Biotechnology for Biofuels and Bioproducts
·
2024
·Vol. 17
·期 1
·1-16
·
IF 3.3
Wei Xiaoyu,Yang Lijie,Chen Zhen,Xia Wenhao,Chen Yongbin,Cao Mingfeng,He Ning
Background The structural diversity of extracellular polymeric substances produced by microorganisms is attracting particular attention. Poly-gamma-glutamic acid (γ-PGA) is a widely studied extracellular polymeric substance from Bacillus species. The function of γ-PGA varies with its molecular weight (Mw). Results Herein, different endogenous promoters in Bacillus licheniformis were selected to regulate the expression levels of pgdS , resulting in the formation of γ-PGA with Mw values ranging from 1.61 × 10 3 to 2.03 × 10 4 kDa. The yields of γ-PGA and exopolysaccharides (EPS) both increased in the pgdS engineered strain with the lowest Mw and viscosity, in which the EPS content was almost tenfold higher than that of the wild-type strain. Subsequently, the compositions of EPS from the pgdS engineered strain also changed. Metabolomics and RT-qPCR further revealed that improving the transportation efficiency of EPS and the regulation of carbon flow of monosaccharide synthesis could affect the EPS yield. Conclusions Here, we present a novel insight that increased pgdS expression led to the degradation of γ-PGA Mw and changes in EPS composition, thereby stimulating EPS and γ-PGA production. The results indicated a close relationship between γ-PGA and EPS in B. licheniformis and provided an effective strategy for the controlled synthesis of extracellular polymeric substances.
研究领域:
微生物学
·
生物化学
·
合成生物学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED SOIL ECOLOGY
·
2024
·
IF 4.8
Jiahui Liao,Yuanyuan Li,Juanping Ni,Tingting Ren,Ke Shi,Xiaoming Zou,Han Y.H. Chen,Manuel Delgado-Baquerizo,Honghua Ruan
Soil microbial extracellular polymeric substances (EPS) are important components of soil organic carbon (SOC), which are thought to promote the formation of soil structures and induce the stabilization of SOC. Earthworms may not only stimulate the production of EPS through the promotion of microbial activity and microbial biomass, but might also accelerate the decomposition of EPS via ingestion, resulting in SOC sequestration or loss. However, the exact impacts of earthworms on EPS in soils have never been evaluated. Here, a pioneering experiment involving two species of endogeic earthworms ( Drawida gisti and Metaphire guillelmi ) with different body sizes was conducted to investigate their impacts on soil EPS. It was found that the D. gisti and M. guillelmi earthworms reduced the soil EPS-protein concentrations by 12.6 % and 17.6 %, respectively; however, they did not affect the EPS-polysaccharide concentration. Moreover, the presence of these endogeic earthworms increased soil microbial biomass, and elevated microbial respiration, microbial metabolic quotient, dissolved organic carbon, and soil pH. The results of this study provide the first evidence for the decoupling effects of earthworms on extracellular residual components. This suggests that earthworms may alter the molecular composition of SOM, thereby influencing its persistence and soil-atmosphere carbon exchange.
研究领域:
生态学
·
土壤学
✓ 已验证
产品关联
DOI
高影响因子
BIOMATERIALS
·
2013
·
IF 7.604
Jingbin Huang,He Zhang,Yuan Yu,Yan Chen,Dong Wang,Guoqing Zhang,Guichen Zhou,Junjie Liu,Zhiguo Sun,Duxin Sun,Ying Lu,Yanqiang Zhong
To develop biodegradable docetaxel-loaded self-assembled nanoparticles of poly ( d , l -lactide-co-glycolide)/hyaluronic acid block copolymers were successfully synthesized. These copolymers could form nanoparticles with small size (<200 nm), an acceptable CMC (∼7.9 mg/L), typical core/shell structure and superior stability in one week. DTX-loaded PLGA 502H -b-HA 5.6k nanoparticles (DTX/SANPs) showed a biphasic release pattern within 120 h, and exhibited enhanced cytotoxicity toward CD44-overexpressing MDA-MB-231 cells. Cellular uptake study indicated that PLGA 502H -b-HA 5.6k nanoparticles (SANPs) were taken up in MDA-MB-231 cells by CD44-mediated endocytosis . Pharmacokinetics study revealed DTX/SANPs could prolong the circulation of DTX in the blood. In vivo studies demonstrated that SANPs exhibited enhanced tumor targeting and antitumor activity with lower systemic toxicity. In conclusion, DTX/SANPs have great potential for targeted chemotherapy for CD44-overexpressing breast cancer.
研究领域:
药剂学
·
肿瘤学
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Jun Wu,Hao Zheng,Jun Hou,Lingzhan Miao,Fang Zhang,Raymond Jianxiong Zeng,Baoshan Xing
The effects of algae on the removal of contaminant by iron sulfide (FeS) are still unknown. Chlorella vulgaris (CV), a remarkable algal specie, was used to prepare the CV-supported FeS (CV-FeS) and to investigate the role that CV plays in the removal of a heavy metal (i.e., hexavalent chromium (Cr(VI)) by FeS. The stabilized effect from algal extracellular polymeric substance (EPS) enhanced the reactivity of FeS due to the decrease of FeS aggregation, thus increasing Cr(VI) removal rate from 0.21 min −1 to 0.79 min −1 . Furthermore, the strong buffering induced by the algal functional groups could effectively prevent the solution pH from increasing, which improved Cr(VI) removal because acidic solution facilitated Cr(VI) reduction by FeS. However, the complexing capacity from algal EPS made Fe(II) unavailable for Cr(VI) reduction, which led to 35% decrease of Cr(VI) removal. The Fe(II) was oxidized to α-FeOOH by Cr(VI) in the absence of CV, while the unreacted Fe(II) was detected as in the form of Fe(OH) 2 in CV-FeS. Cr(VI) was reduced to Cr(III) and S(-II) was oxidized to elemental sulfur (S 8 ) regardless of the CV. This work showed the different roles of algae in the removal of Cr(VI) by FeS and provided value information for the application of FeS in the polluted algae-containing water system.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2021
·
IF 6.609
Antony Rajendran,Hong-Xia Fan,Tian-You Cui,Jie Feng,Wen-Ying Li
Designing an efficient and selective catalyst for the ultra-deep sulfur removal from liquid fuels under mild conditions is vibrant in environmental catalysis. This work reports the preparation of catalysts, i.e., WO x -based active sites generated on SnO 2 , for the sulfur removal from model diesel via biphasic oxidative desulfurization (ODS). The different active species generated on SnO 2 such as monomeric and polymeric WO x species, and crystalline WO 3 are characterized. Besides being the support, SnO 2 adsorbs the sulfur compounds from the oil phase and boosts the ODS performance. No significant change in the ODS activity of WO x @SnO 2 is observed in the presence of intrusive nitrogen and aromatic compounds. The order of ODS activity towards different sulfur compounds is dibenzothiophene (DBT) > 4,6-dimethyl DBT > benzothiophene. While using SnO 2 with a higher surface area (96.5 m 2 /g) instead of that with a lower surface area (19.2 m 2 /g), the formation of highly efficient polymeric WO x species is enhanced. Consequently, the turn over frequency is augmented from 10.99 to 43.23 h −1 , which is closely a 4-fold increase. The polymeric WO x species produced on SnO 2 having the higher surface area are visualized by HAADF-STEM analysis. Scalable preparation and the higher turnover frequency of the present catalyst can develop a promising catalytic system for the ODS.
研究领域:
环境催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2013
·Vol. 21
·期 3
·1786-1795
·
IF 2.618
Song Chao,Sun Xue-Fei,Xing Su-Fang,Xia Peng-Fei,Shi Yi-Jing,Wang Shu-Guang
The antibiotics have attracted global attentions for their impact on aquatic ecosystem. The knowledge about the fate of antibiotics encountering extracellular polymeric substances (EPS) is, however, limited. In this study, we investigated the interacting mechanisms of tetracycline (TC) to EPS extracted from aerobic activated sludge. The contributions of the main components of EPS, extracellular proteins, and polysaccharides were evaluated using bovine serum albumin and alginate sodium, respectively. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and nuclear magnetic resonance indicated that hydroxyl, carboxyl, and amino groups were the domain chemical groups involved in the interaction between TC and EPS, and the binding of TC onto EPS changed the structure of these chemical groups, thus causing shifts in their UV–visible absorption spectra. In addition, we found that extracellular proteins, rather than polysaccharides, were the major active contents involved in the interaction. Three-dimensional excitation–emission matrix fluorescence spectroscopy showed that the fluorophores in EPS were clearly quenched by TC and the static quenching process was observed, implying the complex formation of TC and EPS. Furthermore, thermodynamic analysis indicated that the binding of TC with EPS is spontaneous and dominated by electrostatic forces.
研究领域:
环境科学
·
微生物学
·
光谱学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Current Drug Delivery
·
2024
·
IF 2.8
Zhang Ziyi,Tian Jinyuan,Xu Xiaoqing,Shi Wei,Qi Yajuan,Liu Zhanjun
Introduction: Polymer prodrug nanoparticles have become an emerging drug delivery
system in cancer therapy due to their high drug loading. However, their poor drug release and lack of
tumor cell targeting limit their clinical application.
Objective: This study aimed to prepare targeted and reduction-reactive polyprodrug nanocarriers
based on curcumin (CUR) for co-delivery of doxorubicin (DOX), labeled as DOX/HAPCS NPs, and
to investigate their anticancer activity.
Methods: The polymer was synthesized and characterized by chemical method. The drug loading
and drug release behavior of DOX and CUR in polymer nanoparticles were determined. Moreover,
the antitumor effects of polymer nanoparticles were evaluated using an MTT experiment and tumor
inhibition experiment, and the synergistic effect of co-delivered DOX and CUR was explored.
Results: The particle size of DOX/HAPCS NPs was 152.5nm, and the potential was about -26.74
mV. The drug-carrying capacity of DOX and CUR was about 7.56% and 34.75%, respectively, indicating
high drug-carrying capacity and good stability. DOX and CUR released over 90% within 24
hours in the tumor environment. Compared with free DOX, DOX/HAPCS NPs demonstrated significantly
enhanced cell and tumor inhibitory effects (P<0.05) in vivo and in vitro and changed drug
distribution to avoid toxic side effects on normal tissues. The combined index showed that DOX and
CUR showed synergistic anticancer effects at a set ratio.
Conclusion: The prepared reduction-responsive targeted polymer nanomedical DOX/HAPCS NPs
exhibited a synergistic anti-cancer effect, with high drug loading capacity and the ability to release
drugs in proportion, making it a promising polymer nanoparticle drug delivery system.
研究领域:
药剂学
·
肿瘤学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
Scientific Reports
·
2025
·Vol. 15
·期 1
·1-11
·
IF 3.9
Bie Songtao,Yuan Hui,Shi Chen,Li Chunshuang,Lu Ming,Yao Ze,Liu Ruobing,Lu Ding,Ma Tenglong,Yu Heshui
In chronic infections caused by Staphylococcus aureus , biofilm is a major virulence factor. In Staphylococcus aureus biofilms, bacteria are embedded in a matrix of extracellular polymeric substances and are highly tolerant to antimicrobial drugs. However, the lack of effective solutions to inhibit biofilm formation remains a challenge, and the mechanism of inhibition of biofilm formation targeting extracellular polymeric substances is unclear. The aim of the present study was to investigate the inhibitory mechanisms of Plumbagin against Staphylococcus aureus biofilms formation by affecting secretion of extracellular polymeric substances using the high-content screening. Our results showed Plumbagin (16 µg/mL) inhibited biofilm formation, revealing a significant reduction in both biomass and bacterial metabolic activity, and disrupted the biofilm structure, leading to a significant decrease in both biological volume and average thickness ( P ≤ 0.01). High-content screening imaging indicated that the Plumbagin treatment induced alterations in the extracellular polymeric substances of Staphylococcus aureus biofilm, significantly reducing the quantities of extracellular polysaccharide, proteins and extracellular DNA. Interestingly, extracellular DNA within the matrix was found to be the most sensitive to Plumbagin treatment. Extracellular DNA formation was significantly inhibited at a concentration of 4 µg/mL, whereas the inhibition of extracellular polysaccharide and proteins required a higher concentration of 8 µg/mL. Overall, these results demonstrated the inhibitory effects of Plumbagin on Staphylococcus aureus biofilm formation and extracellular polymeric substances secretion, suggesting that extracellular DNA may be a potential target for the anti-biofilm activity of Plumbagin. These findings will provide new insights into the mode of action of Plumbagin in treating infections caused by Staphylococcus aureus biofilms.
研究领域:
微生物学
·
药理学
·
感染病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2024
·
IF 8.1
Jia-Xin Dai,Yanshuang Yu,Le-Xing You,Hong-Lin Zhong,Yuan-Ping Li,Ai-Jun Wang,Jon Chorover,Ren-Wei Feng,Hend A. Alwathnani,Martin Herzberg,Christopher Rensing
Although the antimicrobial mechanisms of nanomaterials have been extensively investigated, bacterial defense mechanisms associated with AgNPs have not been fully elucidated. We here report that dissolved Ag + (>0.05 μg mL −1 ) displayed higher toxicity on cell growth of strain Cupriavidus metallidurans BS1 (GCA_003260185.2) in comparison to 2 and 20 nm AgNPs. The genes necessary for synthesis of distinct abundance and composition of extracellular polymeric substances (EPS) were induced in strain BS1 exposed to Ag stress. This resulted in 20.1% (Ag(I)-EPS) and 24.2% (2 nm AgNPs-EPS) of the C O band integrated intensities being converted into C-OH/C-O-C group vibrations and the Ag-O bond was formed between EPS and 20 nm AgNPs. Meanwhile, the expression of primary resistance genes of the cus, sil and cup operon encoding HME-RND-driven efflux systems as well as a P IB1 -type ATPase (CupA) were significantly induced after exposure to Ag(I), 2 and 20 nm AgNPs, respectively. Furthermore, distinct genes involved in biosynthesis pathways responsible for production of EPS were induced to relieve the toxicity of Ag(I), 2 nm and 20 nm AgNPs. This combined action is one potential reason why strain BS1 displayed distinct resistances in response to Ag(I) compared to 2 and 20 nm AgNPs. This work will help in understanding processes important in bacterial defensive mechanisms to AgNPs.
研究领域:
微生物学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL GEOLOGY
·
2022
·
IF 4.685
Ming Zhang,Ying Xu,Ke-Qing Xiao,Chun-Hui Gao,Shuang Wang,Di Zhu,Yichao Wu,Qiaoyun Huang,Peng Cai
Extracellular polymeric substances (EPS) exuded by microbes are found in diverse habitats, including soil. The quantification and characterization of EPS are essential prerequisites for understanding the ecological functions of extracellular products in soil. However, few studies have conducted in-depth profiling of soil EPS extraction steps and chemical characteristics. Here we examine the C and N contents, biopolymer contents, and optical properties of EPS involving three soil pre-treatment methods (moist soil, moist soil pre-incubated, and air-dried soil pre-incubated) and simultaneously track the compositional changes during the two-step extraction process (extract with CaCl 2 in Step 1 and phosphate buffer solution (PBS) with cation exchange resin (CER) in Step 2). The optical properties of soil EPS are investigated using ultraviolet-visible adsorption (UV–Vis), excitation-emission-matrix fluorescence (EEM), and fourier transform infrared (FTIR) spectroscopy coupled with multivariate analytical methods such as parallel factor analysis (PARAFAC), principal component analysis (PCA), and correlation analysis. Results show that Step 2 releases significantly more dissolved organic carbon and biopolymers (polysaccharides, proteins, and uronic acids) from soils. UV–Vis and EEM spectroscopy suggest that the fractions extracted in Step 2 exhibit higher mean aromaticity, molecular weight , and humification degree than those extracted in Step 1. When using the standard method to extract EPS from moist aggregates (Step 2), EPS has a distinct fluorescence profile, rich in tryptophan- and tyrosine-like signals. Reassuringly, the fluorescence-profiles found in pre-extracts (Step 1) are very different - except where i) aggregates have an experimental drying step added, and ii) pure water is used as a pre-extractant. Drying of aggregates is thus problematic, and the use of pure water as an alternative pre-extractant is not advisable. Soil treatments have significant effects on the qualities of the various extracts which are detected by both the FTIR-PCA and EEM-PCA analyses. EEM fluorescence profiles of EPS suggest that both tryptophan-like and tyrosine-like substances are key components of the EPS extracted from all soils regardless of pretreatment. Our findings indicate that chemical characterization of soil EPS combined with spectral-chemometric approaches can be applied to identify and characterise the extracellular responses of soil microbes and thus help reveal the ecological functions of extracellular products in soils.
研究领域:
土壤生物学
·
环境科学
·
微生物生态学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2025
·
IF 13.2
Yijin Feng,Xing Liu,Yingshuang Zhang,Zhiyi Wang,Jiming Su,Ziyue Li,Jianchao Wang,Qianqian Xu,Min Wang,Hui Wang,Hongru Jiang,Chongqing Wang
The growing threat of marine microplastics (MPs) demands effective remediation strategies. This study proposed microbubble flotation (MBF) as a promising solution, utilizing the microbubbles with small size and high stability to enhance the capture efficiency of marine MPs. However, the application of MBF is constrained by the limited comprehension of the interfacial interactions among MPs, microbubbles, and marine cations or microbes. Traditional froth flotation for algae-incubated MPs resulted in removal efficiencies of 0.07% (2–2.5 mm) and 22.39% (48–72 μm), while that of MBF achieved 95.26% and 63.82%, respectively. This decrease in removal efficiencies after algae incubation was caused by the enhanced hydrophilicity of MPs. After 28 days of incubation with algae, the contact angle of MPs decreased from 97.88° to 21.62°, and C=O and O–C=O functional groups were formed while C–O group increased from 2.39% to 10.84%. Although algae-secreted extracellular polymeric substances (EPS) adhered to MPs surface and formed hydrophilic membranes, weakening the hydrophobic interaction between MPs and microbubbles, cations and soluble EPS promoted removal efficiency by reducing microbubble size and enhancing microbubble stability. The positive effects of cations on MPs flotation followed the order: Mg 2+ > Na + > K + > Ca 2+ . Moreover, molecular dynamics simulations further confirmed that fucose-containing sulfated polysaccharide molecules intertwined and sealed the gas–liquid interface via hydrogen bonds, thereby enhancing bubble stability and reducing the radius from 25 Å to 16 Å. These findings offer valuable insights into the environmental interfacial interactions during MPs flotation in marine environments, laying the groundwork for the application of MBF in marine MPs remediation.
研究领域:
环境科学
·
海洋学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Yanxiang Zhang,Huiling Liu,Xiaohu Dai,Chen Cai,Jing Wang,Yunpeng Shen,Peng Wang
Erythromycin mycelial dreg (EMD) resulting from erythromycin (ERY) production process may be used as a nutrient resource. However, it has a high moisture content, which makes handling operations complicated. In this study, the EMD dewaterability under heat-activated persulfate (PS) oxidation conditioning was investigated. The variations of physical and chemical properties of EMD were further investigated to uncover the underlying mechanism of EMD dewaterability. Results indicated that EMD dewaterability was worse under single heat process, but significantly improved under heat-activated PS oxidation process. Heat-activated PS oxidation conditioning was capable to increase zeta potential , reduce median particle size, alter EMD flocs morphology, and disrupt mycelial cells. Concurrently, heat-activated PS oxidation conditioning resulted in the decrease of protein in tightly bound (TB) extracellular polymeric substances (EPS) and total EPS, and the decrease of fluorescing constituents (tryptophan protein, tyrosine protein and tryptophan amino acid) in EPS. Furthermore, a possible mechanism was proposed for heat-activated PS oxidation conditioning.
研究领域:
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）