Discovery and Bioactivity Evaluation of Citrinin Derivatives from the Mangrove Sediment-Derived Fungus Talaromyces sp. SCSIO 41428.

A dimeric citrinin derivative with a unique spiro[chroman-2,3'-isochroman] skeleton, xerucitrinic acid C (1), and a new citrinin derivative, cladosporin E (6), along with ten known polyketides (2-5 and 7-12), were isolated from the mangrove sediment-derived fungus Talaromyces sp. SCSIO 41428. Their structures were elucidated through comprehensive spectral data analysis. The absolute configurations of 1 and 6 were determined by quantum chemical calculations. Compound 1 exhibited significant inhibitory effects on Staphylococcus aureus and Streptococcus suis, with the MIC of 25 µg/mL for both bacterial strains. Xerucitrinin C (3) exhibited significant radical scavenging activity against DPPH, with an IC50 value of 25.4 µM, and also demonstrated inhibitory activity against phosphodiesterase-4 (PDE4). Moreover, cladosporin C (7) notably inhibited prostate cancer cells PC-3 and 22Rv1, with IC50 values of 6.10 and 9.25 µM, respectively.

High-efficiency breeding of Bacillus siamensis with hyper macrolactins production using physical mutagenesis and a high-throughput culture system.

Macrolactins have attracted considerable attention due to their value and application in medicine and agriculture. However, poor yields severely hinder their broader application in these fields. This study aimed to improve macrolactins production in Bacillus siamensis using a combined atmospheric and room-temperature plasma mutagenesis and a microbial microdroplet culture system. After 25 days of treatment, a desirable strain with macrolactins production 3.0-fold higher than that of the parental strain was successfully selected. The addition of 30 mg/L ZnSO4 further increased macrolactins production to 503 ± 37.6 µg/mL, representing a 30.9 % improvement in production compared to controls. Based on transcriptome analysis, the synthesis pathways of amino acids, fengycin, and surfactin were found to be downregulated in IMD4036. Further fermentation experiments confirmed that inhibition of the comparative fengycin synthesis pathway was potentially driving the increased production of macrolactins. The strategies and possible mechanisms detailed in this study can provide insight into enhancing the production of other secondary metabolites toxic to the producer strains.

Bio-inspired fabrication of chitosan/PEO/Ti3C2Tx 2D MXene nanosheets supported palladium composite nanofiber catalysts via electrospinning.

In this study, novel chitosan/polyethylene oxide/Ti3C2Tx 2D MXene nanosheets (CS/PEO/Ti3C2Tx) nanofibers were successfully prepared by a continuous electrospinning process. During the electrospinning process, induced by the syringe tip capillary effects and electric field force, the Ti3C2Tx nanosheets were aligned along the direction of the nanofiber formation to occur a highly oriented structure. This well-ordered arrangement of the inorganic Ti3C2Tx nanosheets within the organic polymer matrix nanofiber was similar with nacre-like 'brick-and-motar' structure to some extent, resulting in a marked increase in thermal stability and mechanical properties of the resultant CS/PEO/Ti3C2Tx nanofiber. As 4 wt% of Ti3C2Tx nanosheets loaded, the highest tensile strength of the CS/PEO/Ti3C2Tx nanofiber mats was achieved as 31.7 MPa, about two times that of neat CS/PEO nanofibers. Uniformly dispersed Pd nanoparticles in size of about 1.6 nm have been successfully immobilized on the composite nanofiber with a solution impregnation process. With a loading as low as 0.2 mol% of Pd, the resultant Pd@CS/PEO/Ti3C2Tx composite nanofiber catalysts were highly active for both Heck and Sonogashira coupling reactions with broad reactants application scope, and could be recycled 15 runs without significant loss of activities.

Terpestacin and its derivatives: bioactivities and syntheses.

Terpestacin (1), fusaproliferin (2), and their derivatives are a class of sesterterpenes featured by a trans-fused 5/15-membered ring skeleton. There are 45 natural products (1, 2, 4-27, 65-83) isolated from various wild fungi (Fusarium sp., Bipolaris sorokiniana, Arthrinium sp., etc.) or from genetic mutants via biosynthetic gene clusters mining, and 37 derivatives (28-64) produced by semi-synthetic modifications. These compounds show a diverse range of important bioactivities such as antivirus, antimicrobial, cytotoxic, phytotoxic, anti-flammatory, and brine shrimp lethal activities. To date, two racemic and five enantioselective chemical total syntheses of 1 (including 2 and their isomers) have been developed. Over the past decade, a number of biosynthetic gene clusters or their mutants, along with their encoding enzymes responsible for producing sesterterpenes such as terpestacin and its derivatives, have also been identified. This review covers the literature from the year 1993, when 1 was firstly discovered, to May 2024, focusing on the bioactivities and syntheses of 1 and its derivatives or isomers.

Metabonomic analysis to identify exometabolome changes underlying antifungal and growth promotion mechanisms of endophytic Actinobacterium Streptomyces albidoflavus for sustainable agriculture practice.

In recent years, there has been an increasing focus on microbial ecology and its possible impact on agricultural production, owing to its eco-friendly nature and sustainable use. The current study employs metabolomics technologies and bioinformatics approaches to identify changes in the exometabolome of Streptomyces albidoflavus B24. This research aims to shed light on the mechanisms and metabolites responsible for the antifungal and growth promotion strategies, with potential applications in sustainable agriculture. Metabolomic analysis was conducted using Q Exactive UPLC-MS/MS. Our findings indicate that a total of 3,840 metabolites were identified, with 137 metabolites exhibiting significant differences divided into 61 up and 75 downregulated metabolites based on VIP >1, |FC| >1, and p < 0.01. The interaction of S. albidoflavus B24 monoculture with the co-culture demonstrated a stronger correlation coefficient. The Principal Component Analysis (PCA) demonstrates that PCA1 accounted for 23.36%, while PCA2 accounted for 20.28% distinction. OPLS-DA score plots indicate significant separation among different groups representing (t1) 24% as the predicted component (to1) depicts 14% as the orthogonal component. According to the findings of this comprehensive study, crude extracts from S. albidoflavus demonstrated varying abilities to impede phytopathogen growth and enhance root and shoot length in tested plants. Through untargeted metabolomics, we discovered numerous potential molecules with antagonistic activity against fungal phytopathogens among the top 10 significant metabolites with the highest absolute log2FC values. These include Tetrangulol, 4-Hydroxybenzaldehyde, and Cyclohexane. Additionally, we identified plant growth-regulating metabolites such as N-Succinyl-L-glutamate, Nicotinic acid, L-Aspartate, and Indole-3-acetamide. The KEGG pathway analysis has highlighted these compounds as potential sources of antimicrobial properties. The inhibitory effect of S. albidoflavus crude extracts on pathogen growth is primarily attributed to the presence of specific gene clusters responsible for producing cyclic peptides such as ansamycins, porphyrin, alkaloid derivatives, and neomycin. Overall, it is apparent that crude extracts from S. albidoflavus exhibited varying abilities to inhibit the growth of three phytopathogens and enhancement in both root and shoot length of tested plants. This research enhances our understanding of how secondary metabolites contribute to growth promotion and biocontrol, supporting ecosystem sustainability and resilience while boosting productivity in sustainable agriculture.

One New Quinazoline-Containing Diketopiperazine Isolated from the Marine-Sponge-Derived Fungus Penicillium sp. SCSIO41043.

One new quinazoline-containing diketopiperazine (1), along with 24 known compounds including nine alkaloids (2-9, and 25), thirteen lactones (10-22), aspterric acid (23), and catechol (24), were isolated from the marine sponge-derived Penicillium sp. SCSIO41043. Their planar structures were unequivocally elucidated by spectroscopic analysis. The absolute configuration of 1 was determined by a comparison of reported and experimental electronic circular dichroism (ECD) spectra. Compound 16 was found to notably inhibit the growth of five pathogenic bacteria and fungi with MIC values ranging from 0.5-16.0 µg/mL. Compounds 7, 17, 20, and 22 demonstrated moderate activity against Micrococcus luteus with MIC values ranging from 35.6 to 71.1 µg/mL. Moreover, 1-3 displayed different degrees of antioxidant activity with EC50 values of 0.98, 0.60, 0.46 mg/mL, respectively.

Millmerranones G, a meroterpene isolated from a mangrove-derived fungus Aspergillus sp. GXIMD 03004.

One new meroterpene derivative, millmerranones G (1), and three known analogues (2-4) were identified from the mangrove-derived fungus Aspergillus sp. GXIMD 03004, which was isolated from the leaves of mangrove Acanthus ilicifolius L. collected from Beibu Gulf in China. The structure of 1 was characterised by a comprehensive interpretation of the NMR spectroscopic and HRESIMS data. The absolute configuration for 1 was established using experimental and calculated ECD data. The anti-Vibrio activities of all compounds were evaluated, the result showed that compounds 1 and 2 has weak activity against Vibrio harveyi.

Construction of a PANoptosis-related Prognostic Signature for Predicting Prognosis, Tumor Microenvironment, and Immune Response in Ovarian Cancer

BACKGROUND: The PANoptosis pathway is a recently identified mechanism of cellular death that involves the interaction and synchronization among cellular pyroptosis, apoptosis, and necrosis. More and more evidence suggests that PANoptosis is involved in the development and treatment of cancer. However, a comprehensive understanding of the influence of PANoptosis genes on prognostic value, tumor microenvironment characteristics, and therapeutic outcomes in patients with ovarian cancer (OC) remains incomplete. OBJECTIVE: The present work was designed to devise a PANoptosis signature for OC prognosis and explore its potential molecular function. METHODS: For this study, we obtained RNA sequencing and clinical data for ovarian cancer from the Cancer Genome Atlas (TCGA) and the GSE32062 cohort. Somatic variants of PANoptosis-related genes (PRGs) in OC were analyzed using GSCA. TCGA-OC and GSE32062 were used to construct training and validation cohorts for the model. Differential expression and correlation analyses were performed following the screening of genes with prognostic ability using univariate Cox analysis. Least Absolute Shrinkage nd Selection Operator (LASSO) regression was performed to construct PRG signature based on genes that were differentially expressed and correlated with prognosis. CIBER-SORT and ESTIMATE were used to analyze the relationship between the PRGs signature and immune infiltration. TIDE was used to analyze the relationship between the PRG signature and immune checkpoint genes. OncoPredict was used to analyze the relationship between the PRG signature and the drug sensitivity. Quantitative real-time PCR (qRT-PCR) was used to validate the expression of PRGs in OC. RESULTS: The PRG signature was constructed using three prognostic genes (AIM2, APAF1, and ZBP1) in both TCGA-OC. The results showed that the PRGs signature had an AUC of 0.521, 0.546, and 0.598 in TCGA-OC and 0.620, 0.586, and 0.579 in GSE32062 to predict to predict OS at 1-, 3-, and 5-year intervals. Furthermore, a higher PRG signature risk score was significantly associated with shorter OS (HR = 1.693, 95% CI: 1.303 - 2.202, p = 8.34 × 10^-5 in TCGA-OC and HR = 1.63, 95% CI: 1.13 - 2.35, p = 0.009 in GSE32062). The risk score was identified as the independent prognostic factor for OC. Patients categorized according to their risk score exhibited notable variations in immune status, response to immunotherapy, and sensitivity to drugs. AIM2, APAF1, and ZBP1 were significantly aberrantly expressed in OC cell lines. CONCLUSION: The PRG signature has the potential to serve as a prognostic predictor for OC and to provide new insights into OC treatment.

Pressure pain threshold of the whole foot: Protocol and dense 3D sensitivity map.

When designing footwear products, designers and kinesiologists usually factor in plantar surface pressure, motion capture data, and subjective comfort evaluations. However, these factors alone are not sufficient to guide the design of truly comfortable shoes. Pressure pain threshold (PPT) is a parameter that establishes a connection between psychological quantities and physical quantities. The purpose of this study was to construct a high-precision PPT map of the whole foot. Overall, 20 participants were included in this study, and an electronic, mechanical algometer was used to apply constant pressure to the participants' feet. A MATLAB graphical user interface was developed to simplify the data-collecting process and generate visual representations of the data. Finally, several high-precision unisex, different sex, and dominant side PPT maps were generated. The findings revealed that the foot dorsum area and the medial foot region exhibited the lowest PPTs (indicative of high sensitivity). Notably, the foot dorsum area near the toes displayed the highest pain sensitivity (indicative of the lowest PPT), while the plantar area demonstrated comparatively lower pain sensitivity. The heel area exhibited the lowest pain sensitivity. Simultaneously, the study observed that women's feet exhibited lower pain thresholds than men's. In the future, it is imperative to delve deeper into the correlation between short-term pain sensitivity and the daily, long-term exercise state, as well as other physiological data. This exploration will contribute to a more nuanced guide for footwear comfort design.

Development of a highly spatiotemporally resolved vehicular volatile organic compounds emission inventory based on on-line measurement of speed-dependent emission factor.

The rapid progress of intelligent transportation systems (ITS) has enabled the development of a highly spatiotemporally resolved vehicular VOC emission inventory. However, up to this point, the emission factors applied in vehicular VOC emission inventories worldwide are either independent of driving conditions or estimated by emission models, resulting in significant bias. In this study, by using the speed-dependent VOC emission factor measured online from a typical fleet in Guangzhou and collecting multiple sources of ITS data, we developed, for the first time, a link-level dynamic vehicular VOC emission inventory. The results reveal that the emission factors for vehicles at speeds higher than 50 km/h are only around 30 % of those at 5-20 km/h. Consequently, the total vehicular VOC emission in Guangzhou is estimated to be 16.19 kt in 2019, around 40 % lower than the estimates by the static emission inventory using the average emission factor during a short transient driving (STD) cycle. This discrepancy is mainly due to the much lower average speed of the STD cycle (20 km/h) compared to the average traffic speed on the road network (36 km/h). The discrepancy in VOC emissions was even higher for highways, with the static emission factors being 75-93 % higher than the speed-dependent ones. Such a large discrepancy underscores the necessity of applying localised speed-dependent emission factors to improve the estimation accuracy of vehicular VOC emissions. This study provides more accurate insights for policymakers in formulating targeted strategies to reduce vehicular VOC emissions and mitigate their contributions to ozone and PM2.5 pollution in urban areas.

Self-Produced O2 CNs-Based Nanocarriers of DNA Hydrophobization Strategy Triggers Photodynamic and Mitochondrial-Derived Ferroptosis for Hepatocellular Carcinoma Combined Treatment.

Hypoxia can aggravate tumor occurrence, development, invasion, and metastasis, and greatly inhibit the photodynamic therapy (PDT) effect. Herein, carbon nitride (CNs)-based DNA and photosensitizer co-delivery systems (BPSCNs) with oxygen-producing functions are developed to address this problem. Selenide glucose (Seglu) is used as the dopant to prepare red/NIR-active CNs (SegluCNs). The tumor-targeting unit Bio-PEG2000 is utilized to construct BPSCNs nanoparticles through esterification reactions. Furthermore, DNA hydrophobization is realized via mixing P53 gene with a positively charged mitochondrial-targeted near-infrared (NIR) emitting photosensitizer (MTTPY), which is encapsulated in non-cationic BPSCNs for synergistic delivery. Ester bonds in BPSCNs@MTTPY-P53 complexes can be disrupted by lipase in the liver to facilitate P53 release, upregulated P53 expression, and promoted HIF-1α degradation in mitochondria. In addition, the oxygen produced by the complexes improved the hypoxic microenvironment of hepatocellular carcinoma (HCC), synergistically downregulated HIF-1α expression in mitochondria, promoted mitochondrial-derived ferroptosis and enhanced the PDT effect of the MTTPY unit. Both in vivo and in vitro experiments indicated that the transfected P53-DNA, produced O2 and ROS by these complexes synergistically led to mitochondrial-derived ferroptosis in hepatoma cells through the HIF-1α/SLC7A11 pathway, and completely avoiding PDT resistance caused by hypoxia, exerting a significant therapeutic role in HCC treatment.

Structurally Diverse Secondary Metabolites from a Deep-sea Derived Cladosporium sp. SCSIO 41318 and Their Biological Evaluation.

Four new compounds, including one drimane sesquiterpene lactone (1), one isocoumarin (2), one coumarin (3), and a new natural product (4), as well as fourteen known compounds were obtained from a deep-sea derived Cladosporium sp. SCSIO 41318. The structures of the new compounds were determined using extensive NMR and HRESIMS spectroscopic analysis, electronic circular dichroism calculations, and single-crystal X-ray diffraction measurements. Biological assays showed that compounds (1, 6, 7, 9-12, 14, 15, 17, 18) exhibited varying degrees of antimicrobial activity against the tested human pathogenic bacteria and plant pathogenic fungi. Besides, penicitrinone A (11) and penicitrinol A (12) displayed weak antitumor activities against the 22Rv1 cell line.

Spinal Infections? mNGS Combined with Microculture and Pathology for Answers.

Introduction: This study evaluates the efficacy of metagenomic next-generation sequencing (mNGS) in diagnosing spinal infections and developing therapeutic regimens that combine mNGS, microbiological cultures, and pathological investigations. Methods: Data were collected from 108 patients with suspected spinal infections between January 2022 and December 2023. Lesion tissues were obtained via C-arm assisted puncture or open surgery for mNGS, conventional microbiological culture, and pathological analysis. Personalized antimicrobial therapies were tailored based on these findings, with follow-up evaluations 7 days postoperatively. The sensitivity and specificity of mNGS were assessed, along with its impact on treatment and prognosis. Results: mNGS showed a significantly higher positive detection rate (61.20%) compared to conventional microbiological culture (30.80%) and PCT (28%). mNGS demonstrated greater sensitivity (79.41%) and negative predictive value (63.16%) than cultures (25% and 22.58%, respectively), with no significant difference in specificity and positive predictive value. Seven days post-surgery, a significant reduction in neutrophil percentage (NEUT%) was observed, though decreases in white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were not statistically significant. At the last follow-up, significant improved in Visual Analogue Scale (VAS) scores, Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores were noted. Conclusion: mNGS outperforms traditional microbiological culture in pathogen detection, especially for rare and critical pathogens. Treatment protocols combining mNGS, microbiological cultures, and pathological examinations are effective and provide valuable clinical insights for treating spinal infections.

Estimating the contribution of setting-specific contacts to SARS-CoV-2 transmission using digital contact tracing data.

While many countries employed digital contact tracing to contain the spread of SARS-CoV-2, the contribution of cospace-time interaction (i.e., individuals who shared the same space and time) to transmission and to super-spreading in the real world has seldom been systematically studied due to the lack of systematic sampling and testing of contacts. To address this issue, we utilized data from 2230 cases and 220,878 contacts with detailed epidemiological information during the Omicron outbreak in Beijing in 2022. We observed that contact number per day of tracing for individuals in dwelling, workplace, cospace-time interactions, and community settings could be described by gamma distribution with distinct parameters. Our findings revealed that 38% of traced transmissions occurred through cospace-time interactions whilst control measures were in place. However, using a mathematical model to incorporate contacts in different locations, we found that without control measures, cospace-time interactions contributed to only 11% (95%CI: 10%-12%) of transmissions and the super-spreading risk for this setting was 4% (95%CI: 3%-5%), both the lowest among all settings studied. These results suggest that public health measures should be optimized to achieve a balance between the benefits of digital contact tracing for cospace-time interactions and the challenges posed by contact tracing within the same setting.

Clinical and video-polysomnographic characterization of restless sleep disorder in adult patients.

Adults with restless sleep disorder (RSD) have never been studied clinically and polysomnographically. This study aimed to describe the clinical manifestation, duration, and distribution of sleep-related movements in adult patients with restless sleep disorder. Patients who had performed VPSG from Jan 2021 to Jan 2022 and met the diagnosis criteria of RSD were enrolled in the study. Patients' bed partners were also interviewed or telephoned in identifying this disorder. Scoring of movements during sleep was according to the diagnosis criteria of RSD and scoring of large muscle group movements during sleep proposed by the International RLS Study Group in 2020 and 2021, respectively. The clinical manifestation, the distribution of sleep stage as well as the types and duration of the movements were carefully recorded and analyzed. We included ten patients in the study with a mean age of 27.6 years (range 22-38). There was a male prevalence in adults with RSD. The study highlighted the findings from video-polysomnography, which indicated frequent sleep-related movements occurring throughout the Night. These movements were most prominent during N1 and N2 sleep stage, followed by REM sleep, while fewer movements were observed during N3 sleep. Adults with RSD experienced significant daytime functioning impairments, including non-refreshing sleep, daytime fatigue/sleepiness, and mood disturbance. Two of the patients in the study were diagnosed with anxiety and depression, further underscoring the impact of RSD on mental health. Adult patients also suffer from severe RSD, and the RSD that originates in childhood tends to persist into adulthood. In these cases, longer duration of the disease and poor sleep quality may be associated with an increased risk of developing psychiatric comorbidities. Our cases represent an objectively documented type of RSD in younger adult patients. Supplementary Information: The online version contains supplementary material available at 10.1007/s41105-024-00524-1.

A novel marine-derived anti-acute kidney injury agent targeting peroxiredoxin 1 and its nanodelivery strategy based on ADME optimization.

Insufficient therapeutic strategies for acute kidney injury (AKI) necessitate precision therapy targeting its pathogenesis. This study reveals the new mechanism of the marine-derived anti-AKI agent, piericidin glycoside S14, targeting peroxiredoxin 1 (PRDX1). By binding to Cys83 of PRDX1 and augmenting its peroxidase activity, S14 alleviates kidney injury efficiently in Prdx1-overexpression (Prdx1-OE) mice. Besides, S14 also increases PRDX1 nuclear translocation and directly activates the Nrf2/HO-1/NQO1 pathway to inhibit ROS production. Due to the limited druggability of S14 with low bioavailability (2.6%) and poor renal distribution, a pH-sensitive kidney-targeting dodecanamine-chitosan nanoparticle system is constructed to load S14 for precise treatment of AKI. l-Serine conjugation to chitosan imparts specificity to kidney injury molecule-1 (Kim-1)-overexpressed cells. The developed S14-nanodrug exhibits higher therapeutic efficiency by improving the in vivo behavior of S14 significantly. By encapsulation with micelles, the AUC0‒t , half-life time, and renal distribution of S14 increase 2.5-, 1.8-, and 3.1-fold, respectively. The main factors contributing to the improved druggability of S14 nanodrugs include the lower metabolic elimination rate and UDP-glycosyltransferase (UGT)-mediated biotransformation. In summary, this study identifies a new therapeutic target for the marine-derived anti-AKI agent while enhancing its ADME properties and druggability through nanotechnology, thereby driving advancements in marine drug development for AKI.

Determinants of Perceived Comfort: Multi-Dimensional Thinking in Smart Bedding Design.

Sleep quality is an important issue of public concern. This study, combined with sensor application, aims to explore the determinants of perceived comfort when using smart bedding to provide empirical evidence for improving sleep quality. This study was conducted in a standard sleep laboratory in Quanzhou, China, from March to April of 2023. Perceived comfort was evaluated using the Subjective Lying Comfort Evaluation on a seven-point rating scale, and body pressure distribution was measured using a pressure sensor. Correlation analysis was employed to analyze the relationship between perceived comfort and body pressure, and multiple linear regression was used to identify the factors of perceived comfort. The results showed that body pressure was partially correlated with perceived comfort, and sleep posture significantly influenced perceived comfort. In addition, height, weight, and body mass index are common factors that influence comfort. The findings highlight the importance of optimizing the angular range of boards based on their comfort performance to adjust sleeping posture and equalize pressure distribution. Future research should consider aspects related to the special needs of different populations (such as height and weight), as well as whether users are elderly and whether they have particular diseases. The design optimization of the bed board division and mattress softness, based on traditional smart bedding, can improve comfort and its effectiveness in reducing health risks and enhancing health status.

Reversed oxidative TCA (roTCA) for carbon fixation by an Acidimicrobiia strain from a saline lake.

Acidimicrobiia are widely distributed in nature and suggested to be autotrophic via the Calvin-Benson-Bassham (CBB) cycle. However, direct evidence of chemolithoautotrophy in Acidimicrobiia is lacking. Here, we report a chemolithoautotrophic enrichment from a saline lake, and the subsequent isolation and characterization of a chemolithoautotroph, Salinilacustristhrix flava EGI L10123T, which belongs to a new Acidimicrobiia family. Although strain EGI L10123T is autotrophic, neither its genome nor Acidimicrobiia metagenome-assembled genomes (MAGs) from the enrichment culture encode genes necessary for the CBB cycle. Instead, genomic, transcriptomic, enzymatic, and stable-isotope probing data hinted at the activity of the reversed oxidative TCA (roTCA) coupled with the oxidation of sulfide as the electron donor. Phylogenetic analysis and ancestral character reconstructions of Acidimicrobiia suggested that the essential CBB gene rbcL was acquired through multiple horizontal gene transfer events from diverse microbial taxa. In contrast, genes responsible for sulfide- or hydrogen-dependent roTCA carbon fixation were already present in the last common ancestor of extant Acidimicrobiia. These findings imply the possibility of roTCA carbon fixation in Acidimicrobiia and the ecological importance of Acidimicrobiia. Further research in the future is necessary to confirm whether these characteristics are truly widespread across the clade.