Your search resulted in 186 documents. Displaying 25 entries per page.
A rapid microscale assay for determining growth of wood inhabiting fungi against Lactobacillus metabolites
2009 - IRG/WP 09-20412
Lactobacillus sp. are well known for their ability to produce secondary metabolites with potent inhibitory activity against a wide range of bacterial species and there is increasing evidence to support their antifungal activity. These metabolites are often screened in laboratories using microscale 96-well plate optical density assays. The objective of this study was to develop an optical density a...
D O’Callahan, T Singh, I McDonald
Modelling of onset of mould growth for wood exposed to varying climate conditions
2009 - IRG/WP 09-20414
A performance-based service life design format based on climatic exposure on one hand and “resistance” of wood against mould growth on the other hand, is presented in this paper. A limit state for onset of mould growth is defined as the occurrence of traces of mould observed by microscopy. A dose-response model is proposed by which onset of mould growth can be predicted for an arbitrary climat...
S Thelandersson, T Isaksson, A Ekstrand-Tobin, P Johansson
Assessment of mould growth on coated wood - methods and application
2009 - IRG/WP 09-20423
Discolouring fungi reduce the service life of coated wooden claddings in façades and increase the total cost of ownership due to shorter maintenance intervals. The project “Enhanced service life on coated wooden facades” has as its main objective to develop new methods for early prediction of durability and longer aesthetic service life of coated wooden cladding related to consumer needs and ...
L Ross Gobakken, C M Whist, O Høibø, P J Hovde, E Larnøy
Modelling hyphal growth of the bio-incising fungus Physisporinus vitreus
2010 - IRG/WP 10-10710
The white-rot fungus Physisporinus vitreus preferentially degrades the pit membranes of bordered pits in tracheids and subsequently enhances wood permeability. Thus, P. vitreus can be used to improve the uptake of wood preservatives and environmentally-benign wood modification substances. This process can be used to enhance the use and sustainability of native conifer wood species by the wood indu...
M Fuhr, C Stührk, F W M R Schwarze, M Schubert, H J Herrmann
Postia placenta gene expression during growth in furfurylated wood
2010 - IRG/WP 10-10734
Modified wood can provide protection against a range of wood deteriorating organisms. But we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward for the mode of action against wood decaying fungi, including inhibition of action of specific enzymes, but they still need further testing. In this study gene expression of the b...
G Alfredsen, C G Fossdal
Analyzing hyphal growth of the bio incising fungus Physisporinus vitreus with light-, confocal laser scanning- and, Synchrotron X-ray tomographic microscopy
2010 - IRG/WP 10-20438
Norway spruce wood is an important building material for the forest and wood industry. To improve wood permeability and uptake of wood modification substances Physisporinus vitreus is employed as a bioincising agent. In this study wood specimens were incubated with P. vitreus to assess hyphal colonisation and structural alterations of Norway spruce wood. After different incubation periods, semi-th...
C Stührk, M Fuhr, M Schubert, F W M R Schwarze
Onset of mould growth – the effect of climate variability and different geographic locations
2010 - IRG/WP 10-20446
This paper presents a study on how climate conditions at numerous locations in Sweden affect the risk of onset of mould on wood sheltered outdoors. The results indicate that the risk is clearly higher in the south compared to the north of Sweden. These differences are mainly explained by colder and dryer winter periods in the north which is unfavorable for development of mould. The results also sh...
M Häglund, T Isaksson, S Thelandersson
Drying Rates and Mold Growth on Various Building Materials under Different Environmental Conditions
2010 - IRG/WP 10-20454
Mold growth on building materials is a major problem for homeowners. The most suitable method to control mold growth on building materials is to utilize design features, construction tools and practices that prevent moisture accumulation, and keep the wood as dry as possible. In order to achieve this, engineers and homebuilders have to know the effects of various temperature and moisture conditi...
Dian-Qing Yang
Mould growth on wood-based materials – a comparative study
2010 - IRG/WP 10-20455
Ten different wood-based materials - preservative-treated wood, fire retardant-treated wood, modified wood, WPCs and untreated references of pine sapwood and spruce - were tested for mould growth according to SP method 2899 during 42 days at 90% RH and 22°C.
Even though the results must be interpreted carefully, they indicate significant differences in mould resistance between the materials tes...
P Johansson, J Jermer
Comparison of Bifenthrin Formulations for Their Skin and Eye Irritation Potential Using the Pollen Tube Growth Test
2010 - IRG/WP 10-30521
The Pollen Tube Growth Test (PTGT) is an effective screening method for measuring the potential of a chemical formulation to affect living cells. The PTGT has been compared against other types of testing, and it shows a good correlation with, for example, the Draize rabbit eye test and the human skin patch assay. It measures the EC50, which is the effective concentration at which 50% growth is o...
S Millward, P Lobb
Effects of Cunninghamia Lanceolata Heartwood Extracts on the Growth of Wood Decay Fungi
2010 - IRG/WP 10-30527
China-fir (Cunninghamia lanceolata) wood is well known for its good durability. This species is native to China and has been extensive planted there. Mainly, extractives are responsible for the wood resistance to decay fungi. In this paper, the extractives of China-fir heartwood were studied for their effects on various wood decay fungi. Sequential extraction of heartwood in hexane, ethyl acet...
Shujun Li, Jing Wang, Jian Li
Effects of global climate change on mould growth - Interactions of concern
2010 - IRG/WP 10-50270
An evident change in climate the last decades has been recorded, and combined effects of increased CO2, elevated temperature and altered precipitation regimes have been observed to represent a change to the fundamental drivers within ecosystems. Growth of moulds, both in nature and on man-made constructions and objects, will most likely increase due to changes in the climate. The survival, the rep...
L Ross Gobakken
The effects of acetylation level on the growth of Postia placenta
2011 - IRG/WP 11-10751
To understand the defence mechanisms utilized by decay fungi when exposed to different wood protection systems the study of gene expression can give us some answers. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by differen...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
Growth conditions for fungal decay in wooden constructions – practical experience versus literature
2011 - IRG/WP 11-10758
Data regarding moisture and temperature requirements of decay fungi found in literature have been compared to experience from observations in a large number of Norwegian buildings. A number of selected situations are discussed, among those exposure to high relative humidity, exposure to free water and decay in the supposedly adverse conditions on Svalbard. The moisture content in wood has to be at...
M Sand Sivertsen, J Mattsson
The effects of acetylation level on the growth of Postia placenta over 36 weeks
2012 - IRG/WP 12-40589
Genomic sequencing gives us a tool to systematically and rapidly discover novel genes, how their products function in the cell, and explore their interactions. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by different wood...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
Effect of growth rate and radial position on the natural durability of Douglas-fir
2012 - IRG/WP 12-10791
In terms of natural durability, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) fame owns to the favourable characteristics of centuries-old trees harvested in old-growth North American forests. The properties of wood coming from plantations harvested between 50 and 100 years-old are likely to be different. In such stands, plantation density and thinning intensity may have a large impact on the...
C Pollet, J-M Henin, B Jourez, J Hébert
Mould growth on wood-based materials – a simulated in-service study
2012 - IRG/WP 12-20503
Ten different wood-based materials including preservative-treated wood, fire retardant-treated wood, modified wood, WPCs and untreated references of pine sapwood and spruce were placed in three different environments (an attic and two crawl spaces) for a period of 26 months. Mould growth was analysed at five to seven month intervals in an effort to map the growth development. The relative humidit...
G Bok, P Johansson, J Jermer
Influence of a pulsed electric field on the growth of surface fungi
2013 - IRG/WP 13-10795
The colonization of mold and staining fungi are not only an aesthetical problem. Blue stain fungi are able to penetrate paint films. Maintenance of coatings on wood are time consuming and costly. A new approach uses a pulsed electric field (PLEOT) in order to protect wood against surface fungi. This technology is evaluated in non-sterile laboratory conditions on different coated and uncoated Scots...
M Starck, A Treu
Detection of Aureobasidium as the dominant fungus on coated wood
2013 - IRG/WP 13-10796
Wood is often covered with a coating in order to protect the surface. Unwanted dark mold growth on paint covered surfaces in external conditions is a familiar phenomenon. Simple microbial techniques have commonly been used to determine the dominant fungal species present in the discoloured area, for example morphological analysis of microscopic preparations of fungal pieces sticking to an adhesive...
E J Van Nieuwenhuijzen, M F Sailer, R A Samson, O C G Adan
Inhibitory extractives or nutrients? Mould growth on coated heartwood and sapwood of Pinus sylvestris and Gleditsia triacanthos
2013 - IRG/WP 13-10806
Sometimes mould fungi grow over weathered coated sapwood, whereas the coated heartwood is not colonised. Two factors may be responsible for these differences: Either the larger content of nutrients in the sapwood, or the content of biocidal extractives in the heartwood. In this study the factors for the difference in mould growth on coated heartwood and sapwood of Pinus sylvestris (Scots Pine) and...
D Lukowsky, N Buddruhs
Service life evaluation of wood - an engineering approach
2013 - IRG/WP 13-20515
A performance-based service life design format based on climatic exposure on one hand and “biological wood resistance” on the other hand is presented in this paper. Important concepts are the introduction of limit states as well as reliable performance models for the biological processes, by which onset of deterioration can be predicted for arbitrary climate histories. Examples of applications...
S Thelandersson
Method for determining the critical moisture level for mould growth on building materials
2013 - IRG/WP 13-20530
The natural conditions of relative humidity (RH) and temperature (T) in different parts of a building is rarely constant over time. Instead, RH and T often vary cyclically and may pose a risk of mould growth as these conditions are the two key environmental parameters that controls mould growth. Consideration to both humidity and temperature conditions and the susceptibility to mould in a material...
A Ekstrand-Tobin, P Johansson, G Bok
Modelling the risk for mould growth on timber stored outdoors protected from rain
2013 - IRG/WP 13-20529
A mould resistance design (MRD) model was used to calculate the maximum duration of storage of timber outdoors under cover (protected from rain) before the onset of mould growth on the surface of wood. The prediction model is based on laboratory tests performed in constant and cyclic climates and were also confirmed against exposure tests in attics and crawl spaces. The prediction model presented ...
E Frühwald Hansson, S Bardage, S Thelandersson
Assessment of Scots pine sapwood susceptibility to moulds by determination of fungi growth and ergosterol content in infested wood
2014 - IRG/WP 14-20540
The susceptibility of wood to filamentous fungi (mould) attack is determine mainly by laboratory methods with descriptive grading of fungal growth on the surface of the wood specimens. It is a lot of different grading scale of fungi growth, but determination of the size of fungi growth is many times not easy, not clear and often difficult. Although the filamentous fungi are not included to microor...
A Fojutowski, A Koziróg, A Kropacz
A screening of factors that might influence the result of laboratory decay tests
2014 - IRG/WP 14-20548
Laboratory fungal decay tests provide important tools for performance testing of wood materials. But they are also hampered with some uncertainties regarding reproducibility. In addition to variation between fungal species and strains the test conditions are also believed to have some influence. The aim of this study was to screen the effect of a selection of test parameters that might influence t...
E Larnøy, G Alfredsen, A Treu, S Kolstad