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Wood is an important construction material, but when used incorrectly it can be subjected to deterioration by wood-destroying fungi. The brown rot producing dry rot fungus (Serpula lacrymans) is by far the most dangerous wood-destroying fungus in Europe. In the present publication, 645 fungal samples from damaged wood in the federal state of Styria (Austria) were examined and recorded by isolation date, geographical location, species identification of the wood-destroying fungus, location of damage, construction method, and age and type of building. In Styria, Serpula spp. accounted for 61.5% of damages, followed by Antrodia spp. (10.7%) and the genera Gloeophyllum (8.2%), Coniophora (3.9%) and Donkioporia (1.1%). Properties in the area of the Styrian capital Graz and old buildings were more often infested by wood-destroying fungi than houses in the rural area and new constructions.

The interactions of fungal guilds have recently been proposed as drivers of organic matter transformation in forest soils. We conducted a pot experiment with Norway spruce seedlings planted in spruce needle litter inoculated with several fungal strains belonging to different ecological guilds (saprotrophic, mycorrhizal, and root endophytic) to assess how the fungi and their interactions affect the transformation of humic substances (HS) and phosphorus (P) in the litter. Several methods for the characterization of P forms and HS were employed, including 31P NMR, UV–Vis and FTIR spectroscopy. Our results show that fungal interactions influence not only the flow of P in decaying (plant) litter but also the transformation of the soil organic matter itself. Pots with saprotrophic Gymnopus androsaceus generally retained more P and prevented the accumulation of phosphonates caused by mycorrhizal Hyaloscypha finlandica, highlighting the strong competitive ability of the former species. The increased mineralization of P caused by G. androsaceus was not observed in the combined treatments, suggesting that other present fungi took up part of the inorganic P. The tested fungi did not affect the amount of HS produced but changed the characteristics of the HS. Mycorrhizal H. finlandica and root endophytic Phialocephala fortinii increased the relative proportion of carboxylic moieties in the HS regardless of the presence or absence of G. androsaceus, probably via the production and incorporation of melanins. The UV–Vis absorbance characteristics of the HS were significantly influenced by fungal interactions. Mycorrhizal H. finlandica and Hebeloma bryogenes retarded humification, as determined by the A4/6 ratio. We attribute the similar shift observed in Serpula himantoides to the partial oxidative degradation of HS. Our study shows that fungal root endophytes can significantly contribute to litter transformation along with mycorrhizal and saprotrophic fungi. The extent and patterns of the transformation seem to be species-dependent in all studied fungal groups.

Serpulanines A (1), B (2), and C (3) have been isolated from extracts of the rare Sri Lankan macrofungus Serpula sp. The structures of 1, 2, and 3 were elucidated by a combination of spectroscopic and single-crystal X-ray diffraction analyses. Serpulanines A (1) and B (2) both contain the rare (E)-2-hydroxyimino hydroxamic acid functional group array. A proposed biogenesis for serpulanine B (2) suggests that its (E)-2-hydroxyimino hydroxamic acid moiety arises from a diketopiperazine precursor. Synthetic serpulanine A (1) inhibited class I/II histone deacetylases in murine metastatic lung carcinoma cells with an IC50 of 7 μM.

Studies on the behavior of termites in relation to different Basiodiomycetes. In tests with Reticulitermes flavipes, R. lucifugus, R. santonensis, Heterotermes indicola and Copto-termes amanii the influence of different Basidiomycetes of the brown-rot type on the construction rate of galleries and the food comsumption of groups of termites was examined using decayed pine sapwood and spruce specimens. It was also investigated whether the fungus Lenzites trabea — 7 strains of which were examined — has a special position. This did not apply to any of the strains used. The effects produced by one strain of Serpula (= Merulius) lacrimans were more pronounced. Other Basidiomycete species too of the genera Coniophora, Lenzites, Merulius, Paxillus, and Poria had clearly stimulating effects on gallery construction and feeding, whereas this was often not the case with Lentinus lepideus. Measurements of the oxygen consumption of the termites being exposed only to the odour of the fungal mycelium showed a good agreement of results. The wood species may influence the reaction of the insects. The individual termite species may react differently. Zusammenfassung In Versuchen mit Reticulitermes flavipes, R. lucifugus, R. santonensis, Heterotermes indicola und Coptotermes amanii wurde der Einflus verschiedener Basidiomyceten vom Braunfaule-typ auf Galeriebau und Holzfras von Termitengruppen mittels befallener Kiefernsplint-und Fichtenholz-Proben untersucht. Dabei sollte auch in Erfahrung gebracht werden, ob der Pilz Lenzites trabea, von dem 7 Staymme gepruft wurden, eine Sonderstellung einnimmt. Dies traf fur keinen der verwendeten Stamme zu. Alle wurden an Wirksamkeit durch den benutzten Stamm von Serpula (= Merulius) lacrimans ubertroffen. Auch andere Basidio-myceten-Arten der Gattungen Coniophora, Lenzites, Merulius, Paxillus und Poria ubten eine ausgepragte Galeriebau und Holzfras anregende Wirkung aus, wahrend Lentinus lepi-deus meist nicht gunstig wirkte. Sauerstoffverbrauchsmessungen, bei denen nur der Geruch des Pilzmycels auf die Tiere einwirkte, fuhrten zu ubereinstimmenden Ergebnissen. Die Holzart kann von Einflus auf die Reaktion der Tiere sein. Die einzelnen Termiten-Arten konnen sich unterschiedlich verhalten.

The effects of the interactions of soil filamentous fungi (including saprotrophic, mycorrhizal and endophytic fungi) on several morphological and physiological parameters of Norway spruce seedlings [Picea abies (L.) Karst.] were studied in a pot experiment. Both mycorrhizal variants (Hebeloma bryogenes and Cadophora finlandica) were slightly inhibited with respect to the accumulation of aboveground biomass. However, these variants exhibited significantly improved foliar content of N, P, and Ca (H. bryogenes variant also K), compared to controls. The presence of the saprotrophic fungus Setulipes androsaceus attenuated the positive effect of mycorrhizal fungi on Ca, P, and K content, but did not reduce the positive effect of mycorrhizal fungi on the N content of the seedlings’ needles. Raman spectroscopy revealed that both mycorrhizal fungi increased the foliar content of carotenoids compared to the controls, but the effect diminished in the presence of S. androsaceus. In contrast, in the presence of the dark septate endophyte Phialocephala fortinii, needles exhibited significantly higher wax content and lower carotenoid content compared to the mycorrhizal variants. The presence of the saprotrophic isolate Serpula himantoides resulted in a decrease in needle waxes in comparison to controls. The needles’ carotenoid concentration was positively correlated with the levels of needle nutrients (N, P, K, Ca, Mg), while correlation of needle nutrients (N, P) with the needle wax concentration was negative. We conclude that not only individual fungi but also their interactions profoundly affect the nutrition and needle composition of Norway spruce seedlings.

Wood-degrading fungi commonly grow in contact with calcium (Ca)-containing building materials and may import Ca and iron (Fe) from soil into forest woody debris. For brown rot fungi, imported Ca2+ may neutralize oxalate, while Fe3+ may facilitate Fenton-based degradation mechanisms. We previously demonstrated, in two independent trials, that degradation of spruce by wood-degrading fungi was not promoted when Ca or Fe were imported from gypsum or metallic Fe, respectively. Here, we tested pine wood with lower endogenous Ca than the spruce blocks used in prior experiments, and included a pure gypsum treatment and one amended with 1% with FeSO4. Electron microscopy with microanalysis verified that brown rot fungi Serpula himantioides and Gloeophyllum trabeum and the white rot fungus Irpex lacteus grew on gypsum and produced iron-free Ca-oxalate crystals away from the gypsum surface. Wood cation analysis verified significant Fe import by both brown rot isolates in Fe-containing treatments. Wood degradation was highest in Fe-gypsum-containing treatments for all three fungi, although only wood degraded by I. lacteus had significant Ca import. We suggest that Fe impurities may not exacerbate brown rot, and that both brown and white rot fungi may utilize Ca-containing materials.

In 1768 J.E. Gunnerus first described the species Hydroides norvegicus (Polychaeta, Serpulidae), the type of the genus Hydroides which today includes close to 90 species worldwide and is the largest serpulid genus. This description has therefore great value as a type description, but as it is written in an old-fashioned Danish/Norwegian language with a font which is hard to interpret, the description is rather inaccessible to most polychaetologists. This paper presents a translation of Gunnerus’ description of H. norvegicus and a brief review of the present day status of the species. Comments on Gunnerus’ description of Serpula triqvetra are also included, as well as references to his correspondence with Swedish naturalist Carolus Linnaeus regarding the species in question.

We have approached species identification of wood decay fungi in construction wood by means of sequencing ribosomal DNA. Sequencing of the Internal Transcribed Spacer (ITS), which includes the 5.8S rDNA, is straightforward and provides a basis for species identification. Identification was either by BLAST search on sequences in GenBank or phylogenetic analysis. A number of important wood decay fungi such asSerpula lacrymans, S. himantioides, Antrodia serialis, A. sinuosa, Gloeophyllum sepiarium, Fomitopsis pinicola, Resinicium bicolorandJunghuhnia collabenshave been successfully identified from fruitbodies and directly from wood samples. Sequence variants were found within the species sampled includingS. himantioides, the close relative ofS. lacrymans.But, among 27 samples from fruitbodies and mycelium ofS. lacrymans, unexpectedly, no sequence variation was detected.

In a screening of basidiomycete cultures from Chile for the production of antibiotics we identified a Serpula himantoides strain as a producer of metabolites inhibiting the growth of bacteria and fungi. Bioactivity guided purification resulted in the isolation of four new antibiotics. Their structures were elucidated by spectroscopic methods. All four compounds are succinimide and maleimide derivatives, of which two are N-hydroxylated

The present study was carried out on three trails, each presenting a different degree of disturbance, within the Pau--Ferro Forest Environmentally Protected Area, a 600 ha area of highland forest located in the municipality of Areia (06°58’12”S; 35°42’15”W; elevation, 400-600 m), in the state of Paraiba, Brazil. In 2005, we analyzed the species rich-ness, abundance, constancy and phenology of myxomycetes over seven consecutive months (rainy and dry seasons) in five types of microhabitats: dead tree trunks, the bark of living trees, basidiomata, ground litter and aerial litter. A total of 753 specimens of 48 species were obtained from the trails known as Flores (4 km), Boa Vista (3 km) and Cumbe (700 m). The Sorensen similarity coefficient revealed that the three trails are similar. The most constant and abundant species were Hemitrichia calyculata , H. serpula , Arcyria cinerea , A. denudata and Ceratiomyxa fruticulosa . Although myxomycetes sporulate throughout the year, some species have well-defined sporulation seasons. In terms of the constancy and abundance of species, Trichiaceae is th e most important family in the rain forest studied, which is representative of the highland forests of northeastern Brazil.

A new variety of Hemitrichia serpula (Scop.) Rost. from Brazil, H. serpula var. piauiensis Cavalcanti & Mobin, is described and illustrated. The new taxon has a somewhat less spinulose capillitium, with short and scattered spines; spores are finely reticulate , with well-defined meshes. The type is deposited in the Herbarium UFP, Myxomycete Collection, Federal University of Pernambuco (Recife, Pernambuco State, Brazil). A key to the three varieties of the species is presented as well. Uma nova variedade de Hemitrichia serpula (Scop.) Rost. do Brasil, Hemitrichia serpula var. piauiensis Cavalcanti & Mobin é descrita e ilustrada. O novo táxon tem um capilício menos espinuloso, com espinhos curtos e esparsos; os esporos são delicadamente reticulados, com malhas bem definidas. O tipo está depositado no Herbário UFP, Coleção de Myxomycetes, Universidade Federal de Pernambuco (Recife, Estado de Pernambuco, Brasil). É apresentada também uma chave de identificação para as três variedades da espécie.

Taxonomic studies over the last decade have consistently indicated that the cosmopolitan status of Serpula vermicularis Linnaeus, 1767 is unjustified. A previous morphological survey (Kupriyanova & Rzhavsky 1993) has documented that Serpula columbiana Johnson, 1901 from the Russian Far-Eastern Seas is distinct from Serpula vermicularis from the Norwegian Sea. As a result, the older name, of S. columbiana was re-established for the Russian Far-Eastern population, thereby separating it from synonymy with S. vermicularis. The purpose of the present study was to verify the identity of the Serpula species from the Russian Far-East with Serpula columbiana s. str. Johnson, 1901 that was originally described from the North American Pacific coast. It is shown that at least three regionally distributed species were previously confused under the specific name Serpula vermicularis: S. Vermicularis s. str. (Norwegian Sea), S. columbiana (West coast of USA), and S. sp. A (Russian coast of the Sea of Japan). Th...

The dry-rot fungus Serpula lacrymans has a maximum growth temperature of 28°C which is an unusual feature in comparison to other Serpula species. This has led to the investigation of S. lacrymans sensitivity to higher temperature regimes with respect to increased thermotolerance and the production of heat-shock proteins (hsps). The strategy employed in this study has been to correlate protein synthesis with thermotolerance and the heat-shock response. Protein profiles generated by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (1D SDS-PAGE) of fungal colonies exposed to optimal, supraoptimal (sublethal) and lethal temperatures were probed with rabbit anti-GRoEL serum for the presence of the 60-kDa heat-shock protein. The preliminary findings indicate that an important heat-shock protein, a GRoEL analogue, is produced by S. lacrymans and that this basidiomycete undergoes the classic heat-shock response.

Four isolates of Serpula lacrymans from Australia and one from each of Germany, Japan and Poland were examined for their similarity to the reference isolate FPRL 12C (from England) by RAPD PCR. Results were compared with those published by others using SDS-PAGE and found to be similar. RAPD PCR was shown to be a fast and reliable technique with potential for detecting S. lacrymans as a cause of wood decay. Other possible applications for this assay could include epidemiological and phylogenetic studies.

Summary The presence of basidiomes of wood-decay fungi on living lenga (Nothofagus pumilio) was investigated in seven forest stands in Patagonia (Argentinia). The following species accounted for 85% of the rots: Postia pelliculosa, Phellinus andinopatagonicus, Piptoporus portentosus, Aurantioporus albidus, and Serpula himantoides. Ph. andinopatagonicus and A. albidus cause characteristic white rots, while the other tree species cause unspecific, cubical brown rots. S. himantoides was associated with cords among the decayed wood fragments. One stand was investigated in detail. The volume of decayed timber on this plot was 75%. Postia pelliculosa and Ph. andinopatagonicus probably infected the trees through the roots as well as through the canopy, and accounted for 70% of the wood-rots. Piptoporus portentosus probably infected only through the canopy, while A. albidus and S. himantoides did so through the roots. Only 12% of the trees showed no decay. From trees with decay, 36% were attacked by one fungal species, 35% by two species.

Species of the Poria group causing brown rot of wood in buildings and with similar morphological appearance and biology, namely Antrodia vaillantii, A. seriadis, A. sinuosa, A. xantha, and Tyromyces placenta, were investigated by SDS polyacrylamide gel electrophoresis. Different cultures of A. vaillantii showed a species-specific protein profile separating the fungus from A. serialis, A. sinuosa and A. xantha and from T. placenta. The method also differentiated these pore fungi from the dry rot fungus Serpula lacrymans and detected misidentifications

Background The fungal genus Serpula (Serpulaceae, Boletales) comprises several saprotrophic (brown rot) taxa, including the aggressive house-infecting dry rot fungus Serpula lacrymans. Recent phylogenetic analyses have indicated that the ectomycorrhiza forming genera Austropaxillus and Gymnopaxillus cluster within Serpula. In this study we use DNA sequence data to investigate phylogenetic relationships, historical biogeography of, and nutritional mode transitions in Serpulaceae. Results Our results corroborate that the two ectomycorrhiza-forming genera, Austropaxillus and Gymnopaxillus, form a monophyletic group nested within the saprotrophic genus Serpula, and that the Serpula species S. lacrymans and S. himantioides constitute the sister group to the Austropaxillus-Gymnopaxillus clade. We found that both vicariance (Beringian) and long distance dispersal events are needed to explain the phylogeny and current distributions of taxa within Serpulaceae. Our results also show that the transition from brown rot to mycorrhiza has happened only once in a monophyletic Serpulaceae, probably between 50 and 22 million years before present. Conclusions This study supports the growing understanding that the same geographical barriers that limit plant- and animal dispersal also limit the spread of fungi, as a combination of vicariance and long distance dispersal events are needed to explain the present patterns of distribution in Serpulaceae. Our results verify the transition from brown rot to ECM within Serpulaceae between 50 and 22 MyBP.

Polyclonal antiserum against mycelial suspensions of Serpula lacrimans cross-reacted with protein extracts of other wood-destroying fungi. By absorption the cross-reactions were eliminated, and an antiserum specific to S. lacrimans obtained.

Objective: A survey of Trichiales and Liciales orders in the Catamarca s Yungas was performed. Methodology: Fresh samples were collected and compared with herbarium collections. The most representative and specific features are illustrated. Results: Perichaena chrysosperma, P. depressa, Cribraria aurantiaca, Hemitrichia calyculata, H. serpula, Metatrichia vesparia and Trichia favoginea , were taxonomically identified. Conclusion: Two species are recorded for the first time to the Northwest of Argentina, two genera are recorded for the first time for Catamarca and the distribution area of a single specie is enlarged.

Three extracellular cellulose-depolymerizing enzymes from cotton undergoing decay by the brown rot fungus Meruliporia (Serpula) incrassata were isolated by anion-exchange and hydrophobic interaction chromatographies. Depolymerization was detected by analyzing the changes in the molecular size distribution of cotton cellulose by high-performance size-exclusion chromatography. The average degree of polymerization (DP; number of glucosyl residues per cellulose chain) was calculated from the size-exclusion chromatography data. The very acidic purified endoglucanases, Cel 25, Cel 49, and Cel 57, were glycosylated and had molecular weights of 25,200, 48,500, and 57,100, respectively. Two, Cel 25 and Cel 49, depolymerized cotton cellulose and were also very active on carboxymethyl cellulose (CMC). Cel 57, by contrast, significantly depolymerized cotton cellulose but did not release reducing sugars from CMC and only very slightly reduced the viscosity of CMC solutions. Molecular size distributions of cotton cellulose attacked by the three endoglucanases revealed single major peaks that shifted to lower DP positions. A second smaller peak (DP, 10 to 20) was also observed in the size-exclusion chromatograms of cotton attacked by Cel 49 and Cel 57. Under the reaction conditions used, Cel 25, the most active of the cellulases, reduced the weight average DP from 3,438 to 315, solubilizing approximately 20% of the cellulose. The weight average DP values of cotton attacked under the same conditions by Cel 49 and Cel 57 were 814 and 534; weight losses were 9 and 11% respectively.

Decay of pine-wood by the brown-rot fungi Poria placenta, Fomitopsis pinicola, Serpula lacrimans, Paxillus panuoides and the white-rot fungi Trametes versicolor, Trametes hirsuta, Sporotrichum pulverulentum was investigated with the transmission electron microscope. Material stained with ruthenium red showed extracellular, tripartite structures associated with all fungi throughout all stages of wood decay. These structures surrounded the intensely stained fungal cell wall, were partly embedded in an extracellular slime and were contiguous with the wood cell wall. Besides brown-rot fungi with filter paper activity S. pulverulentum showed similar tripartite structures, however these were branched and extended from the fungal cell wall into the lumen of the wood cell. The origin, formation and function of these extracellular structures are discussed.

Serpula lacrimans can produce under certain conditions surface mycelium which grows from discrete points on and at a markedly faster rate than the parent mycelium. The difference in growth rates is maintained after subculturing on to fresh medium of the same composition. The two types of mycelia differ in pigment production and response to staling conditions. Mycelia with or without clamp connexions exhibit the phenomenon. It appears to be different from true sectoring, since the mycelium undergoes some differentiation but not apparently genetic change. The phenomenon is termed point growth and is similar to flushing and to strand formation; all are stimulated by a change to less favourable growth conditions.

Transmission electron microscope investigations of wood decay by the brown rot fungi Poria placenta and Serpula lacrimans and the white rot fungi Trametes versicolor and Sporotrichum pulverulentum showed that the distribution of the osmiophilic particles in brown-rotted and white-rotted wood conformed to that previously established for other species. When pinewood is degraded by brown rot fungi osmiophilic particles are densely distributed in all cell wall layers. This distribution correlates with the rapid depolymerisation of carbohydrates over the entire cell wall. In white-rotted pinewood osmiophilic particles are found on the surfaces of the cell wall and of cell wall remnants but never within the cell walls. That osmiophilic particles within and around hyphae outside degraded woodblocks and even in and on hyphae 40 mm from the wood suggests that they are not degradation products of a wood component but are produced by the fungus. However their aggregation in regions of strong wood decay suggests that they are associated with this process. Contrary to the literature brown rot fungi have been found capable of lignin metabolism causing complete disintegration of wood cell walls, middle lamella and the cell corners.

Initial stages of mycelial strand development of Serpula lacrimans in culture were compared with the structure of mature strands from infected timber. The mature strands differed from the three- to six-week-old ones in consisting preponderantly of a matrix of extrahyphal material and dead cell walls, surrounding channels of 10–25 μm diam. Also present were numerous thick-walled, narrow hyphae mainly round the edge of the strand. The development of this rigid matrix in mature strands would enable translocation to take place in the channels by means of pressure-driven mass flow. The likely functions of strands are discussed in the light of this and previous work.

Trehalose and arabitol are the most abundant carbohydrates in mycelium of Serpula lacrimans growing over Perspex. Trehalose is the major soluble carbohydrate in strands while arabitol reaches high levels in more marginal regions. Uptake of [14C]glucose results in the bulk of label being found in trehalose in all mycelial regions. It appears that trehalose is the major form by which carbohydrate is translocated.

The genus Diacheopsis is characterized by noncolumellate, sessile fructifications which lack lime and contain brown spores. The four existing species are regarded as valid, and two new species, D. effusa and D. serpula, are described. Three of the species, D. effusa, D. metallica and D. serpula, are snowline myxomycetes, and three, D. depressa, D. insessa and D. pieninica, are basically lowland in distribution. A key to the species and detailed descriptions are included.

The rates of loss of dry weight, and of cross-grain breaking strength, of wood of Pinus sylvestris and some other tree species, were measured during decay by different isolates of Serpula lacrimans (Wulf. ex Fr.) Schrot. Some strains caused losses up to four times greater than others in standard controlled conditions.

Apparatus for continuous in situ monitoring of translocation of radioisotopes in mycelium of Serpula lacrimans is described. Similar velocities of translocation were found for several different isotopes. Velocities were much higher than those previously reported. Addition of a respiratory inhibitor or a concentrated solution to the food source resulted in rapid inhibition of translocation along the full length of the mycelium. The results suggest that solute and water uptake at the food source is the major driving force for translocation which takes place as mass flow of solution.

Serpula lacrimans grows over lime-sand plaster containing more than 1% (w/w) water at a rate comparable to that on nutrient agar. When the water content of the plaster is lower, growth is reduced and occurs non-uniformly in a series of flushes. Growth under these conditions is stimulated by the addition of water or inhibited by the addition of 0.5 molal sucrose to the inoculum and the water content of the plaster is raised as the mycelium grows over it. Studies using agar and liquid culture show that the fungus cannot withstand water potentials of less than about −60 bars. Growth takes place on plaster at a much lower (−600 bars) water potential.

The pathway of translocation in differentiating mycelium of Serpula lacrimans growing on a non-absorbent substrate has been investigated using autoradiography and fluorescein dye. Translocation was found to occur exclusively in developing strands and functional specialization was demonstrated in relatively undifferentiated mycelium. It is concluded that the primary function of young strands is as translocating structures.

Summary The effect of sodium nitrate level on three parameters of growth of Serpula lacrimans was investigated and compared with nitrogen levels normal in wood. The results showed that mycelial extension from a wood food base over non-nutrient substrata is probably not limited by nitrogen availability, but that the rate of increase in mycelial biomass and of cellulose decomposition probably are. The nitrogen required for cellulolysis could be translocated to the site of cellulolysis when supplied at a distance from it. The results are discussed in relation to the biology of the fungus.

Proteinase activity was detected in culture filtrates of eight wood-decaying basidiomycete fungi and compared in terms of ability to clear skimmed milk agar. All the fungi were proteolytic, but to differing extents. Five were compared using azocasein hydrolysis as a measure of proteolytic activity at the centres and margins of agar-grown colonies and it was found that in Coriolus versicolor the marginal mycelium was the more strongly proteolytic, while in all the other fungi proteolysis by central mycelium was greater. The time course of changes in proteolytic activity in culture filtrates of C. versicolor and Serpula lacrimans grown on the surface of liquid media was compared over 4 weeks, and differences were found which suggested that C. versicolor mycelium inactivates its proteinases after secreting them, but that S. lacrimans does not. The results are interpreted in terms of the likely role of proteinases in the nitrogen economy of these fungi when growing on their wood substrates.

The amino acid analogue α-aminoisobutyric acid (AIB) decreased linear extension growth in fifteen out of sixteen wood decay and wood spoilage fungi. In Serpula lacrimans inhibition of extension growth by AIB was accompanied by an increase in the frequency with which the hyphae of the fungus initiated branches. AIB was shown to have a preservative effect against Lentinus lepideus, Serpula lacrimans and Pleurotus ostreatus when wood blocks were impregnated with this chemical prior to challenge by cultures of these fungi. The effectiveness of this compound in limiting growth in a large number of different fungi suggests that competitive inhibitors of nitrogen uptake and metabolism could be used to control fungi which decay wood and similar materials, and may also have wider applications.

The influence of substratum water potential on the growth of Serpula lacrimans and Phallus impudicus was investigated. Two methods of adjusting the water potential of the substratum were used; both gave qualitatively similar results. Linear growth rate decreased with substratum water potential. The turgor potential at the mycelial front and linear growth rate were positively correlated in both species on both media. An experiment concerned with growth from a medium of high water potential to one of lower water potential and vice versa produced results consistent with those obtained for growth on a single medium.

Values have been obtained for water flux and the velocity of flow through mycelium of Serpula lacrimans growing over Perspex. The values are 1–23 times greater than previous measurements of the velocity of solute translocation using isotopic tracers. Addition of 10 μg cm−3 oligomycin to the food source inhibited both linear extension and also water uptake. However, 2.0 moll−1 glucose affected only water uptake. Changes in the water, solute and turgor potentials of hyphae were studied for a 72 h period after the addition of glucose and were in keeping with the observed effects on growth and water uptake. The results are discussed in relation to the mechanisms of translocation and the ability of the mycelium to buffer alterations of the solute potential of the medium external to those hyphae at the food source.

Blocks of seasoned sapwood of Pinus sylvestris were infested with Serpuda lacrimans ([Wulf.] Fr.) Schroeter, then held at 20°C in an apparatus in which the ends of the blocks were exposed to atmospheres of known r.h., while the centre of the block was supplied with unlimited water. In these conditions the fungus grew out from the wood for substantial distance over a non-nutritive surface at humidities between 100 and 95%. It grew only slightly at 90% r.h. and not at all at humidities of 82% and below.

Summary Experiments were carried out on the conditions favouring strand formation in the mycelium of Serpula lacrimans. The mechanism of strand production proposed by Garrett and Butler (1960) was taken as a working hypothesis. Colonies of the fungus were grown on a liquid medium of a nutrient composition found previously to induce stranding. In one set of cultures this medium was renewed daily by slow perfusion of fresh medium through the culture vessels, continued over a 6-week period. In a parallel set of cultures the medium remained static and was not renewed over the same period. Strands formed only in these static cultures and not in the perfused ones. When the fungus was grown from a nutrient-rich food base over media at a range of lower concentrations it was found that there was an optimal lower concentration for strand formation. Another state of nutrient supply that favoured the formation of strands occurred when mycelium growing out from a food base over a non-nutrient medium encountered and began to colonize a fresh food base. This observation, first made on Helicobasidium purpureum by Valder (1958), was repeated using Serpula lacrimans and it was also shown by using 14C-labelled glucose that carbon was transported between old and new food bases. Further experiments using 14C as a tracer showed that there was a loss of substances containing carbon from intact hyphae and from strand-forming mycelium. The significance of these results is discussed, and it is suggested that to Garrett's original hypothesis might be added the proposition that nutrient leakage from older hyphae is part of the process of strand induction.

Fifteen species and one n. comb. of Merulius and Phlebia proposed by Lloyd are redescribed and 8 type specimens illustrated. The following names are placed in synonymy: M. aurantius, M. conchoides, M. ochraceus, and M. succineus with M. corium (Fries) Fries; Phlebia castanea and P. merulioides with M. rufus Fries; M. gelatinosus with Serpula himantioides (Fries) Bond. ex Parm. and M. candidus with Porogramme calcicolor (Sacc. & Syd.) Lowe. Merulius carbonarius, M. consimilis, M. crassus and M. fuscus are neither typically Serpula nor Merulius but are retained temporarily in the latter. The combination M. corium var. pallens is rejected because M. pallens Berk. is a distinct species from M. corium. Merulius debriscolus is discarded because the type lacks any sign of a fungus. Merulius erectus is perhaps a member of Aphelaria Corner. Merulius castaneus is Cystidiophorus castanea (Lloyd) Imazeki.