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1.
Nat Commun ; 15(1): 2827, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38565528

ABSTRACT

Phosphorus (P) limitation of ecosystem processes is widespread in terrestrial habitats. While a few auxiliary metabolic genes (AMGs) in bacteriophages from aquatic habitats are reported to have the potential to enhance P-acquisition ability of their hosts, little is known about the diversity and potential ecological function of P-acquisition genes encoded by terrestrial bacteriophages. Here, we analyze 333 soil metagenomes from five terrestrial habitat types across China and identify 75 viral operational taxonomic units (vOTUs) that encode 105 P-acquisition AMGs. These AMGs span 17 distinct functional genes involved in four primary processes of microbial P-acquisition. Among them, over 60% (11/17) have not been reported previously. We experimentally verify in-vitro enzymatic activities of two pyrophosphatases and one alkaline phosphatase encoded by P-acquisition vOTUs. Thirty-six percent of the 75 P-acquisition vOTUs are detectable in a published global topsoil metagenome dataset. Further analyses reveal that, under certain circumstances, the identified P-acquisition AMGs have a greater influence on soil P availability and are more dominant in soil metatranscriptomes than their corresponding bacterial genes. Overall, our results reinforce the necessity of incorporating viral contributions into biogeochemical P cycling.


Subject(s)
Bacteriophages , Bacteriophages/genetics , Ecosystem , Phosphorus , Metagenome/genetics , Soil
2.
J Am Chem Soc ; 146(11): 7178-7184, 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38466344

ABSTRACT

In the field of catalytic asymmetric synthesis, the less-treated path lies in oxidative catalytic asymmetric transformations. The hurdles of pinpointing the appropriate chemical oxidants and addressing their compatibility issues with catalysts and functionalities present significant challenges. Organic electrochemistry, employing traceless electrons for redox reactions, is underscored as a promising solution. However, the commonly used electrolysis in batch cells introduces its own set of challenges, hindering the advancement of electrochemical asymmetric catalysis. Here we introduce a microfluidic electrochemistry platform with single-pass continuous flow reactors that exhibits a wide-ranging applicability to various oxidative asymmetric catalytic transformations. This is exemplified through the sulfenylation of 1,3-dicarbonyls, dehydrogenative C-C coupling, and dehydrogenative alkene annulation processes. The unique properties of microfluidic electrochemical reactors not only eliminate the need for chemical oxidants but also enhance reaction efficiency and reduce the use of additives and electrolytes. These salient features of microfluidic electrochemistry expedite the discovery and development of oxidative asymmetric transformations. In addition, the continuous production facilitated by parallel single-pass reactors ensures straightforward reaction upscaling, removing the necessity for reoptimization across various scales, as evidenced by direct translation from milligram screening to hectogram asymmetric synthesis.

3.
Acta Pharmaceutica Sinica B ; (6): 781-794, 2024.
Article in English | WPRIM (Western Pacific) | ID: wpr-1011269

ABSTRACT

Small interfering RNA (siRNA) has a promising future in the treatment of ocular diseases due to its high efficiency, specificity, and low toxicity in inhibiting the expression of target genes and proteins. However, due to the unique anatomical structure of the eye and various barriers, delivering nucleic acids to the retina remains a significant challenge. In this study, we rationally design PACD, an A-B-C type non-viral vector copolymer composed of a hydrophilic PEG block (A), a siRNA binding block (B) and a pH-responsive block (C). PACDs can self-assemble into nanosized polymeric micelles that compact siRNAs into polyplexes through simple mixing. By evaluating its pH-responsive activity, gene silencing efficiency in retinal cells, intraocular distribution, and anti-angiogenesis therapy in a mouse model of hypoxia-induced angiogenesis, we demonstrate the efficiency and safety of PACD in delivering siRNA in the retina. We are surprised to discover that, the PACD/siRNA polyplexes exhibit remarkable intracellular endosomal escape efficiency, excellent gene silencing, and inhibit retinal angiogenesis. Our study provides design guidance for developing efficient nonviral ocular nucleic acid delivery systems.

4.
China Pharmacy ; (12): 172-178, 2024.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-1006174

ABSTRACT

OBJECTIVE To analyze the metabolites of Zhideke granules and speculate its metabolic pathway in rats in vivo. METHODS Male SD rats were randomly divided into blank group and administration group (Zhideke granules, 9.45 g/kg); they were given ultrapure water or relevant medicine, twice a day, every 6-8 h, for 3 consecutive days. Serum, urine and feces samples of rats were collected, and their metabolites were identified by UPLC-Q-Exactive-MS technique after intragastric administration of Zhideke granules; their metabolic pathways were speculated. RESULTS After intragastric administration of Zhideke granules, 16 prototype components (i.g. irisflorentin, baicalin, chlorogenic acid) and 11 metabolites (i.g. hydration products of kaempferol or luteolin, methylation products of chlorogenic acid, and hydroxylation products of baicalin) were identified in serum, urine and feces of rats. Among them, 8 prototype components and 4 metabolites were identified in serum samples; 10 prototype components and 7 metabolites were identified in urine samples; 8 prototype components and 5 metabolites were identified in the fecal samples. CONCLUSIONS The metabolites of Zhideke granules in rats mainly include baicalin, irisflorentin,chlorogenic acid, and the main metabolic pathways included methylation, hydroxylation, glucuronidation.

5.
Acta Pharmaceutica Sinica ; (12): 94-104, 2024.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-1005431

ABSTRACT

Decoction is the most commonly used dosage form in the clinical treatment of traditional Chinese medicine (TCM). During boiling, the violent movement of various active ingredients in TCM creates molecular forces such as hydrogen bonding, π-π stacking, hydrophobic interactions and electrostatic interactions, which results in the formation of self-assembled aggregates in decoction (SADs), including particles, gels, fibers, etc. It was found that SADs widely existed in decoction with biological activities superior to both effective monomers and their physical mixtures, providing a new idea to reveal the pharmacodynamic material basis of Chinese herbal medicine from the perspective of component interactions-phase structure. Recently, SADs have become a novel focus of research in TCM. This paper reviewed their relevant studies in recent years and found some issues to be concerned in the research, such as the polydispersity of decoction system, instability of active ingredient interactions during boiling, uncertainty of the aggregates self-assembly rules, and stability, purity, yield of the products. In this regard, some solutions and new ideas were presented for the integrated development and clinical application of SADs.

6.
Fitoterapia ; 171: 105710, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37866423

ABSTRACT

Six new sesquiterpenes, fusarchlamols A-F (1, 2, 4-7); one new natural product of sesquiterpenoid, methyltricinonoate (3); and ten known compounds were found from Fusarium sp. cultured in two different media by the one strain many compounds strategy. The compounds (1, 2, and 4-11) were isolated from Fusarium sp. in PDB medium, and compounds (3-5, 8, and 10-17) were discovered from Fusarium sp. in coffee medium. Additionally, the configuration of 8 was first reported in the research by Mosher's method. The structures were established by 1D, 2D NMR, mass spectrometry, calculated ECD spectra, and Mosher's method. Compounds 1, 2, 6/7, 12, and 16 indicated significant antifungal activities against the phytopathogen Alternaria alternata isolated from Coffea arabica with MICs of 1 µg/mL. The investigation on the anti-phytopathogen activity of metabolites can provide lead compounds for agrochemicals.


Subject(s)
Antifungal Agents , Fusarium , Fusarium/chemistry , Zea mays , Molecular Structure , Mass Spectrometry
7.
AAPS PharmSciTech ; 24(7): 193, 2023 Sep 22.
Article in English | MEDLINE | ID: mdl-37740105

ABSTRACT

Previously, we have shown that thin-film freeze-drying can be applied to prepare dry powders of bacteria such as Lactobacillus acidophilus. Herein, we tested the viability of L. acidophilus in thin-film freeze-dried powders (TFF powders) filled in delayed-release vegetarian capsules in a simulated gastric fluid (SGF) consisting of 0.1N hydrochloric acid and sodium chloride. Initially, we determined the water removal rate from frozen thin films on relatively larger scales (i.e., 10-750 g). We then prepared and characterized two TFF powders of L. acidophilus with either sucrose and maltodextrin or sucrose and hydroxypropyl methylcellulose acetate succinate (HPMC-AS), a pH-sensitive polymer, as excipients and evaluated the viability of the bacteria after the TFF powders were filled in delayed-release vegetarian capsules and the capsules were incubated in the SGF for 30 min. On 10-750 g scales and at the settings specified, water removal from frozen thin films was faster than from slow shelf-frozen bulk solids. When the L. acidophilus in sucrose and HPMC-AS TFF powder was filled into a delayed-release capsule that was placed into another delayed-release capsule, the bacterial viability reduction after incubation in the SGF can be minimized to within 1 log in colony forming unit (CFU). However, for the L. acidophilus in sucrose and maltodextrin TFF powder, even in the capsule-in-capsule dosage form, bacterial CFU reduction was > 2 logs. TFF powders of live microorganisms containing an acid-resistant material in capsule-in-capsule delayed-release vegetarian capsules have the potential for oral delivery of those microorganisms.


Subject(s)
Lactobacillus acidophilus , Sucrose , Humans , Powders , Capsules , Vegetarians , Water
8.
Sci Total Environ ; 898: 165584, 2023 Nov 10.
Article in English | MEDLINE | ID: mdl-37467988

ABSTRACT

The applications of sulphate-reducing microorganisms (SRMs) in acid mine drainage (AMD) treatment systems have received extensive attention due to their ability to reduce sulphate and stabilize metal(loid)s. Despite great phylogenetic diversity of SRMs, only a few have been used in AMD treatment bioreactors. In situ enrichment could be an efficient approach to select new effective SRMs for AMD treatment. Here, we performed in situ enrichment of SRMs in highly stratified AMD sediment cores using different kinds of carbon source mixture. The dsrAB (dissimilatory sulfite reductase) genes affiliated with nine phyla (two archaeal and seven bacterial phyla) and 26 genera were enriched. Remarkably, those genes affiliated with Aciduliprofundum and Vulcanisaeta were enriched in situ in AMD-related environments for the first time, and their relative abundances were negatively correlated with pH. Furthermore, 107 dsrAB-containing metagenome-assembled genomes (MAGs) were recovered from metagenomic datasets, with 14 phyla (two archaeal and 12 bacterial phyla) and 15 genera. The relative abundances of MAGs were positively correlated with total carbon and sulphate contents. Our findings expanded the diversity of SRMs that can be enriched in AMD sediment, and revealed the physiochemical properties that might affect the growth of SRMs, which provided guidance for AMD treatment bioreators.


Subject(s)
Microbiota , Sulfates , Phylogeny , Bacteria/genetics , Archaea , Acids
9.
3 Biotech ; 13(5): 158, 2023 May.
Article in English | MEDLINE | ID: mdl-37151997

ABSTRACT

The difficulty of releasing nutrients from soils in karst areas limits the yield of local crops and leads to poverty. In this study, two strains of plant growth-promoting rhizobacteria (PGPR) were isolated from the rhizosphere soil of typical plants in karst areas, which were both identified as Bacillus sp. and named GS1 and N1. And two isolates were used to construct a composite PGPR named MC1. These three strains of PGPR were used for soil inoculation in the pot experiment and field trial and their capacity to promote rice development was assessed. The results showed that MC1 inoculation exhibited notable rice growth-promoting ability in pot experiments, and, respectively, had an increment of 16.96, 18.74, and 11.50% in shoot biomass, total biomass, and rice height compared with control. This is largely attributed to PGPR's capacity to secrete phytohormones and soil enzymes, particularly urease (UE) in GS1, whose secreted UE content was significantly higher by 12.18% compared to the control. When applied to the field, MC1 inoculation not only increased rice yield by 8.52% and the available nutrient content in rice rhizosphere soil, such as available phosphorus (AP) and exchangeable magnesium (EMg); but also improved the abundance of beneficial rhizobacteria and the diversity of microbial communities in rice rhizosphere soil. Results in this study revealed that inoculated PGPR played a major role in promoting rice growth and development, and a new strategy for facilitating the growth of rice crops in agriculture was elucidated. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03593-0.

10.
Front Med (Lausanne) ; 10: 1149093, 2023.
Article in English | MEDLINE | ID: mdl-37256088

ABSTRACT

Purpose: This study aimed to evaluate the efficacy and safety of predeposit autologous RBC apheresis (PARA) in patients undergoing multilevel spinal fusion surgery. Methods: A total of 112 patients from January 2020 to June 2022 were divided into two groups according to PARA: the PARA group (n = 51) and the control group (n = 61). The baseline characteristics of the patients, outcomes, transfusion cost, hospitalization cost, length of stay, complications, and changes in hemoglobin and hematocrit levels between the two groups were compared. Results: The baseline characteristics were similar in both groups. No significant differences were found in functional outcomes, including VAS score (p = 0.159), ODI score (p = 0.214), JOA score (p = 0.752), and SF-36 score (p = 0.188) between the PARA and control groups. The amount and rate of intraoperative and perioperative allogeneic RBC transfusion were significantly higher in the control group than in the PARA group (p < 0.001). The postoperative (9.04 ± 3.21 vs. 11.05 ± 3.84, p = 0.004) and total length of stay (15.78 ± 3.79 vs. 17.36 ± 4.08, p = 0.038) in the PARA group were significantly lower than those in the control group, respectively. Despite no difference in hospitalization cost (p = 0.737), the total blood transfusion cost in the PARA group was significantly lower, compared with the control group (p < 0.001). For safety evaluation, there were no significant differences in Hb and Hct levels between the two groups at admission, on postoperative day 1, and postoperative day 3, respectively (p > 0.05). Moreover, the number of postoperative infections in the PARA group was significantly lower than that in the control group (p = 0.038). Conclusion: PARA was a novel, safe, and highly efficient technique for mass autologous blood preparation in a quite short preparation time. This method could significantly reduce the amount of allogeneic blood transfusion and length of stay, which could provide a theoretical basis for following clinical practice about the technique.

11.
J Pain Res ; 16: 1453-1475, 2023.
Article in English | MEDLINE | ID: mdl-37163199

ABSTRACT

Background: Since the application of ultrasound-guided erector spinae plane block (ESPB) in 2016, the approach has been gradually applied to perioperative analgesia in various surgeries. In recent years, more and more studies have focused on the effect of ESPB in perioperative analgesia of lumbar spinal surgery, but its clinical effect remains controversial. Objective: This systematic review and meta-analysis was designed to explore the efficacy and safety of ESPB used for perioperative pain management in lumbar spinal surgery. Methods: The Pubmed, Web of Science, Cochrane Library, and EMBASE databases were comprehensively searched for relevant articles from inception to March 2022. Randomized controlled trials (RCTs) comparing ESPB with placebo or without ESPB in lumbar spinal surgery were included. The Review Manager 5.3 software was employed for this meta-analysis. Results: Nineteen RCTs with 1381 participants were included for final analysis. ESPB group exhibited lower intraoperative consumption of sufentanil and remifentanil, lower total opioid consumption within 24 h and 48 h after surgery, lower incidence of rescue analgesia, longer time to first rescue analgesic and lower number of PCA button presses compared to the control group (P<0.05). Moreover, the ESPB group had significantly lower pain scores at rest and on movement within 48 h after surgery compared with the control group (P<0.05). In terms of opioid-related adverse reactions, ESPB reduced the incidence of postoperative nausea, vomitting, somnolence and itching in comparison to the control group (P<0.05). ESPB-related serious complications were not reported in included studies. Conclusion: This meta-analysis demonstrated that ESPB used in lumbar spinal surgery was effective in relieving postoperative pain, decreasing the perioperative consumption of opioids, as well as decreasing the incidence of postoperative opioid-related adverse reactions.

12.
J Immunother Cancer ; 11(2)2023 02.
Article in English | MEDLINE | ID: mdl-36759015

ABSTRACT

BACKGROUND: Tertiary lymphoid structures (TLSs) have been proposed to assess the prognosis of patients with cancer. Here, we investigated the prognostic value and relevant mechanisms of TLSs in colorectal cancer liver metastases (CRCLM). METHODS: 603 patients with CRCLM treated by surgical resection from three cancer centers were included. The TLSs were categorized according to their anatomic subregions and quantified, and a TLS scoring system was established for intratumor region (T score) and peritumor region (P score). Differences in relapse-free survival (RFS) and overall survival (OS) between groups were determined. Multiplex immunohistochemical staining (mIHC) was used to determine the cellular composition of TLSs in 40 CRCLM patients. RESULTS: T score positively correlated with superior prognosis, while P score negatively associated with poor survival (all p<0.05). Meanwhile, T score was positively associated with specific mutation subtype of KRAS. Furthermore, TLSs enrichment gene expression was significantly associated with survival and transcriptomic subtypes of CRCLM. Subsequently, mIHC showed that the densities of Treg cells, M2 macrophages and Tfh cells were significantly higher in intratumor TLSs than in peritumor TLSs (p=0.029, p=0.047 and p=0.041, respectively), and the frequencies of Treg cells and M2 macrophages were positively correlated with P score, while the frequencies of Tfh cells were positively associated with T scores in intratumor TLSs (all p<0.05). Next, based on the distribution and abundance of TLSs, an Immune Score combining T score and P score was established which categorized CRCLM patients into four immune classes with different prognosis (all p<0.05). Among them, patients with higher immune class have more favorable prognoses. The C-index of Immune Class for RFS and OS was higher than Clinical Risk Score statistically. These results were also confirmed by the other two validation cohorts. CONCLUSIONS: The distribution and abundance of TLSs is significantly associated with RFS and OS of CRCLM patients, and a novel immune class was proposed for predicting the prognosis of CRCLM patients.


Subject(s)
Colorectal Neoplasms , Liver Neoplasms , Tertiary Lymphoid Structures , Humans , Lymphocytes, Tumor-Infiltrating , Neoplasm Recurrence, Local/pathology , Liver Neoplasms/pathology , Colorectal Neoplasms/pathology
13.
Int J Pharm ; 632: 122575, 2023 Feb 05.
Article in English | MEDLINE | ID: mdl-36603672

ABSTRACT

Triple-negative breast cancer (TNBC) represents 15-25 % of the new breast cancer cases diagnosed worldwide every year. TNBC is among the most aggressive and worst prognosis breast cancer, mainly because targeted therapies are not available. Herein, we developed a magnetic theranostic hybrid nanovehicle for targeted treatment of TNBC through pH-triggered tumour associated macrophages (TAMs) targeting. The lipid core of the nanovehicle was composed of a Carnaúba wax matrix that simultaneously incorporated iron oxide nanoparticles and doxorubicin (DOX) - a chemotherapeutic drug. These drug-loaded wax nanovehicles were modified with a combination of two functional and complementary molecules: (i) a mannose ligand (macrophage targeting) and (ii) an acid-sensitive sheddable polyethylene glycol (PEG) moiety (specificity). The TAMs targeting strategy relied on the mannose - mannose receptor recognition exclusively after acid-sensitive "shedding" of the PEG in the relatively low tumour microenvironment pH. The pH-induced targeting capability towards TAMs was confirmed in vitro in a J774A.1 macrophage cell line at different pH (7.4 and 6.5). Biocompatibility and efficacy of the final targeted formulations were demonstrated in vitro in the TNBC MDA-MB-231 cell line and in vivo in an M-Wnt tumour-bearing (TNBC) mouse model. A preferential accumulation of the DOX-loaded lipid nanovehicles in the tumours of M-Wnt-tumour bearing mice was observed, which resulted both on an efficient tumour growth inhibition and a significantly reduced off-target toxicity compared to free DOX. Additionally, the developed magnetic hybrid nanovehicles showed outstanding performances as T2-contrast agents in magnetic resonance imaging (r2 ≈ 400-600 mM-1·s-1) and as heat generating sources in magnetic hyperthermia (specific absorption rate, SAR ≈ 178 W·g-1Fe). These targeted magnetic hybrid nanovehicles emerge as a suitable theranostic option that responds to the urgent demand for more precise and personalized treatments, not only because they are able to offer localized imaging and therapeutic potential, but also because they allow to efficiently control the balance between safety and efficacy.


Subject(s)
Hyperthermia, Induced , Nanoparticles , Triple Negative Breast Neoplasms , Humans , Animals , Mice , Triple Negative Breast Neoplasms/pathology , Precision Medicine , Tumor-Associated Macrophages/pathology , Cell Line, Tumor , Mannose , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Polyethylene Glycols , Hydrogen-Ion Concentration , Lipids , Theranostic Nanomedicine/methods , Tumor Microenvironment
14.
Pharm Res ; 40(5): 1141-1152, 2023 May.
Article in English | MEDLINE | ID: mdl-36703028

ABSTRACT

PURPOSE: This study was designed to test the feasibility of using thin-film freezing (TFF) to prepare aerosolizable dry powders of plasmid DNA (pDNA) for pulmonary delivery. METHODS: Dry powders of pDNA formulated with mannitol/leucine (70/30, w/w) with various drug loadings, solid contents, and solvents were prepared using TFF, their aerosol properties (i.e., mass median aerodynamic diameter (MMAD) and fine particle fraction (FPF)) were determined, and selected powders were used for further characterization. RESULTS: Of the nine dry powders prepared, their MMAD values were about 1-2 µm, with FPF values (delivered) of 40-80%. The aerosol properties of the powders were inversely correlated with the pDNA loading and the solid content in the pDNA solution before TFF. Powders prepared with Tris-EDTA buffer or cosolvents (i.e., 1,4-dioxane or tert-butanol in water), instead of water, showed slightly reduced aerosol properties. Ultimately, powders prepared with pDNA loading at 5% (w/w), 0.25% of solid content, with or without Tris-EDTA were selected for further characterization due to their overall good aerosol performance. The pDNA powders exhibited a porous matrix structure, with a moisture content of < 2% (w/w). Agarose gel electrophoresis confirmed the chemical integrity of the pDNA after it was subjected to TFF and after the TFF powder was actuated. A cell transfection study confirmed that the activity of the pDNA did not change after it was subjected to TFF. CONCLUSION: It is feasible to use TFF to produce aerosolizable pDNA dry powder for pulmonary delivery, while preserving the integrity and activity of the pDNA.


Subject(s)
DNA , Water , Powders/chemistry , Administration, Inhalation , Freezing , Edetic Acid , Aerosols/chemistry , DNA/genetics , Plasmids , Water/chemistry , Particle Size , Dry Powder Inhalers/methods
15.
J Vis (Tokyo) ; 26(2): 403-421, 2023.
Article in English | MEDLINE | ID: mdl-36406961

ABSTRACT

Abstract: We propose a user-centered visual explorer (UcVE) for progressive comparing multiple visualization units in spatiotemporal space. We create unique unit visualization with the customizable aggregated view based on the visual metaphor of flower bursts. Each visualization unit is encoded with the abstraction of spatiotemporal properties. To reduce user cognition load, UcVE allows users to visualize, save, and track in-the-process exploration results. In coordination of storage sequence and block tracking views, UcVE can facilitate comparison with multiple visualization units concurrently, selected from historical and current exploration results. UcVE offers a flexible geo-based layout, with aggregation functions and temporal views of the timeline with categorized events, to maximize the user's exploration capabilities. Finally, we demonstrate the usefulness by using COVID-19 datasets, case studies with different user scenarios, and expert feedback.

16.
mSystems ; 8(1): e0073622, 2023 02 23.
Article in English | MEDLINE | ID: mdl-36507660

ABSTRACT

Methylmercury (MeHg) is a notorious neurotoxin, and its production and degradation in the environment are mainly driven by microorganisms. A variety of microbial MeHg producers carrying the gene pair hgcAB and degraders carrying the merB gene have been separately reported in recent studies. However, surprisingly little attention has been paid to the simultaneous investigation of the diversities of microbial MeHg producers and degraders in a given habitat, and no studies have been performed to explore to what extent these two contrasting microbial groups correlate with MeHg accumulation in the habitat of interest. Here, we collected 86 acid mine drainage (AMD) sediments from an area spanning approximately 500,000 km2 in southern China and profiled the sediment-borne putative MeHg producers and degraders using genome-resolved metagenomics. 46 metagenome-assembled genomes (MAGs) containing hgcAB and 93 MAGs containing merB were obtained, including those from various taxa without previously known MeHg-metabolizing microorganisms. These diverse MeHg-metabolizing MAGs were formed largely via multiple independent horizontal gene transfer (HGT) events. The putative MeHg producers from Deltaproteobacteria and Firmicutes as well as MeHg degraders from Acidithiobacillia were closely correlated with MeHg accumulation in the sediments. Furthermore, these three taxa, in combination with two abiotic factors, explained over 60% of the variance in MeHg accumulation. Most of the members of these taxa were characterized by their metabolic potential for nitrogen fixation and copper tolerance. Overall, these findings improve our understanding of the ecology of MeHg-metabolizing microorganisms and likely have implications for the development of management strategies for the reduction of MeHg accumulation in the AMD sediments. IMPORTANCE Microorganisms are the main drivers of MeHg production and degradation in the environment. However, little attention has been paid to the simultaneous investigation of the diversities of microbial MeHg producers and degraders in a given habitat. We used genome-resolved metagenomics to reveal the vast phylogenetic and metabolic diversities of putative MeHg producers and degraders in AMD sediments. Our results show that the diversity of MeHg-metabolizing microorganisms (particularly MeHg degraders) in AMD sediments is much higher than was previously recognized. Via multiple linear regression analysis, we identified both microbial and abiotic factors affecting MeHg accumulation in AMD sediments. Despite their great diversity, only a few taxa of MeHg-metabolizing microorganisms were closely correlated with MeHg accumulation. This work underscores the importance of using genome-resolved metagenomics to survey MeHg-metabolizing microorganisms and provides a framework for the illumination of the microbial basis of MeHg accumulation via the characterization of physicochemical properties, MeHg-metabolizing microorganisms, and the correlations between them.


Subject(s)
Methylmercury Compounds , Methylmercury Compounds/analysis , Bacteria/genetics , Phylogeny , Metagenome , Firmicutes/genetics
17.
Biomater Adv ; 145: 213225, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36527960

ABSTRACT

Zein is a biocompatible and biodegradable corn protein with promising properties for biomedical applications. It is hydrophobic with the ability to self-assemble in an aqueous medium. It can also form a gel in hydroalcoholic solvents at higher concentrations. Few studies have investigated the biomedical significance of zein gels. Herein, we exploited the injectability and water-responsive increase in stiffness of zein gel to achieve hemostasis by physical blockage of the wound and clot formation. The release of components from the gel further aided blood clotting and gave a higher clot strength than a natural clot, which can prevent rebleeding. Rabbit aortic injury and swine femoral artery injury models were used to evaluate the hemostatic efficacy of the zein gel. Zein gel was effective in both hemostatic models without applying external compression due to an in situ increase in stiffness, while the control (Celox™ Gauze) required external compression at the wound site. The zein gel was easily removed after hemostasis due to hydrophobic self-assembly. Overall, zein gel is proposed as an effective hemostatic product for any wound shape owing to its good shape adaptability and rapid in situ blood-responsive stiffness increase.


Subject(s)
Hemostatics , Zein , Swine , Animals , Rabbits , Hemostatics/pharmacology , Zein/chemistry , Hemostasis , Gels , Bandages
18.
Int J Pharm ; 630: 122408, 2023 Jan 05.
Article in English | MEDLINE | ID: mdl-36400132

ABSTRACT

Freeze-drying, or lyophilization, is widely used to produce pharmaceutical solids that contain temperature-sensitive materials. Herein, using Escherichia coli as a model live organism, whose viability in dry powders is highly sensitive to the water content in the powders, we demonstrated that the drying rate from the frozen thin films generated by thin-film freezing (TFF) is significantly faster than from the bulk frozen solids in conventional shelf freeze-drying. This is likely because the loosely stacked frozen thin films provided a larger solid-air interface and the low thickness of the thin films provided a low mass transfer resistance. The highly porous microstructure and high specific surface area of the thin-film freeze-dried powders may also be related to the faster drying observed. Moreover, we demonstrated that TFF can be applied to produce dry powders of E. coli, a Gram-negative bacterium, or Lactobacillus acidophilus, a Gram-positive bacterium, with minimum bacterial viability loss (i.e., within one log reduction). It is concluded that the TFF technology is promising in accelerating water removal from frozen samples.


Subject(s)
Escherichia coli , Water , Water/chemistry , Freezing , Freeze Drying , Powders/chemistry
19.
J Hazard Mater ; 443(Pt B): 130255, 2023 02 05.
Article in English | MEDLINE | ID: mdl-36327844

ABSTRACT

Mining-impacted environments are distributed globally and have become increasingly recognized as hotspots of antibiotic resistance genes (ARGs). However, there are currently no reports on treatment technologies to deal with such an important environmental problem. To narrow this knowledge gap, we implemented a phytostabilization project in an acidic copper mine tailings pond and employed metagenomics to explore ARG characteristics in the soil samples. Our results showed that phytostabilization decreased the total ARG abundance in 0-10 cm soil layer by 75 %, which was companied by a significant decrease in ARG mobility, and a significant increase in ARG diversity and microbial diversity. Phytostabilization was also found to drastically alter the ARG host composition and to significantly reduce the total abundance of virulence factor genes of ARG hosts. Soil nutrient status, heavy metal toxicity and SO42- concentration were important physicochemical factors to affect the total ARG abundance, while causal mediation analysis showed that their effects were largely mediated by the changes in ARG mobility and microbial diversity. The increase in ARG diversity associated with phytostabilization was mainly mediated by a small subgroup of ARG hosts, most of which could not be classified at the genus level and deserve further research in the future.


Subject(s)
Copper , Ponds , Copper/toxicity , Soil Microbiology , Drug Resistance, Microbial/genetics , Soil/chemistry , Anti-Bacterial Agents/pharmacology
20.
Microb Ecol ; 86(2): 843-858, 2023 Aug.
Article in English | MEDLINE | ID: mdl-36205737

ABSTRACT

Metalliferous mine tailings ponds are generally characterized by low levels of nutrient elements, sustained acidic conditions, and high contents of toxic metals. They represent one kind of extreme environments that are believed to resemble the Earth's early environmental conditions. There is increasing evidence that the diversity of fungi inhabiting mine tailings ponds is much higher than previously thought. However, little is known about functional guilds, community assembly, and co-occurrence patterns of fungi in such habitats. As a first attempt to address this critical knowledge gap, we employed high-throughput sequencing to characterize fungal communities in 33 mine tailings ponds distributed across 18 provinces of mainland China. A total of 5842 fungal phylotypes were identified, with saprotrophic fungi being the major functional guild. The predictors of fungal diversity in whole community and sub-communities differed considerably. Community assembly of the whole fungal community and individual functional guilds were primarily governed by stochastic processes. Total soil nitrogen and total phosphorus mediated the balance between stochastic and deterministic processes of the fungal community assembly. Co-occurrence network analysis uncovered a high modularity of the whole fungal community. The observed main modules largely consisted of saprotrophic fungi as well as various phylotypes that could not be assigned to known functional guilds. The richness of core fungal phylotypes, occupying vital positions in co-occurrence network, was positively correlated with edaphic properties such as soil enzyme activity. This indicates the important roles of core fungal phylotypes in soil organic matter decomposition and nutrient cycling. These findings improve our understanding of fungal ecology of extreme environments.


Subject(s)
Ponds , Soil Microbiology , China , Soil , Fungi/genetics
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