FOOD MICROBIOLOGY
·
2025
·
IF 4.6
Ping Lu,Juan Xue,Aiying Shi,Xuemeng Ji
Cronobacter sakazakii is a notorious foodborne pathogen linked to severe infections in neonates, with powdered infant formula serving as a common transmission route due to its ability to survive under desiccated conditions. Understanding the molecular mechanisms underlying its desiccation resistance is crucial for developing effective control strategies. In this study, we employed comparative proteomics and hydropathy profiling to investigate putative core proteins potentially involved in desiccation resilience. Proteomic analysis of wild-type and 22 knockout strains identified 1,354 proteins, of which 156 were defined as putative core proteins due to stable abundance profiles. Among these, two uncharacterized proteins, ESA_03998 and ESA_01764 , exhibited strong hydrophilic properties and were predicted to be surface-associated based on signal peptide analysis. Gene knockout of ESA_03998 or ESA_01764 significantly reduced surface hydrophilicity and survival under prolonged desiccation in both PBS and milk powder matrices. Additionally, Laurdan-based membrane fluidity assays revealed increased membrane rigidification (ΔGP) in mutant strains, indicating that these proteins help preserve membrane hydration and dynamics under low-moisture conditions. These findings establish a novel link between hydrophilic putative core proteins and membrane-associated desiccation resistance in C. sakazakii , offering insights into its persistence in dry food environments and highlighting potential targets for mitigating contamination in powdered infant formula.
研究领域:
微生物学
·
分子生物学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Innovative Food Science & Emerging Technologies
·
2018
·
IF 3.116
Debao Niu,Lang-Hong Wang,Xin-An Zeng,Qing-Hui Wen,Charles S. Brennan,Zhong-Sheng Tang,Man-Sheng Wang
The effects of low concentrations of ethanol (3% to 9%, v/v) on cell membrane fatty acid composition , membrane lipid conformation, membrane fluidity and pulsed electric fields (PEF) resistance of Acetobacter sp. in the stationary phase were investigated. Results showed that the growth of Acetobacter sp. was inhibited, and analysis of gas chromatography–mass spectrometry, Raman spectroscopy and fluorescence polarization indicated that membrane fluidity of Acetobacter sp. cells was significantly increased by modifying membrane fatty acid composition and membrane lipid conformation after exposure to ethanol. Moreover, results showed that cells cultivated in the medium with relatively high ethanol concentrations were more vulnerable to PEF. For example, the inactivation of Acetobacter sp. (10 9 CFU/mL) cultivated with 9% ethanol by PEF (20.0 kV/cm, 6.0 ms) could reach 5.17 log, significantly higher than those cultivated without ethanol (3.22 log). This was confirmed by morphological analysis, showing various changes on the cell surface after PEF treatment. Industrial relevance Acetobacter sp. is one of spoilage microorganisms in winemaking, and it is able to convert the ethanol produced by yeasts into acetic acid and thereby increase volatile acidity in wine. In this study, the effect of ethanol as a growth substrate on PEF resistance in Acetobacter sp. cells was investigated. Results here reported will contribute to better understand the influencing mechanisms of ethanol on the inactivation of Acetobacter sp. cells by PEF treatment and further develop the application of PEF for inactivating acetic acid bacteria (AAB) in the wine industry.
研究领域:
微生物学
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Bao Zhu,Xiaoran Wei,Jian Song,Qiu Zhang,Wei Jiang
Aluminium oxide nanoparticles (Al 2 O 3 NPs) potentially cause health hazards after their release into the environment. The crystalline phase of Al 2 O 3 NPs determines their surface structure and the number of functional groups. The adsorption of natural organic matter (NOM) or biomolecules on the surface Al 2 O 3 NPs also alters their surface properties and subsequent interactions with organisms. In this study, the roles of the Al 2 O 3 crystalline phase and the surface coating of the nanoparticles on the membrane integrity and fluidity were investigated. Giant and small unilamellar vesicles (GUVs and SUVs) were prepared as model cell membranes to detect membrane disruption after exposure to Al 2 O 3 NPs. Due to amorphous structure and high surface activity of γ-Al 2 O 3 NPs, they had a stronger affinity with the membrane and caused more serious membrane rupture than that of α-Al 2 O 3 NPs. The deposition of Al 2 O 3 NPs on the membrane and the induced membrane disruption were monitored by a quartz crystal microbalance with dissipation (QCM-D) method. HA-coated Al 2 O 3 NPs disrupted the SUV layer on the QCM-D sensor, while BSA-coated Al 2 O 3 NPs only adhered to the membrane and induced unremarkable vesicle disruption. In addition, untreated γ-Al 2 O 3 NPs induced remarkable gelation of a negatively charged membrane, but other types of Al 2 O 3 NPs caused negligible membrane phase changes. The outcomes of this study demonstrate that the crystalline phase of the Al 2 O 3 NPs affects the integrity and fluidity of cell membranes. The protein coatings on the NPs weaken the NP-membrane interaction, while HA coatings increase the damage of the NP-induced interaction.
研究领域:
生物学
·
环境科学
·
纳米毒理学
✓ 已验证
DOI
高影响因子
BIOTECHNOLOGY & BIOTECHNOLOGICAL EQUIPMENT
·
2020
·
IF 1.186
Guosong Xin,Miao Yu,Yang Hu,Shiyong Gao,Zheng Qi,Yuan Sun,Wenjing Yu,Jiaxin He,Yubin Ji
Lycorine is an isoquinoline alkaloid in Amaryllidaceae with antitumor, antibacterial, antiviral, diuretic and cardiovascular effects. This study explored the antitumor mechanism of lycorine in vitro and in vivo by focusing on its effects on tumor cell membrane fraction and tumor cell membrane structure. The results showed that lycorine had antitumor effect on H22 tumor-bearing mice in vivo and could effectively prolong the survival time of H22 tumor-bearing mice. In vitro, lycorine inhibited the proliferation of HepG-2 cells and induced cell death significantly. Lycorine reduced the total protein content, sialic acid content and cholesterol content on the surface of tumor cell membrane, and reduced the content of some main components of tumor cell membranes. Lycorine reduced the membrane fluidity and cell membrane integrity of tumor cells. In addition, the ion channel (Na+, K+-ATPase, Ca2+, Mg2+-ATPase) activity on the surface of the tumor cell membrane decreased. This contributed to a significant antitumor effect in vitro and in vivo.
研究领域:
药理学
·
肿瘤学
·
细胞生物学
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Sijia Wang,Yue Sun,Shouhong Xu,Honglai Liu
Conjugating polymers to peptides has become a new strategy of designing functional antitumor agents for their improved stability and enhanced activity. In this paper, a novel peptide–polymer conjugate PEPc–PMAA with pH responsiveness was designed and synthesized. The isoelectric point of PEPc was studied by dynamic light scattering for the targeting effect. Also, the transmittances of PMAA at different pHs were measured using an ultraviolet–visible spectrophotometer for determining the triggering pH of the disrupting effect. The results showed that PEPc–PMAA was hydrophilic under neutral conditions and changed to be amphiphilic composed of positively charged PEPc and hydrophobic PMAA under acidic conditions. The interactions between PEPc–PMAA and mimic cells were investigated by the measurements of membrane fluidity and cargo leakage from 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine and 1,2-dipalmitoyl-sn-glycerol-3-phospho-(1-rac-glycerol) (DPPG) liposomes. It proved that PEPc–PMAA caused a distinct membrane disturbance of the DPPG liposome at pH 5.5, resulting in more serious cargo leakage. Because of its targeting and disrupting effects on negatively charged biomembranes under acidic conditions, PEPc–PMAA showed its good potential as an antitumor agent.
研究领域:
生物化学
·
药理学
·
材料科学
✓ 已验证
DOI
PubMed
高影响因子
Biomaterials Science
·
2020
·Vol. 8
·期 23
·6786-6797
·
IF 6.183
Jing Zhao,Jian Su,Lu Qin,Xin Zhang,Shirui Mao
Liposomes are promising vectors for pulmonary drug delivery, and have been used in marketed inhalation products. Membrane fluidity is an important property of liposomes. However, the influence of liposome membrane fluidity on its interaction with pulmonary physiological barriers is still unclear and needs elucidation. Here, a series of PEGylated DPPC (1,2-dihexadecanoyl-rac-glycero-3-phosphocholine) liposomes with different membrane fluidity were prepared, and their interaction with different pulmonary physiological barriers, including the mucus permeation capacity, macrophage uptake, trachea distribution and retention behavior, was investigated. The liposomes exhibited sizes of around 100 nm, near-neutral surface charge, and the membrane fluidity increased with increasing cholesterol ratio. In vitro studies showed that the liposomes with lower membrane fluidity presented optimal mucus permeation efficiency, while those with higher membrane fluidity displayed lower macrophage uptake. An in vivo trachea distribution study revealed that liposomes with low or medium membrane fluidity exhibited enhanced trachea permeation. No significant difference in lung retention was found among these liposomes. In conclusion, the mucus permeation and macrophage phagocytosis behavior of liposomes could be well tuned by changing their membrane fluidity.
研究领域:
药剂学
·
生物医学工程
·
呼吸系统研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES
·
2017
·
IF 3.498
Lang-Hong Wang,Xin-An Zeng,Man-Sheng Wang,Charles S. Brennan,Deming Gong
In this work, modifications of cell membrane fluidity, fatty acid composition and fatty acid biosynthesis-associated genes of Escherichia coli ATCC 25922 ( E. coli ) and Staphylococcus aureus ATCC 6538 ( S. aureus ), during growth in the presence of naringenin (NAR), one of the natural antibacterial components in citrus plants, was investigated. Compared to E. coli , the growth of S. aureus was significantly inhibited by NAR in low concentrations. Combination of gas chromatography–mass spectrometry with fluorescence polarization analysis revealed that E. coli and S. aureus cells increased membrane fluidity by altering the composition of membrane fatty acids after exposure to NAR. For example, E. coli cells produced more unsaturated fatty acids (from 18.5% to 43.3%) at the expense of both cyclopropane and saturated fatty acids after growth in the concentrations of NAR from 0 to 2.20 mM. For S. aureus grown with NAR at 0 to 1.47 mM, the relative proportions of anteiso-branched chain fatty acids increased from 37.2% to 54.4%, whereas iso-branched and straight chain fatty acids decreased from 30.0% and 33.1% to 21.6% and 23.7%, respectively. Real time q-PCR analysis showed that NAR at higher concentrations induced a significant down-regulation of fatty acid biosynthesis-associated genes in the bacteria, with the exception of an increased expression of fabA gene. The minimum inhibitory concentration (MIC) of NAR against these two bacteria was determined, and both of bacteria underwent morphological changes after exposure to 1.0 and 2.0 MIC.
研究领域:
微生物学
·
分子生物学
·
药理学
✓ 已验证
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 8
·7111
·
IF 5.6
Yanyun Lin,Xingjuan Wu,Kaicheng Wang,Sen Shang,Yubin Gong,Hongwei Zhao,Dai Wu,Peng Zhang,Xiaoyun Lu
Understanding the vibrational information encoded within the terahertz (THz) spectrum of biomolecules is critical for guiding the exploration of its functional responses to specific THz radiation wavelengths. This study investigated several important phospholipid components of biological membranes—distearoyl phosphatidylethanolamine (DSPE), dipalmitoyl phosphatidylcholine (DPPC), sphingosine phosphorylcholine (SPH), and lecithin bilayer—using THz time-domain spectroscopy. We observed similar spectral patterns for DPPC, SPH, and the lecithin bilayer, all of which contain the choline group as the hydrophilic head. Notably, the spectrum of DSPE, which has an ethanolamine head group, was different. Interestingly, density functional theory calculations confirmed that the absorption peak common to DSPE and DPPC at approximately 3.0 THz originated from a collective vibration of their similar hydrophobic tails. Accordingly, the cell membrane fluidity of RAW264.7 macrophages with irradiation at 3.1 THz was significantly enhanced, leading to improved phagocytosis. Our results highlight the importance of the spectral characteristics of the phospholipid bilayers when studying their functional responses in the THz band and suggest that irradiation at 3.1 THz is a potential non-invasive strategy to increase the fluidity of phospholipid bilayers for biomedical applications such as immune activation or drug administration.Keywords:phospholipid bilayers;THz absorption spectra;cell membrane fluidity;phagocytosis
研究领域:
生物物理学
·
医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
iScience
·
2023
·
IF 5.8
Jiayu Fang,Yanping Zhang,Taicheng Zhu,Yin Li
Microbial rhodopsins are widely distributed in the aqua-ecosystem due to their simple structure and multifaceted functions. Conventionally, microbial rhodopsins are considered to be exclusively light active. Here, we report the discovery of light-independent function of a proteorhodopsin from a psychrophile Psychroflexus torquis (ptqPR). ptqPR could improve the growth and viability of Escherichia coli cells under stressful conditions in the absence of light, and this was achieved by improving the energy maintenance, membrane potential, membrane fluidity, and membrane integrity. We further show that this non-canonical function of PR is related to its scramblase activity. PR mutants which lost scramblase activities also lost their ability to confer physiological advantages in E . coli . These findings shed light on why microbial rhodopsins are widely distributed in ecological systems where light is inaccessible.
研究领域:
微生物学
·
分子生物学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2016
·Vol. 17
·期 8
·1374
·
IF 3.257
Ou Yun,Xin-An Zeng,Charles S. Brennan,Zhong Han
Salmonella typhimuriumcells were subjected to pulsed electric field (PEF) treatment at 25 kV/cm for 0–4 ms to investigate the effect of PEF on the cytoplasmic membrane lipids and oxidative injury of cells. Results indicated that PEF treatment induced a decrease of membrane fluidity ofSalmonella typhimurium(S. typhimuriumi), possibly due to the alterations of fatty acid biosynthesis-associated gene expressions (down-regulation ofcfaandfabAgene expressions and the up-regulation offabDgene expression), which, in turn, modified the composition of membrane lipid (decrease in the content ratio of unsaturated fatty acids to saturated fatty acids). In addition, oxidative injury induced by PEF treatment was associated with an increase in the content of malondialdehyde. The up-regulation of cytochrome bo oxidase gene expressions (cyoA,cyoB, andcyoC) indicated that membrane damage was induced by PEF treatment, which was related to the repairing mechanism of alleviating the oxidative injury caused by PEF treatment. Based on these results, we achieved better understanding of microbial injury induced by PEF, suggesting that micro-organisms tend to decrease membrane fluidity in response to PEF treatment and, thus, a greater membrane fluidity might improve the efficiency of PEF treatment to inactivate micro-organisms.Keywords:pulsed electric fields;Salmonella typhimurium;membrane lipids;cytoplasmic membrane fluidity;oxidative injury
研究领域:
微生物学
·
食品科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2025
·
IF 8
Ping Lu,Juan Xue,Aiying Shi,Xuemeng Ji
Cronobacter sakazakii poses significant neonatal health risks due to its exceptional desiccation tolerance and virulence, yet the molecular mechanisms linking membrane lipid regulation to these traits remain poorly defined. This study characterizes the global regulator FadR (ESA_01467) as a key modulator of fatty acid metabolism, membrane fluidity, and pathogenicity. Deletion of fadR resulted in a 52 % decrease in adhesion and 61 % reduction in invasion of intestinal epithelial cells, alongside attenuated virulence and reduced bacterial loads in a neonatal rat model. Proteomic and lipidomic analyses revealed downregulation of FabA and FabB, upregulation of beta-oxidation enzymes, and a 25 % increase in membrane rigidity associated with decreased levels of palmitoleic and oleic acids. The Δ fadR mutant showed a 3.2-log reduction in viability following 14 days of desiccation in phosphate-buffered saline, while survival in milk powder remained unaffected. Supplementation with milk-derived long-chain fatty acids restored both membrane fluidity and desiccation survival to wild-type levels. These findings establish FadR as a central regulator linking lipid homeostasis to environmental adaptation and virulence in C. sakazakii , providing mechanistic insight into its persistence in dry food environments and infection risk.
研究领域:
微生物学
·
分子生物学
·
食品安全
·
传染病学
·
新生儿学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CONTROLLED RELEASE
·
2023
·
IF 10.8
Ziming Lin,Taomei Deng,Yinuo Liu,Shuangyang Zheng,Guangji Wang,Hua He,Jingwei Zhang
Poor tumor penetration is the most significant barrier to the clinical translation of nanomedicines . Despite numerous studies, little is known about how the physicochemical properties and tumor-associated environments impact liposome intratumoral penetration from a multi-factorial perspective. Thus, we developed a set of model liposomes to explore the laws of their intratumoral penetration. Our comprehensive analysis revealed that zeta potential , membrane fluidity, and size of liposomes could influence their penetration in the peripheral, intermediate, or central areas of the tumor, respectively. Moreover, protein corona and stromal cells primarily impeded liposome penetration in the tumor periphery, while the vascular vessels had a similar effect in the tumor center. Our results also revealed a non-monotonic relationship, indicating that the best condition for a single factor may not necessarily be the optimal choice when considering all the factors. The preferred size, zeta potential, and membrane fluidity for excellent tumor penetration are within the ranges of 52–72 nm , 16–24 mV, and 230–320 mp, respectively. Our study provides a comprehensive understanding of the influence of physicochemical properties and tumor-associated environments on liposome intratumoral penetration, offering explicit guidance for the precise design and rational optimization of anti-tumor liposomes.
研究领域:
药学
·
纳米技术
·
肿瘤学
✓ 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）