Search Results (15)

Spalted wood is a natural material characterized by distinctive colors and patterns from wood decay fungi as they digest their substrate and leave behind colored secretions. As an art form, spalted wood was used heavily in western Europe from the 1400s–1600s; however, its use in other parts of the world remains deeply understudied, even in cultures where wood played a dominant social role. The use of spalted wood in China, in particular, is unknown, despite a growing interest by Chinese researchers in modern spalting practices and their potential commercial value. This study systematically reviews the potential historic use, current artistic value, environmental significance, and future application prospects of spalted wood for a Chinese market. By integrating historical records, modern scientific research, and insights from traditional Chinese woodworking, the study provides a comprehensive analysis of the aesthetic and functional value of spalted wood for Chinese markets. The findings indicate that the random and non-reproducible nature of spalted wood imbues it with exceptional artistic appeal and collectability, which has a strong potential to appeal to Chinese furniture design, decorative arts, and high-end interior applications. Furthermore, spalted wood demonstrates considerable potential for resource recycling by turning otherwise non-commercial, pale, white woods into higher value options—a phenomenon that has been studied across Europe and North America. In China, this has the potential to reduce wood waste and advance ecological design. However, challenges remain in fungal infection control, processing techniques, and market adoption. With ongoing advancements in biotechnology and manufacturing processes, spalted wood is poised to gain greater recognition in Chinese art, design, and cultural innovation while also contributing to green manufacturing and sustainable development. Full article

Tropical montane and premontane forests are diverse, including fungi. However, little is known about spalting fungi (decay fungi that change the color of wood) in tropical regions despite the economic importance they could bring by enhancing wood esthetics. To increase the knowledge of the diversity of spalting fungi, a sampling of fallen logs, branches (exposing xylem to identify potential pigmenting and zone line-producing fungi), and fruiting bodies (on wood) was conducted in the premontane moist forest in the district of San Ramon, Junín, Peru. The fungi were collected, cultured, isolated, and sequenced. Also, the identified species were used in a novel test to confirm they were producing spalting on Guazuma crinita. The species found belong to the Ascomycota orders Xylariales and Diaporthales and the Basidiomycota orders Agaricales, Polyporales, and Russulales. The fungi collected produced bleaching, different colors of zone lines, and pigmentation in laboratory conditions. The results increase the database of spalted fungi in Peru, and the test used in this research could be the basis for a quick test to identify spalting fungi. Full article

Wood decayed and colored by fungi, colloquially known as ‘spalted wood’, has been a source of art and folklore across numerous cultures. From intarsia and marquetry in Italy and Germany to woodturning in the U.S. and carving and mythology in Chile, the uses of, and stories about, spalted wood are explored, as well as how those have shaped their surrounding cultures as well as modern science. Full article

UV-light degradation of wood is one of the top reasons for consumer replacement of outdoor wooden structures. This type of degradation is seldom mechanical, and is instead often motivated by loss of aesthetics (graying). There are numerous commercial products available on the market that deal with this loss of color, many of which contain added pigments to ‘rejuvenate’ or ‘revitalize’ greyed wood. These pigments are almost uniformly synthetic. In contrast, pigments from wood decay fungi (spalting), which have been used in woodworking since the 1400s (intarsia), have remarkable optical (UV-light resistance) properties due to their naphthoquinonic configuration. In recent years the pigments made from these fungi have been extracted and tested across numerous substrates, from solar cells to textile dyes. In this work, researchers extracted pigments from Scytalidium cuboideum (red pigmentation) and Chlorociboria aeruginosa (blue-green pigmentation), solubilized the pigments in raw linseed oil, and tested the resulting solution on samples of Douglas-fir (Pseudotsuga menziesii) and western white pine (Pinus monticola). These mixtures were compared against a ‘stain and coat’ treatment (utilizing an aniline stain and coated with raw linseed oil), raw linseed oil, and untreated wood. The wood samples were then placed in an accelerated weathering machine (Q-UV) following the ASTM G154 standard, for 500 and 1000 h. The results showed that while no visible color change occurred to the wood when the pigmented oil was applied, the red pigment oil significantly lowered the coating degradation for both wood types at an exposure of 500 h. The results show the potential applications for fungal pigments in the wood coating industry, as it offers an increased coating service life. As there is a shift to renewable products, the pigments from wood decay fungi show potential as additives for wood coatings. Full article

Most of the research related to Peruvian Amazon fungi is focused on edible mushrooms and pathogens. Other important fungi, such as the spalting type (decay fungi that pigment wood internally), are not broadly studied, as most of them do not produce fruiting bodies and can be difficult to locate. Spalting fungi, however, are of broad economic importance due to their ability to produce pigments that enhance wood aesthetics, resulting in an increased economic value. In order to begin understanding the diversity of spalting fungi within certain regions of the Amazon, a sampling of downed trees and branches (through the opening of the xylem to identify potential pigmenting and zone line producing fungi) was done in the district of Las Piedras, Madre de Dios, Peru. Fungi suspected of causing internal pigment and zone lines were collected, cultured, isolated, and sequenced. The species found belonged to the orders Helotiales, Xylariales, Hypocreales, Russulales, Polyporales, Botryosphaeriales and two specimens of the class Leotiomycetes. The fungi collected produced pigments or zone lines in wild conditions and all of them were capable of wood decomposition. Interestingly, these are the same orders and genera as North American spalting fungi, which may indicate a correlation within species that pigment wood. The results obtained start a specific database of spalted fungi in the Amazon and, with it, help support an effort to increase the forest value of ecosystems primarily used for a few high-valued tree species. Full article

Identification of effective natural dyes with the potential for low environmental impact has been a recent focus of the textile industry. Pigments derived from spalting fungi have previously shown promise as textile dyes; however, their use has required numerous organic solvents with human health implications. This research explored the possibility of using linseed oil as a carrier for the pigment from Scytalidium cuboideum as a textile dye. Colored linseed oil effectively dyed a range of fabrics, with natural fibers showing better coloration. Scanning electron microscopy (SEM) revealed a pigment film over the fabric surface. While mechanical testing showed no strength loss in treated fabric, colorfastness tests showed significant changes in color in response to laundering and bleach exposure with variable effects across fabric varieties. SEM investigation confirmed differences in pigmented oil layer loss and showed variation in pigment crystal formation between fabric varieties. Heating of the pigmented oil layer was found to result in a bright, shiny fabric surface, which may have potential for naturally weatherproof garments. Full article

Textile inkjet printing is an increasingly popular process in the textile industry, as it allows for the incorporation of complex and detailed patterns onto fabrics, as well as the production of small and medium volumes of printed text. Unfortunately, most of the dyes used by the textile industry come from synthetic and/or non-renewable sources. There has been some research to date in using fungal pigments from wood rotting fungi (‘spalting’ fungi) as textile dyes, however these have never been tested in inkjet printing. Of particular interest is the red crystallizing pigment from Scytalidium cuboideum, which has previously shown exceptional stability on textiles. To test this pigment in an inkjet setting, cotton and polyester fabrics were printed with three different ink formulations involving the red pigment: hexadecyltrimethylammonium bromide (CTAB), ethanol, and acetone. The CTAB and ethanol-based ink formulations formed a ‘mesh-like’ structure on the surface of the cotton and polyester fibers, and turned the fabric purple. Acetone formulas formed crystal structures on the surface and turned the fabric red. These results show promise for turning the red pigment of S. cuboideum into an environmentally friendly, inkjet colorant, however further research is required to evaluate the crocking and explain the crystallization differences between inks. Full article

Spalted wood, wood colored by fungi, has been popular in woodcraft for centuries. Most spalted wood, however, is found in an advanced state of decay and cannot be utilized. This project describes the use of viscoelastic thermal compression (VTC) to investigate the potential increase in spalted woods’ strength and stiffness, with the main objective of converting so-called “punky” wood into the top layer (veneer layer or “coating”) on commercial flooring. Spalted Acer macrophyllum logs were cut into veneers of size 7 mm × 7.8 cm × 25 cm and were then VTC-treated at 150 °C and 50 psi for 11.5 min. Statistical analysis on the mixed linear models showed significant increases for both the density and hardness of spalted wood (p < 0.0001). Density and Brinell hardness increased by 84% and 209%, respectively. FTIR analysis revealed that the wood polymers present in spalted wood were more susceptible to degradation imposed by the heat of the VTC treatment compared to sound wood. Additionally, the color analysis of the wood specimens showed statistically significant changes in color after the VTC treatment (p < 0.0001), which turned the wood surface darker and redder. The use of the VTC technology to transform spalted wood into wood flooring is viable. However, when exposed to moisture, the VTC-treated spalted wood showed a high percentage of set recovery (78%), which was significantly different from the set recovery of the sound wood (71%, p = 0.004). Successful use of VTC-treated spalted wood for flooring will require addressing of the swelling issue, and additional studies are needed to fully characterize the anatomy of VTC-treated spalted wood. Full article

Pigments from wood-decay fungi (specifically spalting fungi) have a long history of use in wood art, and have become relevant in modern science due to their longevity and colorfastness. They are presently under investigation as colorants for wood, bamboo, oils, paints and textiles. Major hurdles to their commercialization have been color repeatability (in that the same strain of the same species of fungus may produce different colors over time), and the binding of the pigments to glass storage containers. This is persistent as they do not naturally exist in a loose form. Due to these issues, the ‘standard’ color for each was historically determined not by the amount of pigment, but by the color in a solution of dichloromethane (DCM), using the CIE L*a*b colorspace. This method of standardization severely limited the use of these pigments in industrial applications, as without a dry form, standard methodologies for repeatable color processing into other materials could not be easily implemented. Recent studies have developed a method to crystalize the red pigment from Scytalidium cuboideum (Sacc. & Ellis) Sigler & Kang, producing a highly pure (99%) solid crystal named ‘Dramada’. Herein a method is detailed to compare the molarity of this crystallized pigment to variations in the color, to determine a color saturation curve (by weight) for the pigment from S. cuboideum in DCM and acetone. The molarities for this experiment ranged from 0.024 mM to 19 mM. Each molarity was color read and assigned a CIEL*a*b* value. The results showed that there was a correlation between the molarity and color difference, with the maximum red color occurring between 0.73 mM and 7.3 mM in DCM and between 0.97 mM to 0.73 mM in acetone. Extremely low molarities of pigment produced strong coloration in the solvent, and changes in molarity significantly affected the color of the solution. Having a saturation and color curve for the crystal ‘Dramada’ from S. cuboideum will allow for the reliable production of distinct colors from a known quantity (by weight) of pigment, erasing the final hurdle towards commercial development of the crystallized pigment from S. cuboideum as an industrial dyestuff. Full article

Intarsia was an art form popular between the 15th–18th centuries that used wood pigmented by spalting fungi to create detailed landscapes, portraits, and other imagery. These fungi are still used today in art but are also finding relevance in material science as elements of solar cells, textile dyes, and paint colorants. Here we show that the spalting fungus Scytalidium cuboideum (Sacc. and Ellis) Sigler and Kang produces a red/pink pigment that forms two distinct colors of crystals (red and orange)—a very rare occurrence. In addition, a second structure of the crystal is proved through nuclear magnetic resonance (NMR). This is only the second instance of a stable, naphthoquinone crystal produced by a fungus. Its discovery is particularly valuable for solar cell development, as crystalline materials have a higher electrical conductivity. Other fungi in this order have shown strong potential as thin films for solar cells. Full article

The use of both naturally occurring and synthetic pigmented wood has been prevalent in woodcraft for centuries. Modern manifestations generally involve either woodworkers’ aniline dyes, or pigments derived from a special class of fungi known as spalting fungi. While fungal pigments are more renewable than anilines and pose less of an environmental risk, the carrier required for these pigments—dichloromethane (DCM)—is both problematic for humans and tends to only deposit the pigments on the surface of wood instead of evenly within the material. Internal coloration of wood is key to adoption of a pigmenting system by woodworkers. To address this issue, five solvents that had moderate solubility with the pigments extracted from Chlorociboria aeruginosa and Scytalidium cuboideum were identified, in the hopes that a reduction in solubility would result in a greater amount of the pigment deposited inside the wood. Of the tested solvents, acetonitrile was found to produce the highest internal color in ash, Douglas-fir, madrone, mountain hemlock, Port-Orford cedar, Pacific silver fir, red alder and sugar maple. While these carrier solvents are not ideal for extracting the pigments from the fungi, acetonitrile in particular does appear to allow for more pigment to be deposited within wood. The use of acetonitrile over DCM offers new opportunities for possible industrial spalting applications, in which larger pieces of wood could be uniformly pigmented and sold to the end user in larger quantities than are currently available with spalted wood. Full article

Opportunities for alternatives to synthetic textile dyes are of increasing importance as the world looks to minimize its ecological footprint. Fungal pigments within a unique class of wood-rotting (“spalting”) fungi have been under investigation for several years as a possible solution, and have been shown to be ideally suited as textile dye coatings. Unfortunately, the solvent currently in use for these colorants is dichloromethane (DCM), which is an environmental problem as well as a potential human carcinogen. Recently, researchers found that the pigments from Chlorociboria species, Scytalidium cuboideum, and Scytalidium ganodermophthorum could be carried in some natural oils, which opened up a potential method of delivering pigments onto a host of substrates without utilizing DCM. Although the pigments can be carried in oil, no testing has thus far been conducted as to how oil affects the binding properties of the pigments onto textiles, or how the oil might affect the pigments directly. In this paper, the pigments produced by three well-known wood-rotting fungi were carried in raw linseed oil and applied to cotton, polyester, and nylon. Only the red pigment produced visible color change on the textiles. Cotton and polyester showed the greatest color change when the pigments were dripped onto the fabric, while polyester showed the most color when the textile was submerged into the pigment solution. Unfortunately, the colors faded significantly for all the tests except the saturation test. This indicates that while natural oils may be excellent, nontoxic alternative carriers for DCM, the pigments are not stable within them except at very high concentrations, and therefore natural oils—including raw linseed oil—are not ideal for use in conjunction with these pigments. Full article

Pigments that are currently available in the market usually come from synthetic sources, or, if natural, often need mordants to bind to the target substrate. Recent research on the fungal pigment extracts from Scytalidium cuboideum, Scytalidium ganodermophthorum, Chlorociboria aeruginosa, and Chlorociboria aeruginascens have been shown to successfully dye materials, like wood, bamboo, and textiles, however, there is no information about their binding mechanisms. Due to this, a microscopic study was performed to provide information to future manufacturers interested in these pigments. The results of this study show that S. ganodermophthorum and C. aeruginosa form an amorphous layer on substrates, while S. cuboideum forms crystal-like structures. The attachment and morphology indicate that there might be different chemical and physical interactions between the extracted pigments and the materials. This possibility can explain the high resistance of the pigments to UV light and color fastness that makes them competitive against synthetic pigments. These properties make these pigments a viable option for an industry that demands natural pigments with the properties of the synthetic ones. Full article

Fungal pigments, specifically those generated from spalting fungi, are being developed for broader use in the wood and textile industry, and due to their coloration properties, may also be useful as aesthetic bamboo dyes. This paper evaluates the potential use of fungal pigments in bamboo (Phyllostachys spp.), and compares the difference between natural spalting and the direct application of extracted fungal pigments of three known spalting fungi: Scytalidium cuboideum, Scytalidium ganodermophthorum, and Chlorociboria aeruginosa. Bamboo was significantly spalted by S. cuboideum under live inoculation, while the other two fungi did not colonize. For the direct application of fungal pigments, bamboo did not develop internal pigmentation with any pigment, but did develop visible surface color for S. cuboideium and C. aeruginosa. Light microscopy and scanning electron microscopy confirmed the presence of hyphae in bamboo vessels and parenchyma. An HPLC analysis for simple sugars showed the presence of glucose but no sucrose. Results indicate that the extracted pigments of the aforementioned fungi are ideal for the surface treatment of bamboo, while only direct inoculation of S. cuboideum is appropriate for internal coloration. Full article

The extracellular colorants produced by Chlorociboria aeruginosa, Scytalidium cuboideum, and Scytalidium ganodermophthorum, three commonly utilized spalting fungi, were tested against a standard woodworker’s aniline dye to determine if the fungal colorants could be utilized in an effort to find a naturally occurring replacement for the synthetic dye. Fungal colorants were delivered in two methods within a pressure treater—the first through solubilization of extracted colorants in dichloromethane, and the second via liquid culture consisting of water, malt, and the actively growing fungus. Visual external evaluation of the wood test blocks showed complete surface coloration of all wood species with all colorants, with the exception of the green colorant (xylindein) from C. aeruginosa in liquid culture, which did not produce a visible surface color change. The highest changes in external color came from noble fir, lodgepole pine, port orford cedar and sugar maple with aniline dye, cottonwood with the yellow colorant in liquid culture, lodgepole pine with the red colorant in liquid culture, red alder and Oregon maple with the green colorant in dichloromethane, and sugar maple and port orford cedar with the yellow colorant in dichloromethane. The aniline dye was superior to the fungal colorants in terms of internal coloration, although none of the tested compounds were able to completely visually color the inside of the test blocks. Full article