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Environmental Science and Pollution... Jun 2024More evidence shows that bioaccessibility instead of total concentrations based on exhaustive extraction methods can better reflect the actual risk level of petroleum...
More evidence shows that bioaccessibility instead of total concentrations based on exhaustive extraction methods can better reflect the actual risk level of petroleum hydrocarbon contaminated sites, so it is essential to establish an effective assessment method for bioaccessibility. This study utilized Tenax extraction, butanol extraction, hydroxypropyl-β-cyclodextrin (HPCD) extraction, and a composite extraction method involving HPCD with LMWOAs (citric acid, CA) and surfactants (rhamnolipid, RL; Tween80, TW80; sodium dodecyl sulfate, SDS) at varying concentrations. These methods were employed to predict the bioaccessibility of earthworms to soil at different aging time of petroleum hydrocarbons. The results showed that traditional extraction methods such as Tenax 6h extraction and n-butanol extraction were ineffective in evaluating petroleum hydrocarbons' bioaccessibility. In contrast, the composite extraction of HPCD and solubilizer enhanced the extraction efficiency of HPCD greatly, and the extraction results showed a significant positive correlation with earthworm accumulation. By the comparison of the extraction results of different fractions of petroleum hydrocarbons, heavy fractions of petroleum hydrocarbons (C-C) are essential factors affecting chemical extraction effects. The correlation coefficients of four composite extraction methods and total petroleum hydrocarbons (TPH) of earthworm accumulation by linear regression analysis ranged from 1.1797 to 1.7990, and the slopes ranged from 0.8727 to 0.9792. Among them, the combined extraction method of 50 mmol/L HPCD and 0.5 mmol/L rhamnolipid had the best effect (r = 0.9792, slope = 1.1797), which could be used as an evaluation method suitable for the bioaccessibility of petroleum hydrocarbons in soil. This study could provide a new method for evaluating the bioaccessibility of organic pollutants and technically supporting risk assessment and bioremediation of complex petroleum hydrocarbons in soil.
Topics: Petroleum; Soil Pollutants; Oligochaeta; Hydrocarbons; Soil; Animals; Surface-Active Agents
PubMed: 38847953
DOI: 10.1007/s11356-024-33683-2 -
Nature Microbiology Jun 2024Most autotrophic organisms possess a single carbon fixation pathway. The chemoautotrophic symbionts of the hydrothermal vent tubeworm Riftia pachyptila, however, possess...
Most autotrophic organisms possess a single carbon fixation pathway. The chemoautotrophic symbionts of the hydrothermal vent tubeworm Riftia pachyptila, however, possess two functional pathways: the Calvin-Benson-Bassham (CBB) and the reductive tricarboxylic acid (rTCA) cycles. How these two pathways are coordinated is unknown. Here we measured net carbon fixation rates, transcriptional/metabolic responses and transcriptional co-expression patterns of Riftia pachyptila endosymbionts by incubating tubeworms collected from the East Pacific Rise at environmental pressures, temperature and geochemistry. Results showed that rTCA and CBB transcriptional patterns varied in response to different geochemical regimes and that each pathway is allied to specific metabolic processes; the rTCA is allied to hydrogenases and dissimilatory nitrate reduction, whereas the CBB is allied to sulfide oxidation and assimilatory nitrate reduction, suggesting distinctive yet complementary roles in metabolic function. Furthermore, our network analysis implicates the rTCA and a group 1e hydrogenase as key players in the physiological response to limitation of sulfide and oxygen. Net carbon fixation rates were also exemplary, and accordingly, we propose that co-activity of CBB and rTCA may be an adaptation for maintaining high carbon fixation rates, conferring a fitness advantage in dynamic vent environments.
Topics: Hydrothermal Vents; Carbon Cycle; Animals; Symbiosis; Polychaeta; Oxidation-Reduction; Citric Acid Cycle; Sulfides; Gene Expression Regulation, Bacterial; Hydrogenase; Chemoautotrophic Growth; Gene Expression Profiling; Nitrates; Photosynthesis; Bacteria
PubMed: 38839975
DOI: 10.1038/s41564-024-01704-y -
Journal of Morphology Jun 2024Chaetae are among the most extensively studied structures in polychaetes, serving as a defining morphological trait for annelids. Capitella teleta stands out as one of...
Chaetae are among the most extensively studied structures in polychaetes, serving as a defining morphological trait for annelids. Capitella teleta stands out as one of the few established annelid models for developmental and morphological studies, thus receiving significant scholarly attention. In this study, we unveil a previously unnoticed glandular structure associated with chaetae within the larvae of C. teleta. Our investigations demonstrate the absence of comparable structures in the chaetal follicles of adults and juveniles (older than 1 week), as well as during active chaetogenesis, underscoring the transient nature of these glands. This indicates that larval chaetal follicles transform into a gland that later disappears. Utilizing histology and transmission electron microscopy, we characterized these glands. Our findings underscore the diversity of chaetal ultrastructure in annelids and show that, even in well-studied species, novel morphological details can be found. We emphasize the importance of examining various life-history stages to capture such transient morphological features. This work lays a crucial morphological foundation and deepens our understanding of chaetae and chaetogenesis in C. teleta, paving the way for more accurate interpretations of future experimental studies on chaetogenesis in this species.
Topics: Animals; Polychaeta; Larva; Microscopy, Electron, Transmission; Annelida
PubMed: 38837266
DOI: 10.1002/jmor.21742 -
Plant Signaling & Behavior Dec 2024Earthworms' coelomic fluid (CF) has been discovered to possess properties that promote plant development. In particular, the earthworm's coelomic fluid-associated...
Earthworms' coelomic fluid (CF) has been discovered to possess properties that promote plant development. In particular, the earthworm's coelomic fluid-associated bacteria (CFB) are the primary factor influencing the plants' response. To investigate this, we used bacteria isolated from the CF and selected based on different plant growth-promoting traits, in a mesocosm ecosystem that includes plants. This experiment aimed to assess their impact on the metabolism of plants growing under abiotic stress environments (alkaline soil and nitrogen (N), phosphate (P), and potassium (K) deficit) and compare the lipid profiles of plants under the various treatments. We used seven different bacterial species isolated from the CF of and as a plant model L. For the metabolomic analysis method, we used gas chromatography-mass spectrometry lipidomic. After observing the metabolomic profiles, we found that a few molecular pathways are involved in how plants react to bacterial biostimulants. The bacterial isolates belonging to , , , and have led to a significant increase in synthesizing several metabolites belonging to various chemical categories. Contrary to predictions, abiotic stress did not cause a drop in the composition and concentration of lipids in plants treated with the CFB, demonstrating the rigidity of the protective mechanisms. The statistical analysis based on the Pearson method revealed a positive significant correlation between plant growth parameters (length of the aerial part, surface of the leaves, and biomass) and some metabolites belonging to fatty acids, carboxylic acids, benzene derivatives, and alkanes. Moreover, the standard metabolic components of all treatments in much higher concentrations during bacterial treatments than the control treatment suggests that the bacteria have stimulated the overexpression of these metabolic components. According to these results, we could assume that plants treated with CFB exhibit an adaptability of abiotic stress defense mechanisms, which may be attributed to the upregulation of genes involved in lipid biosynthesis pathways.
Topics: Stress, Physiological; Bacteria; Animals; Zea mays; Oligochaeta
PubMed: 38832593
DOI: 10.1080/15592324.2024.2363126 -
EvoDevo Jun 2024This study sheds light on the genetic blueprints of chaetogenesis (bristle formation), a complex biomineralization process essential not only for the diverse group of...
BACKGROUND
This study sheds light on the genetic blueprints of chaetogenesis (bristle formation), a complex biomineralization process essential not only for the diverse group of bristle worms (annelids) but also for other spiralians. We explore the complex genetic mechanisms behind chaetae formation in Osedax japonicus, the bone-devouring deep-sea worm known for its unique ecological niche and morphological adaptations.
RESULTS
We characterized the chaetal structure and musculature using electron microscopy and immunohistochemistry, and combined RNAseq of larval stages with in-situ hybridization chain reaction (HCR) to reveal gene expression patterns integral to chaetogenesis. Our findings pinpoint a distinct surge in gene expression during the larval stage of active chaetogenesis, identifying specific genes and cells involved.
CONCLUSIONS
Our research underscores the value of studying on non-model, "aberrant" organisms like Osedax, whose unique, temporally restricted chaetogenesis provided insights into elevated gene expression across specific larval stages and led to the identification of genes critical for chaetae formation. The genes identified as directly involved in chaetogenesis lay the groundwork for future comparative studies across Annelida and Spiralia, potentially elucidating the homology of chaetae-like chitinous structures and their evolution.
PubMed: 38831357
DOI: 10.1186/s13227-024-00227-1 -
Gene Oct 2024Earthworm, P. excavatus, is an ideal model organism for studying regeneration. Due to its prodigious regeneration capability, the amputated head part of the earthworm...
Earthworm, P. excavatus, is an ideal model organism for studying regeneration. Due to its prodigious regeneration capability, the amputated head part of the earthworm can regenerate completely within 22 days. MicroRNAs (miRNAs) regulate specific genes and are involved in essential biological processes, including regeneration. In this study, we conducted a comprehensive analysis of miRNA profiling of the earthworm, P. excavatus, during the process of anterior regeneration. Our investigation involved in the identification of 55 miRNAs from 30 distinct miRNA families that exhibit significant relevance to wound healing and regeneration. Notably, we have identified 50 novel miRNAs and predicted their pre-miRNA secondary structures using MIREAP. Both Known and Novel miRNAs are validated using qPCR. In addition, we employed the miRanda algorithm to predict the interactions between these miRNAs and their target mRNA transcripts. Based on the miRanda target prediction results, we identified the target genes such as Wnt, Myc, MAPK, SoxB, IHH, Hox, and Notch. These findings indicate that the potential targets of these miRNAs might play crucial roles in various functions related to wound healing, tissue restoration, and regeneration. Furthermore, the acquisition of these findings provides a unique perspective on understanding the molecular mechanisms driving epimorphosis regeneration in connection with miRNAs for the development of miRNA-based therapeutics.
Topics: Animals; MicroRNAs; Oligochaeta; Regeneration; Gene Expression Profiling; Wound Healing; Gene Expression Regulation
PubMed: 38830517
DOI: 10.1016/j.gene.2024.148636 -
PeerJ 2024, a genus of freshwater macrophagous leeches, belongs to Erpobdelliformes (Salifidae: Clitellata: Annelida), and , a well-known leech within this genus, has a worldwide...
BACKGROUND
, a genus of freshwater macrophagous leeches, belongs to Erpobdelliformes (Salifidae: Clitellata: Annelida), and , a well-known leech within this genus, has a worldwide distribution. However, the systematics of have not yet been adequately investigated, primarily due to a few molecular markers, and only 20 sequences available in the GenBank database. This gap significantly limits our understanding of the species identification, as well as the phylogenetic placement of the genus within Salifidae.
METHODS
Next-generation sequencing (NGS) was used to simultaneously capture the entire mitochondrial genome and the full-length 18S/28S rDNA sequences. The species boundary of species was estimated using bGMYC and bPTP methods, based on all available COI sequences. Uncorrected COI p-distance was calculated in MEGA. A molecular data matrix consisting of four loci (COI, 12S, 18S, and 28S rDNA) for outgroups (three leeches) and 49 erpobdellid leeches, representing eight genera within the Suborder Erpobdelliformes was aligned using MAFFT and LocARNA. This matrix was used to reconstruct the phylogenetic relationship of Bayesian inference (BI) and the maximum likelihood (ML) method.
RESULTS
The full lengths of the mitochondrial genome, 18S and 28S rDNAs of . cf. , are 14847 bp, 1876 bp 1876 bp, and 2863 bp, respectively. Both bGMYC and bPTP results based on COI data are generally congruent, suggesting that the previously proposed taxa (, . formosana, and . or ) are synonyms of . . The specimens listed in the group, however, are split into at least two Primary Species Hypotheses (PSHs). The p-distance of the first PSH is less than 1.3% but increased to 4.5% when including the secondary PSH (., . cf. ). In comparison, the interspecific p-distance between the group and the group ranged from 6.4% to 8.7%, and the intraspecific p-distance within the group is less than 0.8%. Considering the species delimitation results and the sufficient large p-distance, the specimen sampled in China is treated as . cf. . The monophyly of the four Erpobdelliformes families Salifidae, Orobdellidae, Gastrostomobdellidae and Erpobdellidae is well supported in ML and BI analysis based on a data of four markers. Within the Salifidae, a well-supported is closely related to a clade containing and , and these three genera are sister to a clade consisted of and . According to the results of this study, the strategy of simultaneous obtaining both whole mitochondria and nuclear markers from extensively sampled Salifids species using NGS is expected to fathom both the species diversity of and the evolutionary relationship of Salifidae.
Topics: Animals; Phylogeny; Genome, Mitochondrial; Leeches; High-Throughput Nucleotide Sequencing; RNA, Ribosomal, 28S
PubMed: 38827288
DOI: 10.7717/peerj.17480 -
Scientific Reports May 2024This study investigated batch-fed vermicomposting of cow manure, with a specific focus on assessing the effects of tylosin on the weight of earthworms and the overall...
This study investigated batch-fed vermicomposting of cow manure, with a specific focus on assessing the effects of tylosin on the weight of earthworms and the overall quality of the resulting manure. Five reactors, including three concentrations of tylosin (50, 100, and 150 mg/kg) and two control reactors, were employed. Residual tylosin concentrations were measured using high-performance liquid chromatography (HPLC). Quality parameters such as pH, temperature, volatile solids (VS), organic carbon content (OCC), electrical conductivity (EC), ash content, C/N ratio, total Kjeldahl nitrogen (TKN), and microbial content were evaluated. The toxicity and maturity of vermicompost were assessed by determining the germination index (GI). The study also monitored variations in the earthworm's weight. The results demonstrated a decreasing trend in VS, OCC, C/N, and fecal coliforms, along with increased pH, EC, ash content, and TKN during the vermicomposting process. Furthermore, investigations revealed significant reductions in the reactors with tylosin concentrations of 50, 100, and 150 mg/kg, resulting in the removal of 98%, 90.48%, and 89.38% of the initial tylosin, respectively. This result confirms the faster removal of tylosin in reactors with lower concentrations. Degradation of tylosin also conforms to first-order kinetics. The findings showed a significant influence of tylosin on the weight of Eisenia fetida earthworms and the lowest antibiotic concentration led to the highest weight gain. Finally, the high percentage of germination index (90-100%) showed that the quality and maturity of vermicompost is by national and international standards.
Topics: Animals; Tylosin; Manure; Oligochaeta; Cattle; Composting; Soil; Anti-Bacterial Agents; Hydrogen-Ion Concentration
PubMed: 38822086
DOI: 10.1038/s41598-024-62839-w -
Earthworm gut bacteria facilitate cadmium immobilization through the formation of CdS nanoparticles.Chemosphere Aug 2024Gut bacteria of earthworm Amynthas hupeiensis exhibit significant potential for the in-situ remediation of cadmium (Cd)-contaminated soil. However, the mechanisms by...
Gut bacteria of earthworm Amynthas hupeiensis exhibit significant potential for the in-situ remediation of cadmium (Cd)-contaminated soil. However, the mechanisms by which these gut bacteria immobilize and tolerate Cd remain elusive. The composition of the gut bacterial community was characterized by high-throughput sequencing. Cd-tolerant bacteria were isolated from the gut, and their roles in Cd immobilization, as well as their tolerance mechanisms, were explored through chemical characterization and transcriptome analysis. The predominant taxa in the gut bacterial community included unclassified Enterobacteriaceae, Citrobacter, and Bacillus, which were distinctly different from those in the surrounding soil. Notably, the most Cd-tolerant gut bacterium, Citrobacter freundii DS strain, immobilized 63.61% of Cd within 96 h through extracellular biosorption and intracellular bioaccumulation of biosynthetic CdS nanoparticles, and modulation of solution pH and NH concentration. Moreover, the characteristic signals of CdS were also observed in the gut content of A. hupeiensis when the sterilized Cd-contaminated soil was inoculated with C. freundii. The primary pathways involved in the response of C. freundii to Cd stress included the regulation of ABC transporters, bacterial chemotaxis, cell motility, oxidative phosphorylation, and two-component system. In conclusion, C. freundii facilitates Cd immobilization both in vitro and in vivo, thereby enhancing the host earthworm's adaptation to Cd-contaminated soil.
Topics: Oligochaeta; Animals; Cadmium; Soil Pollutants; Gastrointestinal Microbiome; Cadmium Compounds; Nanoparticles; Bacteria; Soil Microbiology; Sulfides; Citrobacter freundii
PubMed: 38821127
DOI: 10.1016/j.chemosphere.2024.142453 -
Chemosphere Aug 2024Earthworm could regulate their body concentration of arsenic via storage or excretion, and the ability of As efflux among different earthworms is not consistent. Here,...
Earthworm could regulate their body concentration of arsenic via storage or excretion, and the ability of As efflux among different earthworms is not consistent. Here, whole and semi As exposure patterns with 0-10-30-60-100 mg kg exposure concentrations were set to characterize the As efflux in geophagous earthworm, Metaphire guillelmi. Cast As (As-C) and earthworms' antioxidative responses were monitored to explore the efflux mechanisms under 30 mg kg As-spiked soil (As30), besides, As concentration in earthworm tissue after egestion and dissection depurations were compared. In the whole exposure pattern, As concentration in gut content (As-G, 19.2-120.3 mg kg) surpassed that in the tissue (As-T, 17.2-53.2 mg kg), and they both increased with exposure concentrations. With the prolong time, they firstly increased and kept stable between day 10-15, then As-G increased while As-T decreased between day 15-20. In the semi-exposure pattern, both As-G and As-T decreased when M. guillelmi was transferred to clean soil for 5 days. During the 42-day incubation in As30, the antioxidative responses including reactive oxygen species (ROS), glutathione (GSH) and glutathione-S-transferase (GST) were firstly increased and then decreased, and As-C (13.9-43.9 mg kg) kept higher than As-G (14.2-35.1 mg kg). Significantly positive correlations were found between As-T and GSH, As-C and GST. Moreover, tissue As after dissection (11.6-22.9 mg kg) was obviously lower than that after egestion (11.4-26.4 mg kg), but significantly related to ROS and GSH. Taken together, M. guillelmi exhibited excellent capacity of As efflux, and GSH explained tissue As accumulation while GST facilitated the As elimination via cast. Besides, dissection instead of egestion revealed the As efflux in M. guillelmi more accurately. These findings contributed to a better understanding of how geophagous earthworm M. guillelmi regulated tissue As accumulation for As stress tolerance, and recommended an optimal depuration mode to characterize As accumulation.
Topics: Arsenic; Animals; Oligochaeta; Soil Pollutants; Glutathione; Reactive Oxygen Species; Soil; Antioxidants; Glutathione Transferase
PubMed: 38815813
DOI: 10.1016/j.chemosphere.2024.142479