TY - JOUR A1 - Schulze-Makuch, D. A1 - Haque, S. A1 - Beckles, D. A1 - Schmitt-Kopplin, P. A1 - Harir, M. A1 - Schneider, Beate A1 - Stumpp, C. A1 - Wagner, D. T1 - A chemical and microbial characterization of selected mud volcanoes in Trinidad reveals pathogens introduced by surface water and rain water N2 - Terrestrial mud volcanoes are unique structures driven by tectonic pressure and fluids from the deep subsurface. These structures are mainly found in active tectonic zones, such as the area near the Los Bajos Fault in Trinidad. Here we report a chemical and microbiological characterization of three mud volcanoes, which included analyses of multiple liquid and solid samples from the mud volcanoes. Our study confirms previous suggestions that at least some of the mud volcano fluids are a mixture of deeper salt-rich water and surficial/precipitation water. No apparent water quality differences were found between sampling sites north and south of a major geological fault line. Microbiological analyses revealed diverse communities, both aerobic and anaerobic, including sulfate reducers, methanogens, carbon dioxide fixing and denitrifying bacteria. Several identified species were halophilic and likely derived from the deeper salt-rich subsurface water, while we also cultivated pathogenic species from the Vibrionaceae, Enterobacteriaceae, Shewanellaceae, and Clostridiaceae. These microorganisms were likely introduced into the mud volcano fluids both from surface water or shallow ground-water, and perhaps to a more minor degree by rain water. The identified pathogens are a major health concern that needs to be addressed. KW - Water stable isotope analysis KW - Mud volcanoe fluids KW - Metabolomics PY - 2020 DO - https://doi.org/10.1016/j.scitotenv.2019.136087 VL - 707 SP - 136087 PB - Elsevier B.V. AN - OPUS4-50499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vandrich, Jasmina A1 - Pfeiffer, F. A1 - Alfaro Espinoza, Gabriela A1 - Kunte, Hans-Jörg T1 - Contribution of mechanosensitive channels to osmoadaptation and ectoine excretion in Halomonas elongata N2 - For osmoadaptation the halophilic bacterium Halomonas elongata synthesizes as its main compatible solute the aspartate derivative ectoine. H. elongata does not rely entirely on synthesis but can accumulate ectoine by uptake from the surrounding environment with the help of the osmoregulated transporter TeaABC. Disruption of the TeaABC-mediated ectoine uptake creates a strain that is constantly losing ectoine to the medium. However, the efflux mechanism of ectoine in H. elongata is not yet understood. H. elongata possesses four genes encoding mechanosensitive channels all of which belong to the small conductance type (MscS). Analysis by qRT-PCR revealed a reduction in transcription of the mscS genes with increasing salinity. The response of H. elongata to hypo- and hyperosmotic shock never resulted in up-regulation but rather in downregulation of mscS transcription. Deletion of all four mscS genes created a mutant that was unable to cope with hypoosmotic shock. However, the knockout mutant grew significantly faster than the wildtype at high salinity of 2 M NaCl, and most importantly, still exported 80% of the ectoine compared to the wildtype. We thus conclude that a yet unknown system, which is independent of mechanosensitive channels, is the major export route for ectoine in H. elongata. KW - Halomonas elongata KW - Ectoine KW - Osmotic shock KW - Solute excretion KW - Osmoadaptation KW - Mechanosensitive channel KW - MscS PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507229 DO - https://doi.org/10.1007/s00792-020-01168-y VL - 24 SP - 421 EP - 432 PB - Springer AN - OPUS4-50722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hobmeier, K. A1 - Goëss, M. C. A1 - Sehr, C. A1 - Schwaminger, S. A1 - Berensmeier, S. A1 - Kremling, A. A1 - Kunte, Hans-Jörg A1 - Pflüger-Grau, K. A1 - Marin-Sanguino, A. T1 - Anaplerotic Pathways in Halomonas elongata: The Role of the Sodium Gradient N2 - Salt tolerance in the γ-proteobacterium Halomonas elongata is linked to its ability to produce the compatible solute ectoine. The metabolism of ectoine production is of great interest since it can shed light on the biochemical basis of halotolerance as well as pave the way for the improvement of the biotechnological production of such compatible solute. Ectoine belongs to the biosynthetic family of aspartate-derived amino-acids. Aspartate is formed from oxaloacetate, thereby connecting ectoine production to the anaplerotic reactions that refill carbon into the tricarboxylic acid cycle (TCA cycle). This places a high demand on these reactions and creates the need to regulate them not only in response to growth but also in response to extracellular salt concentration. In this work, we combine modeling and experiments to analyze how these different needs shape the anaplerotic reactions in H. elongata. First, the stoichiometric and thermodynamic factors that condition the flux distributions are analyzed, then the optimal patterns of operation for oxaloacetate production are calculated. Finally, the phenotype of two deletion mutants lacking potentially relevant anaplerotic enzymes: phosphoenolpyruvate carboxylase (Ppc) and oxaloacetate decarboxylase (Oad) are experimentally characterized. The results show that the anaplerotic reactions in H. elongata are indeed subject to evolutionary pressures that differ from those faced by other gram-negative bacteria. Ectoine producing halophiles must meet a higher metabolic demand for oxaloacetate and the reliance of many marine bacteria on the Entner-Doudoroff pathway compromises the anaplerotic efficiency of Ppc, which is usually one of the main enzymes fulfilling this role. The anaplerotic flux in H. elongata is contributed not only by Ppc but also by Oad, an enzyme that has not yet been shown to play this role in vivo. Ppc is necessary for H. elongata to grow normally at low salt concentrations but it is not required to achieve near maximal growth rates as long as there is a steep sodium gradient. On the other hand, the lack of Oad presents serious difficulties to grow at high salt concentrations. This points to a shared role of these two enzymes in guaranteeing the supply of oxaloacetate for biosynthetic reactions. KW - Metabolic flux analysis KW - Halophilic bacteria KW - Halomonas elongata KW - Metabolic modeling PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513124 DO - https://doi.org/10.3389/fmicb.2020.561800 VL - 11 SP - 561800 AN - OPUS4-51312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wittmar, J. A1 - Meyer, Susann A1 - Sieling, T. A1 - Kunte, Hans-Jörg A1 - Smiatek, Jens A1 - Brand, Izabella T1 - What Does Ectoine Do to DNA? A Molecular-Scale Picture of Compatible Solute−Biopolymer Interactions N2 - Compatible solutes are accumulated in the cytoplasm of halophilic microorganisms. These molecules enable their survival in a high salinity environment. Ectoine is such a compatible solute. It is a zwitterionic molecule which strongly interacts with surrounding water molecules and changes the dynamics of the local hydration shell. Ectoine interacts with biomolecules such as lipids, proteins and DNA. The molecular interaction between ectoine and biomolecules in particular the interaction between ectoine and DNA is far from being understood. In this paper we describe molecular aspects of the interaction between ectoine and double stranded DNA(dsDNA). Two 20 base pairs long dsDNA fragments were immobilized on a Gold surface via a thiol-tether. The interaction between the dsDNA monolayers with diluted and concentrated ectoine solutions was examined by means of X-ray photoelectron and polarization modulation infrared reflection absorption spectroscopies (PM IRRAS). Experimental results indicate that the ability of ectoine to bind water reduces the strength of hydrogen bonds formed to the ribose-phosphate backbone in the dsDNA. In diluted (0.1 M) ectoine solution, DNA interacts predominantly with water molecules. The sugar-phosphate backbone is involved in the formation of strong hydrogen bonds to water, which with elapsing time leads to a reorientation of the planes of nucleic acid bases. This reorientation destabilizes the hydrogen bonds strength between the bases and leads to a partial dehybridizaiton of the dsDNA. In concentrated ectoine solution (2.5 M), almost all water molecules interact with ectoine. Under this condition ectoine is able to interact directly with DNA. Density functional theory (DFT) calculations demonstrate that the direct interaction involves the nitrogen atoms in ectoine and phosphate groups in the DNA molecule. The results of the quantum chemical calculations Show that rearrangements in the ribose-phosphate backbone, caused by a direct interaction with ectoine, facilitates contacts between O atom in the phosphate group and H atoms in a nucleic acid base. In the PM IRRA spectra, an increase in the number of the IR absorption modes in the base pair frequency region proves that the hydrogen bonds between bases become weaker. Thus, a sequence of reorientations caused by interaction with ectoine leads to a breakdown of hydrogen bonds between bases in the double helix. KW - Compatible solute KW - Ectoine KW - DNA KW - Self-assembled monolayer KW - IR spectroscopy KW - XPS PY - 2020 DO - https://doi.org/10.1021/acs.jpcb.0c05273 VL - 124 IS - 37 SP - 7999 EP - 8011 PB - ACS Publicatios AN - OPUS4-51182 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Xu, Yong A1 - Huang, Yanliang A1 - Yang, D. A1 - Kunte, Hans-Jörg A1 - De Marco, R. A1 - Wang, X. T1 - Investigation of the calcareous deposits formation controlled by interfacial pH and its effect on the hydrogen entry into AISI 4135 steel in seawater N2 - The influence of interfacial pH between AISI 4135 steel and seawater under different polarization potentials on the formation of calcareous deposits has been studied. An interfacial pH of 9.61 at −0.9 V vs. SCE using state of the art iridium oxide microelectrode was found to be the critical pH for the precipitation of magnesium hydroxide. Calcareous deposits with a double-layer structure comprising an inner-brucite layer and an outer-aragonite layer were found to form at potentials between −1.0 V and −1.2 V vs. SCE. Furthermore, the facilitation of hydrogen permeation into steel induced by the formation of calcareous deposits was verified using the Devanathan-Stachurski electrochemical test. The mechanism of calcareous deposits facilitates hydrogen permeation into steel is related to its inhibition on hydrogen recombination and escape processes. KW - Low alloy steel KW - Cathodic protection KW - Calcareous deposits KW - Hydrogen permeation PY - 2020 DO - https://doi.org/10.1016/j.ijhydene.2020.11.040 SN - 0360-3199 SP - 1 EP - 18 PB - Elsevier Ltd. AN - OPUS4-51730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Richter, Anja A1 - Possling, A. A1 - Malysheva, N. A1 - Yousef, K. P. A1 - Herbst, S. A1 - von Kleist, M. A1 - Hengge, R. T1 - Local c-di-GMP signaling in the control of synthesis of the E. coli biofilm exopolysaccharide pEtN-cellulose N2 - In many bacteria, the biofilm-promoting second messenger c-di-GMP is produced and degraded by multiple diguanylate cyclases (DGC) and phosphodiesterases (PDE), respectively. High target specificity of some of these enzymes has led to theoretical concepts of "local" c-di-GMP signaling. In Escherichia coli K-12, which has 12 DGCs and 13 PDEs, a single DGC, DgcC, is specifically required for the biosynthesis of the biofilm exopolysaccharide pEtN-cellulose without affecting the cellular c-di-GMP pool, but the mechanistic basis of this target specificity has remained obscure. DGC activity of membrane-associated DgcC, which is demonstrated in vitro in nanodiscs, is shown to be necessary and sufficient to specifically activate cellulose biosynthesis in vivo. DgcC and a particular PDE, PdeK (encoded right next to the cellulose operon), directly interact with cellulose synthase subunit BcsB and with each other, thus establishing physical proximity between cellulose synthase and a local source and sink of c-di-GMP. This arrangement provides a localized, yet open source of c-di-GMP right next to cellulose synthase subunit BcsA, which needs allosteric activation by c-di-GMP. Through mathematical modeling and simulation, we demonstrate that BcsA binding from the low cytosolic c-di-GMP pool in E. coli is negligible, whereas a single c-di-GMP molecule that is produced and released in direct proximity to cellulose synthase increases the probability of c-di-GMP binding to BcsA several hundred-fold. This local c-di-GMP signaling could provide a blueprint for target-specific second messenger signaling also in other bacteria where multiple second messenger producing and degrading enzymes exist. KW - Biofilm KW - Cellulose synthase KW - Bacterial second messenger KW - C-di-GMP PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511214 DO - https://doi.org/10.1016/j.jmb.2020.06.006 SN - 0022-2836 VL - 432 IS - 16 SP - 4576 EP - 4595 PB - Elsevir Ltd. AN - OPUS4-51121 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wittmar, J. A1 - Ohle, Corina A1 - Kunte, Hans-Jörg A1 - Brand, I. T1 - Effect of Ectoine on the Conformation and Hybridization of dsDNA in Monolayer Films: A Spectroelectrochemical Study N2 - Lack of long-time stability of dsDNA-based supramolecular assemblies is an important issue that hinders their applications. In this work, 20 base pairs long dsDNA fragments [(dCdG)20 65%] composed of 65% dCdG and 35% dAdT nucleotides were tethered via a thiol to the surface of a gold electrode. The selfassembled (dCdG)20 -65% monolayer was immersed in solutions containing ectoine, a compatible solute. Electrochemical results showed that these monolayers were stable for one month. In situ IR spectroscopy indicated that ectoine interacts weakly with the phosphate-ribose backbone, dehydrating the phosphate groups and stabilizing the A-DNA conformation. This structural reorganization led to a reorientation of nucleic acid base pairs and a local disruption of the double-helix structure. However, the conformation and orientation of the dsDNA fragment was stable in the KW - Ectoine KW - dsDAN monolayer KW - A-DNA conformation PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533346 DO - https://doi.org/10.1002/celc.202100816 SN - 2196-0216 VL - 8 IS - 20 SP - 3844 EP - 3854 PB - Wiley-VCH GmbH AN - OPUS4-53334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulze-Makuch, D. A1 - Lipus, D. A1 - Arens, F. L. A1 - Baque, M. A1 - Bornemann, T. L. V. A1 - de Vera, J. P. A1 - Flury, M. A1 - Froesler, J. A1 - Heinz, J. A1 - Hwang, Y. A1 - Kounaves, S. P. A1 - Mangelsdorf, K. A1 - Meckenstock, R. U. A1 - Pannekens, M. A1 - Probst, A. J. A1 - Saenz, J. S. A1 - Schirmack, J. A1 - Schloter, M. A1 - Schmitt-Kopplin, P. A1 - Schneider, Beate A1 - Uhl, J. A1 - Vestergaard, G. A1 - Valenzuela, B. A1 - Zamorano, P. A1 - Wagner, D. T1 - Microbial hotspots in lithic microhabitats inferred from DNA fractionation and metagenomics in the Atacama Desert N2 - The existence of microbial activity hotspots in temperate regions of Earth is driven by soil heterogeneities, especially the temporal and spatial availability of nutrients. Here we investigate whether microbial activity hotspots also exist in lithic microhabitats in one of the most arid regions of the world, the Atacama Desert in Chile. While previous studies evaluated the total DNA fraction to elucidate the microbial communities, we here for the first time use a DNA separation approach on lithic microhabitats, together with metagenomics and other analysis methods (i.e., ATP, PLFA, and metabolite analysis) to specifically gain insights on the living and potentially active microbial community. Our results show that hypolith colonized rocks are microbial hotspots in the desert environment. In contrast, our data do not support such a conclusion for gypsum crust and salt rock environments, because only limited microbial activity could be observed. The hypolith community is dominated by phototrophs, mostly Cyanobacteria and Chloroflexi, at both study sites. The gypsum crusts are dominated by methylotrophs and heterotrophic phototrophs, mostly Chloroflexi, and the salt rocks (halite nodules) by phototrophic and halotolerant endoliths, mostly Cyanobacteria and Archaea. The major environmental constraints in the organic-poor arid and hyperarid Atacama Desert are water availability and UV irradiation, allowing phototrophs and other extremophiles to play a key role in desert ecology. KW - Desert ecology KW - Extremophile KW - Hyperarid PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527959 DO - https://doi.org/10.3390/microorganisms9051038 SN - 2076-2607 VL - 9 IS - 5 SP - 1038 PB - MDPI CY - Basel AN - OPUS4-52795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hobmeier, K. A1 - Cantone, M. A1 - Nguyen, Q. A. A1 - Pflüger-Grau, K. A1 - Kremling, A. A1 - Kunte, Hans-Jörg A1 - Pfeiffer, F. A1 - Marin-Sanguino, A. T1 - Adaptation to varying salinity in Halomonas elongata: Much more than ectoine accumulation N2 - The halophilic γ-proteobacterium Halomonas elongata DSM 2581T thrives at salt concentrations well above 10 % NaCl (1.7 M NaCl). A well-known osmoregulatory mechanism is the accumulation of the compatible solute ectoine within the cell in response to osmotic stress. While ectoine accumulation is central to osmoregulation and promotes resistance to high salinity in halophilic bacteria, ectoine has this effect only to a much lesser extent in non-halophiles. We carried out transcriptome analysis of H. elongata grown on two different carbon sources (acetate or glucose), and low (0.17 M NaCl), medium (1 M), and high salinity (2 M) to identify additional mechanisms for adaptation to high saline environments. To avoid a methodological bias, the transcripts were evaluated by applying two methods, DESeq2 and Transcripts Per Million (TPM). The differentially transcribed genes in response to the available carbon sources and salt stress were then compared to the transcriptome profile of Chromohalobacter salexigens, a closely related moderate halophilic bacterium. Transcriptome profiling supports the notion that glucose is degraded via the cytoplasmic Entner-Doudoroff pathway, whereas the Embden-Meyerhoff-Parnas pathway is employed for gluconeogenesis. The machinery of oxidative phosphorylation in H. elongata and C. salexigens differs greatly from that of non-halophilic organisms, and electron flow can occur from quinone to oxygen along four alternative routes. Two of these pathways via cytochrome bo' and cytochrome bd quinol oxidases seem to be upregulated in salt stressed cells. Among the most highly regulated genes in H. elongata and C. salexigens are those encoding chemotaxis and motility proteins, with genes for chemotaxis and flagellar assembly severely downregulated at low salt concentrations. We also compared transcripts at low and high-salt stress (low growth rate) with transcripts at optimal salt concentration and found that the majority of regulated genes were down-regulated in stressed cells, including many genes involved in carbohydrate metabolism, while ribosome synthesis was up-regulated, which is in contrast to what is known from non-halophiles at slow growth. Finally, comparing the acidity of the cytoplasmic proteomes of non-halophiles, extreme halophiles and moderate halophiles suggests adaptation to an increased cytoplasmic ion concentration of H. elongata. Taken together, these results lead us to propose a model for salt tolerance in H. elongata where ion accumulation plays a greater role in salt tolerance than previously assumed. KW - Ectoine KW - Osmoadaptation PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545608 DO - https://doi.org/10.3389/fmicb.2022.846677 SN - 1664-302X VL - 13 SP - 1 EP - 19 PB - Frontiers Media CY - Lausanne AN - OPUS4-54560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cros, A. A1 - Alfaro Espinoza, Gabriela A1 - De Maria, A. A1 - Wirth, N. T. A1 - Nikel, P. I. T1 - Synthetic metabolism for biohalogenation N2 - The pressing need for novel bioproduction approaches faces a limitation in the number and type of molecules accessed through synthetic biology. Halogenation is widely used for tuning physicochemical properties of molecules and polymers, but traditional halogenation chemistry often lacks specificity and generates harmful by-products. Here, we pose that deploying synthetic metabolism tailored for biohalogenation represents an unique opportunity towards economically attractive and environmentally friendly organohalide production. On this background, we discuss growth-coupled selection of functional metabolic modules that harness the rich repertoire of biosynthetic and biodegradation capabilities of environmental bacteria for in vivo biohalogenation. By rationally combining these approaches, the chemical landscape of Living cells can accommodate bioproduction of added-value organohalides which, as of today, are obtained by traditional chemistry. KW - Halogenation KW - Synthetic metabolism PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542013 DO - https://doi.org/10.1016/j.copbio.2021.11.009 SN - 0958-1669 SN - 1879-0429 VL - 74 SP - 180 EP - 193 PB - Elsevier CY - Amsterdam AN - OPUS4-54201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Beate A1 - Pfeiffer, F. A1 - Dyall-Smith, M. A1 - Kunte, Hans-Jörg T1 - Genome Sequence of Micromonospora aurantiaca Strain G9, a Member of a Bacterial Consortium Capable of Polyethylene Degradation N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G9 was determined by PacBio sequencing. Using the TYGS server for taxonomic classification, strain G9 was assigned to the species Micromonospora aurantiaca. KW - Polyethylene KW - Micromonospora aurantiaca KW - Degradation KW - iChip PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547181 DO - https://doi.org/10.1128/mra.01148-21 SN - 2576-098X VL - 11 IS - 5 SP - 1 EP - 2 PB - American Society for Microbiology CY - Washington, DC AN - OPUS4-54718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Beate A1 - Pfeiffer, F. A1 - Dyall-Smith, M. A1 - Kunte, Hans-Jörg T1 - Genome Sequence of Pseudomonas veronii Strain G2, a Member of a Bacterial Consortium Capable of Polyethylene Degradation N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G2 was determined by PacBio sequencing. Using the TYGS server for taxonomic classification, strain G2 was assigned to the species Pseudomonas veronii. KW - Polyethylene KW - Next generation sequencing KW - Pseudomonas veronii PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548973 DO - https://doi.org/10.1128/mra.00365-22 SP - 1 EP - 2 PB - ASM AN - OPUS4-54897 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Beate A1 - Pfeiffer, F. A1 - Dyall-Smith, M. A1 - Kunte, Hans-Jörg T1 - Genome Sequence of Cupriavidus campinensis Strain G5, a Member of a Bacterial Consortium Capable of Polyethylene Degradation N2 - Nine different bacterial isolates were recovered from landfills. Each isolate was obtained in pure culture. As a consortium, the bacteria degrade polyethylene. The complete genome sequence of strain G5 was determined by PacBio sequencing. Using the TYGS for taxonomic classification, strain G5 was assigned to the species Cupriavidus campinensis. KW - Polyethylene KW - Cupriavidus campinensis KW - Plastic degradation KW - Genome sequence PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557897 DO - https://doi.org/10.1128/mra.00553-22 SP - 1 EP - 2 PB - ASM AN - OPUS4-55789 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hobmeier, K. A1 - Oppermann, M. A1 - Stasinski, N. A1 - Kremling, A. A1 - Pflüger-Grau, K. A1 - Kunte, Hans-Jörg A1 - Marin Sanguino, A. T1 - Metabolic engineering of Halomonas elongata: Ectoine secretion is increased by demand and supply driven approaches N2 - The application of naturally-derived biomolecules in everyday products, replacing conventional synthetic manufacturing, is an ever-increasing market. An example of this is the compatible solute ectoine, which is contained in a plethora of treatment formulations for medicinal products and cosmetics. As of today, ectoine is produced in a scale of tons each year by the natural producer Halomonas elongata. In this work, we explore two complementary approaches to obtain genetically improved producer strains for ectoine production. We explore the effect of increased precursor supply (oxaloacetate) on ectoine production, as well as an implementation of increased ectoine demand through the overexpression of a transporter. Both approaches were implemented on an already genetically modified ectoine-excreting strain H. elongata KB2.13 (ΔteaABC ΔdoeA) and both led to new strains with higher ectoine excretion. The supply driven approach led to a 45% increase in ectoine titers in two different strains. This increase was attributed to the removal of phosphoenolpyruvate carboxykinase (PEPCK), which allowed the conversion of 17.9% of the glucose substrate to ectoine. For the demand driven approach, we investigated the potential of the TeaBC transmembrane proteins from the ectoine-specific Tripartite ATP-Independent Periplasmic (TRAP) transporter as export channels to improve ectoine excretion. In the absence of the substrate-binding protein TeaA, an overexpression of both subunits TeaBC facilitated a three-fold increased excretion rate of ectoine. Individually, the large subunit TeaC showed an approximately five times higher extracellular ectoine concentration per dry weight compared to TeaBC shortly after its expression was induced. However, the detrimental effect on growth and ectoine titer at the end of the process hints toward a negative impact of TeaC overexpression on membrane integrity and possibly leads to cell lysis. By using either strategy, the ectoine synthesis and excretion in H. elongata could be boosted drastically. The inherent complementary nature of these approaches point at a coordinated implementation of both as a promising strategy for future projects in Metabolic Engineering. Moreover, a wide variation of intracelllular ectoine levels was observed between the strains, which points at a major disruption of mechanisms responsible for ectoine regulation in strain KB2.13. KW - Osmoadaptation KW - Metabolic engineering PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555644 DO - https://doi.org/10.3389/fmicb.2022.968983 SN - 1664-302X VL - 13 SP - 1 EP - 13 PB - Frontiers Media CY - Lausanne AN - OPUS4-55564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Keshmiri, Hamid A1 - Cikes, Domagoj A1 - Samalova, Marketa A1 - Schindler, Lukas A1 - Appel, Lisa-Marie A1 - Urbanek, Michal A1 - Yudushkin, Ivan A1 - Slade, Dea A1 - Weninger, Wolfgang J. A1 - Peaucelle, Alexis A1 - Penninger, Josef A1 - Elsayad, Kareem T1 - Brillouin light scattering anisotropy microscopy for imaging the viscoelastic anisotropy in living cells N2 - Maintaining and modulating mechanical anisotropy is essential for biological processes. However, how this is achieved at the microscopic scale in living soft matter is not always clear. Although Brillouin light scattering (BLS) spectroscopy can probe the mechanical properties of materials, spatiotemporal mapping of mechanical anisotropies in living matter with BLS microscopy has been complicated by the need for sequential measurements with tilted excitation and detection angles. Here we introduce Brillouin light scattering anisotropy microscopy (BLAM) for mapping high-frequency viscoelastic anisotropy inside living cells. BLAM employs a radial virtually imaged phased array that enables the collection of angle-resolved dispersion in a single shot, thus enabling us to probe phonon modes in living matter along different directions simultaneously. We demonstrate a precision of 10 MHz in the determination of the Brillouin frequency shift, at a spatial resolution of 2 µm. Following proof-of-principle experiments on muscle myofibres, we apply BLAM to the study of two fundamental biological processes. In plant cell walls, we observe a switch from anisotropic to isotropic wall properties that may lead to asymmetric growth. In mammalian cell nuclei, we uncover a spatiotemporally oscillating elastic anisotropy correlated to chromatin condensation. Our results highlight the role that high-frequency mechanics can play in the regulation of diverse fundamental processes in biological systems. We expect BLAM to find diverse applications in biomedical imaging and material characterization. KW - Optical and magnetic materials KW - Atomic and molecular physics and optics KW - Electronic PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595125 DO - https://doi.org/10.1038/s41566-023-01368-w SN - 1749-4885 SN - 1749-4893 VL - 18 IS - 3 SP - 276 EP - 285 PB - Nature Publ. Group CY - London AN - OPUS4-59512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schneider, Beate A1 - Pfeiffer, Friedhelm A1 - Remus, Daniela A1 - Dyall-Smith, Mike A1 - Kunte, Hans-Jörg ED - Klepac-Ceraj, Vanja T1 - Genome sequence of Pseudomonas silesiensis strain G3, a member of a bacterial consortium capable of polyethylene degradation N2 - A consortium of landfill bacteria including strain G3 can break down polyethylene, a long-lasting plastic that accumulates in the environment. The complete genome sequence of strain G3 was determined by PacBio and Nanopore sequencing and consists of three circular replicons. Genome-based classification assigned strain G3 to the species Pseudomonas silesiensis. KW - PE degradation KW - Polyethylene PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611618 DO - https://doi.org/10.1128/mra.00138-24 SN - 2576-098X VL - 13 IS - 11 SP - 1 EP - 3 PB - American Society for Microbiology AN - OPUS4-61161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braymer, Joseph J. A1 - Stehling, Oliver A1 - Stümpfig, Martin A1 - Rösser, Ralf A1 - Spantgar, Farah A1 - Blinn, Catharina M. A1 - Mühlenhoff, Ulrich A1 - Pierik, Antonio J. A1 - Lill, Roland T1 - Requirements for the biogenesis of [2Fe-2S] proteins in the human and yeast cytosol N2 - The biogenesis of iron–sulfur (Fe/S) proteins entails the synthesis and trafficking of Fe/S clusters, followed by their insertion into target apoproteins. In eukaryotes, the multiple steps of biogenesis are accomplished by complex protein machineries in both mitochondria and cytosol. The underlying biochemical pathways have been elucidated over the past decades, yet the mechanisms of cytosolic [2Fe-2S] protein assembly have remained ill-defined. Similarly, the precise site of glutathione (GSH) requirement in cytosolic and nuclear Fe/S protein biogenesis is unclear, as is the molecular role of the GSH-dependent cytosolic monothiol glutaredoxins (cGrxs). Here, we investigated these questions in human and yeast cells by various in vivo approaches. [2Fe-2S] cluster assembly of cytosolic target apoproteins required the mitochondrial ISC machinery, the mitochondrial transporter Atm1/ABCB7 and GSH, yet occurred independently of both the CIA system and cGrxs. This mechanism was strikingly different from the ISC-, Atm1/ABCB7-, GSH-, and CIA-dependent assembly of cytosolic–nuclear [4Fe-4S] proteins. One notable exception to this cytosolic [2Fe-2S] protein maturation pathway defined here was yeast Apd1 which used the CIA system via binding to the CIA targeting complex through its C-terminal tryptophan. cGrxs, although attributed as [2Fe-2S] cluster chaperones or trafficking proteins, were not essential in vivo for delivering [2Fe-2S] clusters to either CIA components or target apoproteins. Finally, the most critical GSH requirement was assigned to Atm1-dependent export, i.e. a step before GSH-dependent cGrxs function. Our findings extend the general model of eukaryotic Fe/S protein biogenesis by adding the molecular requirements for cytosolic [2Fe-2S] protein maturation. KW - Biokorrosion KW - Hydrogenasen KW - Microbially Induced Corrosion PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602328 DO - https://doi.org/10.1073/pnas.2400740121 SN - 0027-8424 VL - 121 IS - 21 SP - 1 EP - 12 PB - Proceedings of the National Academy of Sciences CY - Washington D.C. AN - OPUS4-60232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Usmani, S. A1 - Voss, L. A1 - Stephan, Ina A1 - Hübert, Thomas A1 - Kemnitz, E. T1 - Improved Durability of Wood Treated with Nano Metal Fluorides against Brown-Rot and White-Rot Fungi N2 - Low-water soluble metal fluorides such as magnesium fluoride (MgF2) and calcium Fluoride (CaF2) were evaluated for decay protection of wood. Initially, the biocidal efficacy of nano metal fluorides (NMFs) against wood destroying fungi was assessed with an in-vitro agar test. The results from the test showed that agar medium containing MgF2 and CaF2 was more efficient in preventing fungal decay than stand-alone MgF2 or CaF2. These metal fluorides, in their nanoscopic form synthesized using fluorolytic sol-gel synthesis, were introduced into the sapwood of Scots pine and beech wood and then subjected to accelerated ageing by leaching (EN 84). MAS 19F NMR and X-ray micro CT images showed that metal fluorides were present in treated wood, unleached and leached. Decay resistance of Scots pine and beech wood treated with NMFs was tested against Wood destroying fungi Rhodonia placenta and Trametes versicolor in accordance with EN 113. Results revealed that mass losses were reduced to below 3% in wood treated with the combination of MgF2 and CaF2. It is concluded that NMFs provide full protection to wood even after it has been leached and can be used as wood preservatives in outdoor environments. KW - Nanoparticles KW - Fluoride KW - Wood protection KW - Fluorolytic sol-gel synthesis KW - Brown-rot fungi KW - White-rot fungi KW - Basidiomycetes PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543877 DO - https://doi.org/10.3390/app12031727 VL - 12 IS - 3 SP - 1 EP - 11 PB - MDPI AN - OPUS4-54387 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Barkeshli, Mandana A1 - Stephan, Ina A1 - Shevchuk, Ivan A1 - Soltani, Mojtaba T1 - Characteristics of Sizing Materials Used in Persian Medieval Manuscripts: Physical, Optical, Spectral Imaging, and Fungicidal Properties N2 - In this study, we investigated the diverse range of materials used for sizing in Iranian paper manuscripts during the Timurid (fifteenth century) to Safavid (sixteenth century) and Qajar (nineteenth century) periods. Our approach combined historical analysis with scientific examination of reconstructed sizings. We reconstructed 15 sizing materials based on identified Persian historical recipes and analysed their physical, optical, and spectral characteristics. Additionally, we assessed their behaviour against the mould fungus Aspergillus flavus. The results revealed distinctive properties for each sizing material, shedding light on their potential applications in paper preservation. Furthermore, our investigation demonstrated variations in hygroscopicity, thickness, grammage, and ash content post-sizing. The sizing materials also exhibited different effects on paper reflectance properties. Additionally, our study revealed insights into the impact of sizing on burnished papers, indicating that the mechanical process of burnishing did not significantly alter the chemical composition or spectral properties of the paper, with only minor changes in brightness observed in specific cases. All tested sizing materials supported varying levels of mould growth, indicating potential implications for paper conservation. Our findings provide valuable insights into the historical practices of Iranian paper sizing and offer practical considerations for the preservation of paper manuscripts. KW - Paper sizings KW - Persian historical recipes KW - Physical and optical characteristics KW - Fungicidal property KW - Spectral imaging PY - 2024 DO - https://doi.org/10.1080/00393630.2024.2342647 VL - 69 SP - 519 EP - 536 PB - Informa UK Limited AN - OPUS4-60159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brischke, C. A1 - Bollmus, S. A1 - Melcher, E. A1 - Stephan, Ina T1 - Biological durability and moisture ynamics of Dawn redwood (Metasequoia glyptostroboides) and Port Orford cedar (Chamaecyparis lawsoniana) N2 - Numerous non-native tree species are given attention with respect to the reforestation of calamity areas in Europe. Among them, several species may form durable wood which can be used for outdoor applications, but differences in wood durability are expected between original and European growth sites. This study aimed at examining the biological durability against wooddestroying fungi and water permeability of German-grown Dawn redwood (Metasequoia glyptostroboides) and Port Orford cedar (Chamaecyparis lawsoniana). The heartwood of both wood species was assigned to durability class 4 (DC 4, less durable) in soil contact and DC 1–4 (very to less durable) against wood-destroying basidiomycetes. However, according to the Meyer-Veltrup model, their material resistance dose was notably higher compared to the reference species Norway spruce (Picea abies), and the resulting service life of above ground structures should be a multiple of the reference. KW - Natural durability KW - Fungal decay KW - Moisture performance KW - Permeability KW - Resistance model KW - Water uptake PY - 2022 DO - https://doi.org/10.1080/17480272.2022.2101941 SN - 1748-0272 SP - 1 EP - 11 PB - Taylor & Francis CY - London AN - OPUS4-55490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -