Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 26
Filter
Add more filters










Publication year range
1.
Front Neurol ; 15: 1362061, 2024.
Article in English | MEDLINE | ID: mdl-38737351

ABSTRACT

Background: The efficacy and safety of combining epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) with whole-brain radiotherapy (WBRT) for treating brain metastases in non-small cell lung cancer patients remains to be determined. Methods: A systematic search was conducted using databases including PubMed, Embase, Web of Science, Cochrane, Wanfang, and China National Knowledge Infrastructure (CNKI), aiming to identify relevant clinical studies on the treatment of brain metastases originating from non-small cell lung cancer through the combination of EGFR-TKI and WBRT. Statistical analysis was performed utilizing Stata 17.0 software, covering clinical studies published until March 1, 2023. Results: This analysis incorporated 23 randomized controlled trials (RCTs), involving a total of 2,025 patients. Of these, 1,011 were allocated to the group receiving both EGFR-TKI and WBRT, while 1,014 were assigned to the WBRT alone group. The findings reveal that the combination of EGFR-TKI and WBRT significantly improves the intracranial objective remission rate (RR = 1.57, 95% CI: 1.42-1.74, p < 0.001), increases the intracranial disease control rate (RR = 1.30, 95% CI: 1.23-1.37, p < 0.001), and enhances the 1-year survival rate (RR = 1.48, 95% CI: 1.26-1.73, p < 0.001). Additionally, this combined treatment was associated with a significant survival advantage (RR = 1.48, 95% CI: 1.26-1.73, p < 0.001) and a reduced incidence of adverse effects (RR = 0.65, 95% CI: 0.51-0.83, p < 0.001), particularly with respect to nausea and vomiting (RR = 0.54, 95% CI: 0.37-0.81, p = 0.002) and myelosuppression (RR = 0.59, 95% CI: 0.40-0.87, p = 0.008). However, no statistically significant differences were observed for diarrhea (RR = 1.15, 95% CI: 0.82-1.62, p = 0.418), and skin rash (RR = 1.35, 95% CI: 0.88-2.07, p = 0.164). Conclusion: In contrast to WBRT alone, the combination of EGFR-TKI and WBRT significantly improves intracranial response, enhancing the objective response rate, disease control rate, and 1-year survival rate in NSCLC patients with brain metastases. Moreover, aside from mild cases of rash and diarrhea, there is no statistically significant increase in the incidence of additional adverse effects. Based on the comprehensive evidence collected, the use of third-generation EGFR-TKI combined with WBRT is recommended as the preferred treatment for NSCLC patients with brain metastases, offering superior management of metastatic brain lesions. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/#, CRD42023415566.

2.
J Colloid Interface Sci ; 668: 1-11, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-38669987

ABSTRACT

Hierarchical engineering of magnetic-dielectric composite microspheres has attracted increasing attention owing to its potential to enhance electromagnetic wave absorption (EMA) through magnetic-dielectric synergy. However, optimizing magnetic-dielectric balance in composite microspheres at the nanoscale remains a formidable task due to their limited component optimization and microstructural regulation. Herein, a novel approach is proposed to modify conventional carbonyl iron powder (CIP) microspheres via synergistic etching-assembly strategy. By applying a polydopamine coating, successive tannic acid (TA) etching-assembly, and pyrolysis, hierarchical iron@carbon-1/N-doped carbon (Fe@C-1/NC) composite microspheres are obtained. This overcomes the drawbacks of CIP microspheres, including their high density and poor impedance matching, which hinder EMA performance. Hierarchical carbon layer engineering can introduce abundant dipole centers, heterogeneous interfaces, and conductive networks to induce dielectric loss, while magnetic components contribute to magnetic resonance and eddy current loss, as demonstrated by the results. Accordingly, Fe@C-1/NC composite microspheres demonstrate a minimum reflection loss (RLmin) of -70.7 dB and an effective absorption bandwidth of 3.75 GHz at a matching thickness of 2.3 mm. Generally, this work paves the way towards CIP engineering to provide guidance to the future exploration of hierarchical magnetic-dielectric EMA materials.

3.
Pest Manag Sci ; 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38482986

ABSTRACT

BACKGROUND: The discovery of agricultural fungicide candidates from natural products is one of the key strategies for developing environment friendly agricultural fungicides with high efficiency, high selectivity and unique modes-of-action. Based on previous work, a series of novel α-methylene-γ-butyrolactone (MBL) derivatives containing benzothiophene moiety were designed and synthesized. RESULTS: The majority of the proposed compounds displayed moderate to considerable antifungal efficacy against the tested pathogenic fungi and oomycetes, some exhibiting broad spectrum antifungal activity. Notably, compounds 2 (3-F-Ph) and 7 (4-Cl-Ph) showed excellent antifungal activity against Rhizoctonia with half maximal effective concentration (EC50) values of 0.94 and 0.99 mg L-1, respectively, comparable to the commercial fungicide tebuconazole (EC50 = 0.96 mg L-1), and also displayed significant inhibitory effects against V alsa mali with EC50 values of 2.26 and 1.67 mg L-1, respectively - better than famoxadone and carabrone. The in vivo protective and curative effects against R. solani of compound 2 were 57.2% and 53.7% at 100 mg L-1, respectively, which were equivalent to tebuconazole (51.6% and 52.4%). Further investigations found that compound 2 altered the ultrastructure of R. solani cell, significantly increased the relative conductivity of the cells, and reduced the activity of complex III in a dose-dependent manner. Molecular docking results showed that compound 2 matched well with the Qo pocket. CONCLUSION: The results revealed that MBL derivatives containing benzothiophene moiety are promising antifungal candidates and provide a new backbone structure for further optimization of novel fungicides. © 2024 Society of Chemical Industry.

4.
Front Cell Infect Microbiol ; 14: 1341032, 2024.
Article in English | MEDLINE | ID: mdl-38415012

ABSTRACT

Objective: This study is aim to discern the Traditional Chinese Medicine (TCM) syndrome classifications relevant to immunotherapy sensitive in non-small cell lung cancer (NSCLC) patients, and to delineate intestinal microbiota biomarkers and impact that wield influence over the efficacy of NSCLC immunotherapy, grounded in the TCM theory of "lung and large intestine stand in exterior-interior relationship." Methods: The study cohort consisted of patients with advanced NSCLC who received treatment at the Oncology Department of Chengdu Fifth People's Hospital. These patients were categorized into distinct TCM syndrome types and subsequently administered immune checkpoint inhibitors (ICIs), specifically PD-1 inhibitors. Stool specimens were collected from patients both prior to and following treatment. To scrutinize the differences in microbial gene sequences and species of the intestinal microbiota, 16S rRNA amplicon sequencing technology was employed. Additionally, peripheral blood samples were collected, and the analysis encompassed the assessment of T lymphocyte subsets and myeloid suppressor cell subsets via flow cytometry. Subsequently, alterations in the immune microenvironment pre- and post-treatment were thoroughly analyzed. Results: The predominant clinical manifestations of advanced NSCLC patients encompassed spleen-lung Qi deficiency syndrome and Qi-Yin deficiency syndrome. Notably, the latter exhibited enhanced responsiveness to ICIs with a discernible amelioration of the immune microenvironment. Following ICIs treatment, significant variations in microbial abundance were identified among the three strains: Clostridia, Lachnospiraceae, and Lachnospirales, with a mutual dependency relationship. In the subset of patients manifesting positive PD-L1 expression and enduring therapeutic benefits, the study recorded marked increases in the ratios of CD3+%, CD4+%, and CD4+/CD8+ within the T lymphocyte subsets. Conversely, reductions were observed in the ratios of CD8%, Treg/CD4+, M-MDSC/MDSC, and G-MDSC/MDSC. Conclusion: The strains Clostridia, Lachnospiraceae, and Lachnospirales emerge as potential biomarkers denoting the composition of the intestinal microbiota in the NSCLC therapy. The immunotherapy efficacy of ICIs markedly accentuates in patients displaying durable treatment benefits and those expressing positive PD-L1.


Subject(s)
Carcinoma, Non-Small-Cell Lung , Gastrointestinal Microbiome , Lung Neoplasms , Humans , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/genetics , Immune Checkpoint Inhibitors/therapeutic use , Lung Neoplasms/drug therapy , B7-H1 Antigen , RNA, Ribosomal, 16S/genetics , Immunotherapy , Programmed Cell Death 1 Receptor , Lung , Tumor Microenvironment
5.
Nat Commun ; 15(1): 119, 2024 Jan 02.
Article in English | MEDLINE | ID: mdl-38168072

ABSTRACT

The sophisticated hierarchical structure that precisely combines contradictory mechanical and biological characteristics is ideal for biomaterials, but it is challenging to achieve. Herein, we engineer a spatiotemporally hierarchical guided bone regeneration (GBR) membrane by rational bilayer integration of densely porous N-halamine functionalized bacterial cellulose nanonetwork facing the gingiva and loosely porous chitosan-hydroxyapatite composite micronetwork facing the alveolar bone. Our GBR membrane asymmetrically combine stiffness and flexibility, ingrowth barrier and ingrowth guiding, as well as anti-bacteria and cell-activation. The dense layer has a mechanically matched space maintenance capacity toward gingiva, continuously blocks fibroblasts, and prevents bacterial invasion with multiple mechanisms including release-killing, contact-killing, anti-adhesion, and nanopore-blocking; the loose layer is ultra-soft to conformally cover bone surfaces and defect cavity edges, enables ingrowth of osteogenesis-associated cells, and creates a favorable osteogenic microenvironment. As a result, our all-in-one porous membrane possesses full protective abilities in GBR.


Subject(s)
Bone Regeneration , Membranes, Artificial , Porosity , Bone Regeneration/physiology , Osteogenesis , Biocompatible Materials/chemistry
6.
Adv Mater ; 36(4): e2305300, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37547955

ABSTRACT

Lipid nanoparticles (LNPs) are currently the most promising clinical nucleic acids drug delivery vehicles. LNPs prevent the degradation of cargo nucleic acids during blood circulation. Upon entry into the cell, specific components of the lipid nanoparticles can promote the endosomal escape of nucleic acids. These are the basic properties of lipid nanoparticles as nucleic acid carriers. As LNPs exhibit hepatic aggregation characteristics, enhancing targeting out of the liver is a crucial way to improve LNPs administrated in vivo. Meanwhile, endosomal escape of nucleic acids loaded in LNPs is often considered inadequate, and therefore, much effort is devoted to enhancing the intracellular release efficiency of nucleic acids. Here, different strategies to efficiently deliver nucleic acid delivery from LNPs are concluded and their mechanisms are investigated. In addition, based on the information on LNPs that are in clinical trials or have completed clinical trials, the issues that are necessary to be approached in the clinical translation of LNPs are discussed, which it is hoped will shed light on the development of LNP nucleic acid drugs.


Subject(s)
Nanoparticles , Nucleic Acids , Lipids , Liposomes , RNA, Small Interfering
7.
Small ; 20(8): e2306656, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37817351

ABSTRACT

Herein, carbon dot (CD)-supported Fe single-atom nanozymes with high content of pyrrolic N and ultrasmall size (ph-CDs-Fe SAzyme) are fabricated by a phenanthroline-mediated ligand-assisted strategy. Compared with phenanthroline-free nanozymes (CDs-Fe SAzyme), ph-CDs-Fe SAzyme exhibit higher peroxidase (POD)-like activity due to their structure similar to that of ferriporphyrin in natural POD. Aberration-corrected high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) and X-ray absorption fine structure spectroscopy (XAFS) analyses show that metal Fe is dispersed in ph-CDs-Fe SAzyme as single atoms. Steady-state kinetic studies show that the maximum velocity (Vmax ) and turnover number (kcat ) of H2 O2  homolytic cleavage catalyzed by ph-CDs-Fe SAzyme are 3.0 and 6.2 more than those of the reaction catalyzed by CDs-Fe SAzyme. Density functional theory (DFT) calculations show that the energy barrier of the reaction catalyzed by ph-CDs-Fe SAzyme is lower than that catalyzed by CDs-Fe SAzyme. Antitumor efficacy experiments show that ph-CDs-Fe SAzyme can efficiently inhibit the growth of tumor cells both in vitro and in vivo by synergistic chemodynamic and photothermal effects. Here a new paradigm is provided for the development of efficient antitumor therapeutic approaches based on SAzyme with POD-like activity.


Subject(s)
Carbon , Hemin , Kinetics , Pyrroles , X-Ray Absorption Spectroscopy
8.
ACS Nano ; 17(24): 24593-24618, 2023 Dec 26.
Article in English | MEDLINE | ID: mdl-38055350

ABSTRACT

Tumor immunotherapy is a safe and effective strategy for precision medicine. However, immunotherapy for most cancer cases still ends in failure, with the root causes of the immunosuppressive and extraordinary heterogeneity of the solid tumors microenvironment. The emerging biomimetic nanodelivery system provides a promising tactic to improve the immunotherapy effect while reducing the adverse reactions on nontarget cells. Herein, we summarize the relationship between tumor occurrence and tumor immune microenvironment, mechanism of tumor immune escape, immunotherapy classification (including adoptive cellular therapy, cytokines, cancer vaccines, and immune checkpoint inhibitors) and recommend target cells for immunotherapy first, and then emphatically introduce the recent advances and applications of the latest biomimetic nanodelivery systems (e.g., immune cells, erythrocytes, tumor cells, platelets, bacteria) in tumor immunotherapy. Meanwhile, we separately summarize the application of tumor vaccines. Finally, the predictable challenges and perspectives in a forward exploration of biomimetic nanodelivery systems for tumor immunotherapy are also discussed.


Subject(s)
Nanoparticle Drug Delivery System , Neoplasms , Humans , Biomimetics , Immunotherapy , Neoplasms/pathology , Cytokines , Tumor Microenvironment
9.
Front Cardiovasc Med ; 10: 1180698, 2023.
Article in English | MEDLINE | ID: mdl-38028476

ABSTRACT

Objective: This study identified the independent risk factors for hypertension in overweight and obese people and also analyzed the interaction between the risk factors. Methods: A total of 5,098 overweight and obese people were enrolled in this study. First, the clinical metabolic characteristics of hypertension and control groups were compared. The logistic regression (LR) and classification and regression trees (CRT)-based decision tree (DT) models were used to screen the independent risk factors for hypertension in overweight and obese people. The multiplicative and additive scale analyses were used to analyze the two risk factors with interaction from the perspective of statistics and biological interaction. Finally, the receiver operating characteristic (ROC) and calibration curves were used to analyze the accuracy and identification ability of the LR and DT models. Results: Age, UA, FPG, SBP, Cr, AST, TG, and FPG were higher in the hypertension group than in the control group (P < 0.05). The results of LR revealed that NAFLD, FPG, age, TG, LDL-c, UA, and Cr were positively correlated with hypertension in overweight and obese people, and GFR was negatively correlated with hypertension in overweight and obese people (P < 0.05). The DT model suggested that the risk factors of age, FPG, and UA interacted with each other. The multiplicative single and multiple factor analysis for FPG + UA, age + UA, age + FPG revealed a positive multiplicative interaction (P < 0.05, B ≠ 0, OR > 1). The additive single and multiple factor analysis for age + UA indicated a positive additive interaction. The ROC and calibration curve analysis indicated that the CRT decision tree, FPG + UA, age + UA, and age + FPG have certain accuracy and discrimination ability. Conclusion: The independent risk factors for hypertension in overweight and obese people included NAFLD, FPG, age, TG, LDL-c, UA, and Cr. Among these, age + UA exhibited synergistic interaction, thereby providing a reference for the prevention and control of hypertension in overweight and obese people.

10.
Heliyon ; 9(10): e20677, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37829807

ABSTRACT

Background: The risk of bone mineral density abnormalities is inconsistent between eastern and western regions owing to differences in ethnicity and dietary habits. A diet comprising carbohydrates and dietary fiber is not the common daily diet of the American population. Thus far, no studies have assessed the risk of bone mineral density abnormalities in the American population, and no predictive model has considered the intake of carbohydrates, dietary fiber, and coffee, as well as levels of various electrolytes for assessing bone mineral density abnormalities, especially in the elderly. This study conducted a neural network analysis and established a predictive nomogram considering an unusual diet to determine risk factors for bone mineral density abnormalities in the American population, mainly to provide a reference for the prevention and treatment of related bone mineral density abnormalities. Methods: Overall, 9871 patients who had complete data were selected from the National Health and Nutrition Examination Survey database during 2017-2020 as the research object, and patients' general clinical characteristics were compared. Neural networks and nomograms were analyzed to screen for and quantify risk factors for bone mineral density abnormalities. Finally, the receiver operating characteristic (ROC) curve, calibration curve, decision curve analysis (DCA), and community indifference curve (CIC) were constructed to comprehensively verify the accuracy, differential ability, and clinical practicability of the neural network and nomogram. Results: The important risk factors for bone mineral density abnormalities were caffeine intake, carbohydrate consumption, body mass index (BMI), height, blood sodium, blood calcium, blood phosphorus, blood potassium, dietary fiber, vitamin D, participant age, weight, race, family history, and sex. The nomogram revealed that caffeine intake, carbohydrate consumption, blood potassium, and age were positively correlated with bone mineral density abnormalities, whereas BMI, height, blood phosphate, dietary fiber, and blood sodium were negatively correlated with bone mineral density abnormalities. Women were more prone to these abnormalities than men. The area under the ROC curve values of the neural network and nomogram were 85.8 % and 77.7 %, respectively. The Youden index was 58.04 % and 41.87 %, respectively. The detection sensitivity was 75.73 % and 65.06 %, respectively, and the specificity was 82.31 % and 76.81 %, respectively. Calibration curves of the neural network and nomogram showed better discrimination ability from the standard curve (P > 0.05). DCA and CIC analyses showed that the application of the neural network and nomogram to explore risk factors for bone mineral density abnormalities had certain clinical practicability, and the overall predictive effect of the model was good. Conclusion: The outcomes of the neural network and nomogram analyses suggested that diet structure and electrolyte changes are important significant risk factors for bone mineral density abnormalities, especially with increasing carbohydrate and caffeine intake and decreasing dietary fiber intake. The established model can also provide a reference for future risk prediction.

11.
J Colloid Interface Sci ; 650(Pt B): 1434-1445, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37481781

ABSTRACT

Magnetic-dielectric synergy is currently regarded as among the most effective approaches to achieve low-frequency electromagnetic wave absorption (EMA). However, designing and fabricating EMA materials with tunable magnetic-dielectric balance towards high-performance low-frequency EMA remains challenging. Herein, a polymer self-assembly guided heterogeneous structure engineering strategy is proposed to fabricate hierarchical magnetic-dielectric nanocomposite. Polymer assemblies not only can be employed as intermediates to encapsulate metal-organic frameworks and load metal hydroxide, but also that they play a crucial role for the in-situ formation of polycrystalline FeCo/Co composite nanoparticles. As a result, the minimum reflection loss (RLmin) can reach -59.61 dB at 5.4 GHz (4.8 mm) with a 20 wt% filler loading, while the effective absorption bandwidth (EAB, RLmin ≤ -10 dB) is 2.16 GHz, exhibiting excellent low-frequency EMA performance. Systematic investigations demonstrate that hierarchical mesoporous carbon matrix that supports FeCo/Co composite nanoparticles is beneficial for optimizing impedance matching and increasing attenuation capacity. In general, this study opens up new prospects for developing magnetic-dielectric EMA materials using a polymer self-assembly guided heterogeneous structure engineering strategy, which may receive significant attention in future research.

12.
J Agric Food Chem ; 71(29): 11008-11015, 2023 Jul 26.
Article in English | MEDLINE | ID: mdl-37432089

ABSTRACT

Developing fungicides from active botanical skeletons is one of the effective methods to tackle the resistance of plant pathogens. Based on our previous discoveries, a series of novel α-methylene-γ-butyrolactone (MBL) derivatives containing heterocycles and phenyl rings were designed according to the antifungal molecule carabrone first discovered in plant Carpesium macrocephalum. The target compounds were synthesized, and the inhibitory activity against pathogenic fungi as well as the mechanism of action were then systematically investigated. Several compounds showed promising inhibitory activities against a variety of fungi. The most potent compound 38 exhibited the EC50 value of 0.50 mg/L against Valsa mali (V. mali), which was more effective than that of commercial fungicide famoxadone. The protective effect of compound 38 against V. mali on apple twigs was superior to that of famoxadone, with an inhibition rate of 47.9% at 50 mg/L. The physiological and biochemical results showed that compound 38 inhibits V. mali by causing cell deformation and contraction, reducing the number of intracellular mitochondria, thickening the cell wall, as well as increasing the permeability of the cell membrane. Based on three-dimensional quantitative structure-activity relationship (3D-QSAR) analyses, it was shown that the introduction of the bulky and negatively charged groups favored the antifungal activity of the novel MBL derivatives. These findings suggest that compound 38 can be a potential candidate for novel fungicides worthy of further investigation further.


Subject(s)
Ascomycota , Fungicides, Industrial , Antifungal Agents/chemistry , Quantitative Structure-Activity Relationship , Fungicides, Industrial/chemistry , Structure-Activity Relationship
13.
Front Bioeng Biotechnol ; 11: 1211753, 2023.
Article in English | MEDLINE | ID: mdl-37351470

ABSTRACT

As a promising strategy, gene delivery for cancer treatment accepts encouraging progress due to its high efficacy, low toxicity, and exclusive selectivity. However, the delivery efficiency, specific biological distribution, targeted uptake, and biosafety of naked nucleic acid agents still face serious challenges, which limit further clinical application. To overcome the above bottleneck, safe and efficient functional nanovectors are developed to improve the delivery efficiency of nucleic acid agents. In recent years, emerging membrane-wrapped biomimetic nanoparticles (MBNPs) based on the concept of "imitating nature" are well known for their advantages, such as low immunogenicity and long cycle time, and especially play a crucial role in improving the overall efficiency of gene delivery and reducing adverse reactions. Therefore, combining MBNPs and gene delivery is an effective strategy to enhance tumor treatment efficiency. This review presents the mechanism of gene therapy and the current obstacles to gene delivery. Remarkably, the latest development of gene delivery MBNPs and the strategies to overcome these obstacles are summarized. Finally, the future challenges and prospects of gene delivery MBNPs toward clinical transformation are introduced. The principal purpose of this review is to discuss the biomedical potential of gene delivery MBNPs for cancer therapy and to provide guidance for further enhancing the efficiency of tumor gene therapy.

14.
Article in English | MEDLINE | ID: mdl-35564521

ABSTRACT

Assessing the bacteria pathogens in the lakes with reclaimed water as major influents are important for public health. This study investigated microbial communities of five landscape lakes replenished by reclaimed water, then analyzed driven factors and identified health effects of bacterial pathogens. 16S rRNA gene sequence analysis demonstrated that Proteobacteria, Actinobacteria, Cyanobacteria, Firmicutes, and Verrucomicrobia were the most dominant phyla in five landscape lakes. The microbial community diversities were higher in June and July than that in other months. Temperature, total nitrogen and phosphorus were the main drivers of the dominant microbial from the Redundancy analysis (RDA) results. Various potential bacterial pathogens were identified, including Pseudomonas, GKS98_freshwater_group, Sporosarcina, Pseudochrobactrum, Streptomyces and Bacillus, etc, some of which are easily infectious to human. The microbial network analysis showed that some potential pathogens were nodes that had significant health effects. The work provides a basis for understanding the microbial community dynamics and safety issues for health effects in landscape lakes replenished by reclaimed water.


Subject(s)
Cyanobacteria , Microbiota , Beijing , China , Humans , Lakes/microbiology , RNA, Ribosomal, 16S/genetics , Water
15.
Prep Biochem Biotechnol ; 50(8): 763-767, 2020.
Article in English | MEDLINE | ID: mdl-32134358

ABSTRACT

Vitamin B12 and propionic acid that were simultaneous produced by Propionibacterium freudenreichii are both favorable chemicals widely used in food preservatives, medicine, and nutrition. While the carbon source and propionic acid accumulation reflected fermentation efficiency. In this study, using corn stalk as a carbon source and fed-batch fermentation process in an expanded bed adsorption bioreactor was studied for efficient and economic biosynthesis of acid vitamin B12 and propionic. With liquid hot water pretreated corn stalk hydrolysates as carbon source, 28.65 mg L-1 of vitamin B12 and 17.05 g L-1 of propionic acid were attained at 168 h in batch fermentation. In order to optimize the fermentation outcomes, fed-batch fermentation was performed with hydrolyzed corn stalk in expanded bed adsorption bioreactor (EBAB), giving 47.6 mg L-1 vitamin B12 and 91.4 g L-1 of propionic acid at 258 h, which correspond to product yields of 0.37 mg g-1 and 0.75 g g-1, respectively. The present study provided a promising strategy for economically sustainable production of vitamin B12 and propionic acid by P. freudenreichii fermentation using biomass cornstalk as carbon source and expanded bed adsorption bioreactor.


Subject(s)
Bioreactors , Propionates/metabolism , Propionibacterium freudenreichii/metabolism , Vitamin B 12/metabolism , Zea mays/metabolism , Bioreactors/microbiology , Fermentation , Hydrolysis , Industrial Microbiology/methods
16.
mSphere ; 5(2)2020 03 18.
Article in English | MEDLINE | ID: mdl-32188746

ABSTRACT

Substantial concentrations of penicillin V potassium (PVK) have been found in livestock manure, soil, and wastewater effluents, which may pose potential threats to human health and contribute to the emergence of penicillin-resistant bacterial strains. In this study, bacterial strains capable of degrading PVK were isolated from sludge and characterized. Strain X-2 was selected for biodegradation of PVK. Based on morphological observations and 16S rRNA gene sequencing, strain X-2 was identified as an Ochrobactrum tritici strain. To enhance the PVK degradation ability of PVK, a whole-cell biodegradation process of Ochrobactrum tritici X-2 was established and optimized. In the whole-cell biodegradation process, the optimal temperature and pH were 30°C and 7.0, respectively. Under the optimized conditions, the degradation rate using 0.5 mg/ml PVK reached 100% within 3 h. During biodegradation, two major metabolites were detected: penicilloic acid and phenolic acid. The present study provides a novel method for the biodegradation of PVK using Ochrobactrum tritici strains, which represent promising candidates for the industrial biodegradation of PVK.IMPORTANCE Substantial concentrations of penicillin V potassium (PVK) have been found in the environment, which may pose potential threats to human health and contribute to the emergence of penicillin-resistant bacterial strains. In this study, antibiotic-degrading bacterial strains for PVK were isolated from sludge and characterized. Ochrobactrum tritici was selected for the biodegradation of PVK with high efficiency. To enhance its PVK degradation ability, a whole-cell biodegradation process was established and optimized using Ochrobactrum tritici The degradation rate with 0.5 mg/ml PVK reached 100% within 3 h. The potential biodegradation pathway was also investigated. To the best of our knowledge, the present study provides new insights into the biodegradation of PVK using an Ochrobactrum tritici strain, a promising candidate strain for the industrial biodegradation of ß-lactam antibiotics.


Subject(s)
Anti-Bacterial Agents/metabolism , Ochrobactrum/genetics , Ochrobactrum/metabolism , Penicillin V/metabolism , Sewage/microbiology , Biodegradation, Environmental , Hydroxybenzoates/metabolism , Industrial Microbiology , Penicillanic Acid/analogs & derivatives , Penicillanic Acid/metabolism , RNA, Ribosomal, 16S/genetics , Soil Microbiology
17.
J Biol Eng ; 14: 5, 2020.
Article in English | MEDLINE | ID: mdl-32123541

ABSTRACT

BACKGROUND: An efficient biodegradation-strengthening approach was developed to improve penicillin G degradation from industrial bacterial residue in an expanded bed adsorption bioreactor (EBAB) is reported in this paper. RESULTS: Paracoccus sp. strain KDSPL-02 was isolated based on its ability to use penicillin G as the sole carbon and nitrogen source. Strain identification was based on analyses of morphology, physio-biochemical characteristics, and 16S rDNA sequences. The effects of temperature, pH, PVA-sodium alginate concentration, calcium chloride concentration and initial penicillin G concentration were investigated. Repeated operations of immobilized cells with EBAB, At initial penicillin concentrations below 2.0 g L- 1, the continuous mode could reach more than 20 times, and the degradation rate reached 100%. CONCLUSIONS: The present study suggests that the EBAB system can be utilized for the simple and economical biodegradation of penicillin G from industrial bacterial residue.

18.
Environ Res ; 183: 109217, 2020 04.
Article in English | MEDLINE | ID: mdl-32065914

ABSTRACT

The microbial community is an important factor influencing the health of the water ecosystem in landscape lakes; in particular, proliferation of some cyanobacteria could cause odor problems. Exploring the microbial community is important for water quality management. In this study, focusing on seven landscape lakes in Beijing, the microbial communities were investigated based on 16S rRNA gene amplicon sequencing, and typical odor-causing compounds and interfering factors were identified. The results showed that 2-methylisoborneol (MIB) was the major odor-causing compound responsible for the earthy/musty odor in landscape lakes. For algal communities, Chlorella and Diatoms were the main eukaryote algae in the water. The bacterial community was dominated by Proteobacteria at the phylum level, and then Cyanobacteria, Actinobacteria, and Firmicutes, etc., most of which were the major phyla of the heterotrophic bacterial population. The richness and diversity of bacteria in natural-water-source lakes were higher than those in reclaimed-water-source lakes. Synechococcus (Cyanobacteria) and GKS98 (Proteobacteria) in reclaimed-water-source lakes were higher than those in natural-water-source lakes, however, CL500-29 (Actinobacteria) in natural-water-source lakes was higher than that in reclaimed-water-source lakes. These bacteria also had significantly positive correlations with MIB. Cyanobacteria and Actinobacteria were the main MIB compound contributors to the variability of MIB in the landscape lakes in Beijing.


Subject(s)
Camphanes , Chlorella , Microbiota , Beijing , Lakes , RNA, Ribosomal, 16S , Water Microbiology
19.
Environ Pollut ; 227: 444-450, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28486187

ABSTRACT

Nano zero valent iron/Ni bimetal materials (nZVI/Ni) were prepared by borohydride reduction method to remediate toxic Cr(Ⅵ) contaminated in soil leachate. nZVI/Ni was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Different factors including pH value of soil leachate, reaction time, temperature, humic acid and coexisting anions (SO42-, NO3-, HCO3-, CO32-) were studied to analyze the reduction rate. Results showed that the reduction rate of Cr(Ⅵ) could reach 99.84% under the condition of pH of 5 and temperature of 303 K. pH values and temperature of soil leachate had a significant effect on the reduction efficiency, while humic acid had inhibition effect for the reduction reaction. SO42-, HCO3- and CO32- had inhibition effect for reduction rate, while NO3- barely influenced the reduction process of nZVI/Ni. Moreover, Langumir-Hinshelwood first order kinetic model was studied and could describe the reduction process well. The thermodynamic studies indicated that the reaction process was endothermic and spontaneous. Activation energy was 143.80 kJ mol-1, showing that the reaction occurred easily. Therefore, the study provides an idea for nZVI/Ni further research and practical application of nZVI/Ni in soil remediation.


Subject(s)
Chromium/chemistry , Environmental Restoration and Remediation/methods , Humic Substances/analysis , Temperature , Water Pollutants, Chemical/chemistry , Anions , Chromium/analysis , Hydrogen-Ion Concentration , Iron/chemistry , Kinetics , Microscopy, Electron, Scanning , Photoelectron Spectroscopy , Soil/chemistry , Water Pollutants, Chemical/analysis , X-Ray Diffraction
20.
J Hazard Mater ; 321: 103-110, 2017 Jan 05.
Article in English | MEDLINE | ID: mdl-27614323

ABSTRACT

Microwave-assisted inverse emulsion polymerization method was used to prepare Cd(II) imprinted polymer (IIP) by using ß-cyclodextrin (ß-CD) and acrylamide (AM) as functional monomer, epichlorohydrin (ECH) as crossing-linking agent, ammonium persulfate as initiator. The Cd(II) imprinted polymer was characterized by SEM, FTIR and TGA. The influences of initial concentration of Cd(II), pH values, temperature, time and competitive ions on adsorption capacity and recognition properties are investigated. Under the optimal conditions, the adsorption capacity could reach 107mg/g. Furthermore, pseudo first order kinetic model, pseudo second order kinetic model and intra-particular diffusion model were used to describe the adsorption kinetic behavior. Results showed that the pseudo-second-order model (R2 0.9928-0.9961) had the best agreement with the experimental data. Langmuir adsorption isotherm model described the experimental data well, which indicated that adsorption was mainly monolayer absorption. Moreover, the study of adsorption thermodynamics (ΔG0<0, ΔH0>0, ΔS0>0) suggested that the adsorption process was a spontaneous and endothermic process. Competitive selectivity experiment revealed that imprinted polymer could selectively recognize Cd(II). It provides a new idea for removing Cd(II) from aqueous solution.

SELECTION OF CITATIONS
SEARCH DETAIL
...