Search

Bacillus subtilis is ubiquitously and broadly distributed in various environments but is mostly isolated from soil. Given that B. subtilis is known as a plant growth‐promoting rhizobacterium in agriculture, we aimed to describe the natural distribution of this species and uncover how biotic and abiotic factors affect its distribution. When comparing different soils, we discovered that B. subtilis group species are most abundant in grasslands but can rarely be isolated from forest soil, even if the soil sample sites are situated in proximity. Differential analysis revealed that spore‐forming bacteria exhibited enrichments in the grassland, suggesting niche overlap or synergistic interactions leading to the proliferation of certain Bacillus species in grassland environments. Network analysis further revealed that Bacillus and other Bacillota established a densely interconnected hub module in the grassland, characterised by positive associations indicating co‐occurrence, a pattern not observed in the forest soil. Speculating that this difference was driven by abiotic factors, we combined amplicon sequencing with physico‐chemical analysis of soil samples and found multiple chemical variables, mainly pH, to affect microbial composition. Our study pinpoints the factors that influence B. subtilis abundance in natural soils and, therefore, offers insights for designing B. subtilis‐based biocontrol products in agricultural settings. [ABSTRACT FROM AUTHOR]

The infant gut microbiome is increasingly recognized as a reservoir of antibiotic resistance genes, yet the assembly of gut resistome in infants and its influencing factors remain largely unknown. We characterized resistome in 4132 metagenomes from 963 infants in six countries and 4285 resistance genes were observed. The inherent resistome pattern of healthy infants (N = 272) could be distinguished by two stages: a multicompound resistance phase (Months 0–7) and a tetracycline‐mupirocin‐β‐lactam‐dominant phase (Months 8–14). Microbial taxonomy explained 40.7% of the gut resistome of healthy infants, with Escherichia (25.5%) harboring the most resistance genes. In a further analysis with all available infants (N = 963), we found age was the strongest influencer on the resistome and was negatively correlated with the overall resistance during the first 3 years (p < 0.001). Using a random‐forest approach, a set of 34 resistance genes could be used to predict age (R2 = 68.0%). Leveraging microbial host inference analyses, we inferred the age‐dependent assembly of infant resistome was a result of shifts in the gut microbiome, primarily driven by changes in taxa that disproportionately harbor resistance genes across taxa (e.g., Escherichia coli more frequently harbored resistance genes than other taxa). We performed metagenomic functional profiling and metagenomic assembled genome analyses whose results indicate that the development of gut resistome was driven by changes in microbial carbohydrate metabolism, with an increasing need for carbohydrate‐active enzymes from Bacteroidota and a decreasing need for Pseudomonadota during infancy. Importantly, we observed increased acquired resistance genes over time, which was related to increased horizontal gene transfer in the developing infant gut microbiome. In summary, infant age was negatively correlated with antimicrobial resistance gene levels, reflecting a composition shift in the gut microbiome, likely driven by the changing need for microbial carbohydrate metabolism during early life. Highlights: We first examined the natural assembly of resistome in healthy infants' guts and identified resistance genes that were significantly impacted by age.We inferred that the age‐dependent assembly of infant resistome was a result of the shift of the gut microbiome, which was due to resistance genes being disproportionally distributed across taxa.Age‐dependent assembly of infant resistome reflected the shift in the gut microbiome, and such modifications were often a result of dietary transitions during infancy.Maturation of gut resistome was driven by infants' changing carbohydrate metabolism, which demonstrated an increasing need for carbohydrate‐active enzymes from Bacteroidota and decreasing involvements from Pseudomonadota during infancy. [ABSTRACT FROM AUTHOR]

Members of the Bacillus genus are widely distributed throughout natural environments and have been studied for decades among others for their physiology, genetics, ecological functions, and applications. However, despite its prevalence in nature, the characterization and classification of Bacillus remain challenging due to its complex and ever‐evolving taxonomic framework. This review addresses the current state of the Bacillus taxonomic landscape and summarizes the critical points in the development of Bacillus phylogeny. With a clear view of Bacillus phylogeny as a foundation, we subsequently review the methodologies applied in identifying and quantifying Bacillus, while also discussing their respective advantages and disadvantages. [ABSTRACT FROM AUTHOR]

Background: Co‐occurrence of Alzheimer's disease (AD) and Parkinson's disease (PD) has been observed. However, there is limited knowledge on how family history of AD is associated with PD. Objectives: To prospectively examine the associations of family history of AD/dementia and polygenic risk score for AD (AD‐PRS) with PD risk. Methods: The study included 477,190 participants from UK Biobank who were free of PD at baseline (2006–2010) and had complete data on the studied exposure variables, family history of AD and AD‐PRS. Cox proportional hazards model was used to examine the hazard ratios (HRs) and their 95% confidence intervals (CIs) of family history of AD/dementia and AD‐PRS for PD risk. We also conducted mediation analysis to examine the proportion of the association between family history of AD/dementia and PD risk that could be mediated by AD‐PRS. Results: During a median follow‐up of 12.5 years, we identified 2550 incidences of PD. Family history of AD/dementia (adjusted HR = 1.21; 95% CI 1.09–1.35) and AD‐PRS (adjusted HR = 1.10 per 1 unit increment; 95% CI 1.05–1.14) were associated with PD risk, after adjustment for age, sex, lifestyle factors, and other potential confounders. The association between family history of AD/dementia and PD risk was mediated by 13.1% by the AD‐PRS. As expected, we observed significant associations of family history of AD/dementia and AD‐PRS with risks of dementia and AD (P < 0.001 for all). Conclusions: Family history of AD/dementia appeared to be associated with PD risk, and this association could be mediated partially by AD‐related genetic factors. [ABSTRACT FROM AUTHOR]

The 3‐D structure of continental metamorphic core complexes (MCCs) and their coevolution along with the associated extensional detachments are still not well understood. In this study, analysis of a newly acquired high‐resolution 3‐D seismic reflection volume reveals for the first time a well‐imaged MCC in the proximal northern South China Sea (SCS) rifted margin, the Kaiping MCC (KP MCC). These data provide a 3‐D view of the KP MCC and the associated KP detachment fault. The KP MCC is characterized by ascend of ductile midcrustal materials, and it is partially exhumed in the KP9 High. The KP detachment fault displays a domed low‐angle geometry, and is characterized by pronounced NS‐plunging corrugations, among which two megacorrugations of tens of kilometers are revealed. Evidence show that the KP MCC developed according to the classical rolling‐hinge model. A group of secondary normal faults and fractures, which are parallel to the axis of the KP MCC and offset the KP detachment surface at the crest of the MCC, developed in response to inelastic bending during progressive warping of the footwall. The migration of the domal seismic reflection layers provides a visual evidence for the kinematic process of the rolling‐hinge activity, during which the brittle‐ductile transition and the rolling hinge gradually migrate as the detachment fault slips. The origin of the KP MCC in the northern SCS margin is suggested to have been favored by the existence of a pre‐existing midcrustal ductile layer and basement structures within the upper brittle crust. Plain Language Summary: A metamorphic core complex (MCC) is an exposure of deep crust associated with extensional processes. Current understanding on MCCs is mainly derived from outcrop and geomorphic studies that only allow their exhumed part to be observed. A newly acquired 3‐D seismic reflection volume reveals a well‐imaged MCC, the Kaiping MCC (KP MCC), in the proximal northern South China Sea (SCS) rifted margin, permitting, for the first time, a detailed 3‐D examination of the MCC structure and its associated detachment fault. In this study, we present the 3‐D structure of the KP MCC, the geometry and kinematics of the associated KP detachment fault, and then we discuss the development and origin of the KP MCC. We propose that the KP MCC developed according to the rolling‐hinge model, with our data providing a visual evidence for the kinematic processes during which the brittle‐ductile transition and the rolling hinge gradually migrate as the detachment fault slips. We suggest that the origin of the KP MCC is favored by the existence of a pre‐existing midcrustal ductile layer and basement structures within the upper crust. Our study not only have implication for the SCS rifting but also advance understanding on the development and origin of MCCs. Key Points: A first imaged metamorphic core complex (MCC) in the proximal northern South China Sea rifted margin and its 3‐D structure is describedVisual evidence for the gradual migration of the brittle‐ductile transition and rolling hinge during the rolling‐hinge evolution of a MCCThe origin of the MCC was favored by a pre‐existing midcrustal ductile layer and basement structures within the upper crust [ABSTRACT FROM AUTHOR]

In this article, we report the stereoselective Horner–Wadsworth–Emmons reaction of reactive carbonyl‐substituted chlorophyll a derivatives with diethyl cyanomethylphosphonate. We found that the formyl or keto group at the chlorin periphery can react stereoselectively with phosphonate carbanions to produce a series of cyanomethylene‐substituted chlorins with predominantly E geometry. Considering that no consistent records are available in the literature on the results of the allomerization of methyl pyropheophorbide a, we propose a reliable process for the transformation of this chlorophyll derivative. Our methodology represents a simple and efficient way for the preparation of novel, differently functionalized long‐wavelength absorbing chlorins, those can be applied for photodynamic therapy, solar cells, and other relevant purposes. [ABSTRACT FROM AUTHOR]

Self‐healing capability in wet oxygen atmospheres is the key issue for long term service of SiC/SiC composites in aero‐engines. Polymer derived SiBCN ceramic (PDC SiBCN) was introduced into SiC fiber reinforced SiC as a self‐healing component to obtain SiC/(SiC‐SiBCN)x composites by a newly developed method, namely chemical vapor infiltration combined with polymer infiltration online pyrolysis (CVI + PIOP) process. The weight loss behavior and three‐point bending performance of the samples under different temperatures (1200, 1300 and 1400°C) and different wet oxygen partial pressures were tested up to 100 hours to demonstrate the oxidation behavior of the samples in wet oxygen environments. According to these tests, the antioxidant capacities of samples prepared from different preforms were compared. It has been found that the 2D plain weave samples with higher density have the best resistance to wet oxygen corrosion while the 2D plain weave samples have the worst resistance to wet oxidation and the antioxidant capacities of 2D satin weave samples is between them. [ABSTRACT FROM AUTHOR]