| 1. |
- Eiland, F, et al.
(author)
-
Influence of initial C/N ratio on chemical and microbial composition during long term composting of straw
- 2001
-
In: Microbial Ecology. - : Springer Science and Business Media LLC. - 1432-184X .- 0095-3628. ; 41:3, s. 272-280
-
Journal article (peer-reviewed)abstract
- Shredded straw of Miscanthus was composted in 800-L boxes with different amounts of pig slurry added as nitrogen source. The impact of the different initial CIN ratios (11, 35, 47, 50, and 54) on the composting process and the end product was evaluated by examining chemical and microbiological parameters during 12 months of composting. Low initial C/N ratios caused a fast degradation of fibers during the first three months of composting (hemicellulose: 50-80%, cellulose: 40-60%), while high initial C/N ratios resulted in 10-20% degradation of both hemicellulose and cellulose. These differences were reflected in the microbial biomass and respiration, which initially were higher in low C/N treatments than in high C/N treatments. After 12 months of composting, this situation was reversed. Composts with high initial CIN ratios had high microbial biomass (15-20 mug ATP g(-1) OM) and respiration rates (200 mug CO, h(-1) g(-1) OM) compared to treatments with low initial C/N ratios (less than 10 mug ATP g(-1) OM and 25 mug CO2 h(-1) g(-1) OM). This could be explained by the microorganisms being nitrogen limited in the high C/N ratio treatments. In the low C/N ratio treatments, without nitrogen limitation, the high activity in the beginning decreased with time because of exhaustion of easily available carbon. Different nitrogen availability was also seen in the nitrification patterns, since nitrate was only measured in significant amounts in the treatments with initial C/N ratios of 11 and 35. The microbial community structure (measured as phospholipid fatty acid, PLFA, profile) was also affected by the initial C/N ratios, with lower fungal/bacterial ratios in the low compared to the high C/N treatments after 12 months of composting. However, in the low C/N treatments higher levels of PLFAs indicative of thermophilic gram-positive bacteria were found compared to the high C/N treatments. This was caused by the initial heating phase being longer in the low than in the high C/N treatments. The different fungal/bacterial ratios could also be explained by the initial heating phase, since a significant correlation between this ratio and heat generated during the initial composting phase was found.
|
|
| 2. |
- Humar, Miha, et al.
(author)
-
Introduction of the COST FP 1303 Cooperative Performance Test
- 2015
-
In: Proceedings of the 46th IRG Annual Meeting.
-
Conference paper (peer-reviewed)abstract
- COST Action FP 1303 “Performance of bio-based building materials” successfully started in October 2013 and an ambitious program was set up for the four year programme. COST Actions provide an excellent opportunity for collaborative research, e.g. in the frame of Round Robin tests.The idea of this respective test was to distribute a fairly simple test set up to as many places in Europe as possible in order to collect performance data reflecting the range of climatic exposure conditions. Furthermore we wanted to consider performance in its manifold meaning, i.e. optical, aesthetical, moisture and functional performance and durability. In contrast to traditional Round Robin tests aiming on comparative evaluation and validation of results from different test laboratories, this initiative aims on collecting performance data under climatically different exposure conditions. Therefore it was required to provide weather data from the respective test sites to allow establishing relationships between climate conditions and the following measured, which shall be evaluated regularly: decay, discolouration, development of mould and other staining fungi, corrosion, formation of cracks and moisture performance (if data logging device is included). Further details about the test and the first outcomes are presented in this paper.
|
|
| 3. |
- Klamer, Morten, et al.
(author)
-
Estimation of conversion factors for fungal biomass determination in compost using ergosterol and PLFA 18 : 2 omega 6,9
- 2004
-
In: Soil Biology & Biochemistry. - : Elsevier BV. - 0038-0717. ; 36:1, s. 57-65
-
Journal article (peer-reviewed)abstract
- Eleven species of common fungi from compost were analysed for their content of ergosterol and phospholipid fatty acids (PLFAs) after growth on agar media. Mean content of ergosterol was 3.1 mg g(-1) dw of fungal mycelium (range 1-24 mg g(-1) dw). Total amount of PLFAs varied between 2.6 and 43.5 mumol g(-1) dw of fungi (mean 14.9 mumol g(-1) dw). The most common PLFAs were 16:0,18:2omega6,9 and 18:1omega9 comprising between 79 and 97 mol% of the total amount of PLFAs. The PLFA 18:2omega6,9, suggested as a marker molecule for fungi, comprised between 36 and 61 mol% of the total PLFAs in the Ascomycetes, between 45 and 57 mol% in the Basidiomycetes and 1222 mol% in the Zygomycetes. There was a good correlation between the content of the two fungal marker molecules, ergosterol and the PLFA 18:2omega6,9, with a mean content of 1 mg ergosterol being equivalent to 2.1 mumol of 18:2omega6,9. Based on results from the fungal isolates, conversion factors were calculated (5.4 mg ergosterol g(-1) biomass C and 11.8 mumol 18:2omega6,9 g(-1) biomass Q and applied to compost samples in which both the ergosterol and the PLFA 18:2omega6,9 content had been measured. This resulted in similar estimates of fungal biomass C using the two marker molecules, but was three to five times higher than total microbial biomass C calculated using ATP content in the compost. This could partly be explained by the fact that both of the markers used for fungal biomass are cell membrane constituents. Thus, the ergosterol and the PLFA content were related to the hyphal diameter of the fungi, where fungi with thinner hyphae had higher ergosterol concentrations than fungi with thicker hyphae. This could also partly explain the large interspecific variation in content of the two marker molecules. (C) 2003 Elsevier Ltd. All rights reserved.
|
|
| 4. |
- Klamer, Morten, et al.
(author)
-
Fungal diversity in set-aide agricultural soil investigated using terminal-restriction fragment length polymorphism
- 2004
-
In: Soil Biology & Biochemistry. - : Elsevier BV. - 0038-0717. ; 36:6, s. 983-988
-
Journal article (peer-reviewed)abstract
- As part of the restoration of biodiversity on former agricultural land there has been focused on methods to enhance the rate of transition from agricultural land towards natural grasslands or forest ecosystems. Management practices such as sowing seed mixtures and inoculating soil of later successional stages have been used. The aim of this study was to determine the effects of a managed plant community on the diversity of soil fungi in a newly abandoned agricultural land. A field site was set up consisting of 20 plots where the plant diversity was managed by either sowing 15 plant species, or natural colonization was allowed to occur. The plant mixture contained five species each of grasses, legumes and forbs that all were expected to occur at the site. A subset of the plots (five from each treatment) was inoculated with soil cores from a late successional stage. The plant community composition was subject to a principal component analysis based on the coverage of each species. Five years after abandonment, soil samples were taken from the plots, DNA was extracted and the ITS region of the rDNA gene was amplified using fluorescently labelled fungal specific primers (ITS 1F/ITS 4). The PCR products were digested using HinfI and TaqI and sequenced. Results from both restriction enzymes were combined and a principal component analysis performed on the presence/absence of fragments. Also the fungal diversity expressed as number of restriction fragments were analysed. There was significantly higher fungal species richness in the experimental plots compared to the forest and field soils, but no differences between sown and naturally colonized plots. The different plant treatments did not influence the below ground fungal community composition. Soil water content on the other hand had an impact on the fungal community composition.
|
|
| 5. |
- Klamer, Morten, et al.
(author)
-
Influence of elevated CO2 on the fungal community in a coastal scrub oak forest soil investigated with terminal-restriction fragment length polymorphism analysis
- 2002
-
In: Applied and Environmental Microbiology. - 0099-2240. ; 68:9, s. 4370-4376
-
Journal article (peer-reviewed)abstract
- Sixteen open-top chambers (diameter, 3.66 m) were established in a scrub oak habitat in central Florida where vegetation was removed in a planned burn prior to chamber installation. Eight control chambers have been continuously exposed to ambient air and eight have been continuously exposed to elevated CO2 at twice-ambient concentration (similar to700 ppm) for 5 years. Soil cores were collected from each chamber to examine the influence of elevated atmospheric CO, on the fungal community in different soil fractions. Each soil sample was physically fractionated into bulk soil, rhizosphere soil, and roots for separate analyses. Changes in relative fungal biomass were estimated by the ergosterol technique. In the bulk soil and root fractions, a significantly increased level of ergosterol was detected in the elevated CO, treatments relative to ambient controls. Fungal community composition was determined by terminal-restriction fragment length polymorphism (T-RFLP) analysis of the internal transcribed spacer (ITS) region. The specificities of different ITS primer sets were evaluated against plant and fungal species isolated from the experimental site. Changes in community composition were assessed by principal component analyses of T-RFLP profiles resolved by capillary electrophoresis. Fungal species richness, defined by the total number of terminal restriction fragments, was not significantly affected by either CO2 treatment or soil fraction.
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
