotoxic effects in high concentrations. This showed for the first time possible chemical compounds to explain toxic effects of hydrochars on plant growth. It is concluded that the HTC process did not result in a consistent product with defined chemical composition. Furthermore, possible toxic effects urgently need to be investigated for each individual hydrochar to assess effects on the soil organic matter composition and the soil biota before hydrochar applications as an amendment on agricultural soils.

Identifying potential antioxidant compounds in NaOH extracts of UK soils and vegetation by untargeted mass spectrometric screening

NaOH extracts of soil and vegetation have been shown to have antioxidant capacity (AOC). However, the identification of specific antioxidant compounds within extracts has proved to be difficult. In earlier work we demonstrated that the presence of some lignin-derived phenolic compounds, which were antioxidants, could only account for a very small percentage of the overall antioxidant capacity of soil extracts. The aims of the work reported here were to measure AOC of both vegetation and soil extracts by the Trolox equivalent antioxidant assay and photochemiluminescence and to analyse them using pyrolysis-field ionisation mass spectrometry (Py-FIMS), which allows a tentative assignment of specific compounds and an amalgamation to broad groups of compounds (e.g. carbohydrates) for the soil extracts. With this information we could find which compounds were closely related to the AOCs of the extracts and of those which might potentially be antioxidants. We extracted six soil samples, which had a range of antioxidant capacities, and the vegetation associated with those soils. The AOC results by the two methods were well correlated, and comparing soil and vegetation AOCs suggested that some antioxidants in vegetation were lost during humification, and that some others were soil-derived. For the soil samples we found that, because most of the compound groups quantified by Py-FIMS were correlated with the antioxidant capacities, a clear assignment of antioxidant properties to groups was restricted. However, individual compounds could be linked to the AOC using multivariate statistics, grouping the samples by their antioxidant capacity. Some compounds were present in both soil and vegetation, and presumably survived humification, while others were only found in the soil, in which they had probably been formed. Further investigation of these tentatively identified compounds provides a way forward in explaining the AOC of soil and vegetation extracts.

Controlled experimental soil organic matter modification for study of organic pollutant interactions in soil

Interactions of organic pollutants with soil organic matter can be studied by adsorption of the pollutants on well-characterized soil samples with constant mineralogy but different organic matter compositions. Therefore, the objectives of the current study are establishing a set of different, well-characterized soil samples by systematic modifications of their organic matter content and molecular composition and prove these modifications by advanced complementary analytical techniques. Modifications were done by off-line pyrolysis and removal/addition of hot-water extracted organic fraction (HWE) from/to the original soil sample. Both pyrolysis-field ionization mass spectrometry (Py-FIMS) and synchrotron-based C- and N- X-ray absorption near-edge structure spectroscopy (XANES) were applied to investigate the composition of the soil organic matter. These complementary analytical methods in addition to elemental analysis agreed in showing the following order of organic matter contents: pyrolyzed soil<soil residue<original soil<soil+3 HWE<soil+6 HWE<HWE. The addition of HWE to the soil sample increases the relative proportions of carbohydrates, N-containing heterocyclic compounds and peptides, and decreases the relative proportions of phenols, lignin monomers and dimers, and lipids. The most abundant organic compound classes in the pyrolyzed sample are aromatics, aliphatic nitriles, aldehydes, five- and six-membered N-containing heterocyclic compounds, and aliphatic carboxylic acids. It can be expected that removal or addition of HWE, that mimic biomass inputs to soil or soil amendments, change the binding capacity for organic pollutants less intensively than heat impact, e.g. from vegetation burning. It will be possible to interpret kinetic data on the pollutants adsorption by these original and modified soil samples on the basis of the bond- and element-specific speciation data through C-XANES and N-XANES and the molecular-level characterization through Py-FIMS. Finally, this combination of analytical techniques can be recommended for similar problems that require characterizing the bulk, non-extracted SOM instead of pre-selected compounds or compound classes.