The cryptic lifestyle of most fungi necessitates molecular identification of the guild in environmental studies.Over the past decades, rapid development and affordability of molecular tools have tremendously improved insights of the fungal diversity in all ecosystems and habitats. Yet, in spite of the progress of molecular methods, knowledge about functional properties of the fungal taxa is vague and interpretation of environmental studies in an ecologically meaningful manner remains challenging. In order to facilitate functional assignments and ecological interpretation of environmental studies we introduce a user friendly traits and character database FungalTraits operating at genus and species hypothesis levels. Combining the information from previous efforts such as FUNGuild and Fun Fun together with involvement of expert knowledge, we reannotated 10210 and 151 fungal and Stramenopila genera, respectively. This resulted in a stand-alone spreadsheet dataset covering 17 lifestyle related traits of fungal and Stramenopila genera, designed for rapid functional assignments of environmental studies. In order to assign the trait states to fungal species hypotheses, the scientific community of experts manually categorised and assigned available trait information to 697413 fungal ITS sequences. On the basis of those sequences we were able to summarise trait and host information into 92623 fungal species hypotheses at 1% dissimilarity threshold.
The psbH gene encodes a small protein which copurifies with photosystem 2. In the cyanobacterium Synechocystis sp. PCC 6803, psbH is located upstream of the cytochrome b6-f complex genes petC and petA. In striking contrast, in the genomes of plant chloroplasts, psbH is cotranscribed with petB and petD, encoding the other two major subunits of the cytochrome b6-f complex. We report that in Synechocystis sp. PCC 6803 monocistronic psbH and dicistronic petCA transcripts are probably initiated separately, each from DNA regions bearing some similarity to Escherichia coli sigma 70 promoters. Synechocystis sp. PCC 6803 psbH null mutants were generated by cartridge mutagenesis. Studies using a rapid screening procedure involving in situ complementation showed that the PsbH protein is not absolutely required for the assembly of a functionally active photosystem 2 complex since psbH insertion and deletion strains were able to grow photoautotrophically. The rate of photoautotrophic growth was, however, slower than the wild type, and studies of oxygen evolution, chlorophyll fluorescence, and thermoluminescence indicated that this reduction in growth rate is probably due mainly to an impairment in electron flow from QA to QB. We conclude, therefore, that the PsbH protein is not an absolute requirement for photosystem 2 activity but that it functions to optimize electron flow between the two secondary plastoquinone acceptors by interacting with the QB site on the D1 protein.
High-aspect-ratio titanate nanotubes (NT) and nanowires (NW) were produced by the hydrothermal conversion of TiO2 at 400 K. The titanate morphology was studied by high-resolution transmission electron microscopy (HRTEM). The formation of ordered titanate nanoobjects depended on the time of conversion. Shorter synthesis times favored hollow nanotube production while during prolonged treatment the thermodynamically more stable nanowires were formed. Titanate nanotubes and nanowires were decorated by Rh nanoparticles. The structure and stability of titanate nanocomposites were studied by thermal gravimetric (TG), X-ray diffraction (XRD), X-ray photoelectron spectroscopic (XPS), Fourier transformed infrared spectroscopic (FTIR), and Raman spectroscopic methods. The nanowires preserve their structure up to 850 K, while the nanotubes start to recrystallize above 600 K. FTIR measurements showed that the water and hydroxyl content gradually decreased with increasing temperature in both cases. XPS data revealed the existence of high binding energy, highly dispersed Rh species on both supports. A small portion of Rh may participate in an ion exchange process. Support transformation phenomena were observed in Rh containing titanate nanowires and nanotubes. Rh decorated nanowires transform into the β-TiO2 structure, whereas their pristine counterparts' recrystallize into anatase. The formation of anatase was dominant during the thermal annealing process in both acid treated and Rh decorated nanotubes. Transformation to anatase was enhanced in the presence of Rh. The average diameters Rh nanoparticles were 4.9 ± 1.4 and 2.8 ± 0.7 nm in the case of nanowires and nanotubes, respectively.
The role of characteristic phospholipids of native membranes, phosphatidylcholine (PC), phosphatidylglycerol (PG), and cardiolipin (CL), was studied in the energetics of the acceptor quinone side in photosynthetic reaction centers of Rhodobacter sphaeroides. The rates of the first, k(AB)(1), and the second, k(AB)(2), electron transfer and that of the charge recombination, k(BP), the free energy levels of Q(A)(-)Q(B) and Q(A)Q(B)(-) states, and the changes of charge compensating protein relaxation were determined in RCs incorporated into artificial lipid bilayer membranes. In RCs embedded in the PC vesicle, k(AB)(1) and k(AB)(2) increased (from 3100 to 4100 s(-1) and from 740 to 3300 s(-1), respectively) and k(BP) decreased (from 0.77 to 0.39 s(-1)) compared to those measured in detergent at pH 7. In PG, k(AB)(1) and k(BP) decreased (to values of 710 and 0.26 s(-1), respectively), while k(AB)(2) increased to 1506 s(-1) at pH 7. The free energy between the Q(A)(-)Q(B) and Q(A)Q(B)(-) states decreased in PC and PG (DeltaG degrees (Q)A-(Q)B(-->)(Q)A(Q)B- = -76.9 and -88.5 meV, respectively) compared to that measured in detergent (-61.8 meV). The changes of the Q(A)/Q(A)(-) redox potential measured by delayed luminescence showed (1) a differential effect of lipids whether RC incorporated in micelles or vesicles, (2) an altered binding interaction between anionic lipids and RC, (3) a direct influence of PC and PG on the free energy levels of the primary and secondary quinones probably through the intraprotein hydrogen-bonding network, and (4) a larger increase of the Q(A)/Q(A)(-) free energy in PG than in PC both in detergent micelles and in single-component vesicles. On the basis of recent structural data, implications of the binding properties of phospholipids to RC and possible interactions between lipids and electron transfer components will be discussed.
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