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Historic wooden structures in Polar Regions are being adversely affected by decay fungi and a warming climate will likely accelerate degradation. Fort Conger and the Peary Huts at Lady Franklin Bay in northern Ellesmere Island are important international heritage sites associated with early exploration in the High Arctic. Fort Conger, built by Adolphus Greely and expedition members during the First International Polar Year in 1881, was dismantled and used by Robert Peary and his expedition crew in the early 1900's to build several smaller shelters. These historic structures remain at the site but are deteriorating. This investigation examines the fungi associated with wood decay in the historic woods. Soft rot was observed in all 125 wood samples obtained from the site. The major taxa found associated with the decayed wood were Coniochaeta (18%), Phoma (13%) Cadophora (12%), Graphium (9%), and Penicillium (9%) as well as many other Ascomycota that are known to cause soft rot in wood. Micromorphological observations using scanning electron microscopy of historic wooden timbers that were in ground contact revealed advanced stages of type I soft rot. No wood destroying Basidiomycota were found. Identification of the fungi associated with decay in these historic woods is a first step to better understand the unusual decomposition processes underway in this extreme environment and will aid future research to help control decay and preserve this important cultural heritage., Competing Interests: The authors have declared that no competing interests exist.

Abydos is a large, complex archaeological site located approximately 500 km south of Cairo in Upper Egypt. The site has served as a cemetery for thousands of years and is where most of the Early Dynastic royal tombs are located. North Abydos includes the Middle Cemetery and the North Cemetery, which are separated from each other by a wadi. The Middle Cemetery was the burial ground for important Sixth Dynasty (2407-2260 BC) officials and over time for thousands of elite and non-elite individuals as well. Excavations at the core area of the Old Kingdom mortuary landscape have revealed many culturally important wooden objects but these are often found with extensive deterioration that can compromise their preservation. The objectives of this study were to characterize the biodegradation that has taken place in excavated wooden objects, elucidate the type of wood degradation present, obtain information on soil properties at the site and identify fungi currently associated with the wood and soils. Light and scanning electron microscopy studies were used to observe the micromorphological characteristics of the wood, and culturing on different media was done to isolate fungi. Identification of the fungi was done by examining morphological characteristics and extracting rDNA from pure cultures and sequencing the ITS region. Wooden objects, made from Cedrus, Juniperus and Acacia as well as several unidentified hardwoods, were found with extensive degradation and were exceedingly fragile. Termite damage was evident and frass from the subterranean termites along with sand particles were present in most woods. Evidence of soft rot attack was found in sections of wood that remained. Fungi isolated from wood and soils were identified as species of Aspergillus, Chaetomium, Cladosporium, Fusarium, Penicillium, Stemphylium Talaromyces and Trichoderma. Results provide important information on the current condition of the wood and gives insights to the identity of the fungi in wood and soils at the site. These results provide needed information to help develop conservation plans to preserve these degraded and fragile wooden objects., Competing Interests: The authors have declared that no competing interests exist.

Wood-decaying fungi tend to have characteristic substrate ranges that partly define their ecological niche. Fomitopsis pinicola is a brown rot species of Polyporales that is reported on 82 species of softwoods and 42 species of hardwoods. We analyzed the gene expression levels and RNA editing profiles of F. pinicola from submerged cultures with ground wood powder (sampled at 5 days) or solid wood wafers (sampled at 10 and 30 days), using aspen, pine, and spruce substrates (aspen was used only in submerged cultures). Fomitopsis pinicola expressed similar sets of wood-degrading enzymes typical of brown rot fungi across all culture conditions and time points. Nevertheless, differential gene expression and RNA editing were observed across all pairwise comparisons of substrates and time points. Genes exhibiting differential expression and RNA editing encode diverse enzymes with known or potential function in brown rot decay, including laccase, benzoquinone reductase, aryl alcohol oxidase, cytochrome P450s, and various glycoside hydrolases. There was no overlap between differentially expressed and differentially edited genes, suggesting that these may provide F. pinicola with independent mechanisms for responding to different conditions. Comparing transcriptomes from submerged cultures and wood wafers, we found that culture conditions had a greater impact on global expression profiles than substrate wood species. In contrast, the suites of genes subject to RNA editing were much less affected by culture conditions. These findings highlight the need for standardization of culture conditions in studies of gene expression in wood-decaying fungi. IMPORTANCE All species of wood-decaying fungi occur on a characteristic range of substrates (host plants), which may be broad or narrow. Understanding the mechanisms that enable fungi to grow on particular substrates is important for both fungal ecology and applied uses of different feedstocks in industrial processes. We grew the wood-decaying polypore Fomitopsis pinicola on three different wood species, aspen, pine, and spruce, under various culture conditions. We examined both gene expression (transcription levels) and RNA editing (posttranscriptional modification of RNA, which can potentially yield different proteins from the same gene). We found that F. pinicola is able to modify both gene expression and RNA editing profiles across different substrate species and culture conditions. Many of the genes involved encode enzymes with known or predicted functions in wood decay. This work provides clues to how wood-decaying fungi may adjust their arsenal of decay enzymes to accommodate different host substrates., (Copyright © 2018 American Society for Microbiology.)

The laccate (shiny or varnished) Ganoderma contain fungi that are important wood decay fungi of living trees and decomposers of woody debris. They are also an important group of fungi for their degradative enzymes and bioprocessing potential. Laboratory decay microcosms (LDMs) were used to study the relative decay ability of G anoderma curtisii, Ganoderma meredithiae, Ganoderma sessile, and G anoderma zonatum, which are four commonly encountered Ganoderma species in the U.S., across four wood types (Pinus taeda, Quercus nigra, Q uercus virginiana, and Sabal palmetto). Generally, all Ganoderma species were able to decay all types of wood tested despite not being associated with only certain wood types in nature. G. sessile, on average caused the most decay across all wood types. Among the wood types tested, water oak (Q. nigra) had the most mass loss by all species of Ganoderma. Scanning electron microscopy was used to assess micromorphological decay patterns across all treatments. All Ganoderma species simultaneously decayed wood cells of all wood types demonstrating their ability to attack all cell wall components. However, G. zonatum caused selective delignification in some sclerenchyma fibers of the vascular bundles in palm (S. palmetto) as well as in fibers of water oak. In addition, G. zonatum hyphae penetrated fibers of palm and oak wood causing an unusual decay not often observed in basidiomycetes resulting in cavity formation in secondary walls. Cavities within the secondary walls of fibers gradually expanded and coalesced resulting in degradation of the S2 layer. Differences in colony growth rates were observed when Ganoderma species were grown on medium amended with water soluble sapwood extracts from each wood type. G. meredithiae had enhanced growth on all media amended with sapwood extracts, while G. curtisii, G. sessile and G. zonatum had slower growth on loblolly pine extract amended medium., (Copyright © 2018 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

Recent investigations of filamentous fungi isolated from coastal areas and historic wooden structures in the Ross Sea and Peninsula regions of Antarctica have identified the genus Cadophora as one of the most abundant fungal groups, comprising more than 30% of culturable fungi at some locations. A methanol extract of Cadophora luteo-olivacea grown on rice media yielded the known polyketides spiciferone A, spiciferol A, dihydrospiciferone A and dihydrospiciferol A. Additionally, nine related hexaketides were identified, including spiciferone F, two isomers of the known fungal bicyclic ketal colomitide B, cadopherones A-D, similin C, and spicifernin B. HPLC and NMR analysis of extracts from other isolates collected in Antarctica suggests that the spiciferones and colomitides are produced by at least two different Cadophora species. Preliminary precursor feeding experiments provided evidence for the biosynthesis of the colomitides from the same polyketide pathway as the spiciferone phytotoxins, possibly via a type III polyketide synthase (PKS). None of the compounds were active in a panel of anti-bacterial, anti-fungal, and mammalian cytotoxicity assays., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Very little is known about fungal diversity in Antarctica as compared to other biomes and how these important organisms function in this unusual ecosystem. Perhaps one of the most unusual ecosystems is that of Deception Island; an active volcanic island part of the South Shetland Islands of the Antarctic Peninsula. Here we describe the fungal diversity associated with historic wood from structures on the island, which reveals a diverse fungal assemblage of known wood decay fungi as well as the discovery of undescribed species. The major group of wood decay fungi identified were species of Cadophora and as shown in previous studies in other geographic regions of Antarctica, they caused a soft-rot type of decay in the introduced woods. Additionally, unlike other areas of Antarctica that have been studied, filamentous basidiomycetes (Hypochniciellum spp. and Pholiota spp.) were also identified that have different modes of degradation including brown and white rot. Matches of fungal sequences to known species in temperate regions likely introduced on building materials indicates human influences and volcanic activity have greatly impacted fungal diversity. Lahars (mudslides from volcanic activity) have partially buried many of the structures and the buried environment as well as the moist, warm soils provided conditions conducive for fungal growth that are not found in other regions of Antarctica. The diverse assemblage of decay fungi and different forms of wood decomposition add to the difficulty of conserving wooden structures at these important polar heritage sites., (Copyright © 2016 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

Wood decay mechanisms in Agaricomycotina have been traditionally separated in two categories termed white and brown rot. Recently the accuracy of such a dichotomy has been questioned. Here, we present the genome sequences of the white-rot fungus Cylindrobasidium torrendii and the brown-rot fungus Fistulina hepatica both members of Agaricales, combining comparative genomics and wood decay experiments. C. torrendii is closely related to the white-rot root pathogen Armillaria mellea, while F. hepatica is related to Schizophyllum commune, which has been reported to cause white rot. Our results suggest that C. torrendii and S. commune are intermediate between white-rot and brown-rot fungi, but at the same time they show characteristics of decay that resembles soft rot. Both species cause weak wood decay and degrade all wood components but leave the middle lamella intact. Their gene content related to lignin degradation is reduced, similar to brown-rot fungi, but both have maintained a rich array of genes related to carbohydrate degradation, similar to white-rot fungi. These characteristics appear to have evolved from white-rot ancestors with stronger ligninolytic ability. F. hepatica shows characteristics of brown rot both in terms of wood decay genes found in its genome and the decay that it causes. However, genes related to cellulose degradation are still present, which is a plesiomorphic characteristic shared with its white-rot ancestors. Four wood degradation-related genes, homologs of which are frequently lost in brown-rot fungi, show signs of pseudogenization in the genome of F. hepatica. These results suggest that transition toward a brown-rot lifestyle could be an ongoing process in F. hepatica. Our results reinforce the idea that wood decay mechanisms are more diverse than initially thought and that the dichotomous separation of wood decay mechanisms in Agaricomycotina into white rot and brown rot should be revisited., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Collectively classified as white-rot fungi, certain basidiomycetes efficiently degrade the major structural polymers of wood cell walls. A small subset of these Agaricomycetes, exemplified by Phlebiopsis gigantea, is capable of colonizing freshly exposed conifer sapwood despite its high content of extractives, which retards the establishment of other fungal species. The mechanism(s) by which P. gigantea tolerates and metabolizes resinous compounds have not been explored. Here, we report the annotated P. gigantea genome and compare profiles of its transcriptome and secretome when cultured on fresh-cut versus solvent-extracted loblolly pine wood. The P. gigantea genome contains a conventional repertoire of hydrolase genes involved in cellulose/hemicellulose degradation, whose patterns of expression were relatively unperturbed by the absence of extractives. The expression of genes typically ascribed to lignin degradation was also largely unaffected. In contrast, genes likely involved in the transformation and detoxification of wood extractives were highly induced in its presence. Their products included an ABC transporter, lipases, cytochrome P450s, glutathione S-transferase and aldehyde dehydrogenase. Other regulated genes of unknown function and several constitutively expressed genes are also likely involved in P. gigantea's extractives metabolism. These results contribute to our fundamental understanding of pioneer colonization of conifer wood and provide insight into the diverse chemistries employed by fungi in carbon cycling processes.

We examined gene expression patterns in the lignin-degrading fungus Phanerochaete chrysosporium when it colonizes hybrid poplar (Populus alba × tremula) and syringyl (S)-rich transgenic derivatives. A combination of microarrays and liquid chromatography-tandem mass spectrometry (LC-MS/MS) allowed detection of a total of 9,959 transcripts and 793 proteins. Comparisons of P. chrysosporium transcript abundance in medium containing poplar or glucose as a sole carbon source showed 113 regulated genes, 11 of which were significantly higher (>2-fold, P < 0.05) in transgenic line 64 relative to the parental line. Possibly related to the very large amounts of syringyl (S) units in this transgenic tree (94 mol% S), several oxidoreductases were among the upregulated genes. Peptides corresponding to a total of 18 oxidoreductases were identified in medium consisting of biomass from line 64 or 82 (85 mol% S) but not in the parental clone (65 mol% S). These results demonstrate that P. chrysosporium gene expression patterns are substantially influenced by lignin composition., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)

Basidiomycota (basidiomycetes) make up 32% of the described fungi and include most wood-decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot). To assess the generality of the white-rot/brown-rot classification paradigm, we compared the genomes of 33 basidiomycetes, including four newly sequenced wood decayers, and performed phylogenetically informed principal-components analysis (PCA) of a broad range of gene families encoding plant biomass-degrading enzymes. The newly sequenced Botryobasidium botryosum and Jaapia argillacea genomes lack PODs but possess diverse enzymes acting on crystalline cellulose, and they group close to the model white-rot species Phanerochaete chrysosporium in the PCA. Furthermore, laboratory assays showed that both B. botryosum and J. argillacea can degrade all polymeric components of woody plant cell walls, a characteristic of white rot. We also found expansions in reducing polyketide synthase genes specific to the brown-rot fungi. Our results suggest a continuum rather than a dichotomy between the white-rot and brown-rot modes of wood decay. A more nuanced categorization of rot types is needed, based on an improved understanding of the genomics and biochemistry of wood decay.

The use of wood in construction has had a long history and Chile has a rich cultural heritage of using native woods for building churches and other important structures. In 2000, UNESCO designated a number of the historic churches of Chiloé, built entirely of native woods, as World Heritage Sites. These unique churches were built in the late 1700 s and throughout the 1800 s, and because of their age and exposure to the environment, they have been found to have serious deterioration problems. Efforts are underway to better understand these decay processes and to carryout conservation efforts for the long-term preservation of these important structures. This study characterized the types of degradation taking place and identified the wood decay fungi obtained from eight historic churches in Chiloé, seven of them designated as UNESCO World Heritage sites. Micromorphological observations identified white, brown and soft rot in the structural woods and isolations provided pure cultures of fungi that were identified by sequencing of the internal transcribed region of rDNA. Twenty-nine Basidiomycota and 18 Ascomycota were found. These diverse groups of fungi represent several genera and species not previously reported from Chile and demonstrates a varied microflora is causing decay in these historic buildings.

Rationale: It is important for the enforcement of the CITES treaty to determine whether agarwood (a resinous wood produced in Aquilaria and Gyrinops species) seen in trade is from a plantation that was cultivated for sustainable production or was harvested from natural forests which is usually done illegally., Methods: We analyzed wood directly using Direct Analysis in Real Time (DART™) ionization coupled with Time-of-Flight Mass Spectrometry (TOFMS). Agarwood was obtained from five countries, and the collection contained over 150 samples. The spectra contained ions from agarwood-specific 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromones as well as many other ions. The data was analyzed using either kernel discriminant analysis or kernel principal component analysis. Probability estimates of origin (wild vs cultivated) were assigned to unknown agarwood samples., Results: Analysis of the DART-TOFMS data shows that many of the chromones found in cultivated and wild agarwood samples are similar; however, there is a significant difference in particular chromones that can be used for differentiation. In certain instances, the analysis of these chromones also allows inferences to be made as to the country of origin. Mass Mountaineer™ software provides an estimate of the accuracy of the discriminate model, and an unknown sample can be classified as cultivated or wild. Eleven of the thirteen validation samples (85%) were correctly assigned to either cultivated or wild harvested for their respective geographic provenance. The accuracy of each classification can be estimated by probabilities based on Z scores., Conclusions: The direct analysis of wood for the diagnostic chromones using DART-TOFMS followed by discriminant analysis is sufficiently robust to differentiate wild from cultivated agarwood and provides strong inference for the origin of the agarwood., (Copyright © 2013 John Wiley & Sons, Ltd.)

Wood decomposition is an important component in forest ecosystems but information about the diversity of fungi causing decay is lacking. This is especially true for the temperate rain forests in Chile. These investigations show results of a biodiversity study of white-rot fungi in wood obtained from Chiloé National Park in Los Lagos region, Chile. Culturing from white-rotted wood followed by sequencing of the complete internal transcribed spacer region of the ribosomal DNA (rDNA) or partial large subunit region of the rDNA, identified 12 different species in the Basidiomycota. All of these fungi were characterized as white rot fungi and were identified with a BLAST match of 97 % or greater to sequences in the GenBank database. Fungi obtained were species of Phlebia, Mycoacia, Hyphodontia, Bjerkandera, Phanerochaete, Stereum, Trametes, and Ceriporiopsis. This report identifies for the first time in Chile the species Ceriporiopsis subvermispora, Hyphodontia radula, Phlebia radiata, Phanerochaete affinis, Peniophora cinerea, Stereum gausapatum, Phlebia setulosa and Phanerochaete sordida. Scanning electron microscopy was used to characterize the type of decay caused by the fungi that were isolated and a combination of selective lignin degraders and simultaneous white rot fungi were found. Fungi that cause a selective degradation of lignin are of interest for bioprocessing technologies that require modification or degradation of lignin without cellulose removal.

Identification of specific genes and enzymes involved in conversion of lignocellulosics from an expanding number of potential feedstocks is of growing interest to bioenergy process development. The basidiomycetous wood decay fungi Phanerochaete chrysosporium and Postia placenta are promising in this regard because they are able to utilize a wide range of simple and complex carbon compounds. However, systematic comparative studies with different woody substrates have not been reported. To address this issue, we examined gene expression of these fungi colonizing aspen (Populus grandidentata) and pine (Pinus strobus). Transcript levels of genes encoding extracellular glycoside hydrolases, thought to be important for hydrolytic cleavage of hemicelluloses and cellulose, showed little difference for P. placenta colonizing pine versus aspen as the sole carbon source. However, 164 genes exhibited significant differences in transcript accumulation for these substrates. Among these, 15 cytochrome P450s were upregulated in pine relative to aspen. Of 72 P. placenta extracellular proteins identified unambiguously by mass spectrometry, 52 were detected while colonizing both substrates and 10 were identified in pine but not aspen cultures. Most of the 178 P. chrysosporium glycoside hydrolase genes showed similar transcript levels on both substrates, but 13 accumulated >2-fold higher levels on aspen than on pine. Of 118 confidently identified proteins, 31 were identified in both substrates and 57 were identified in pine but not aspen cultures. Thus, P. placenta and P. chrysosporium gene expression patterns are influenced substantially by wood species. Such adaptations to the carbon source may also reflect fundamental differences in the mechanisms by which these fungi attack plant cell walls.

The historic expedition huts located in the Ross Sea Region of the Antarctic and the thousands of artifacts left behind by the early explorers represent important cultural heritage from the "Heroic Era" of Polar exploration. The hut at Cape Royds built by Ernest Shackleton and members of the 1907-1908 British Antarctic Expedition has survived the extreme Antarctic environment for over 100 years, but recent studies have shown many forms of deterioration are causing serious problems, and microbial degradation is evident in the historic wood. Conservation work to reduce moisture at the hut required removal of fodder, wood, and many different types of organic materials from the stables area on the north side of the structure allowing large numbers of samples to be obtained for these investigations. In addition, wood from historic food storage boxes exposed in a ravine adjacent to the hut were also sampled. Fungi were cultured on several different media, and pure cultures were obtained and identified by sequencing of the internal transcribed spacer region of rDNA. From the 69 cultures of filamentous fungi obtained, the most predominant genera were Cadophora (44%) followed by Thielavia (17%) and Geomyces (15%). Other fungi found included Cladosporium, Chaetomium, and isolates identified as being in Pezizomycotina, Onygenales, Nectriaceae, and others. No filamentous basidiomycetes were found. Phylogenetic analyses of the Cadophora species showed great species diversity present revealing Cadophora malorum, Cadophora luteo-olivacea, Cadophora fastigiata, as well as Cadophora sp. 4E71-1, a C. malorum-like species, and Cadophora sp. 7R16-1, a C. fastigiata-like species. Scanning electron microscopy showed extensive decay was present in the wood samples with type 1 and type 2 forms of soft rot evident in pine and birch wood, respectively. Fungi causing decay in the historic wooden structures and artifacts are of great concern, and this investigation provides insight into the identity and species diversity of fungi found at the site. The historic woods and other organic materials at this site represent a large input of carbon into the Antarctic environment. This as well as nutrient additions from the nearby Adélie penguin (Pygoscelis adeliae) colony and favorable conditions for fungal growth at Cape Royds appear responsible for the significant fungal diversity, and where extensive decay is taking place in wood in contact with the ground.

Cellulose degradation by brown rot fungi, such as Postia placenta, is poorly understood relative to the phylogenetically related white rot basidiomycete, Phanerochaete chrysosporium. To elucidate the number, structure, and regulation of genes involved in lignocellulosic cell wall attack, secretome and transcriptome analyses were performed on both wood decay fungi cultured for 5 days in media containing ball-milled aspen or glucose as the sole carbon source. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), a total of 67 and 79 proteins were identified in the extracellular fluids of P. placenta and P. chrysosporium cultures, respectively. Viewed together with transcript profiles, P. chrysosporium employs an array of extracellular glycosyl hydrolases to simultaneously attack cellulose and hemicelluloses. In contrast, under these same conditions, P. placenta secretes an array of hemicellulases but few potential cellulases. The two species display distinct expression patterns for oxidoreductase-encoding genes. In P. placenta, these patterns are consistent with an extracellular Fenton system and include the upregulation of genes involved in iron acquisition, in the synthesis of low-molecular-weight quinones, and possibly in redox cycling reactions.

Investigations of microbial diversity in Antarctic are important to begin to understand ecosystem functioning and decomposition processes. This study documents fungi at 9 historic sites on the Antarctic Peninsula collected from wooden structures, other organic materials, and soils during a joint National Science Foundation and British Antarctic Survey expedition in 2007. Many of these sites had wooden structures built by the British during the World War II Operation Tabarin, but others visited included the American "East Base" on Stonington Island and the Swedish hut on Snow Hill Island. Fungi were cultured on several different media and pure cultures were obtained and identified by DNA sequencing of the internal transcribed spacer region. Cadophora species previously found to attack historic wooden structures on Ross Island, Antarctica, were found at all but 1 location sampled in the Peninsula region. Fungi causing decay in the historic wooden structures and artifacts and those causing mold problems inside the structures are of great concern, and conservation efforts are urgently needed to help preserve these important polar heritage structures. The results presented also expand our knowledge on the identity of fungi present throughout the Antarctic Peninsula region and provide insights into the organisms responsible for decomposition and nutrient recycling.

Early explorers of Antarctica's Heroic Era erected wooden buildings and brought large quantities of supplies to survive in Antarctica. The introduction of wood and other organic materials provided nutrient sources for fungi that were indigenous to Antarctica or were brought in with the materials and adapted to the harsh conditions. Seventy-two isolates of filamentous fungi were cultured on selective media from interior structural wood of the Cape Evans historic hut and 27 of these screened positive for the ability to degrade carboxymethyl cellulose (CMC). Four non-CMC-degrading isolates were added to a group of 14 CMC-degrading isolates for further study, and endo-1, 4-beta-glucanase activity was demonstrated in the extracellular supernatant from all of these 18 isolates when grown at 4 degrees C, and also when they were grown at 15 degrees C. Isolates of Penicillium roquefortii and Cadophora malorum showed preference for growth at 15 degrees C rather than 25 degrees C or 4 degrees C indicating psychrotrophic characteristics. These results demonstrate that cellulolytic filamentous fungi found in Antarctica are capable of growth at cold temperatures and possess the ability to produce extracellular endo-1, 4-beta-glucanase when cultured at cold and temperate temperatures.

Three expedition huts in the Ross Sea region of Antarctica, built between 1901 and 1911 by Robert F. Scott and Ernest Shackleton, sheltered and stored the supplies for up to 48 men for 3 years during their explorations and scientific investigation in the South Pole region. The huts, built with wood taken to Antarctica by the early explorers, have deteriorated over the past decades. Although Antarctica has one of the coldest and driest environments on earth, microbes have colonized the wood and limited decay has occurred. Some wood in contact with the ground contained distinct microscopic cavities within secondary cell walls caused by soft rot fungi. Cadophora spp. could be cultured from decayed wood and other woods sampled from the huts and artifacts and were commonly associated with the soft rot attack. By using internal transcribed spacer sequences of ribosomal DNA and morphological characteristics, several species of Cadophora were identified, including C. malorum, C. luteo-olivacea, and C. fastigiata. Several previously undescribed Cadophora spp. also were found. At the Cape Evans and Cape Royds huts, Cadophora spp. commonly were isolated from wood in contact with the ground but were not always associated with soft rot decay. Pure cultures of Cadophora used in laboratory decay studies caused dark staining of all woods tested and extensive soft rot in Betula and Populus wood. The presence of Cadophora species, but only limited decay, suggests there is no immediate threat to the structural integrity of the huts. These fungi, however, are widely found in wood from the historic huts and have the capacity to cause extensive soft rot if conditions that are more conducive to decay become common.

Archaeological wood in ancient tombs is found usually with extensive degradation, limiting what can be learned about the diet, environment, health, and cultural practices of the tomb builders and occupants. Within Tumulus Midas Mound at Gordion, Turkey, thought to be the tomb of the Phrygian King Midas of the 8th century B.C., we applied a stable nitrogen isotope test to infer the paleodiet of the king and determine the nitrogen sources for the fungal community that decomposed the wooden tomb, cultural objects, and human remains. Here we show through analysis of the coffin, furniture, and wooden tomb structure that the principal degrader, a soft-rot fungus, mobilized the king's highly (15)N-enriched nutrients, values indicative of a diet rich in meat, to decay wood throughout the tomb. It is also evident from the delta(15)N values of the degraded wood that the nitrogen needed for the decay of many of the artifacts in the tomb came from multiple sources, mobilized at potentially different episodes of decay. The redistribution of nutrients by the fungus was restricted by constraints imposed by the cellular structure of the different wood materials that apparently were used intentionally in the construction to minimize decay.

Wood extractives, commonly referred to as pitch, cause major problems in the manufacturing of pulp and paper. Treatment of nonsterile southern yellow pine chips for 14 days with Pseudomonas fluorescens, Pseudomonas sp., Xanthomonas campestris, and Serratia marcescens reduced wood extractives by as much as 40%. Control treatments receiving only water lost 11% of extractives due to the growth of naturally occurring microorganisms. Control treatments were visually discolored after the 14-day incubation, whereas bacterium-treated wood chips were free of dark staining. Investigations using P. fluorescens NRRL B21432 showed that all individual resin and fatty acid components of the pine wood extractives were substantially reduced. Micromorphological observations showed that bacteria were able to colonize resin canals, ray parenchyma cells, and tracheids. Tracheid pit membranes within bordered pit chambers were degraded after treatment with P. fluorescens NRRL B21432. P. fluorescens and the other bacteria tested appear to have the potential for biological processing to substantially reduce wood extractives in pine wood chips prior to the paper making process so that problems associated with pitch in pulp mills can be controlled.