Colonization Phase Research Articles

Understanding the invasion of the macroalga Rugulopteryx okamurae (Ochrophyta) in the northern Alboran Sea through the use of biogeographic models

Rugulopteryx okamurae is a brown alga native to the northwestern Pacific and invasive elsewhere. It was first sighted in the southern Strait of Gibraltar in 2015, expanded to the northern Strait of Gibraltar in 2016, and had covered most of the northern Alboran Sea by 2021. Understanding the factors that may explain its different phases of colonisation is crucial for developing mitigation and control measures. We modelled the yearly distribution of R. okamurae in the northern Alboran Sea from 2016 to 2021 using the favourability function, which produces commensurable biogeographic models despite variations in species prevalence across years. This function also allows the use of fuzzy logic operations to combine previous environmental models based on different explanatory factors, namely biotope, biocoenosis, coastal influence, accessibility through dispersion, and oceanographic characteristics. Significant environmental models were assembled, and their fuzzy intersection and union applied. This resulted in two final biogeographic models for each year, which were used to predict the distribution of the species in following years. The biogeographic models exhibited a high predictive capacity, as most years accurately predicted colonisation in the following year or even multiple years ahead. Accessibility through dispersion and oceanographic characteristics were critical during the initial years of establishment, while complete establishment depended on all five factors together. Expansion to the whole northern Alboran coast was explained by favourable conditions for any of the explanatory factors, while all factors except coastal influence explained the saturation of the invasion. We conclude that the biogeographic models prove valuable in understanding the factors that contributed to the spread of R. okamurae in the northern Alboran Sea. This approach could help prevent further colonisation and mitigate the ecosystem and commercial consequences of R. okamurae's invasion.

An array of Zymoseptoria tritici effectors suppress plant immune responses.

Zymoseptoria tritici is the most economically significant fungal pathogen of wheat in Europe. However, despite the importance of this pathogen, the molecular interactions between pathogen and host during infection are not well understood. Herein, we describe the use of two libraries of cloned Z. tritici effectors that were screened to identify effector candidates with putative pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI)-suppressing activity. The effectors from each library were transiently expressed in Nicotiana benthamiana, and expressing leaves were treated with bacterial or fungal PAMPs to assess the effectors' ability to suppress reactive oxygen species (ROS) production. From these screens, numerous effectors were identified with PTI-suppressing activity. In addition, some effectors were able to suppress cell death responses induced by other Z. tritici secreted proteins. We used structural prediction tools to predict the putative structures of all of the Z. tritici effectors and used these predictions to examine whether there was enrichment of specific structural signatures among the PTI-suppressing effectors. From among the libraries, multiple members of the killer protein-like 4 (KP4) and killer protein-like 6 (KP6) effector families were identified as PTI suppressors. This observation is intriguing, as these protein families were previously associated with antimicrobial activity rather than virulence or host manipulation. This data provides mechanistic insight into immune suppression by Z. tritici during infection and suggests that, similar to biotrophic pathogens, this fungus relies on a battery of secreted effectors to suppress host immunity during early phases of colonization.

The effect of nitrosative stress on histone H3 and H4 acetylation in Phytophthora infestans life cycle

The oomycete Phytophthora infestans is one of the most destructive phytopathogens globally. It has a proven ability to adapt to changing environments rapidly; however, molecular mechanisms responsible for host invasion and adaptation to new environmental conditions still need to be explored. The study aims to understand the epigenetic mechanisms exploited by P. infestans in response to nitrosative stress conditions created by the (micro)environment and the host plant. To characterize reactive nitrogen species (RNS)-dependent acetylation profiles in avirulent/virulent (avr/vr) P. infestans, a transient gene expression, ChIP and immunoblot analyses, and nitric oxide (NO) emission by chemiluminescence were used in combination with the pharmacological approach. Nitrosative stress increased total H3/H4 acetylation and some histone acetylation marks, mainly in sporulating hyphae of diverse (avr/vr) isolates and during potato colonization. These results correlated with transcriptional up-regulation of acetyltransferases PifHAC3 and PifHAM1, catalyzing H3K56 and H4K16 acetylation, respectively. NO or peroxynitrite–mediated changes were also associated with H3K56 and H4K16 mark deposition on the critical pathogenicity-related gene promoters (CesA1, CesA2, CesA3, sPLD-like1, Hmp1, and Avr3a) elevating their expression. Our study highlights RNS-dependent transcriptional reprogramming via histone acetylation of essential gene expression in the sporulating and biotrophic phases of plant colonization by P. infestans as a tool promoting its evolutionary plasticity.

Ecosystem engineers enhance the multifunctionality of an urban novel ecosystem: Population persistence and ecosystem resilience since the 1980s

In degraded urban habitats, nature-based solutions aim to enhance ecosystem functioning and service provision. Bivalves are increasingly reintroduced to urban environments to enhance water quality through biofiltration, yet their long-term sustainability remains uncertain. Following the restoration of the disused South Docks in Liverpool in the 1980s, natural colonization of mussels rapidly improved dock-basin water quality and supported diverse taxa, including other filter feeders. While the initial colonization phase has been well documented, there has been limited published research since the mid-1990s, despite ongoing routine water quality monitoring. Here, we assessed the long-term persistence of mussel populations, their associated biodiversity, and physico-chemical parameters of the water in Queens and Albert Docks by comparing historical (1980s to 1990s) and contemporary data from follow-up surveys (2012,2022). Following an initial period of poor water quality (high contamination and turbidity, low oxygen), the natural colonization of mussels from Albert Dock in 1988 extended throughout the South Docks. By the mid-1990s, the environment of the South Docks and its mussel populations had stabilized. The dock walls were dominated by mussels which provided important complex secondary substrate for invertebrates and macroalgae. Surveys conducted in 2012 and 2022 confirmed the continued dominance of mussels and estimates of mussel biofiltration rates confirm that mussels are continuing to contribute to maintaining water quality. A decline in salinity was observed in both docks in 2022, with evidence of recovery. While these ecosystems appear relatively stable, careful management of the hydrological regime is crucial to ensuring the persistence of mussels and resilient ecosystem service provision through biofiltration.

Evaluation of nutrients effect on the arsenic bioaccessibility of contaminated soil

Soil is considered the primary source of heavy metals. Even at very low concentrations, chronic exposure to harmful heavy metal (arsenic) has a significant negative impact on human health. In this study, we evaluated the effect of nutrients including glucose, proteins, calcium and control (fasted condition) on soil arsenic (As) bioaccessibility by PBET (Physiologically Based Extraction Test) technique with SHIME (simulator of the human intestinal microbial ecosystem). As bioaccessibility of the NJY soil sample was 4.43 to 8.28%, 2.56 to 8.55% and 5.66 to 23.49% in gastric phase, intestine phase and colon phase respectively with different nutrients. CFI soil sample’s As bioaccessibility varied depending on the nutrients used, and was 5.78 to 23.86%, 2.32% to 12.54% and 1.06 to 13.85% in gastric phase, intestine phase and colon phase correspondingly. As bioaccessibility of the ZZH soil sample was 2.26 to 25.16%, 24.38% to 57.27% and 9.92 to 23.10% in gastric phase, intestine phase and colon phase with varying nutrients. The outcomes showed that, As bioaccessibility of the soil samples was greatly influenced with plant protein, animal protein, calcium and glucose in the three phases of the digestive system. Therefore, nutrients have a considerable effect on As bioaccessibility and assessment of human health risk.

Characterization of lactic acid bacteria isolated from human breast milk and their bioactive metabolites with potential application as a probiotic food supplement.

The probiotic properties of twenty-five lactic acid bacteria (LAB) isolated from human breast milk were investigated considering their resistance to gastrointestinal conditions and proteolytic activity. Seven LAB were identified and assessed for auto- and co-aggregation capacity, antibiotic resistance, and behavior during in vitro gastrointestinal digestion. Three Lacticaseibacillus strains were further evaluated for antifungal activity, metabolite production (HPLC-Q-TOF-MS/MS and GC-MS/MS) and proteolytic profiles (SDS-PAGE and HPLC-DAD) in fermented milk, whey, and soy beverage. All strains resisted in vitro gastrointestinal digestion with viable counts higher than 7.9 log10 CFU mL-1 after the colonic phase. Remarkable proteolytic activity was observed for 18/25 strains. Bacterial auto- and co-aggregation of 7 selected strains reached values up to 23 and 20%, respectively. L. rhamnosus B5H2, L. rhamnosus B9H2 and L. paracasei B10L2 inhibited P. verrucosum, F. verticillioides and F. graminearum fungal growth, highlighting L. rhamnosus B5H2. Several metabolites were identified, including antifungal compounds such as phenylacetic acid and 3-phenyllactic acid, and volatile organic compounds produced in fermented milk, whey, and soy beverage. SDS-PAGE demonstrated bacterial hydrolysis of the main milk (caseins) and soy (glycines and beta-conglycines) proteins, with no apparent hydrolysis of whey proteins. However, HPLC-DAD revealed alpha-lactoglobulin reduction up to 82% and 54% in milk and whey, respectively, with L. rhamnosus B5H2 showing the highest proteolytic activity. Overall, the three selected Lacticaseibacillus strains demonstrated probiotic capacity highlighting L. rhamnosus B5H2 with remarkable potential for generating bioactive metabolites and peptides which are capable of promoting human health.

Population dynamics of the Lyme disease bacterium, Borrelia burgdorferi, during rapid range expansion in New York State.

Recent changes in climate and human land-use have resulted in alterations of the geographic range of many species, including human pathogens. Geographic range expansion and population growth of human pathogens increase human disease risk. Relatively little empirical work has investigated the impact of range changes on within-population variability, a contributor to both colonization success and adaptive potential, during the precise time in which populations are colonized. This is likely due to the difficulties of collecting appropriate natural samples during the dynamic phase of migration and colonization. We systematically collected blacklegged ticks (Ixodes scapularis) across New York State (NY), USA, between 2006 and 2019, a time period coinciding with a rapid range expansion of ticks and their associated pathogens including Borrelia burgdorferi, the etiological agent of Lyme disease. These samples provide a unique opportunity to investigate the population dynamics of human pathogens as they expand into novel territory. We observed that founder effects were short-lived, as gene flow from long-established populations brought almost all B. burgdorferi lineages to newly colonized populations within just a few years of colonization. By 7 years post-colonization, B. burgdorferi lineage frequency distributions were indistinguishable from long-established sites, indicating that local B. burgdorferi populations experience similar selective pressures despite geographic separation. The B. burgdorferi lineage dynamics elucidate the processes underlying the range expansion and demonstrate that migration into, and selection within, newly colonized sites operate on different time scales.

AG1®, a Novel Synbiotic, Maintains Gut Barrier Function following Inflammatory Challenge in a Caco-2/THP1-Blue™ Co-Culture Model.

Nutritional interventions to reduce gastrointestinal (GI) permeability are of significant interest to physically active adults and those experiencing chronic health conditions. This in vitro study was designed to assess the impact of AG1, a novel synbiotic, on GI permeability following an inflammatory challenge. Interventions [AG1 (vitamins/minerals, pre-/probiotics, and phytonutrients) and control (control medium)] were fed separately into a human GI tract model (stomach, small intestine, and colon). In the colonic phase, the GI contents were combined with fecal inocula from three healthy human donors. GI permeability was evaluated with transepithelial electrical resistance (TEER) in a Caco-2 (apical)/THP1-Blue™ (basolateral) co-culture model. The apical side received sodium butyrate (positive control) or Caco-2 complete medium (negative control) during baseline testing. In the 24 h experiment, the apical side received colonic simulation isolates from the GI model, and the basolateral side was treated with Caco-2 complete medium, then 6 h treatment with lipopolysaccharide. TEER was assessed at 0 h and 24 h, and inflammatory markers were measured at 30 h in triplicate. Paired samples t-tests were used to evaluate endpoint mean difference (MD) for AG1 vs. control. TEER was higher for AG1 (mean ± SD: 99.89 ± 1.32%) vs. control (mean ± SD: 92.87 ± 1.22%) following activated THP1-induced damage [MD: 7.0% (p < 0.05)]. AG1 maintained TEER similar to the level of the negative control [-0.1% (p = 0.02)]. No differences in inflammatory markers were observed. These in vitro data suggest that acute supplementation with AG1 might stimulate protective effects on GI permeability. These changes may be driven by SCFA production due to the pre-/probiotic properties of AG1, but more research is needed.

Different behavioral profiles between invasive and native nudibranchs: means for invasion success?

Behavior is predicted to be a primary determinant of the success of the invasion process during the early phases of colonization. Comparing invaders with sympatric native species may provide a good approach to unravel behavioral traits involved in an invasion process. In this study, we carried out an experimental simulation of the introduction and the acclimatization phase into a new environment and assessed the expression of activity, alertness, and habituation in an invasive Mediterranean population of the South African nudibranch Godiva quadricolor comparing its profiles with those of the sympatric Mediterranean native nudibranchs Cratena peregrina and Caloria quatrefagesi. Individuals of these 3 species were subjected to 3 behavioral tests: spontaneous activity, carried out in the introduction phase (immediately after sampling) and after a week of acclimatization; alert test, in which a potential threat was simulated by means of a tactile stimulus, and habituation test, in which the same alert test stimulus was repeated 5 times at 30-min intervals. The invasive G. quadricolor showed higher levels of exploration activity, thigmotaxis, alertness, and sensitization than the native species. These behavioral traits may represent pivotal drivers of the ongoing invasion process.

Abrupt onset of intensive human occupation 44,000 years ago on the threshold of Sahul

Archaeological evidence attests multiple early dispersals of Homo sapiens out of Africa, but genetic evidence points to the primacy of a single dispersal 70-40 ka. Laili in Timor-Leste is on the southern dispersal route between Eurasia and Australasia and has the earliest record of human occupation in the eastern Wallacean archipelago. New evidence from the site shows that, unusually in the region, sediment accumulated in the shelter without human occupation, in the window 59–54 ka. This was followed by an abrupt onset of intensive human habitation beginning ~44 ka. The initial occupation is distinctive from overlying layers in the aquatic focus of faunal exploitation, while it has similarities in material culture to other early Homo sapiens sites in Wallacea. We suggest that the intensive early occupation at Laili represents a colonisation phase, which may have overwhelmed previous human dispersals in this part of the world.

Hydrological variability of middle European peatland during the Holocene, inferred from subfossil bog pine and bog oak dendrochronology and high-resolution peat multiproxy analysis of the Budwity peatland (northern Poland)

Subfossil pine and oak tree trunks were excavated during exploitation of the Budwity peatland in Northern Poland. Based on dendrochronological analysis, the woodland successions in peatland were reconstructed and correlated with moisture dynamics of the peatland ecosystem inferred from the high-resolution multi-proxy analysis of the peatland deposits. From the results of dendrochronological analysis and the 14C wiggle matching methods, four floating pine chronologies (5882–5595; 5250–5089; 3702–3546; and 2222–1979 mod. cal BP) and two oak chronologies (4932–4599 and 4042–3726 mod. cal BP) were developed. The organic sediments of the peatland (6 m thick) were deposited over approximately nine thousand years. The lower complex (525–315 cm) comprises minerogenic peat, while the upper complex (315.0–0.0 cm) is composed of ombrogenic peat. Subfossil tree trunks are distributed across various peat horizons, which suggests multiple stages of tree colonisation followed by subsequent dying-off phases. Multiproxy sediment analyses (lithological, geochemical and δ13C stable isotope, pollen, plant macrofossils, Cladocera, diatom, and Diptera analyses) indicate that the two earliest phases of pine colonisation (5882–5595 and 5250–5089 mod. cal BP) and the two stages of oak colonisation (4932–4599 and 4042–3726 mod. cal BP) were associated with periodic drying of the peatland. Conversely, tree dying-off phases occurred during periods of increased water levels in the peatland, coinciding with stages of increasing climate humidity during the Holocene. The two most recent phases of pine colonisation occurred during the ombrogenic stage of mire development. Remnants of the dead forest from these phases, marked by subfossil trunks still rooted in the ground, were preserved and exposed presently during peat exploitation, approximately 2.5 m below ground level. The identified phases of tree colonisation and subsequent dying-off phases show correlation with analogical phenomena observed in the other investigated European peatlands.

Tracking shifts in Society Islands marine subsistence through time: Intra‐site analysis of faunal remains and fishing gear

AbstractWe discuss new data from Colonization Phase and Early Expansion/Development Phase assemblages in the pre‐contact Society Islands. We focus on analysis of marine faunal remains and fishing gear to infer diachronic shifts in subsistence practices at two well‐dated coastal sites. Both Colonization Phase (AD 950–1200) and Early Expansion Phase (AD 1200–1450) faunal assemblages are dominated by fish and mollusks as opposed to animal domesticates. Colonization Phase assemblages see higher capture of Scombrids and higher capture of marine mammals and turtle. Early Expansion fishhook assemblages and faunal remains document a movement towards increased capture of reef fish as well as the adoption of local styles and locally specific fishing practices. Overall, the diachronic trend in the Society Island diets is towards a decrease in turtle, marine mammal, and wild bird remains and an increase in terrestrial domesticated species roughly two hundred years after colonization, similar to patterns seen elsewhere in Eastern Polynesia.

Evaluating tracemaker recovery after the Cretaceous–Paleogene (K–Pg) boundary event: different biotic responses at the Caravaca section

AbstractTrace fossils are an aid to characterize major extinction events, enriching evolutionary paleoecology research. Ichnological analysis at the Cretaceous–Paleogene (K–Pg) marine boundary interval, worldwide, points to a relatively minor disruption in the macrobenthic tracemaker community; that is, trace-fossil assemblages do not change significantly across the K–Pg boundary, showing relatively rapid recovery, locally in just a few years post-impact. To evaluate the incidence of this event and the rapid recovery of the tracemaker community afterwards, the evolution of planktic and benthic groups at the K–Pg boundary interval was analysed in the Caravaca section (Betic Cordillera) based on the integration of available data. In general terms, planktic foraminifera and calcareous nannoplankton dropped in abundance and diversity at the K–Pg boundary, whereas benthic foraminifera did not show significant extinction, but rather a sudden and dramatic decrease in diversity and reorganization. After the K–Pg boundary event, planktic communities exhibit a prolonged delay in recovery—mainly occurring above the dark boundary layer—with respect to benthic foraminifera. The K–Pg boundary event did not induce a severe crisis for the burrowing macroinfauna, as revealed by the similarity between pre- and post-event ichnotaxa, showing a comparatively rapid first colonization phase, less than 2 ky after the event. The record of Zoophycos and Chondrites at the base of the dark boundary layer evidences an opportunistic behaviour of tracemakers and a high independence from oxygen in pore waters and food in the sediment, allowing for the colonization of an overall unfavorable environment.

Aflatoxin M1 mitigation by novel biological agents and evaluation of bioaccessibility with enzymatic digestion in milk

Aflatoxin M1 (AFM1) is a metabolite of AFB1 that is formed in the liver and excreted in the mammary glands of ruminants who fed an AFB1-contaminated feed. This study focused on the AFM1 binding ability of biological agents including lactic acid bacteria (Leuconostoc mesenteroides) and yeast (Saccharomyces cerevisiae), chitosan as a biopolymer, and inulin as a prebiotic besides their effects on the AFM1 bioaccessibility in milk. Bioaccessibility refers to the amount of a contaminant in food that can reach the systemic circulation and exert its toxic effects on the body. In vitro gastrointestinal digestion model developed by RIVM for specifically mycotoxins was employed for assessing AFM1 bioaccessibility. Moreover, the colon phase was enzymatically simulated to evaluate the state of bound and unbound AFM1 that passed from the intestine to the colon and excreted from the body. Unbound AFM1 levels were determined by high-performance liquid chromatography (HPLC). The bound AFM1 percentages after incubation varied between 26.7% and 50.9%, and the best binder was found as S. cerevisiae while chitosan showed the lowest binding level. Following in vitro digestion practice, the lowest bioaccessibility after small intestine (29.30 ± 2.29%) digestion was acquired with S. cerevisiae, however; the lowest bioaccessibility after the colon phase (51.55 ± 3.38%) was acquired with L. mesenteroides. On the other hand, L. mesenteroides and chitosan were found more stable binders through the gastrointestinal tract (GIT). The present results showed that the bound AFM1 levels in food and absorbed from the gastrointestinal tract were affected by natural binders.

The Persian plateau served as hub for Homo sapiens after the main out of Africa dispersal

A combination of evidence, based on genetic, fossil and archaeological findings, indicates that Homo sapiens spread out of Africa between ~70-60 thousand years ago (kya). However, it appears that once outside of Africa, human populations did not expand across all of Eurasia until ~45 kya. The geographic whereabouts of these early settlers in the timeframe between ~70-60 to 45 kya has been difficult to reconcile. Here we combine genetic evidence and palaeoecological models to infer the geographic location that acted as the Hub for our species during the early phases of colonisation of Eurasia. Leveraging on available genomic evidence we show that populations from the Persian Plateau carry an ancestry component that closely matches the population that settled the Hub outside Africa. With the paleoclimatic data available to date, we built ecological models showing that the Persian Plateau was suitable for human occupation and that it could sustain a larger population compared to other West Asian regions, strengthening this claim.

Immobilisation remediation of arsenic-contaminated soils with promising CaAl-layered double hydroxide and bioavailability, bioaccessibility, and speciation-based health risk assessment

Arsenic (As)-contaminated soil poses great health risk to human mostly through inadvertent oral exposure. We investigated CaAl-layered double hydroxide (CaAl-LDH), a promising immobilising agent, for the remediation of As-contaminated Chinese soils. The effects on specific soil properties and As fractionation were analyzed, and changes in the health risk of soil As were accurately assessed by means of advanced in vivo mice model and in vitro PBET-SHIME model. Results showed that the application of CaAl-LDH significantly increased soil pH and concentration of Fe and Al oxides, and effectively converted active As fractions into the most stable residual fraction, guaranteeing long-term remediation stability. Based on in vivo test, As relative bioavailability was significantly reduced by 37.75%. Based on in vitro test, As bioaccessibility in small intestinal and colon phases was significantly reduced by 25.65% and 28.57%, respectively. Furthermore, As metabolism (reduction and methylation) by the gut microbiota inhabiting colon was clearly observed. After immobilisation with CaAl-LDH, the concentration of bioaccessible As(Ⅴ) in the colon fluid was significantly reduced by 61.91%, and organic As (least toxic MMA(V) and DMA(V)) became the main species, which further reduced the health risk of soil As. In summary, CaAl-LDH proved to be a feasible option for immobilisation remediation of As-contaminated soils, and considerable progress was made in relevant health risk assessment.

In vitro digestion and colonic fermentation of phenolic compounds and their antioxidant potential in Australian beach-cast seaweeds

Beach-cast seaweed has recently garnered attention for its nutrient-rich composition, including proteins, carbohydrates, vitamins, minerals, and phytochemicals. This study focuses on the phenolic content and antioxidant potential of five Australian beach-cast seaweed species during in vitro digestion and colonic fermentation. The bioaccessibility of the selected phenolic compounds was estimated and short chain fatty acids (SCFAs) production was determined. Cystophora sp., showed a notable increase in phenolic content (23.1 mg GAE/g) and antioxidant capacity (0.42 mg CE/g) during the intestinal and gastric phases of in vitro digestion. Durvillaea sp. demonstrated a significant release of flavonoids (0.35 mg QE/g), while Phyllosphora comosa released high levels of tannins (0.72 mg CE/g) during the intestinal phase. During colonic fermentation, P. comosa released the highest levels of phenolic compounds (4.3 mg GAE/g) after 2 h, followed by an increase in flavonoids (0.15 mg QE/g), tannins (0.07 mg CE/g), and antioxidant activity (DPPH: 0.12 mg TE/g; FRAP: 0.61 mg TE/g) after 4 h. Moreover, P. comosa released a considerable amount of phenolic compounds during both in vitro digestion and colonic fermentation. All species consistently released phenolic compounds throughout the study. Phloroglucinol, gallic acid, and protocatechuic acid were identified as the most bioaccessible phenolic compounds in all five Australian beach-cast seaweeds in the in vitro digestion. Nevertheless, compound levels declined during the colonic fermentation phase due to decomposition and fermentation by gut microbiota. With regard to SCFAs, P. comosa displayed elevated levels of acetic (0.51 mmol/L) and propionic acid (0.36 mmol/L) at 2 h, while Durvillaea sp. showed increased butyric (0.42 mmol/L) and valeric (0.26 mmol/L) production acid after 8 h. These findings suggest that seaweed such as Cystophora sp., Durvillaea sp., and P. comosa are promising candidates for food fortification or nutraceutical applications, given their rich phenolic content and antioxidant properties that potentially offer gut health benefits.

Bioinspired Living Coating System for Regenerative and Circular Architecture

Surfaces of exposed materials are affected by biotic and abiotic degradation processes. They often are protected by architectural coatings that not only provide a decorative layer but also enhance integrity of the material structure. Common surface treatments often include mineral oil binders and other ingredients that are known to have a negative impact on the environment. To address these issues, an alternative bioinspired concept for materials protection based on engineered fungal biofilm is under development. This paper presents the first results related to the bioreceptivity of building materials and the initial steps of natural biofilm formation. This research concluded that fungal colonisation and the variability of microorganisms is influenced by the type of material and climate condition at the exposure site. Fungal infestation was lower on protected materials (e.g., with commercial coatings). Samples from the eastern and western exposure exhibited the highest fungal colonisation, whereas samples from the northern and southern exposure exhibited the least growth. Furthermore, the samples in close spatial proximity were colonized by different fungal microbiota. It was determined that Aureobasidium sp. is the dominant species in the early phase of colonisation. In the following steps, a bioactive protective coating system that works in synergy with nature will be developed. Based on the initial results Aureobasidium appears to be a viable candidate as an active, living component of a new nature-inspired coating system. The novel protection concept is based on three interrelated components – bioinspiration as a driving force for materials design, bio-based ingredients, and living fungal cells that will provide self-healing and bioremediation capacity. The living coating will be designed to protect various architectonic materials, including porous materials such as biomaterials, concrete, stone, and non-porous, as well as plastics, and metals. The ultimate goal is to advance the development of engineered living materials that interact, adapt, and respond to environmental changes.

SARS-CoV-2 Infection is Associated with Age- and Gender-Specific Changes in the Nasopharyngeal Microbiome.

The recent Coronavirus Disease 2019 (COVID-19) pandemic has dramatically exposed our gap in understanding the pathogenesis of airborne infections. Within such a context, it is increasingly clear that the nasal cavity represents a critical checkpoint not only in the initial colonization phase but also in shaping any infectious sequelae. This is particularly relevant to COVID-19 in that the nasal cavity is characterized by high-level expression of the Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) receptor, Angiotensin-Converting Enzyme 2 (ACE2), all along the respiratory tract. As part of the nasal mucosa, commensal microbes harbored by the nasal cavity likely are far more than just innocent bystanders in the interaction between SARS-CoV-2 and the local microenvironment. Yet the role of the qualitative composition of the nasal microbiome is unclear, as is its function, whether protective or not. In this study, individuals undergoing SARS-CoV-2 molecular testing at the Hospital of Perugia (Italy) were recruited, with their residual material from the nasopharyngeal swabs being collected for microbiome composition analysis and short-chain fatty acid (SCFA) measurements (by 16S rRNA sequencing and gas chromatography-mass spectrometry), respectively. After stratification by age, gender, and viral load, the composition of the nasopharyngeal microbiome appeared to be influenced by age and gender, and SARS-CoV-2 infection further determined compositional changes. Notwithstanding this variability, a restricted analysis of female subjects-once SARS-CoV-2-infected-unraveled a shared expansion of Lachnospirales-Lachnospiraceae, irrespective of the viral load and age. This was associated with a reduction in the branched SCFA isobutanoic acid, as well as in the SCFAs with longer chains. Our results indicate that the nasopharyngeal microbiome is influenced by age, gender, and viral load, with consistent patterns of microbiome changes being present across specific groups. This may help in designing a personalized medicine approach in COVID-19 patients with specific patterns of nasal microbial communities.

Trace fossils from the Maastrichtian chalk of the Isle of Rügen, north-east Germany

Abstract The lower Maastrichtian chalk of the Isle of Rügen was deposited in a pelagic setting in the aphotic zone. Its rich fossil content has attracted research attention for centuries, whereas its ichnological characteristics remain poorly understood, even though horizons with intense bioturbation and occurrences of trace fossils in flint are common. The enhanced colour contrast of smooth chalk faces reveals repeated phases of benthic colonisation; larger burrows are commonly subject to silicification, while flint nodules also can preserve burrows in chalk. A total of 37 ichnogenera, including 47 ichnospecies of bioturbation and bioerosion trace fossils have been recognised; these are here briefly described, in addition to indeterminate material. Many ichnotaxa are recorded for the first time from the Rügen chalk. Bioerosion is restricted mainly to local hardgrounds in the form of biogenic components (such as shells and belemnite guards).