TY - JOUR A1 - Wen, Keqing A1 - Gorbushina, Anna A1 - Schwibbert, Karin A1 - Bell, Jérémy T1 - Microfluidic platform with precisely controlled hydrodynamic parameters and integrated features for generation of microvortices to accurately form and monitor biofilms in flow N2 - Microorganisms often live in habitats characterized by fluid flow, and their adhesion to surfaces in industrial systems or clinical settings may lead to pipe clogging, microbially influenced corrosion, material deterioration, food spoilage, infections, and human illness. Here, a novel microfluidic platform was developed to investigate biofilm formation under precisely controlled (i) cell concentration, (ii) temperature, and (iii) flow conditions. The developed platform central unit is a single-channel microfluidic flow cell designed to ensure ultrahomogeneous flow and condition in its central area, where features, e.g., with trapping properties, can be incorporated. In comparison to static and macroflow chamber assays for biofilm studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes and have better environment control and smaller sample requirements. Flow simulations and experiments with fluorescent particles were used to simulate bacteria flow in the platform cell for calculating flow velocity and direction at the microscale level. The combination of flow analysis and fluorescent strain injection in the cell showed that microtraps placed at the center of the channel were efficient in capturing bacteria at determined positions and to study how flow conditions, especially microvortices, can affect biofilm formation. The microfluidic platform exhibited improved performances in terms of homogeneity and robustness for in vitro biofilm formation. We anticipate the presented platform to be suitable for broad, versatile, and high-throughput biofilm studies at the microscale level. KW - Topographical pattern KW - E. coli KW - Fluorescence KW - Bacteria trapping KW - Particle velocimetry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610450 DO - https://doi.org/10.1021/acsbiomaterials.4c00101 SN - 2373-9878 VL - 10 IS - 7 SP - 4626 EP - 4634 PB - ACS Publ. CY - Washington, DC AN - OPUS4-61045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Catanzaro, Ilaria A1 - Gorbushina, Anna A1 - Onofri, Silvano A1 - Schumacher, Julia T1 - 1,8‐Dihydroxynaphthalene (DHN) melanin provides unequal protection to black fungi Knufia petricola and Cryomyces antarcticus from UV‐B radiation N2 - Black fungi on rock surfaces endure a spectrum of abiotic stresses, including UV radiation. Their ability to tolerate extreme conditions is attributed to the convergent evolution of adaptive traits, primarily highly melanized cell walls. However, studies on fungal melanins have not provided univocal results on their photoprotective functions. Here, we investigated whether the black fungi Knufia petricola and Cryomyces antarcticus only use DHN melanin or may employ alternative mechanisms to counteract UV‐induced damage. For this, melanized wild types and non‐melanized Δpks1 mutants were exposed to different doses of UV‐B (312 nm) followed by incubation in constant darkness or in light–dark cycles to allow light‐dependent DNA repair by photolyases (photoreactivation). C. antarcticus could tolerate higher UV‐B doses but was sensitive to white light, whereas K. petricola showed the opposite trend. DHN melanin provided UV‐B protection in C. antarcticus, whereas the same pigment or even carotenoids proved ineffective in K. petricola. Both fungi demonstrated functional photoreactivation in agreement with the presence of photolyase‐encoding genes. Our findings reveal that although the adaptive trait of DHN melanization commonly occurs across black fungi, it is not equally functional and that there are species‐specific adaptations towards either UV‐induced lesion avoidance or repair strategies. KW - Rock-inhabiting Ascomycetes KW - Pigment KW - Photoprotection KW - Photolyase KW - Disinfection PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-616859 DO - https://doi.org/10.1111/1758-2229.70043 VL - 16 IS - 6 SP - 1 EP - 13 PB - Wiley AN - OPUS4-61685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wild, B. A1 - Gerrits, Ruben A1 - Bonneville, S. T1 - The contribution of living organisms to rock weathering in the critical zone N2 - Rock weathering is a key process in global elemental cycling. Life participates in this process with tangible consequences observed from the mineral interface to the planetary scale. Multiple lines of evidence show that microorganisms may play a pivotal—yet overlooked—role in weathering. This topic is reviewed here with an emphasis on the following questions that remain unanswered: What is the quantitative contribution of bacteria and fungi to weathering? What are the associated mechanisms and do they leave characteristic imprints on mineral surfaces or in the geological record? Does biogenic weathering fulfill an ecological function, or does it occur as a side effect of unrelated metabolic functions and biological processes? An overview of efforts to integrate the contribution of living organisms into reactive transport models is provided. We also highlight prospective opportunities to harness microbial weathering in order to support sustainable agroforestry practices and mining activities, soil remediation, and carbon sequestration. KW - Bio-weathering KW - Fungi KW - Mineral PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-566748 DO - https://doi.org/10.1038/s41529-022-00312-7 SN - 2397-2106 VL - 6 SP - 1 EP - 16 PB - Macmillan CY - London AN - OPUS4-56674 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kleinbub, Sherin A1 - Braymer, Joseph J A1 - Pfeiffer, Friedhelm A1 - Dyall-Smith, Mike A1 - Spirgath, Kristin A1 - Alfaro-Espinoza, Gabriela A1 - Koerdt, Andrea T1 - From Genes to Black Rust: Genomic insights into corrosive methanogens N2 - Within the past ten years, genetic evidence has been increasing for the direct role that microbes play in microbiologically influenced corrosion (MIC), also known as biocorrosion or biodeterioration. One prominent example is the correlation between the corrosion of metal and the presence of genes encoding an extracellular [NiFe]-hydrogenase (MIC hydrogenase) in the methanogenic archaeon, Methanococcus maripaludis. In this study, DNA sequencing and bioinformatic analysis were used to classify the MIC hydrogenase as belonging to a core set of genes, the MIC core, found so far in Methanococci and Methanobacteria classes of methanogens. Genetic evidence is provided for the mobilization of the MIC core via multiple mechanisms, including a horizontal gene transfer event from Methanobacteria to Methanococci and a newly described MIC-transposon. A detailed comparison of M. maripaludis genomes further pointed to the relevance that cell wall modifications involving N-glycosylation of S-layer proteins and the MIC hydrogenase likely play in methanogen-induced MIC (Mi-MIC). Microscopic analysis of corrosive methanogens encoding the MIC core indicated that Methanobacterium-affiliated strain IM1 can form extensive biofilms on the surface of corrosion products whereas individual cells of M. maripaludis Mic1c10 were only found localized to crevices in the corrosion layer. An updated model of Mi-MIC involving two modes of action is presented, which predicts that the propensity of cells to adhere to iron surfaces directly influences the rate of corrosion due to the localization of the MIC hydrogenase at the metal-microbe interface. KW - Biocorrosion KW - Hydrogenases KW - Metalloprotein KW - Microbes PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649425 DO - https://doi.org/10.1093/femsmc/xtaf018 SN - 2633-6685 VL - 6 SP - 1 EP - 19 PB - Oxford University Press (OUP) AN - OPUS4-64942 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Duarte-Ruiz, D. A1 - Saßnick, H.-D. A1 - Ferreira De Araujo, F. A1 - Gentzmann, Marie A1 - Huthwelker, T. A1 - Cocchi, C T1 - X-ray absorption spectroscopy of scandium oxide polymorphs N2 - Scandium oxide (Sc2O3) is a rare-earth oxide with significant potential in key technological areas, but due to its limited supply a deep understanding of its characteristics in different crystalline phases is still missing. Here, we present a combined experimental and ab initio X-ray absorption spectroscopy investigation of Sc2O3 focusing on excitations from the O K-edge and the Sc L2,3-edge. While measurements are performed on a cubic sample, the most stable phase under ambient conditions, six different polymorphs are computed, including two high-pressure phases with a trigonal and monoclinic lattice in addition to the cubic phase, as well as three computationally predicted structures. Our analysis of the structural and electronic properties reveals significant similarities between the cubic polymorph and the high-pressure trigonal phase, while the monoclinic crystal exhibits distinct features. The spectra simulated for these similar phases from the solution of the Bethe–Salpeter equation show very good agreement with measurements. Additional comparison with results computed in the independent-particle approximation highlights the dominant role of electron–hole correlations in shaping the absorption features, particularly at the O K-edge, where a common pattern with the features of other sesquioxides is identified. Our findings offer new insight into the spectral fingerprints of Sc2O3 polymorphs, aiding in situ characterization and informing sustainable materials management. KW - Scandium PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650806 DO - https://doi.org/10.1039/d5ra06446e VL - 15 IS - 56 SP - 47814 EP - 47825 AN - OPUS4-65080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sathiyamani, S. A1 - Ngiam, S. A1 - Bonnerot, O. A1 - Jaengsawang, S. A1 - Panarut, P. A1 - Helman-Wazny, Agnieszka A1 - Colini, C. T1 - Material Characterisation of 19–20th Century Manuscripts from Northern Thailand N2 - Material analysis was carried out on four manuscripts from Northern Thailand, which included two palm-leaf manuscripts and two paper manuscripts. The two palm-leaf manuscripts MS 6 and MS 7 were found to have been written in the traditional method, wherein text was incised on the surface of the leaves, and then soot applied to the surfaces, confirmed by the identification of carbon ink. MS 7 additionally showed the presence of trace levels of iron in the ink, either from soot paste or from the stylus used for inscribing. The paper manuscript MS 3 was written in iron-gall ink, with sections written using a methyl-violet based ink while MS 4 was written in carbon ink. The paper used in the case of MS 3 was found to be machine made, while khoi fibres (Streblus asper) were used for making the paper used for MS 4. A combination of traditional and modern pigments, like molybdenum orange, was used for decorating the edges and cover. The results improved our understanding of these manuscripts in particular, and also provided us with insights about the rapid adoption of modern materials and their incorporation into the production of written artefacts from Northern Thailand in the late 19th and early 20th centuries. KW - Materials analysis KW - Paper manuscript KW - Palm-leaf manuscript KW - Writing inks PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652586 DO - https://doi.org/10.1515/res-2023-0028 SN - 0034-5806 VL - 45 IS - 2-3 SP - 117 EP - 140 PB - Walter de Gruyter GmbH AN - OPUS4-65258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poliakova, A. A1 - Ciotti, G. A1 - Helman-Wazny, Agnieszka A1 - Fromm, J. T1 - Phytolith assemblages from palm leaves and palm-leaf manuscripts: what is the difference and what it could mean? N2 - We studied freshly collected, dried and herbarized leaf fragments of two palms, namely Borassus flabellifer L. and Corypha umbraculifera L., most commonly used for palm-leaf manuscript (PLM) production in South (S) and Southeast Asia (SE) in order to reveal differences in their phytolith assemblages. For each of the two palms, 25 leaf samples were taken from the two Indian states of Kerala and Tamil Nadu. Dried leaf material was obtained from the fresh one by drying the leaves in air. Herbarium samples were obtained from two independent herbaria, specimen origin comprises S and SE Asia with the main focus on South India and Sri Lanka. Additionally, 25 manuscripts made of Borassus flabellifer leaves and 25 manuscripts made of Corypha umbraculifera leaves were investigated for phytoliths. All manuscripts are preliminary dated back to between the 16th and the beginning of the 20th century CE; most of them assumedly were produced in S India (Tamil Nadu and Kerala), Sri Lanka, Burma or Indonesia. Phytolith assemblages significantly differed between fresh, dry and herbarized palm leaves in comparison to PLM material, both qualitatively and quantitatively (mean r2 = - 0.61 ± 9.3 for Borassus samples and r2 = - 0.75 ± 5.3 for Corypha samples, at p < 0.001). Fifty-three phytolith types described for PLM material were not observed in any of the fresh, dry or herbarized palm-leaf samples. Geographical analysis of PLM-specific phytoliths suggests that the combination of those phytoliths could be region-related. In this paper, we prove that the methods of palaeoecological reconstructions based on detailed microscopy of the PLMs surface and phytolith analysis applied in combination with methods of mathematical and computer data analysis can contribute to answer the questions posed by material codicology by revealing lost manuscript production recipes and by studying manuscript provenance in terms of the geographical origin of the artefacts. Our approach can potentially open a new perspective for palaeoecological studies expanding their traditional scope and making them applicable to a new research field. KW - Palm-leaf manuscripts KW - Material codicology KW - Palaeoecology PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652517 DO - https://doi.org/10.3389/fpls.2024.1482790 SN - 1664-462X VL - 15 SP - 1 EP - 29 PB - Frontiers Media SA AN - OPUS4-65251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koester, M. A1 - Stock, S. C. A1 - Nájera, F. A1 - Abdallah, Khaled A1 - Gorbushina, Anna A1 - Prietzel, J. A1 - Matus, F. A1 - Klysubun, W. A1 - Boy, J. A1 - Kuzyakov, Y. A1 - Dippold, M. A. A1 - Spielvogel, S. T1 - From rock eating to vegetarian ecosystems — Disentangling processes of phosphorus acquisition across biomes N2 - Low-molecular-weight organic acids (LMWOAs) are crucial for the mobilization and acquisition of mineral phosphorus by plants. However, the role of LMWOAs in mobilizing organic phosphorus, which is the predominant phosphorus form in at least half of the world’s ecosystems, especially in humid climates, is unclear. The mechanisms of phosphorus mobilization by LMWOAs depend on climate, mainly precipitation, and shape the phosphorus nutrition strategies of plants. We disentangled the impact of roots and associated microorganisms on mechanisms of phosphorus cycling mediated by LMWOAs by studying soils along an ecosystem-sequence (ecosequence) from arid shrubland (~70 mm yr-1), and Mediterranean woodland (~370 mm yr-1) to humid-temperate forest (~1470 mm yr-1). Phosphorus speciation in soil was examined by X-ray absorption near edge structure analysis (XANES). LMWOAs were quantified as biological rock-weathering and organic phosphorus mobilization agents and compared to kinetics of acid phosphatase as a proxy for organic phosphorus mineralization. Calcium-bound phosphorus in topsoils decreased from 126 mg kg-1 in the arid shrubland, to 19 mg kg-1 in the Mediterranean woodland and was undetectable in the humid-temperate forest. In contrast, organic phosphorus in topsoils in close root proximity (0–2 mm distance to roots) was absent in the arid shrubland but raised to 220 mg kg-1 in the Mediterranean woodland and to 291 mg kg-1 in the humid-temperate forest. The organic phosphorus content in topsoils was 1.6 to 2.4 times higher in close root proximity (0–2 mm distance to roots) compared to bulk soil (4–6 mm distance to roots) in the Mediterranean woodland and humid-temperate forest, showing intensive phosphorus bioaccumulation in the rhizosphere. Redundancy analysis (RDA) revealed that LMWOAs were explained by the content of hydroxyapatite and variscite phosphorus-species in the arid shrubland, indicating that LMWOAs contribute to mineral weathering in this soil. LMWOA contents, phosphatase activity, and microbial biomass carbon correlated strongly with organic phosphorus in the humid-temperate forest soil, which implies a high relevance of LMWOAs for organic phosphorus recycling. In the Mediterranean woodland soil, however, oxalic acid correlated with organic phosphorus in the topsoil (suggesting phosphorus recycling), whereas in the subsoil malic and citric acid were correlated with primary and secondary phosphorus minerals (implying mineral weathering). We conclude that phosphorus acquisition and cycling depend strongly on climate and that the functions of LMWOAs in the rhizosphere change fundamentally along the precipitation gradient. In the arid shrubland LMWOAs facilitate biochemical weathering (rock eating), while in the humid-temperate forest their functions change towards supporting organic phosphorus recycling (vegetarian). KW - Rhizosphere processes KW - Phosphorus K-edge-XANES spectroscopy KW - Low-molecular-weight organic substances KW - Organic phosphorus breakdown KW - Biogenic weathering KW - Climate gradient PY - 2020 DO - https://doi.org/10.1016/j.geoderma.2020.114827 VL - 388 SP - 114827 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-51931 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tonon, C. A1 - Breitenbach, Romy A1 - Voigt, Oliver A1 - Turci, F. A1 - Gorbushina, Anna A1 - Favero-Longo, S. E. T1 - Hyphal morphology and substrate porosity -rather than melanization- drive penetration of black fungi into carbonate substrates N2 - Due to their ability to penetrate, deteriorate and discolour stone surfaces, rock-inhabiting black fungi represent a remarkable issue for cultural heritage conservation. Black microcolonial fungi (MCF) can also adapt to different environmental conditions, by converting from yeast-like morphology to a peculiar meristematic development with swollen cells (torulose hyphae, TH), to extremely thin structures (filamentous hyphae, FH). Furthermore, black MCF produce protective pigments: melanin, dark pigment particularly evident on light stone surfaces, and carotenoids. Black fungi produce melanin in critical, oligotrophic conditions as well as constitutively. Melanin function is mostly related to stress resistance and the ability of fungi to generate appressorial turgor to actively penetrate plant cells in pathogenic species. An involvement of melanins in stone surface penetration has been suggested, but not experimentally proved. In this work, we tested the role of hyphal melanisation in penetration mechanisms on the model black fungus Knufia petricola A95 in lab conditions. The wild-type and three mutants with introduced targeted mutations of polyketide-synthases (melanin production) and/or phytoene dehydrogenase (carotenoid synthesis) were inoculated on artificial carbonate pellets (pressed Carrara marble powder) of different porosity. After 5, 10, 17 and 27 weeks, hyphal penetration depth and spread were quantified on periodic acid Schiff-stained cross-sections of the pellets, collecting measurements separately for TH and FH. Droplet assay of the mutants on different media were conducted to determine the role of nutrients in the development of different fungal morphologies. In our in vitro study, the hyphal penetration depth, never exceeding 200 μm, was proven to be consistent with observed penetration patterns on stone heritage carbonate substrates. Pellet porosity affected penetration patterns of TH, which developed in voids of the more porous pellets, instead than actively opening new passageways. Oppositely, the thin diameter of FH allowed their penetration independently of substrate porosity. Instead, the long-hypothesized crucial role of melanin in black MCF hyphal penetration should be rejected. TH were developed within the pellets also by melanin deficient strains, and melanized strains showed an endolithic component of non-melanized TH. FH were non-melanized for all the strains, but deeply penetrated all pellet types, with higher penetration depth probably related to their potential exploratory (nutrient-seeking) role, while TH may be more related to a resistance to surface stress factors. In the melanin deficient strains, the absence of melanin caused an increased penetration rate of FH, hypothetically related to an earlier necessity to search for organic nutrients. KW - Biodeterioration KW - Bioreceptivity KW - Black microcolonial fungi KW - Marble KW - Stone cultural heritage KW - Stress tolerance PY - 2020 DO - https://doi.org/10.1016/j.culher.2020.11.003 VL - 48 SP - 244 EP - 253 PB - Elsevier Masson SAS CY - Paris, Amsterdam AN - OPUS4-51933 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schraut, Katharina A1 - Adamczyk, Burkart A1 - Adam, Christian A1 - Stephan, Dietmar A1 - Meng, Birgit A1 - Simon, Sebastian A1 - von Werder, Julia A1 - Hirsch, Tamino A1 - Manninger, Tanja T1 - Effect of gypsum on the hydration of fused cement clinker from basic oxygen furnace slag N2 - Fused cement clinker can be produced from molten basic oxygen furnace slag (BOFS) by way of a reductive thermochemical treatment. During the thermochemical treatment, oxidic iron is reduced to metallic iron and separated. The resulting low-iron slag has a chemical and mineralogical composition similar to ordinary Portland cement (OPC) clinker. In this study, the hydraulic reactivity of the fused clinker from BOFS with and without gypsum was investigated using isothermal calorimetry, differential scanning calorimetry, in situ X-ray diffraction and powder X-ray diffraction. Furthermore, a synthetic fused clinker without foreign ions and fused clinker produced by a mixture of both materials was studied. The hydraulic reaction of the fused clinker from BOFS was considerably slower than that of OPC. However, the reaction can be accelerated by adding gypsum as a sulfate carrier. Furthermore, the results showed an increased reaction rate with decreasing content of foreign ions such as Fe, P or Mn. KW - General Materials Science KW - Building and Construction PY - 2024 DO - https://doi.org/10.1680/jadcr.23.00070 SN - 0951-7197 SP - 1 EP - 19 PB - Telford AN - OPUS4-59391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -