scholarly journals Mycotoxins in Crude Building Materials from Water-Damaged Buildings

2000 ◽  
Vol 66 (5) ◽  
pp. 1899-1904 ◽  
Author(s):  
Tapani Tuomi ◽  
Kari Reijula ◽  
Tom Johnsson ◽  
Kaisa Hemminki ◽  
Eeva-Liisa Hintikka ◽  
...  

ABSTRACT We analyzed 79 bulk samples of moldy interior finishes from Finnish buildings with moisture problems for 17 mycotoxins, as well as for fungi that could be isolated using one medium and one set of growth conditions. We found the aflatoxin precursor, sterigmatocystin, in 24% of the samples and trichothecenes in 19% of the samples. Trichothecenes found included satratoxin G or H in five samples; diacetoxyscirpenol in five samples; and 3-acetyl-deoxynivalenol, deoxynivalenol, verrucarol, or T-2-tetraol in an additional five samples. Citrinine was found in three samples. Aspergillus versicolor was present in most sterigmatocystin-containing samples, and Stachybotrys spp. were present in the samples where satratoxins were found. In many cases, however, the presence of fungi thought to produce the mycotoxins was not correlated with the presence of the expected compounds. However, when mycotoxins were found, some toxigenic fungi usually were present, even if the species originally responsible for producing the mycotoxin was not isolated. We conclude that the identification and enumeration of fungal species present in bulk materials are important to verify the severity of mold damage but that chemical analyses are necessary if the goal is to establish the presence of mycotoxins in moldy materials.

2021 ◽  
Vol 2069 (1) ◽  
pp. 012207
Author(s):  
O Ekberg

Abstract A source of indoor malodor in older buildings are chloroanisoles, a methylation from chlorophenols. Chlorophenols were commonly used in wood preservatives 50 years ago which were used to treat construction details exposed to high moisture loads. The methylation process requires a methylator in the form of fungi or bacteria in conjunction with adequate growth conditions for said fungi. The food industry has a history of issues with chloroanisoles contaminating different food items. There have been studies made on fungi species found in the packaging materials or surfaces in proximity and their ability to methylate various chlorophenols. Different species of fungi are present in many places, not only packaging materials but also various building materials. A literature review has been made in this study to compare fungi species able to methylate chlorophenols and their potential occurrence in wooden construction details in buildings. Two species were found to be considered strong methylators and also commonly found in wooden constructions, Aspergillus versicolor and Paecilomyces variotii. The properties of these fungi will be used for future studies of the conditions achievable in wooden constructions where the historic wood preservatives were likely used.


2009 ◽  
Vol 1183 ◽  
Author(s):  
Yôtarõ Nishio ◽  
Kôichirô Ishikawa ◽  
Shinji Kuroda ◽  
Masanori Mitome ◽  
Yoshio Bando

AbstractThe correlation between the Cr aggregation and magnetic properties are investigated for the series of Zn1-xCrxTe films grown by MBE with a systematic variation of growth conditions. Structural and chemical analyses using TEM and energy-dispersive X-ray spectroscopy (EDS) reveal that the crystallinity and the Cr distribution change significantly with the substrate temperature during the MBE growth. For a relatively low average Cr content x ≅ 0.05, it is found that the crystal quality is improved with the increase of the substrate temperature. For a higher average Cr content x ≅ 0.2, the shape of Cr-rich regions is transformed from isolated clusters into one-dimensional nanocolumns with the increase of the substrate temperature. The direction of the nanocolumn formation changes depending on the crystallographic orientation of the grown films. In the magnetization measurements, anisotropic magnetic properties are observed in the films in which Cr-rich nanocolumns are formed in the vertical direction, depending on the relation between the direction of the nanocolumns and the applied magnetic fields.


1927 ◽  
Vol 5 (1) ◽  
pp. 27-42
Author(s):  
JOSEPH NEEDHAM

1. The percentage growth-rate curves for carbohydrate and protein in the chick enbryo have been determined and compared with those already in the literature for the percentage growth-rates of the whole embryo, the dry substance, the fat, and the calorific value. 2. The composition of the embryo in gm. per cent, of dry weight has been calculated and an ontogenetic succession of carbohydrate, protein, and fat, has been brought to light. These three cell-constituents are at their highest levels in the embryo at 4, 11 and 20 days of incubation respectively. This may be correlated with the succession of maximum intensities of combustion, which have the same order (about 5,8.5 and about 18 days). 3. By comparing the curves for absorption-intensity with those representing the constitution of the embryo, it has been possible to trace the passage of building-materials from the yolk and white into the embryo and to analyse still further the movements of the fat and carbohydrate fractions. 4. The concentration of the carbohydrate and protein in the water of the embryonic body has been calculated and compared with a curve already in existence for fat. 5. The curve for intensity of absorption of total foodstuff has been calculated from the results of chemical analyses. It agrees as well as can be expected at present with that calculated from the oxygen consumption and the increase of dry substance in the embryo. 6. The ratio Carbohydrate : Protein decreases during development, thus falling into line with the ratios Water : Solid, Inorganic Substance : Organic Substance, and Protein : Fat. Certain speculations arising out of these facts are discussed. 7. There is a relation of simultaneity between the combustion of carbohydrate, protein, and fat, and the part these types of molecule play in the constitution of the whole embryo.


2016 ◽  
Vol 82 (8) ◽  
pp. 2479-2493 ◽  
Author(s):  
Anne Mette Madsen ◽  
Søren T. Larsen ◽  
Ismo K. Koponen ◽  
Kirsten I. Kling ◽  
Afnan Barooni ◽  
...  

ABSTRACTIn the indoor environment, people are exposed to several fungal species. Evident dampness is associated with increased respiratory symptoms. To examine the immune responses associated with fungal exposure, mice are often exposed to a single species grown on an agar medium. The aim of this study was to develop an inhalation exposure system to be able to examine responses in mice exposed to mixed fungal species aerosolized from fungus-infested building materials. Indoor airborne fungi were sampled and cultivated on gypsum boards. Aerosols were characterized and compared with aerosols in homes. Aerosols containing 107CFU of fungi/m3air were generated repeatedly from fungus-infested gypsum boards in a mouse exposure chamber. Aerosols containedAspergillus nidulans,Aspergillus niger,Aspergillus ustus,Aspergillus versicolor,Chaetomium globosum,Cladosporiumherbarum,Penicillium brevicompactum,Penicillium camemberti,Penicillium chrysogenum,Penicillium commune,Penicillium glabrum,Penicillium olsonii,Penicillium rugulosum,Stachybotrys chartarum, andWallemia sebi. They were all among the most abundant airborne species identified in 28 homes. Nine species from gypsum boards and 11 species in the homes are associated with water damage. Most fungi were present as single spores, but chains and clusters of different species and fragments were also present. The variation in exposure level during the 60 min of aerosol generation was similar to the variation measured in homes. Through aerosolization of fungi from the indoor environment, cultured on gypsum boards, it was possible to generate realistic aerosols in terms of species composition, concentration, and particle sizes. The inhalation-exposure system can be used to study responses to indoor fungi associated with water damage and the importance of fungal species composition.


1998 ◽  
Vol 64 (8) ◽  
pp. 2914-2919 ◽  
Author(s):  
Anne Korpi ◽  
Anna-Liisa Pasanen ◽  
Pertti Pasanen

ABSTRACT We examined growth of mixed microbial cultures (13 fungal species and one actinomycete species) and production of volatile compounds (VOCs) in typical building materials in outside walls, separating walls, and bathroom floors at various relative humidities (RHs) of air. Air samples from incubation chambers were adsorbed on Tenax TA and dinitrophenylhydrazine cartridges and were analyzed by thermal desorption-gas chromatography and high-performance liquid chromatography, respectively. Metabolic activity was measured by determining CO2 production, and microbial concentrations were determined by a dilution plate method. At 80 to 82% RH, CO2 production did not indicate that microbial activity occurred, and only 10% of the spores germinated, while slight increases in the concentrations of some VOCs were detected. All of the parameters showed that microbial activity occurred at 90 to 99% RH. The microbiological analyses revealed weak microbial growth even under drying conditions (32 to 33% RH). The main VOCs produced on the building materials studied were 3-methyl-1-butanol, 1-pentanol, 1-hexanol, and 1-octen-3-ol. In some cases fungal growth decreased aldehyde emissions. We found that various VOCs accompany microbial activity but that no single VOC is a reliable indicator of biocontamination in building materials.


Viruses ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 759 ◽  
Author(s):  
Jasmine L. Madrigal ◽  
Sutonuka Bhar ◽  
Samantha Hackett ◽  
Haley Engelken ◽  
Ross Joseph ◽  
...  

The presence of commensal bacteria enhances both acute and persistent infection of murine noroviruses. For several enteric viral pathogens, mechanisms by which these bacteria enhance infection involve direct interactions between the virus and bacteria. While it has been demonstrated that human noroviruses bind to a variety of commensal bacteria, it is not known if this is also true for murine noroviruses. The goal of this study was to characterize interactions between murine noroviruses and commensal bacteria and determine the impact of bacterial growth conditions, incubation temperature and time, on murine norovirus attachment to microbes that comprise the mammalian microbiome. We show that murine noroviruses bind directly to commensal bacteria and show similar patterns of attachment as human norovirus VLPs examined under the same conditions. Furthermore, while binding levels are not impacted by the growth phase of the bacteria, they do change with time and incubation temperature. We also found that murine norovirus can bind to a commensal fungal species, Candida albicans.


Author(s):  
O. N. Akoma ◽  
C. C. Ezeh ◽  
K. I. Chukwudozie ◽  
C. C. Iwuchukwu ◽  
D. O. Apeh

The maize value chain in the Kogi State and most parts of the country from where maize is purchased into the State lacks mechanisms that ensure grain quality and safety. Against the above-backdrop, this study was designed to evaluate toxigenic fungi and associated mycotoxins in maize produced within different agro-zones of Kogi State. Harvested and stored maize seeds under different storage conditions were collected from three different zones (Zone B Bassa, Zone C Lokoja, and Zone D Idah) and cultured. Different fungal species were isolated by culturing using the spread plate technique on potato dextrose agar (PDA) and identified microscopically. Mycotoxin production by isolated fungi was subsequently evaluated for Deoxynivalenol (DON) contamination using the High-Performance Liquid Chromatography technique (HPLC). The outcome of the study was statistically analysed using simple frequencies and percentages. Aspergillus spp. and Penicillium spp. were the fungi found to be associated with the stored seeds in Kogi, while Fusarium spp. Mucor spp. and Rhizopus spp. were the field fungi identified. Of the thirteen samples collected, the most common genera were Aspergillus (isolated from 41.67% of the evaluated samples), Fusarium (27%) and in a lesser extent Rhizopus spp. (8.33%). The result also shows DON was detected in 92.3% of the stored maize samples, making it one of the widespread mycotoxin contaminants of maize grain. Implications of this study for human and animal health and economic development were discussed and appropriate recommendations made especially for adoption of proper storage technology among small-scale farmers for improved maize quality and safety.


Author(s):  
Doaa Montaser Ahmed Khali ◽  
Mohamed Salah Massoud ◽  
Soad A El-Zayat ◽  
Magdi A El-Sayed

Background and Objectives: The use of endophytic fungi for management of phenol residue in paper and pulp industries has been shown as cost-effective and eco-friendly approach. In this study, isolation of endophytic fungi from roots, stems, and leaves of Hibiscus sabdariffa was conducted. Additionally, the isolated fungi were examined for their ability to degrade phenol and its derivatives in paper and pulp industrial samples, using different growth conditions. Materials and Methods: Out of 35 isolated endophyitc fungi, 31 were examined for their phenol biodegradation capacity using Czapek Dox broth medium containing Catechol and Resorcinol as a sole carbon source at final concentrations of 0.4, 0.6 and 0.8%. Results: A total of 35 fungal species belonging to 18 fungal genera were isolated and identified from different parts of H. sabdariffa plants. All strains have the capability for degrading phenol and their derivatives with variable extents. The optimum condition of degrading phenol in paper and pulp effluent samples by Fusarium poae11r7 were at pH 3-5, temperature at 28-35°C, good agitation speed at no agitation and 100 rpm. Conclusion: All endophytic fungal species can utilize phenol and its derivatives as a carbon source and be the potential to degrade phenol in industrial contaminants.


2021 ◽  
Author(s):  
Paris Chakravarty

The interactions between six commonly occurring fungal species in damp or water-damaged houses in southern California were studied. These fungal species were Alternaria alternata, Aspergillus niger, Chaetomium globosum, Cladosporium herbarum, Penicillium chrysogenum and Stachybotrys chartarum. In the damp building materials, S. chartarum was found to be associated with A. niger, C. globosum, and P. chrysogenum but not with A. alternata and C. herbarum. Stachybotrys chartarum showed strong antagonistic effect against A. alternata and C. herbarum and significantly inhibited in vitro growth of A. alternata and C. herbarum but had no effect on A. niger, C. globosum, and P. chrysogenum. Two trichothecenes, produced by S. chartarum, trichodermin and trichodermol, significantly inhibited spore germination and in vitro growth of A. alternata and C. herbarum but had no effect on A. niger, C. globosum, P. chrysogenum and S. chartarum. In the damp building materials (drywall, ceiling tile, and oak woods), S. chartarum significantly inhibited the growth of A. alternata and C. herbarum and had no effect on the growth and colonization of A. niger, C. globosum, P. chrysogenum in these substrata.


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