TY - JOUR A1 - Grote, M. A1 - Noll, S. A1 - Noll, B. A1 - Johannsen, B. A1 - Kraus, Werner T1 - Syntheses of novel modified acyclic purine and pyrimidine nucleosides as potential substrates of herpes simplex virus type-1 thymidine kinase for monitoring gene expression JF - Canadian journal of chemistry = Revue canadienne de chimie N2 - Suicide gene therapy with the herpes simplex virus type-1 thymidine kinase gene (HSV-1 tk) is considered to be a promising approach to the treatment of cancer. Making use of the lower specificity of the viral enzyme compared to human thymidine kinase, the therapy involves the administration of antiviral agents (e.g., ganciclovir) as prodrugs to induce enzymatic cell death in those cells that express the transferred gene. 18F-labelled derivatives have been described for monitoring location, duration, and magnitude of the viral kinase enzyme activity by positron emission tomography (PET). Since an optimal radiotracer has not been developed, novel substances were synthesized for monitoring gene expression. A group of 13 nucleoside analogues were synthesized, among them N1-methyl-9-[(1,3-dihydroxy-2-propoxy)methyl]guanine (5) and N1-methyl-9-[(4-hydroxy)-3-hydroxymethylbutyl]guanine (7) as methyl analogues of ganciclovir and penciclovir and their related fluoro compounds (6, 8). Further novel derivatives include N6-methyl-9-[(1,3-dihydroxy-2-propoxy)methyl]-, N6-methyl-9-[(4-hydroxy)-3-hydroxymethylbutyl]adenine (9, 10), as well as the uracil derivatives 5-hydroxy-1-[(1,3-dihydroxy-2-propoxy)methyl]uracil (11), 6-methyl-1-[(1,3-dihydroxy-2-propoxy)-methyl]uracil (12), and its 3-fluoro-derivative (13). KW - Fluorinated nucleoside analogues KW - Gene therapy KW - PET KW - Thymidine kinase PY - 2004 DO - https://doi.org/10.1139/v04-005 SN - 0008-4042 SN - 1480-3291 VL - 82 SP - 513 EP - 523 PB - National Research Council of Canada CY - Ottawa, Ont. AN - OPUS4-3490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lasota, S. A1 - Horn, M. A1 - Noll, M. A1 - Stephan, Ina A1 - Otto, W. T1 - Copper in wood preservatives delayed wood decomposition and shifted soil fungal but not bacterial community composition JF - Applied and Environmental Microbiology N2 - Copper-based fungicides are routinely used for wood and plant protection, which can lead to an enrichment of copper-tolerant microbial communities in soil. To investigate the effect of such wood preservatives on the soil fungal and bacterial community compositions, five different vineyard and fruit-growing soil environments were evaluated using incubation studies over time. Pine sapwood specimens were impregnated with either water or different biocide treatment solutions containing a mixture of copper, triazoles, and quaternary ammonium compounds (CuTriQAC), a mixture of triazoles and quaternary ammonium compounds (TriQAC), or copper alone (Cu). Specimens were incubated in soil from each sample site for 8, 16, 24, and 32 weeks. The effects of preservative treatment on the modulus of elasticity (MOE) of the wood specimens and on the soil fungal as well as bacterial community composition at the soil-wood interface were assessed by quantitative PCR and amplicon sequencing of the fungal internal transcribed spacer (ITS) region and bacterial 16S rRNA gene. Specimens impregnated with CuTriQAC and Cu showed decreased MOE and reduced fungal and bacterial copy numbers over time compared to those impregnated with water and TriQAC. Fungal but not bacterial community composition was significantly affected by wood preservative treatment. The relative abundance of members of the family Trichocomaceae compared to other genera increased in the presence of the Cu and CuTriQAC treatments at three sites, suggesting these to be Cu-tolerant fungi. In conclusion, the copper-containing treatments resulted in marginally increased MOE, lowered microbial gene copy numbers compared to those in the TriQAC and water treatments, and thus enhanced wood protection against soil microbial wood degradation KW - 16S rRNA gene KW - ITS region KW - Amplicon sequencing KW - Community composition KW - Copper-based wood preservatives KW - Soil incubation study PY - 2019 DO - https://doi.org/10.1128/AEM.02391-18 SN - 1098-5336 SN - 0099-2240 VL - 85 IS - 4 SP - e02391-18, 1 EP - 13 PB - American Society for Microbiology CY - Washington, DC AN - OPUS4-47370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shrestha, M. A1 - Abraham, W.-R. A1 - Shrestha, P.M. A1 - Noll, Matthias A1 - Conrad, R. T1 - Activity and composition of methanotrophic bacterial communities in planted rice soil studied by flux measurements, analyses of pmoA gene and stable isotope probing of phospholipid fatty acids JF - Environmental microbiology N2 - Methanotrophs in the rhizosphere of rice field ecosystems attenuate the emissions of CH4 into the atmosphere and thus play an important role for the global cycle of this greenhouse gas. Therefore, we measured the activity and composition of the methanotrophic community in the rhizosphere of rice microcosms. Methane oxidation was determined by measuring the CH4 flux in the presence and absence of difluoromethane as a specific inhibitor for methane oxidation. Methane oxidation started on day 24 and reached the maximum on day 32 after transplantation. The total methanotrophic community was analysed by terminal restriction fragment length polymorphism (T-RFLP) and cloning/sequencing of the pmoA gene, which encodes a subunit of particulate methane monooxygenase. The metabolically active methanotrophic community was analysed by stable isotope probing of microbial phospholipid fatty acids (PLFA-SIP) using 13C-labelled CH4 directly added to the rhizospheric region. Rhizospheric soil and root samples were collected after exposure to 13CH4 for 8 and 18 days. Both T-RFLP/cloning and PLFA-SIP approaches showed that type I and type II methanotrophic populations changed over time with respect to activity and population size in the rhizospheric soil and on the rice roots. However, type I methanotrophs were more active than type II methanotrophs at both time points indicating they were of particular importance in the rhizosphere. PLFA-SIP showed that the active methanotrophic populations exhibit a pronounced spatial and temporal variation in rice microcosms. KW - Methane oxidation KW - Active methanotrophs KW - Rice microcosms KW - PLFA KW - pmoA gene PY - 2008 DO - https://doi.org/10.1111/j.1462-2920.2007.01462.x SN - 1462-2912 SN - 1462-2920 VL - 10 IS - 2 SP - 400 EP - 412 PB - Blackwell Science CY - Oxford AN - OPUS4-16493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noll, Matthias A1 - Wellinger, M. T1 - Changes of the soil ecosystem along a receding glacier: Testing the correlation between environmental factors and bacterial community structure JF - Soil biology & biochemistry N2 - As a glacier retreats, it leaves behind it a forefield that has a natural gradient of soil formation age. We systematically sampled the Damma glacier forefield (Switzerland) along a temporal gradient of soils deglaciated between 1956 and 2002. A significant change in organic carbon content, sulfate concentration, pH, water and nucleic acid content was observed along the forefield chronosequence. Based on 16S rRNA gene based fingerprinting, the structure of the bacterial community also shifted along the forefield. Shifts in the structure of the bacterial community were significantly correlated to changes of pH, soil water content and soil age. To test the impacts of an array of environmental variables including soil age, soil water content, and different anions on the structure of the bacterial community we incubated different glacier forefield soils under specific treatment conditions for 30 days at 25 °C. The incubation of recently deglaciated soils resulted into an increase of bacteria from the family Methylocystaceae and from the class Betaproteobacteria while the community composition from matured soil changed to a lesser extent. The total nitrogen concentration in matured soil doubled during incubation, whereas the nitrogen concentrations in recently deglaciated soil stayed constant. This suggested that the microbial ecosystem functioned differently in the mature versus the recently deglaciated soils. Only soil age and soil water content could be singled out as having significant effects on the structure and composition of the bacterial community, despite the fact that bacterial communities in glacier forefields are exposed to other steep environmental gradients. KW - Alpine glacier forefield KW - Bacteria KW - Environmental explanatory variable KW - Soil age KW - Soil water content KW - Succession KW - Nitrogen KW - Inorganic anion PY - 2008 DO - https://doi.org/10.1016/j.soilbio.2008.07.012 SN - 0038-0717 VL - 40 IS - 10 SP - 2611 EP - 2619 PB - Elsevier CY - Amsterdam AN - OPUS4-17935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Conrad, R. A1 - Klose, M. A1 - Noll, Matthias A1 - Kemnitz, D. A1 - Bodelier, P.L.E. T1 - Soil type links microbial colonization of rice roots to methane emission JF - Global change biology N2 - Most of the methane (CH4) emission from rice fields is derived from plant photosynthates, which are converted to CH4. Rice cluster I (RC-1) archaea colonizing the rhizosphere were found to be the methanogens responsible for this process. Hence, RC-1 methanogens seem to play a crucial role in emission of the greenhouse gas CH4. We determined the community composition and activity of methanogens colonizing the roots of eight different rice cultivars after growth on both Italian rice soil and river bank soil, which contained different communities of methanogenic archaea. The community composition was analyzed by terminal restriction fragment length polymorphism and cloning/sequencing of the archaeal 16S rRNA gene and the mcrA gene coding for a subunit of the methyl coenzyme M reductase. When grown on rice field soil, the methanogenic community of the different rice cultivars was always dominated by RC-1 methanogens. In contrast, roots were colonized by Methanomicrobiales when grown on river bank soil, in which RC-1 methanogens were initially not detectable. Roots colonized with Methanomicrobiales compared with RC-1 exhibited lower CH4 production and CH4 emission rates. The results show that the type of methanogens colonizing rice roots has a potentially important impact on the global CH4 cycle. KW - Gene sequence KW - Methane emission KW - Methanomicrobiales KW - Methyl coenzyme M reductase KW - Ribosomal RNA KW - Rice cluster I KW - Rice cultivar KW - Rice field soil KW - Rice root KW - Terminal restriction fragment length polymorphism PY - 2008 DO - https://doi.org/10.1111/j.1365-2486.2007.01516.x SN - 1354-1013 SN - 1365-2486 VL - 14 IS - 3 SP - 657 EP - 669 PB - Blackwell Science CY - Oxford AN - OPUS4-16517 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noll, Matthias A1 - Klose, M. A1 - Conrad, R. T1 - Effect of temperature change on the composition of the bacterial and archaeal community potentially involved in the turnover of acetate and propionate in methanogenic rice field soil JF - FEMS microbiology ecology N2 - The microbial community structure was investigated together with the path of methane production in Italian rice field soil incubated at moderate (35 °C) and high (45 °C) temperature using terminal restriction fragment length polymorphism and stable isotope fractionation. The structure of both the archaeal and bacterial communities differed at 35 °C compared with 45 °C, and acetoclastic and hydrogenotrophic methanogenesis dominated, respectively. Changing the incubation of the 45 °C soil to different temperatures (25, 30, 35, 40, 45, 50 °C) resulted in a dynamic change of both microbial community structure and stable isotope fractionation. In all treatments, acetate first accumulated and then decreased. Propionate was also transiently produced and consumed. It is noteworthy that acetate was also consumed at thermophilic conditions, although archaeal community composition and stable isotope fractionation indicated that acetoclastic methanogenesis did not operate. Instead, acetate must have been consumed by syntrophic acetate oxidizers. The transient accumulation and subsequent consumption of acetate at thermophilic conditions was specifically paralleled by terminal restriction fragments characteristic for clostridial cluster I, whereas those of clostridial clusters I and III, Acidaminococcaceae and Heliobacteraceae, paralleled the thermophilic turnover of both acetate and propionate. KW - Syntrophic acetate oxidation KW - Thermophilic microbial community KW - Terminal restriction fragment length polymorphism KW - Bacteria KW - Archaea KW - Structure and function KW - Methanogenic archael community KW - Temperature shift PY - 2010 DO - https://doi.org/10.1111/j.1574-6941.2010.00883.x SN - 0168-6496 SN - 1574-6941 VL - 73 IS - 2 SP - 215 EP - 225 PB - Blackwell Publishing CY - Oxford AN - OPUS4-21671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Conrad, R. A1 - Klose, M. A1 - Noll, Matthias T1 - Functional and structural response of the methanogenic microbial community in rice field soil to temperature change JF - Environmental microbiology N2 - The microbial community in anoxic rice field soil produces CH4 over a wide temperature range up to 55°C. However, at temperatures higher than about 40°C, the methanogenic path changes from CH4 production by hydrogenotrophic plus acetoclastic methanogenesis to exclusively hydrogenotrophic methanogenesis and simultaneously, the methanogenic community consisting of Methanosarcinaceae, Methanoseataceae, Methanomicrobiales, Methanobacteriales and Rice Cluster I (RC-1) changes to almost complete dominance of RC-1. We studied changes in structure and function of the methanogenic community with temperature to see whether microbial members of the community were lost or their function impaired by exposure to high temperature. We characterized the function of the community by the path of CH4 production measuring δ13C in CH4 and CO2 and calculating the apparent fractionation factor (αapp) and the structure of the community by analysis of the terminal restriction fragment length polymorphism (T-RFLP) of the microbial 16S rRNA genes. Shift of the temperature from 45°C to 35°C resulted in a corresponding shift of function and structure, especially when some 35°C soil was added to the 45°C soil. The bacterial community (T-RFLP patterns), which was much more diverse than the archaeal community, changed in a similar manner upon temperature shift. Incubation of a mixture of 35°C and 50°C pre-incubated methanogenic rice field soil at different temperatures resulted in functionally and structurally well-defined communities. Although function changed from a mixture of acetoclastic and hydrogenotrophic methanogenesis to exclusively hydrogenotrophic methanogenesis over a rather narrow temperature range of 42-46°C, each of these temperatures also resulted in only one characteristic function and structure. Our study showed that temperature conditions defined structure and function of the methanogenic microbial community. KW - Structure and function KW - Methanogenic archaeal community KW - Temperature shift PY - 2009 DO - https://doi.org/10.1111/j.1462-2920.2009.01909.x SN - 1462-2912 SN - 1462-2920 VL - 11 IS - 7 SP - 1844 EP - 1853 PB - Blackwell Science CY - Oxford AN - OPUS4-19596 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nöll, G. A1 - Daub, J. A1 - Lutz, M. A1 - Rurack, Knut T1 - Synthesis, spectroscopic properties, and electropolymerization of azulene dyads JF - The journal of organic chemistry N2 - Four azulene dyads have been synthesized and studied by spectroscopic and electrochemical methods. A triarylamine, a boron-dipyrromethene (BDP or BODIPY), a porphyrin, and an isoalloxazine moiety have been linked to an extended π electron system at the 2-position of azulene, leading to the dyads 1–4, respectively. For the synthesis of 1–4, first 2-(4-ethynyl-phenyl)azulene (EPA) was prepared, which was further reacted with the halogenated chromophores by Pd-catalyzed cross-coupling reactions. The dyads 1–4 exhibit strong absorption bands in the visible range, which are dominated by the absorption spectra of the individual subchromophores. Fluorometric studies of 2–4 revealed that after excitation of the subchromophoric unit attached to the parent azulene moiety, quenching mainly through energy transfer to azulene is effective, whereas possible charge-transfer interactions play only a minor role. Potentiodynamic oxidation of the dyads 1–4 leads to the formation of polymer films, which are deposited at the electrode. The polymer film derived from 1 was further characterized by spectroelectrochemistry. During positive doping of poly-1, a strong absorption band appears at 13,200 cm–1, which is typical for triarylamine radical cations. This band is overlapping with a broad absorption band in the low-energy region that might be caused by charge-transfer interactions within the polymer. KW - Azulen KW - Elektropolymerisation KW - Energietransfer KW - Farbstoffe KW - Fluoreszenz PY - 2011 DO - https://doi.org/10.1021/jo200080v SN - 0022-3263 SN - 1520-6904 VL - 76 IS - 12 SP - 4859 EP - 4873 PB - American Chemical Society CY - Washington, DC AN - OPUS4-23987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shrestha, P.M. A1 - Noll, Matthias A1 - Liesack, W. T1 - Phylogenetic identity, growth-response time and rRNA operon copy number of soil bacteria indicate different stages of community succession JF - Environmental microbiology N2 - Bacterial community succession corresponds to changes in the phylogenetic identity, growth-response time and rRNA operon (rrn) copy number of culturable populations. To test this hypothesis, we compared the bacterial fractions culturable from the oxic zone of flooded, unplanted paddy soil microcosms after 1-day (early succession) and 70-day (late succession) incubation periods. The proportion of bacteria that was cultivable on solid media corresponded for early and late succession to 37–40% and 31–35% of total DAPI cell counts, which were 7.40 (±0.36) × 108 and 5.54 (±0.28) × 108 cells per gram of dry soil, respectively. In colony-forming curve analysis, late successional bacteria showed a significant delay in their growth response compared with those from early succession. A total of 59 early successional isolates grouped into 16 species-level clusters (SLC) plus three Bacilli-like SLC, while 66 late successional isolates formed 25 SLC plus five Bacilli-like SLC. Except Bacilli-like spp., isolates from early succession always belonged to different SLC than those from late succession. Betaproteobacteria and Gammaproteobacteria were typical of the early stage, while Alphaproteobacteria and Actinobacteria prevailed in late succession. Considering all SLC except those assigned to Bacilli, growth-response time and rrn copy number were significantly correlated with successional stage. Isolates of most early successional SLC (14 of 16) formed visible colonies within 1 (11 SLC) or 2 days (three SLC) and contained = 4 rrn copies. In contrast, isolates of late successional SLC (23 of 25) formed visible colonies within 2 days (four SLC) or, in most cases, only within 3–15 days (19 SLC) and contained = 2 rrn copies. Regardless of whether isolated from early or late succession, Bacilli-like isolates always showed a colony-forming time of 2 days and had 9–11 rrn copies. KW - Paddy soil KW - Oxic zone KW - Succession KW - Cultivation KW - Bacterial community PY - 2007 SN - 1462-2912 SN - 1462-2920 VL - 9 IS - 10 SP - 2464 EP - 2474 PB - Blackwell Science CY - Oxford AN - OPUS4-15785 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Urmann, K. A1 - Schroth, M.H. A1 - Noll, Matthias A1 - Gonzalez-Gil, G. A1 - Zeyer, J. T1 - Assessment of microbial methane oxidation above a petroleum-contaminated aquifer using a combination of in situ techniques JF - Journal of geophysical research / G N2 - Emissions of the greenhouse gas CH4, which is often produced in contaminated aquifers, are reduced or eliminated by microbial CH4 oxidation in the overlying vadose zone. The aim of this field study was to estimate kinetic parameters and isotope fractionation factors for CH4 oxidation in situ in the vadose zone above a methanogenic aquifer in Studen, Switzerland, and to characterize the involved methanotrophic communities. To quantify kinetic parameters, several field tests, so-called gas push-pull tests (GPPTs), with CH4 injection concentrations ranging from 17 to 80 mL L-1 were performed. An apparent Vmax of 0.70 ± 0.15 mmol CH4 (L soil air)-1 h-1 and an apparent Km of 0.28 ± 0.09 mmol CH4 (L soil air)-1 was estimated for CH4 oxidation at 2.7 m depth, close to the groundwater table. At 1.1 m depth, Km (0.13 ± 0.02 mmol CH4 (L soil air)-1) was in a similar range, but Vmax (0.076 ± 0.006 mmol CH4 (L soil air)-1 h-1) was an order of magnitude lower. At 2.7 m, apparent first-order rate constants determined from a CH4 gas profile (1.9 h-1) and from a single GPPT (2.0 ± 0.03 h-1) were in good agreement. Above the groundwater table, a Vmax much higher than the in situ CH4 oxidation rate prior to GPPTs indicated a high buffer capacity for CH4. At both depths, known methanotrophic species affiliated with Methylosarcina and Methylocystis were detected by cloning and sequencing. Apparent stable carbon isotope fractionation factors a for CH4 oxidation determined during GPPTs ranged from 1.006 to 1.032. Variability was likely due to differences in methanotrophic activity and CH4 availability leading to different degrees of mass transfer limitation. This complicates the use of stable isotopes as an independent quantification method. KW - In situ quantification KW - Kinetics of microbial methane (CH4) oxidation KW - Stable isotope fractionation PY - 2008 DO - https://doi.org/10.1029/2006JG000363 SN - 0148-0227 VL - 113 SP - 02006-1-02006-11 PB - American Geophysical Union CY - Washington, DC AN - OPUS4-17332 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -