Phylogenetic and morphological assessment of two new species of Amniculicola and their allies (Pleosporales).

Two new species of Amniculicola, A. immersa sp. nov. and A. parva sp. nov. from submerged wood in a freshwater environment in Denmark and France are respectively described and illustrated. In addition, partial 28S rDNA sequence data is analysed to investigate their phylogenetic relationships with other pleosporalean taxa. All presently known Amniculicola species, A. immersa, A. lignicola and A. parva, form a robust clade together with the anamorphic species Anguillospora longissima, Spirosphaera cupreorufescens and Repetophragma ontariense. These six species, which are all from freshwater and mostly from Europe, constitute a well-supported group containing Pleospora rubicunda and Massariosphaeria typhicola. This putative monophyletic assemblage may represent an aquatic group in the Pleosporales. It is also pertinent that all five ascomycete taxa in this group stain their host substrates purple.

Multi-locus phylogeny of Pleosporales: a taxonomic, ecological and evolutionary re-evaluation.

Five loci, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, are used for analysing 129 pleosporalean taxa representing 59 genera and 15 families in the current classification of Pleosporales. The suborder Pleosporineae is emended to include four families, viz.Didymellaceae, Leptosphaeriaceae, Phaeosphaeriaceae and Pleosporaceae. In addition, two new families are introduced, i.e. Amniculicolaceae and Lentitheciaceae. Pleomassariaceae is treated as a synonym of Melanommataceae, and new circumscriptions of Lophiostomataceaes. str., Massarinaceae and Lophiotrema are proposed. Familial positions of Entodesmium and Setomelanomma in Phaeosphaeriaceae, Neophaeosphaeria in Leptosphaeriaceae, Leptosphaerulina, Macroventuria and Platychora in Didymellaceae, Pleomassaria in Melanommataceae and Bimuria, Didymocrea, Karstenula and Paraphaeosphaeria in Montagnulaceae are clarified. Both ecological and morphological characters show varying degrees of phylogenetic significance. Pleosporales is most likely derived from a saprobic ancestor with fissitunicate asci containing conspicuous ocular chambers and apical rings. Nutritional shifts in Pleosporales likely occured from saprotrophic to hemibiotrophic or biotrophic.

A class-wide phylogenetic assessment of Dothideomycetes.

We present a comprehensive phylogeny derived from 5 genes, nucSSU, nucLSU rDNA, TEF1, RPB1 and RPB2, for 356 isolates and 41 families (six newly described in this volume) in Dothideomycetes. All currently accepted orders in the class are represented for the first time in addition to numerous previously unplaced lineages. Subclass Pleosporomycetidae is expanded to include the aquatic order Jahnulales. An ancestral reconstruction of basic nutritional modes supports numerous transitions from saprobic life histories to plant associated and lichenised modes and a transition from terrestrial to aquatic habitats are confirmed. Finally, a genomic comparison of 6 dothideomycete genomes with other fungi finds a high level of unique protein associated with the class, supporting its delineation as a separate taxon.

Early colonization of thermal niches in a silica-depositing hot spring in central Tibet.

Thermophilic microbial mats dominated by the anoxygenic phototroph Roseiflexus castenholzii commonly develop around sinter-depositing geysers in the Daggyai Tso geothermal field of central Tibet. In this study we used morphological and molecular genetic techniques to reveal a diverse pioneer biofilm community including both archaea and bacteria involved in early colonization of such thermal niches at temperatures ranging from 46 to 77 degrees C. Sinter precipitation and biomineralization were evident at all locations, but the latter was selective between taxa and most evident on filamentous cells. Evidence for possible indirect biosignatures from biofilms overwhelmed by sinter deposition was found. Succession to a mature community appeared to relate to the growth rate for key taxa outpacing that of silicification within an optimum temperature range of 54-61 degrees C. The thin surface layer of silicification-resistant cyanobacteria that developed on the surface of mature mats may play a role in preventing biomineralization of the susceptible R. castenholzii beneath within these communities.

Feasibility of bioremediation by white-rot fungi.

The ligninolytic enzymes of white-rot fungi have a broad substrate specificity and have been implicated in the transformation and mineralization of organopollutants with structural similarities to lignin. This review presents evidence for the involvement of these enzymes in white-rot fungal degradation of munitions waste, pesticides, polychlorinated biphenyls, polycyclic aromatic hydrocarbons, bleach plant effluent, synthetic dyes, synthetic polymers, and wood preservatives. Factors relating to the feasibility of using white-rot fungi in bioremediation treatments for organopollutants are discussed.

Lignocellulose-degrading marine fungi.

Evidence for lignocellulose-degrading ability among marine fungi is reviewed. Enzyme production, mass loss and micromorphological data suggest that most strains capable of decay activity are likely to be soft-rot fungi, with relatively few capable of white-rot decay. This probably reflects the relatively high number of ascomycete genera compared to basidiomycetes described to date. The ecological and biotechnological importance of marine fungal lignocellulolytic enzymes is discussed.

Production of wood decay enzymes, loss of mass, and lignin solubilization in wood by diverse tropical freshwater fungi.

In vitro production of cellulase and xylanase was common among diverse freshwater ascomycetes and their hyphomycetous anamorphs. Production of enzymes involved in lignin degradation was rare. Most isolates were capable of causing mass loss in angiosperm wood, although values were low, at approximately 10% during a 24-week period. A few isolates caused higher mass loss of up to 26.5%, and five of these were shown to solubilize significant amounts of lignin. This is the first report of lignin solubilization by freshwater fungi. Torula herbarum (hyphomycete) and Ophioceras dolichostomum (ascomycete) produced indices of lignin solubilization equivalent to those of terrestrial white-rot basidiomycetes. In all cases wood decay was 2.2- to 3-fold higher in exposed rather than submerged conditions.