Chemical evidence for the mechanism of the biodecoloration of Amaranth by <Emphasis Type="Italic">Trametes versicolor</Emphasis>

The white-rot fungus Trametes versicolor decolorized Amaranth. The hypothesis that the carbon structure of Amaranth was broken down in smaller mass fragments was investigated analyzing the products of decoloration. FTIR spectroscopy, ion chromatography, sulfite and ammonia analysis were used to compare the culture filtrate before dye addition, with the pure dye, the culture filtrate after dye addition, and the culture filtrate during the treatment. The hypothesis of polymerization of the decoloration products was tested by spectrophotometric analysis of dialysates of the pure dye, the culture filtrate before dye addition, and the culture filtrates after dye addition and decoloration. FTIR showed that the signals typical for the azo group disappeared after decoloration, while new peaks appeared that were characteristic of substituted naphthalenic or benzenic compounds. Ion chromatography showed that the level of sulfate in the treatment increased when compared with the level of the sulfate in control, suggesting that the sulfonic groups were being stripped from Amaranth’s structure and metabolized to sulfate. Sulfite measurements for the treatment and controls showed no significant difference, and were well below the saturation concentration for sulfite in water, confirming that the medium was aerobic. Ammonia concentration did not change with the decoloration. Absorbance scans after dialysis of decolorized samples showed no new peaks, suggesting that the decoloration products were not polymerized. These observations suggests that the decoloration mechanism starts with the azo link removal, followed by desulfonation, naphthalene ring opening, and the formation of smaller mass fragments, similar to fungal metabolites.     

Unusual Observations in the Histology of Pityriasis Versicolor

Histological studies were carried out on 25 patients with various morphological types of pityriasis vesicolor. In addition to the usual features, acanthosis nigricans-like picture in papular lesions, dilated blood vessels in erythematous lesions were observed. In sections stained with Periodic acid Schiff's stain (PAS) absence of granular layer in areas of close approximation of filaments to the stratum malpighii and presence of only mycelia in the vicinity of acrosyringium were found unusual, interesting and are new findings to our knowledge. This revised version was published online in June 2006 with corrections to the Cover Date.     

Individual, nightly, and seasonal variation in calling behavior of the gray tree frog, Hyla versicolor: implications for energy expenditure

We investigated individual, nightly, and seasonal variationin calling behavior of a population of gray tree frogs (Hylaversicolor) from Connecticut, USA. Repeated recordings of individualmales on seven nights revealed significant differences amongmales in calling rate on all but one night and differences innumber of pulses per call and number of pulses produced perhour (pulse effort) on four nights. Most males reduced callingactivity late at night (after 2230 h), but some maintained arelatively steady rate of call production before dropping outof the chorus. Data collected for 26 individuals recorded onthree or more nights throughout the breeding season revealedsignificant differences among males in calling rate, numberof pulses per call, and pulse effort, but repeatabilities forall three variables were low (0.17, 0.35, and 0.12, respectively).The highest repeatability was for number of pulses per call,a variable strongly influenced by proximity to calling neighbors,probably because males often interacted with neighbors at similardistances on several successive nights. Males tended to reducethe number of pulses per call as the season progressed and thedistance between neighbors decreased, but they showed no clearseasonal change in calling rate or pulse effort. There was asubstantial seasonal decline in the number of hours of chorusactivity, resulting in a median decrease of 43% in nightly energyexpenditure by calling males.     

Seedling growth declines in warmed tropical forest soils

The response of plants to a warming climate could have a large feedback on further climatic change. This feedback is especially important for tropical forests, where the global peak in plant productivity and biodiversity occurs. Here we test the response of tropical forest tree seedling growth, photosynthesis and herbivory to 3 years of in situ full-soil profile warming. We studied six species, three of which are known nitrogen-fixers and we hypothesized that the warming response of growth will be mediated by nutrient availability to plants. Across species, growth was significantly lower in warmed soil compared to soil at ambient temperature, and the same pattern was observed for light-saturated photosynthesis, pointing toward a growth decline associated with decreased C fixation. Within species, the relative growth decline was significant for two species, Inga laurina and Tachigali versicolor, both of which are N-fixers. Together our results suggest a growth decline may have resulted from a negative effect of warming on N-fixation, rather than via changes in nutrient mineralization from soil organic matter, which was unchanged for N and increased for P during the dry-to-wet season transition. Overall, our study demonstrates that belowground warming causes species-specific declines in the growth and photosynthesis of seedlings, with a suggestion—requiring further investigation—that this growth decline is larger in N-fixing species.     

Indoor fungal contamination of moisture-damaged and allergic patient housing analysed using real-time PCR

Aims:  The aim of our study was to compare, using real-time (Rt) PCR, quantitative levels of five fungal species in three kinds of dwellings.
Methods and Results:  Three groups of homes were recruited: moisture-damaged homes (MDH, n  = 30), allergic patient homes (APH, n  = 25) and paired control homes (CH, n  = 55). Five moulds with allergenic compounds or mycotoxin production characteristics ( Cladosporium sphaerospermum , Penicillium chrysogenum , Aspergillus versicolor , Alternaria alternata and Stachybotrys chartarum ) were quantified using Rt-PCR. Cycle threshold results were expressed in spore equivalent per volume or surface unit using a direct calculation based on a spore standard curve. MDH presented significantly higher amounts of DNA from C. sphaerospermum in both air and surface samples than CH ( P  < 0·001). APH presented slightly elevated amounts of DNA from A. versicolor in both air and surface samples, compared to CH ( P  < 0·05).
Conclusion:  Rt-PCR quantification of targeted fungal species is a rapid, reliable tool that could be included in a global indoor mould evaluation.
Significance and Impact of the Study:  Quantification of C. sphaerospermum using Rt-PCR can help to better target social service intervention in MDH. Quantification of A. versicolor DNA could be informative for characterization of APH.     

Formation of new acetal linkages in the metabolism of syringaresinol structure of lignin by Coriolus versicolor

Abstract In the metabolism of a lignin substructure model; syringaresinol by wood-rot fungi ( Coriolus versicolor ), formation of a new type of acetal linkage was detected. The new acetal linkage was formed by the addition of a primary alcohol group of metabolites to the quinone methide of syringaresinol, and these reactions were catalyzed by the phenol oxidizing enzyme. This is a first evidence indicating the possibility that the acetal linkage was one of the intermonomer linkages in lignin or one of the linkages in lignin-carbohydrate complex in plant cell wall.     

Molecular phylogeny of Trametes and related genera

Mitochondrial small subunit ribosomal DNAs were sequenced and phylogenetically analyzed for Trametes and related genera of Ryvarden's Trametes group. Parsimony and distance analyses indicated that most of trimitic genera with white rotting habit of the Trametes group clustered within a single clade, suggesting that they may have originated from a common ancestor. The phylogenetic position and generic placement of Trametes consors was uncertain as yet. Trametes trogii grouped with Coriolopsis gallica and indicated that color of the basidiocarp is a poor character at generic level. Nucleotide differences between Daedaleopsis confragosa and D. tricolor were quite few and both species closely grouped together in a same clade, thus supporting that D. tricolor might be an ecotype of D. confragosa.     

Biosolubilization of low-rank coal by aTrametes versicolor siderophore-like product and other complexing agents

Summary A heat stable, low molecular weight (<1000) extracellular product inTrametes versicolor (=Coriolus versicolor=Polyporous versicolor) cultures was demonstrated to be a principal factor in the solubilization of leonardite and other low-rank coals. The solubilization of leonardite byT. versicolor cell-free cultures and active fractions was inhibited by Fe³⁺ and was mimicked by the siderophore desferal mesylate and the iron chelating agents EDTA and 8-hydroxyquinoline. Leonardite solubilization by these later compounds was also inhibited by Fe³⁺. The ferrated and unferrated form of the partially purified active component fromT. versicolor cultures demonstrated absorption spectra that were similar to the ferrated and unferrated form of desferal mesylate.