Age-dependent content of polymerized lipids in Sphagnum fuscum

The polymerized lipids of Sphagnum fuscum cell wall fragments were found to be composed of long chain hydroxy acids, long chain dicarboxylic acids, fatty alcohols and fatty acids. Their content, on a dry weight basis, was low in the topmost 3 cm of the shoot and increased with shoot age (and depth). A pronounced increase (16-fold) occurred in the contents of hydroxy acids which comprised 76% of the totals at the depth of 40–43 cm. The increase at the depth of 40-43 cm is considered to be at least partly associated with the frequently found destruction of the most suscptible part, the thin-walled stem center. The results suggest that aliphatic lipid polymers are present and acumulated in cell walls resistant to breakdown.     

Response of Sphagnum fuscum to water levels and CO2 concentration

Abstract

Sphagnum fuscum samples collected from an ombrotrophic bog were grown in a greenhouse at six water levels (0, 5, 10, 15, 25 and 30 cm) below the capitulum level and in four concentrations of CO₂ (350, 700, 1000 and 2000 ppm). The cores of S. fuscum were treated for 87 days and length increment was measured by the plastic strip method and by innate time markers. Water content of the shoot, dry mass of the capitulum, dry mass per unit length of stem and production of dry mass were measured at the end of the experiment.

The water content, capitulum dry mass, dry mass per unit length of stem, length increment and dry mass production differed markedly for S. fuscum grown in different water levels. With lower water levels, the water content of the shoot decreased and the dry mass of both the capitulum and unit length of stem increased. The total length increment was highest when the water level was at or near the capitulum level (0–10 cm). No clear trend in dry mass production on an areal basis could be found due to uncoupled responses in length increment and stem dry mass at the experimental water levels.

Neither capitulum dry mass nor dry mass per unit length of stem showed distinct trends in S. fuscum grown at different ambient CO₂ concentrations. Some increase in length increment and in dry mass production was detected at CO₂ concentrations above 350 ppm, but this effect appeared only at high water levels. It is suggested that the low response in length increment and production to CO₂ concentration resulted in part from insufficient moisture for photosynthesis at the lower water levels. Also, the possibility of increased nonstructural production is discussed.     

芽胞杆菌B13解养分效果研究

目的评价芽胞杆菌B13的功能。方法通过培养基及土壤培养分析其解钾、解磷的效果。结果芽胞杆菌B13培养7d后液体培养基中的有效磷含量（0．94μg／mL）比对照组（0．75μg/mL）增加25．33％,有效钾含量（0．54μg/mL）比对照组（0．31μg／mL）增加74．19％,解磷和解钾差异均有统计学意义（P〈0．01）。芽胞杆菌B13添加在灭菌土壤和不灭菌土壤中都具有明显的解磷、解钾功效,说明芽胞杆菌B13有较好的土壤定植能力。平板解磷试验证明芽胞杆菌B13同时具有解无机磷和有机磷的功效。结论芽胞杆菌B13具有很大的研究与开发价值。     

Effect of carbon levels from three organic substrates on egyptian soil fungi

Summary The fungal composition of soils with an equivalent percentage of carbon levels 2%, 5%, 10% and 20% fromOlea europea,, Citrus sinensis andEucalyptus rostrato leaves was studied after 10, 45 and 120 days using the dilution-plate method. They all induced significant increases in the total count of fungi, but their effect on the individual fungi was selective. The best substrate for the total fungus flora wasCitrus sinensis and the poorest wasOlea europeae leaves. The best three colonisers (possessing the highest counts), at carbon levels 2%, 5%, 10% and 20% at the end of the experimental periods were, respectively, as follows: forOlea europeae leaves,Scopulariaopsis brevicaulis, Drechslera halodes andCylindrocarpon sp.;Aspergillus quadrilineatus, A. sydowi andCurvularia lunata; A. quadrilineatus, Alternaria alternata andC. lunata andA. quadrilineatus, A. egyptiacus andA. terreus; forCitrus sinensis leaves,A. quadrilineatus, A. fumigatus andS. brumptii; A. fumigatus, A. quadrilineatus andA. versicolor; A. quadrilineatus, A. terreus andS. brumptii; andA. quadrilineatus, A. flavus andA. sydowi; and forEucalyptus rostrata leaves,A. quadrilineatus, Rhizopus stolonifer andA. sydowi; A. quadrilineatus, A. niger andA. terreus; A. niger, A. quadrilineatus andS. brevicaulis; andA. terreus, A. niger andA. quadrilineatus.     

Effects of enhanced UV-B radiation on production-related properties of a Sphagnum fuscum dominated subarctic bog

1. The aim of the study was to investigate effects of enhanced UV-B radiation on the balance between biomass production and decay in an ombrotrophic bog which is dominated by one species of Sphagnum ( S. fuscum). This paper concerns production.
2. Enhanced UV-B radiation (simulating 15% ozone depletion under clear sky conditions) was applied by means of fluorescent tubes during two growing seasons.
3. In S. fuscum, shoot density, mass relations and length increment over time were measured and productivity was estimated. Pigment concentration, rates of dark respiration and maximum net photosynthesis were recorded.
4. Sphagnum fuscum productivity was not changed by enhanced UV-B radiation while properties determining production were highly influenced although in opposite directions.
5. Height increment was decreased by 20% in the first growing season and by 31% in the second growing season under enhanced UV-B radiation. After two growing seasons spatial shoot density was decreased by 8% by enhanced UV-B radiation. The shoots became stunted as capitulum dry mass and stem dry mass per unit length were increased by 21 and 17%, respectively, under enhanced UV-B radiation.
6. Dark respiration was significantly decreased by 31% after growth under enhanced UV-B radiation.
7. The UV-B induced change in shoot biometry together with the reduced spatial shoot density involve potential long-term effects on peat structure with possible feedback on productivity, decomposition and the strength of the system as a carbon sink.     

Comparative morphology and phylogenetic placement of two microsclerotial black fungi from Sphagnum

Capnobotryella renispora and Scleroconidioma sphagnicola form black, irregularly shaped microsclerotia that are indistinguishable in gross morphology on leaves of Sphagnum fuscum. In culture, microsclerotia of these fungi were similar, in that mature component cells possessed thick, highly melanized cell walls, poorly defined organelles, large lipid bodies and simple septa. They were different in morphogenesis, in the way their component cells were organized and in disseminative propagules. Microsclerotia of S. sphagnicola formed phialidic conidiogenous cells on their surface, whereas in C. renispora, adjacent cells in mature microsclerotia often separated from each other by septum schizolysis and formed chlamydospores. The identification of C. renispora from Sphagnum is provisional despite a 100% ITS sequence match with data for a culture derived from the type strain. No holoblastic, reniform conidia typical of the species were formed in nature or in culture, and the SSU sequence for a separately preserved culture of the ex-type strain was markedly divergent. Parsimony analyses of nuclear ribosomal DNA sequences showed that these two fungi were related to separate orders of Dothideomycetes. Both SSU and ITS data supported a close relationship for S. sphagnicola to the Dothideales sensu stricto, while the closest ITS match was to Rhizosphaera spp. In the SSU analyses, C. renispora was nested within the Capnodiales.     

Utilisation of carbon substrates by orchid and ericoid mycorrhizal fungi from Australian dry sclerophyll forests

The utilisation of a range of cell-wall-related and aromatic carbon substrates by multiple genotypes of three ericoid mycorrhizal fungal taxa was compared with two orchid mycorrhizal fungal taxa. Both groups of fungi catabolised most common substrates, though significant inter- and intraspecific variability was observed in the use of a few carbon substrates. Orchid mycorrhizal fungi had limited access to tannic acid as a carbon source and did not use phenylalanine, while the ericoid mycorrhizal fungi used both. Utilisation of tryptophan was limited to single genotypes of each of the orchid mycorrhizal fungi, and to only two of the three ericoid mycorrhizal fungi examined. Although broadly similar, some significant differences apparently exist in carbon catabolism of ericoid and orchid mycorrhizal fungi from the same habitat. Functional and ecological implications of these observations are discussed.     

Extracellular mannanases and galactanases from selected fungi

Summary Eight thermophilic fungi were tested for production of mannanases and galactanases. Highest mannanase activities were produced byTalaromyces byssochlamydoides andTalaromyces emersonii. Mannanases from all strains tested were induced by locust bean gum except in the case ofThermoascus aurantiacus, where mannose had a greater inducing effect. Locust bean gum was also the best inducer of -mannosidase and galactanase except in the case ofT. emersonii where galactose was a better inducer of both these enzymes. Highest mannanase activity was produced byTalaromyces species when peptone was used as nitrogen source whereas sodium nitrate promoted maximum production of this enzyme byThielavia terrestris andT. aurantiacus. The pH optima of mannanases from the thermophilic fungi were in the range 5.0–6.6 and contrasted with the low pH optimum (3.2) of the enzyme fromAspergillus niger. Galactanases had pH optima in the range 4.3–5.8. The mannanase fromT. emersonii and the galactanase fromT. terrestris were most thermostable, each retaining 100% activity for 3 h at 60°C.     

Protoplast formation from selected species of ectomycorrhizal fungi

Summary Conditions for the formation of protoplasts from selected species of ectomycorrhizal fungi are described. The age of the fungal culture and extent of incubation in a lytic enzyme mixture are critical factors for efficient formation of protoplasts. There is a correlation between the distribution of nuclei in hyphal fragments and protoplasts and the frequency of protoplast regeneration. Protoplasts from at least two of the species studied are formed in sufficient numbers and regenerate at suitable frequencies to be useful for development of genetic transformation and cell fusion systems. These fungi can now be considered in experiments designed for the improvement of ectomycorrhizal associations through genetic manipulation of the fungal component.Dedicated to Professor Dr. Dr. hc. K. Esser on the occasion of his 65th birthdayThis research was supported in part by the McIntire-Stennis Cooperative Forestry Research Program and is published as Alabama Agriculture Experiment Station Journal No. 6-881863P     

The ability of soil-borne fungi to degrade organophosphonate carbon-to-phosphorus bonds

The ability of a wide variety of soil-borne fungal strains to degrade four structurally different com pounds containing PC bonds, namely the naturally occurring amino acid ciliatine, the popular herbicide glyphosate, phosphonoacetic acid and 2-amino-3-phosphonopropionic acid, was studied in order to show that soil fungi may play an important role in the biodegradation of organophosphonates. Most of the strains appeared to utilize ciliatine as the sole source of phosphorus for growth. Only a limited number of strains were able to grow on the other phosphonates used in this work. The strains of Trichoderma harzianum, Scopulariopsis sp. and Aspergillus niger chosen for more detailed study show the ability to degrade ciliatine, glyphosate and also amino(3-methoxyphenyl)mehtylphosphonic acid effectively. Received: 14 May 1997 / Received revision: 10 June 1997 / Accepted: 14 June 1997     

The ability of white-rot fungi to degrade the endocrine-disrupting compound nonylphenol

Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor and Bjerkandera sp. BOL13 were tested for their ability to degrade the endocrine-disrupting compound nonylphenol at an initial concentration of 100 mg l^–1. The highest removals were achieved with T. versicolor and Bjerkandera sp. BOL13, which were able to degrade 97 mg l^–1 and 99 mg l^–1 of nonylphenol in 25 days of incubation, respectively. Nonylphenol removal was associated with the production of laccase by T. versicolor, but the levels of laccase, manganese peroxidase and lignin peroxidase produced by Bjerkandera sp. BOL13 were very low. At 14°C, T. versicolor and Bjerkandera sp. BOL13 sustained the removal of 88 mg l^–1 and 79 mg l^–1 of nonylphenol, respectively. No pollutant removal was recorded at 4°C, although both fungi could grow at this temperature in the absence of nonylphenol. A microtoxicity assay showed that the fungi produced compounds that were toxic to Vibrio fischerii; and thus a reduction in toxicity could not be correlated with nonylphenol metabolism. T. versicolor and Bjerkandera sp. BOL13 were capable of colonizing soil artificially contaminated with 430 mg kg^–1 of nonylphenol. Only 1.3±0.1% of nonylphenol remained in the soil after 5 weeks of incubation.     

Degradation of keratin substrates by fungi isolated from sewage sludge

Four fungal species including two dermatophytes and two saprophytes were isolated from sewage sludge samples at Basrah (Iraq) they were tested for their degradative ability towards three types of keratin substrates (human hair, chicken feathers and wool). The rate of keratin degradation was expressed as weight loss over three weeks of incubation using a liquid culture medium. Human hair had the highest degradation rate by colonization of Chrysosporium pannicola and Microsporum gypseum at a rate of 62% and 4% respectively. Chicken feathers were highly degraded by Aspergillus flavus (32%) while wool degradation was highest by C. pannicola (45.5%) and Trichophyton mentagrophytes var. erinacei (38%). There was a significant difference (p < 0.00l) in keratin substrate degradation rates by the examined fungi. Keratinase activity was highest for C. pannicola and M. gypseum in the culture medium baited with human hair. Aspergillus flavus revealed the highest activity of this enzyme in cultures amended with chicken feathers while T. mentagrophytes var. erinacei showed highest keratinase activity in cultures with wool substrate. The amount of protein released into the culture medium varied among the tested fungi. The medium's alkalinity increased over incubation time from 6.5 to 7.8. Microscopic examination showed maceration of the keratin substrates by the fungi. This revised version was published online in June 2006 with corrections to the Cover Date.     

The adhesion of thin carbon films to metallic substrates.

As part of the development of carbon-coated prosthetic devices, the adhesion of thin carbon films to metallic substrates has been studied. The bond strength of carbon films about 5000 A thick on Ti-6A1-4V and stainless steel was measured in a pull test and found to be greater than 4700 psi. Auger electron spectroscopy showed a reactive film/substrate interface. The ultimate bond strength was found to be dependent on the substrate and the deposition parameters.     

Microcosm tests of the effects of temperature and microbial species number on the decomposition of Carex aquatilis and Sphagnum fuscum litter from southern boreal peatlands

Increased decomposition rates in boreal peatlands with global warming might increase the release of atmospheric greenhouse gases, thereby producing a positive feedback to global warming. How temperature influences microbial decomposers is unclear. We measured in vitro rates of decomposition of senesced sedge leaves and rhizomes (Carex aquatilis), from a fen, and peat moss (Sphagnum fuscum), from a bog, at 14 and 20 degrees C by the three most frequently isolated fungi and bacteria from these materials. Decomposition rates of the bog litter decreased (5- to 17-fold) with elevated temperatures, and decomposition of the sedge litters was either enhanced (2- to 30-fold) or remained unaffected by elevated temperatures. The increased temperature regime always favoured fungal over bacterial decomposition rates (2- to 3-fold). Different physiological characteristics of these microbes suggest that fungi using polyphenolic polymers as a carbon source cause greater mass losses of these litters. Litter quality exerted a stronger influence on decomposition at elevated temperatures, as litter rich in nutrients decomposed more quickly than litter poorer in nutrients at higher temperatures (8.0%-25.7% for the sedge litters vs. 0.2% for the bryophyte litter). We conclude that not all peatlands may provide a positive feedback to global warming. Cautious extrapolation of our data to the ecosystem level suggests that decomposition rates in fens may increase and those in bogs may decrease under a global warming scenario.     

The ability of filamentous fungi to produce acids on indoor building materials

Sixty two filamentous fungi isolated from paint coatings, wallpaper, carton-gypsum board, and indoor air in buildings were screened for acid activity. It was found that 64.5% of strains produce acids on medium with bromo-cresol purple, where 18% of the strains were distinguished by very high acid activity (acid activity coefficient Q = 1.32–2.83), including the species:Aspergillus niger, Aspergillus versicolor, Penicillium expansum, Penicillium brevicom pactum, Penicillium chrysogenum, Cladosporium cladosporioides, Stachybotrys chartarum, Mucor globosus, Ulocladium chartarum andAlternaria alternata. Research indicated that filamentous fungi considerably decrease the pH of the medium when that medium containing building material. The greatest acid production and pH decrease of the medium was observed during the growth of filamentous fungi in a medium with mortar, while the production of acids was less in a medium with cartongypsum board, gypsum, and wallpaper. Filamentous fungi produced succinic, oxalic, malic and fumaric acids in the medium with indoor building materials. It was stated that the type of building material affects the spectrum and quantity of organic acids produced by filamentous fungi.     

Production of plant protoplasts by enzymes from selected wood-destroying fungi

The goal of this work was to select higher fungi for the production of enzymes able to produce plant protoplasts. The hydrolytic capacity of various species of wood-detsroying fungi was examined to select those with the maximal hydrolytic capacity. The selection criteria included attack on cellulose, and oligo-and polysaccharides by each fungus species. Lenzites elegans, gonoderma applanatum and Pycnoporus sanguineus produced thr richest enzymatic mixtures, which were evaluated for their protoplasting ability. L. elegans has the best enzymatic mixture able to [roduced plant protoplasts with the shortest time for maceration of plant tissues, followed by G. applanatum and P. sanguineus. The potential of these fungi and the simplicity of enzyme proudtcion suggest the possibility of commercial applications.Correepondence to: A. R. Sampietro     

Ability of ectomycorrhizal fungi to utilize starch and related substrates

Basidiomycetous fungi of 55 strains of 33 species in 15 genera which are thought to be ectomycorrhizal were grown on starch and related substrates as a sole carbon source, and their ability to utilize these substrates was determined. Mycellial weights of the fungi grown on agar media containing starch and amylose varied between the strains from 1.1 to 94.9 mg/flask and from 0.4 to 93.3mg/flask, respectively. Mycelial growth rates ranged from 0 to 1.17 mm/d on barley grain medium and from 0 to 2.03 mm/d on rice grain medium; the highest rate corresponded to about half of the average of reference wood-rotting fungi. Most of the mycorrhizal fungi that grew well on amylose gave higher growth rates on barley. Several strains inLyophyllum, Hebeloma, Sarcodon, andTricholoma grew well on both glucose and starch media.