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The rapid emergence and spread of multidrug-resistant bacterial pathogens require the development of antibacterial agents that are robustly effective while inducing no toxicity or resistance development. In this context, we designed and synthesized amphiphilic dendrimers as antibacterial candidates. We report the promising potent antibacterial activity shown by the amphiphilic dendrimer AD1b, composed of a long hydrophobic alkyl chain and a tertiary amine-terminated poly(amidoamine) dendron, against a panel of Gram-negative bacteria, including multidrug-resistant Escherichia coli and Acinetobacter baumannii. AD1b exhibited effective activity against drug-resistant bacterial infections in vivo. Mechanistic studies revealed that AD1b targeted the membrane phospholipids phosphatidylglycerol (PG) and cardiolipin (CL), leading to the disruption of the bacterial membrane and proton motive force, metabolic disturbance, leakage of cellular components, and, ultimately, cell death. Together, AD1b that specifically interacts with PG/CL in bacterial membranes supports the use of small amphiphilic dendrimers as a promising strategy to target drug-resistant bacterial pathogens and addresses the global antibiotic crisis. [ABSTRACT FROM AUTHOR]

The strain designated as Y139T is a novel Gram-stain-negative, aerobic, and nonmotile bacterium, was isolated from a soil sample in McClain County, Oklahoma, United States. The cells of strain Y139T were a rod-shaped, with the width of 0.4-0.7 µm and the length of 1.5-2.0 µm. Growth occurred at 20-37°C (optimum, 30°C), pH 5.5-9.5 (optimum, pH 7.0), and 0-1.0% NaCl (w/v) (optimum, 0%). The polar lipid profiles included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine, and an unidentified lipid. The major fatty acids included C16:0, iso-C14:0, and C16:1 -9c. Menaquinone-9 (MK-9) was recognized as the only respiratory quinone. Strain Y139T showed the highest 16S rRNA gene sequence similarity to Luteolibacter flavescens MCCC 1K03193T (98.3%). Phylogenetic analysis positioned it within the genus Luteolibacter. The draft genome of strain Y139T consisted of 7,106,054 bp, and contained 5,715 open reading frames (ORFs), including 5,656 coding sequences (CDSs) and 59 RNA genes. The genomic DNA G + C content was found to be 62.5%. Comparing strain Y139T with L. flavescens MCCC 1K03193T and Luteolibacter arcticus CCTCC AB 2014275T, the average nucleotide identity (ANI) values were 80.6 and 82.1%, respectively. Following phylogenetic, physiological, biochemical, and chemotaxonomic analyses, a novel species within the genus Luteolibacter, designated as Luteolibacter soli sp. nov., was proposed for strain Y139T, which was also assigned as the type strain (=KCTC 92644T = MCCC 1H01451T). Further analysis of core genes across 9 Luteolibacter species uncovered significant genomic divergence, particularly in those related to cofactor, vitamin, and energy metabolism. Analysis of biogeographic distribution suggested that lake and soil were the main habitats for the genus Luteolibacter. Additionally, the genus Luteolibacter was sensitive to climate warming and precipitation. [ABSTRACT FROM AUTHOR]

[Display omitted] Infectious diseases, particularly those associated with biofilms, are challenging to treat due to an increased tolerance to commonly used antibiotics. This underscores the urgent need for innovative antimicrobial strategies. Here, we present an alternative simple-by-design approach focusing on the development of biocompatible and antibiotic-free nanocarriers from docosahexaenoic acid (DHA) that has the potential to combat microbial infections and phosphatidylglycerol (DOPG), which is attractive for use as a biocompatible prominent amphiphilic component of Gram-positive bacterial cell membranes. We assessed the anti-bacterial and anti-biofilm activities of these nanoformulations (hexosomes and vesicles) against S. aureus and S. epidermidis , which are the most common causes of infections on catheters and medical devices by different methods (including resazurin assay, time-kill assay, and confocal laser scanning microscopy on an in vitro catheter biofilm model). In a DHA-concentration-dependent manner, these nano-self-assemblies demonstrated strong anti-bacterial and anti-biofilm activities, particularly against S. aureus. A five-fold reduction of the planktonic and a four-fold reduction of biofilm populations of S. aureus were observed after treatment with hexosomes. The nanoparticles had a bacteriostatic effect against S. epidermidis planktonic cells but no anti-biofilm activity was detected. We discuss the findings in terms of nanoparticle-bacterial cell interactions, plausible alterations in the phospholipid membrane composition, and potential penetration of DHA into these membranes, leading to changes in their structural and biophysical properties. The implications for the future development of biocompatible nanocarriers for the delivery of DHA alone or in combination with other anti-bacterial agents are discussed, as novel treatment strategies of Gram-positive infections, including biofilm-associated infections. [ABSTRACT FROM AUTHOR]

[Display omitted] Docosahexaenoic acid monoacylglycerol represents a promising lipid constituent in the development of drug nanocarriers owing to its amphiphilicity and the beneficial health effects of this docosahexaenoic acid precursor in various disorders including cancer and inflammatory diseases. Here, we describe the formation and characterization of simple-by-design and stabilizer-free lamellar and non-lamellar crystalline nanoparticles (vesicles and cubosomes, respectively) from binary mixtures of docosahexaenoic acid monoacylglycerol and phosphatidylglycerol, which is a ubiquitous amphiphilic component present in biological systems. At the physiological temperature of 37 °C, these single amphiphilic components tend to exhibit inverse hexagonal and lamellar liquid crystalline phases, respectively, on exposure to excess water. They can also be combined and dispersed in excess water by employing a high-energy emulsification method (by means of ultrasonication) to produce through an electrostatic stabilization mechanism colloidally stable nanodispersions. A colloidal transformation from vesicles to cubosomes was detected with increasing MAG-DHA content. Through use of synchrotron small-angle X-ray scattering, cryo-transmission electron microscopy, and nanoparticle tracking analysis, we report on the structural and morphological features, and size characteristics of these nanodispersions. Depending on the lipid composition, their internal liquid crystalline architectures were spanning from a lamellar (L α) phase to biphasic features of coexisting inverse bicontinuous (Q 2) cubic Pn3m and Im3m phases. Thus, a direct colloidal vesicle-cubosome transformation was detected by augmenting the concentration of docosahexaenoic acid monoacylglycerol. The produced cubosomes were thermally stable within the investigated temperature range of 5–60 °C. Collectively, our findings contribute to understanding of the imperative steps for production of stabilizer-free cubosomes from biocompatible lipids through a simple-by-design approach. We also discuss the potential therapeutic use and future implications for development of next-generation of multifunctional vesicles and cubosomes for co-delivery of docosahexaenoic acid and drugs in treatment of diseases. [ABSTRACT FROM AUTHOR]

The fundamental differences in phospholipids between bacterial and mammalian cell membranes present remarkable opportunities for antimicrobial design. However, it is challenging to distinguish bacterial anionic phospholipid phosphatidylglycerol (PG) from mammalian anionic phosphatidylserine (PS) with the same net charge. Here, we report a class of radially amphiphilic a helix antimicrobial peptides (RAPs) that can selectively discriminate PG from PS, relying on the helix structure. The representative RAP, L10-MMBen, can direct the rearrangement of PG vesicles into a lamellar structure with its helix axis parallel to the PG membrane surface. The helical structure imparts both the thermodynamic and kinetic advantages of L10-MMBen/PG assembly, and the hiding of hydrophobic regions in RAPs is crucial for PG recognition. L10-MMBen exhibits high selectivity against bacteria depending on PG recognition, showing low in vivo toxicity and significant treatment efficacy in mice infection models. Our study introduces a helicity-direct bacterial phospholipid recognition paradigm for designing highly selective antimicrobial peptides. [ABSTRACT FROM AUTHOR]

A Gram‐positive, aerobic, rod‐shaped mesophilic bacterium was isolated from birch wood, referred to as the AB strain. Allergological tests suggest that this strain may cause allergic alveolitis in sawmill workers. Employing a polyphasic taxonomic approach, the AB strain's 16S rRNA gene sequence showed high similarity to Microbacterium barkeri and M. oryzae, with 97.25% and 96.91%, respectively, a finding supported by rpoB and gyrB sequence analysis. Further genome sequence comparison with the closely related M. barkeri type strain indicated a digital DNA–DNA hybridization value of 25.5% and an average nucleotide identity of 82.52%. The AB strain's cell wall peptidoglycan contains ornithine, and its polar lipids comprise diphosphatidylglycerol, phosphatidylglycerol, and unidentified glycolipids. Its major fatty acids include anteiso C15:0, anteiso C17:0, and iso C16:0, while MK‐10 is its predominant respiratory quinone. Comprehensive analysis through 16S rRNA, whole‐genome sequencing, phenotyping, chemotaxonomy, and MALDI‐TOF MS profiling indicates that the AB strain represents a new species within the Microbacterium genus. It has been proposed to name this species Microbacterium betulae sp. nov., with ABT (PCM 3040T = CEST 30706T) designated as the type strain. [ABSTRACT FROM AUTHOR]

A novel Gram-stain-negative, facultatively anaerobic, and mixotrophic bacterium, designated as strain LZ166T, was isolated from the bathypelagic seawater in the western Pacific Ocean. The cells were short rod-shaped, oxidase- and catalase-positive, and motile by means of lateral flagella. The growth of strain LZ166T was observed at 10–45 °C (optimum 34–37 °C), at pH 5–10 (optimum 6–8), and in the presence of 0–5% NaCl (optimum 1–3%). A phylogenetic analysis based on the 16S rRNA gene showed that strain LZ166T shared the highest similarity (98.58%) with Aquibium oceanicum B7T and formed a distinct branch within the Aquibium genus. The genomic characterization, including average nucleotide identity (ANI, 90.73–76.79%), average amino identity (AAI, 88.50–79.03%), and digital DNA–DNA hybridization (dDDH, 36.1–22.2%) values between LZ166T and other species within the Aquibium genus, further substantiated its novelty. The genome of strain LZ166T was 6,119,659 bp in size with a 64.7 mol% DNA G+C content. The predominant fatty acid was summed feature 8 (C18:1ω7c and/or C18:1ω6c). The major polar lipids identified were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), glycolipid (GL), and phosphatidylglycerol (PG), with ubiquinone-10 (Q-10) as the predominant respiratory quinone. The genomic annotation indicated the presence of genes for a diverse metabolic profile, including pathways for carbon fixation via the Calvin–Benson–Bassham cycle and inorganic sulfur oxidation. Based on the polyphasic taxonomic results, strain LZ166T represented a novel species of the genus Aquibium, for which the name Aquibium pacificus sp. nov. is proposed, with the type strain LZ166T (=MCCC M28807T = KACC 23148T = KCTC 82889T). [ABSTRACT FROM AUTHOR]

The degradation of farmland in China underscores the need for developing and utilizing saline-alkali soil. Soil health relies on microbial activity, which aids in the restoration of the land's ecosystem, and hence it is important to understand microbial diversity. In the present study, two Gram-stain-positive strains HR 1-10T and J-A-003T were isolated from saline-alkali soil. Preliminary analysis suggested that these strains could be a novel species. Therefore, the taxonomic positions of these strains were evaluated using polyphasic analysis. Phylogenetic and 16S rRNA gene sequence analysis indicated that these strains should be assigned to the genus Halalkalibacter. Cell wall contained meso-2,6-diaminopimelic acid. The polar lipids present in both strains were diphosphatidyl-glycerol, phosphatidylglycerol, and an unidentified phospholipid. The major fatty acids (>10%) were anteiso-C15:0, C16:0 and iso-C15:0. Average nucleotide identity and digital DNA#x2013;DNA hybridization values were below the threshold values (95% and 70%, respectively) for species delineation. Based on the above results, the strains represent two novel species of the genus Halalkalibacter, for which the names Halalkalibacter flavus sp. nov., and Halalkalibacter lacteus sp. nov., are proposed. The type strains are HR 1-10T (=GDMCC 1.2946T = MCCC 1K08312T = JCM 36285T), and J-A-003T (=GDMCC 1.2949T = MCCC 1K08417T = JCM 36286T). [ABSTRACT FROM AUTHOR]

Cutaneous wound healing is a complex biological process involving a series of well-coordinated events aimed at restoring skin integrity and function. Various experimental models have been developed to study the mechanisms underlying skin wound repair and to evaluate potential therapeutic interventions. This review explores the diverse array of skin wound healing models utilized in research, ranging from rodent excisional wounds to advanced tissue engineering constructs and microfluidic platforms. More importantly, the influence of lipids on the wound healing process is examined, emphasizing their role in enhancing barrier function restoration, modulating inflammation, promoting cell proliferation, and promoting remodeling. Lipids, such as phospholipids, sphingolipids, and ceramides, play crucial roles in membrane structure, cell signaling, and tissue repair. Understanding the interplay between lipids and the wound microenvironment provides valuable insights into the development of novel therapeutic strategies for promoting efficient wound healing and tissue regeneration. This review highlights the significance of investigating skin wound healing models and elucidating the intricate involvement of lipids in the healing process, offering potential avenues for improving clinical outcomes in wound management. [ABSTRACT FROM AUTHOR]

In our earlier works, we have shown that the rate-limiting steps, associated with the dark-to-light transition of Photosystem II (PSII), reflecting the photochemical activity and structural dynamics of the reaction center complex, depend largely on the lipidic environment of the protein matrix. Using chlorophyll-a fluorescence transients (ChlF) elicited by single-turnover saturating flashes, it was shown that the half-waiting time (Δτ 1/2) between consecutive excitations, at which 50% of the fluorescence increment was reached, was considerably larger in isolated PSII complexes of Thermostichus (T.) vulcanus than in the native thylakoid membrane (TM). Further, it was shown that the addition of a TM lipid extract shortened Δτ1/2 of isolated PSII, indicating that at least a fraction of the 'missing' lipid molecules, replaced by detergent molecules, caused the elongation of Δ τ1/2. Here, we performed systematic experiments to obtain information on the nature of TM lipids that are capable of decreasing Δ τ1/2. Our data show that while all lipid species shorten Δ τ1/2, the negatively charged lipid phosphatidylglycerol appears to be the most efficient species - suggesting its prominent role in determining the structural dynamics of PSII reaction center. [ABSTRACT FROM AUTHOR]

We investigated the properties of extracellular vesicles from the probiotic Weizmannia coagulans lilac-01 (Lilac-01EVs). The phospholipids in the Lilac-01EV membrane were phosphatidylglycerol and mitochondria-specific cardiolipin. We found that applying Lilac-01EVs to primary rat microglia in vitro resulted in a reduction in primary microglial cell death (P  < .05). Lilac-01EVs, which contain cardiolipin and phosphatidylglycerol, may have the potential to inhibit cell death in primary microglia. The addition of Lilac-01EVs to senescent human dermal fibroblasts suggested that Lilac-01 EVs increase the mitochondrial content without affecting their membrane potential in these cells. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Although Staphylococcus aureus is the leading cause of biofilm-related infections, the lipidomic distributions within these biofilms is poorly understood. Here, lipidomic mapping of S. aureus biofilm cross-sections was performed to investigate heterogeneity between horizontal biofilm layers. METHODS: S. aureus biofilms were grown statically, embedded in a mixture of carboxymethylcellulose/gelatin, and prepared for downstream matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS). Trapped ion mobility spectrometry (TIMS) was also applied prior to mass analysis. RESULTS: Implementation of TIMS led to a ∼ threefold increase in the number of lipid species detected. Washing biofilm samples with ammonium formate (150 mM) increased signal intensity for some bacterial lipids by as much as tenfold, with minimal disruption of the biofilm structure. MALDI TIMS IMS revealed that most lipids localize primarily to a single biofilm layer, and species from the same lipid class such as cardiolipins CL(57:0) - CL(66:0) display starkly different localizations, exhibiting between 1.5 and 6.3-fold intensity differences between layers (n = 3, p

A Gram-stain-negative, yellow, moist and circular, aerobic, motile, and rod-shaped bacterium, designated YIM 151497T, was isolated from soil sample collected from Blue-Bridge, Weizhou Island, Guangxi province, China. Classification using a polyphasic approach suggested that strain YIM 151497T belonged to the genus Pelagibacterium, and was closely relevant to Pelagibacterium nitratireducens JLT2005T (98.8%), Pelagibacterium halotolerans CGMCC 1.7692T (98.7%), Pelagibacterium lixinzhangensis H64T (98.1%), and Pelagibacterium luteolum CGMCC 1.10267T (97.1%). The growth ranges of temperature, pH, and NaCl were 4–40 ℃, pH 4.0–10.0, and 0–7% NaCl, respectively. It was positive for catalase and oxidase. The primary respiratory quinone was Q-10. The elemental fatty acids were Summed Feature 8 (constituting C18:1ω7c and/or C18:1ω6c), C19:0 cyclo ω8c, C16:0, and C18:1ω7c 11-methyl. The major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, and three unidentified glycolipids. The DNA G+C content based on the complete genome sequence was 60.7 mol%. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) between strain YIM 151497T and species of Pelagibacterium were in the ranges of 73.9–86.3% and 19.7–31.3%, respectively. The Average Amino Acid Identity (AAI) between strain YIM 151497T and species of Pelagibacterium were in the ranges of 68.8–88.8%. On the basis of these data, strain YIM 151497T is considered to represent a novel species of the genus Pelagibacterium with the name of Pelagibacterium flavum sp. nov. Type strain is strain YIM 151497T (= KCTC 49826T = CGMCC 1.61521T = MCCC 1K08053T). [ABSTRACT FROM AUTHOR]

Photosynthetic organisms often encounter phosphorus (P) limitation in natural habitats. When faced with P limitation, seed plants degrade nucleic acids and extra-plastid phospholipids to remobilize P, thereby enhancing their internal-P utilization efficiency. Although prokaryotic and eukaryotic photosynthetic organisms decrease the content of phosphatidylglycerol (PG) under P-limited conditions, it remains unclear whether PG is degraded for P remobilization. Moreover, information is limited on internal-P remobilization in photosynthetic microbes. This study investigates internal-P remobilization under P-starvation (-P) conditions in a cyanobacterium, Synechocystis sp. PCC 6803, focusing on PG and nucleic acids. Our results reveal that the PG content increases by more than double in the -P culture, indicating preferential PG synthesis among cellular P compounds. Simultaneously, the faster increases of glycolipids counteract this PG increase, which decreases the PG proportion in total lipids. Two genes, glpD and plsX, contribute to the synthesis of diacylglycerol moieties in glycerolipids, with glpD also responsible for the polar head group synthesis in PG. The mRNA levels of both glpD and plsX are upregulated during -P, which would cause the preferential metabolic flow of their P-containing substrates toward glycerolipid synthesis, particularly PG synthesis. Meanwhile, we find that RNA accounts for 62% of cellular P, and that rRNA species, which makes up the majority of RNA, are degraded under -P conditions to less than 30% of their initial levels. These findings emphasize the importance of PG in -P-acclimating cell growth and the role of rRNA as a significant internal-P source for P remobilization, including preferential PG synthesis. [ABSTRACT FROM AUTHOR]

The Gram-negative marine bacterium GXY010T, which has been isolated from the surface seawater of the western Pacific Ocean, is aerobic, non-motile and non-flagellated. Strain GXY010T exhibits growth across a temperature range of 10–42 °C (optimal at 37 °C), pH tolerance from 7.0 to 11.0 (optimal at 7.5) and a NaCl concentration ranging from 1.0 to 15.0% (w/v, optimal at 5.0%). Ubiquinone-8 (Q-8) was the predominant isoprenoid quinone in strain GXY010T. The dominant fatty acids (>10%) of strain GXY010T were iso-C15:0 (14.65%), summed feature 9 (iso-C17:1 ω9c and/or 10-methyl C16:0) (12.41%), iso-C17:0 (10.85%) and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c) (10.41%). Phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), unidentifiable glycolipid (GL) and four non-identifiable aminolipids (AL1-AL4) were the predominant polar lipids of strain GXY010T. The genomic DNA G+C content was identified as a result of 48.0% for strain GXY010T. The strain GXY010T genome consisted of 2,766,857 bp, with 2664 Open Reading Frames (ORFs), including 2586 Coding sequences (CDSs) and 78 RNAs. Strain GXY010T showed Average Nucleotide Identity (ANI) values of 73.4% and 70.6% and DNA–DNA hybridization (DDH) values of 19.2% and 14.5% with reference species Pseudidiomarina tainanensis MCCC 1A02633T (=PIN1T) and Pseudidiomarina taiwanensis MCCC 1A00163T (=PIT1T). From the results of the polyphasic analysis, a newly named species, Pseudidiomarina fusca sp. nov. within the genus Pseudidiomarina, was proposed. The type strain of Pseudidiomarina fusca is GXY010T (=JCM 35760T = MCCC M28199T = KCTC 92693T). [ABSTRACT FROM AUTHOR]

Understanding the membrane interactions of the N-terminal 17 residues of the huntingtin protein (HttN) is essential for unraveling its role in cellular processes and its impact on huntingtin misfolding. In this study, we used atomic force microscopy (AFM) to examine the effects of lipid specificity in mediating bilayer perturbations induced by HttN. Across various lipid environments, the peptide consistently induced bilayer disruptions in the form of holes. Notably, our results unveiled that cholesterol enhanced bilayer perturbation induced by HttN, while phosphatidylethanolamine (PE) lipids suppressed hole formation. Furthermore, anionic phosphatidylglycerol (PG) and cardiolipin lipids, along with cholesterol at high concentrations, promoted the formation of double-bilayer patches. This unique structure suggests that the synergy among HttN, anionic lipids, and cholesterol can enhance bilayer fusion, potentially by facilitating lipid intermixing between adjacent bilayers. Additionally, our AFM-based force spectroscopy revealed that HttN enhanced the mechanical stability of lipid bilayers, as evidenced by an elevated bilayer puncture force. These findings illuminate the complex interplay between HttN and lipid membranes and provide useful insights into the role of lipid composition in modulating membrane interactions with the huntingtin protein. [ABSTRACT FROM AUTHOR]

Photosynthetic organisms often encounter phosphorus (P) limitation in natural habitats. When faced with P limitation, seed plants degrade nucleic acids and extra-plastid phospholipids to remobilize P, thereby enhancing their internal-P utilization efficiency. Although prokaryotic and eukaryotic photosynthetic organisms decrease the content of phosphatidylglycerol (PG) under P-limited conditions, it remains unclear whether PG is degraded for P remobilization. Moreover, information is limited on internal-P remobilization in photosynthetic microbes. This study investigates internal-P remobilization under P-starvation (-P) conditions in a cyanobacterium, Synechocystis sp. PCC 6803, focusing on PG and nucleic acids. Our results reveal that the PG content increases by more than double in the -P culture, indicating preferential PG synthesis among cellular P compounds. Simultaneously, the faster increases of glycolipids counteract this PG increase, which decreases the PG proportion in total lipids. Two genes, glpD and plsX, contribute to the synthesis of diacylglycerol moieties in glycerolipids, with glpD also responsible for the polar head group synthesis in PG. The mRNA levels of both glpD and plsX are upregulated during -P, which would cause the preferential metabolic flow of their P-containing substrates toward glycerolipid synthesis, particularly PG synthesis. Meanwhile, we find that RNA accounts for 62% of cellular P, and that rRNA species, which makes up the majority of RNA, are degraded under -P conditions to less than 30% of their initial levels. These findings emphasize the importance of PG in -P-acclimating cell growth and the role of rRNA as a significant internal-P source for P remobilization, including preferential PG synthesis.

The novel bacterial strain MBLB1776T was isolated from marine mud in Uljin, the Republic of Korea. Cells were Gram-positive, spore-forming, non-motile, and non-flagellated rods. Growth was observed at a temperature range of 10–45 °C, pH range of 6.0–8.0, and NaCl concentrations of 0–4% (w/v). Phylogenetic analysis of the 16S rRNA gene sequence revealed that MBLB1776T belonged to the genus Paenibacillus and was closely related to Paenibacillus cavernae C4-5T (94.83% similarity). Anteiso-C15:0, iso-C16:0, C16:0, and iso-C15:0 were the predominant fatty acids. Menaquinone 7 was identified as the major isoprenoid quinone. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Its whole genome was 6.3 Mb in size, with a G+C content of 55.8 mol%. Average nucleotide identity and in silico DNA–DNA hybridization values were below the species delineation threshold. Gene function analysis revealed the presence of a complete C30 carotenoid biosynthetic pathway. Intriguingly, MBLB1776T harbored carotenoid pigments, imparting an orange color to whole cells. Based on this comprehensive polyphasic taxonomy, the MBLB1776T strain represents a novel species within the genus Paenibacillus, for which the name Paenibacillus aurantius sp. nov is proposed. The type strain was MBLB1776T (=KCTC 43279T = JCM 34220T). This is the first report of a carotenoid-producing Paenibacillus sp. [ABSTRACT FROM AUTHOR]

Objective: Welding fume exposure is inevitable of welding workers and poses a severe hazard to their health since welding is a necessary industrial process. Thus, preclinical diagnostic symptoms of worker exposure are of great importance. The aim of this study was to screen serum differential metabolites of welding fume exposure based on UPLC–QTOF-MS/MS. Methods: In 2019, 49 participants were recruited at a machinery manufacturing factory. The non-target metabolomics technique was used to clarify serum metabolic signatures in people exposed to welding fume. Differential metabolites were screened by OPLS-DA analysis and Student's t-test. The receiver operating characteristic curve evaluated the discriminatory power of differential metabolites. And the correlations between differential metabolites and metal concentrations in urine and whole blood were analyzed utilizing Pearson correlation analysis. Results: Thirty metabolites were increased significantly, and 5 metabolites were decreased. The differential metabolites are mainly enriched in the metabolism of arachidonic acid, glycero phospholipid, linoleic acid, and thiamine. These results observed that lysophosphatidylcholine (20:1/0:0) and phosphatidylglycerol(PGF1α/16:0) had a tremendous anticipating power with relatively increased AUC values (AUC > 0.9), and they also presented a significant correlation of Mo concentrations in whole blood and Cu concentrations in urine, respectively. Conclusion: The serum metabolism was changed significantly after exposure to welding fume. Lysophosphatidylcholine (20:1/0:0) and phosphatidylglycerol (PGF1α/16:0) may be a potential biological mediator and biomarker for laborers exposure to welding fume. [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, aerobic, motile by gliding, and rod-shaped bacterium, designated IMCC34845T, was isolated from a freshwater stream in the Republic of Korea. The results of 16S rRNA gene-based phylogenetic analyses showed that strain IMCC34845T was affiliated with the genus Zwartia and was most closely related to 'Achromobacter panacis' DCY105T (100%) and Zwartia hollandica LF4-65T (98.9%). The whole-genome sequence of strain IMCC34845T was 3.2 Mbp in size with a 51.5% DNA G+C content. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain IMCC34845T and 'Achromobacter panacis' KCTC 42751T were 77.7% and 20.7%, respectively, revealing that they are independent species. Moreover, the strains IMCC34845T and KCTC 42751T exhibited ≤ 72.5% ANI and ≤18.5% dDDH values with closely related species Zwartia hollandica LF4-65T, further supporting that the two strains represent each novel species of the genus. The major respiratory quinone of strain IMCC34845T was ubiquinone-8 (Q-8), and the predominant cellular fatty acids were C16:0 (41.3%) and C17:0 cyclo (34.5%). The major polar lipids of the strain were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipids, and unidentified aminolipids. Based on the phylogenetic, genomic, physiological, and chemotaxonomic characteristics, strain IMCC34845T was considered to represent a novel species within the genus Zwartia, for which the name Zwartia vadi sp. nov. is proposed. The type of strain is IMCC34845T (=KCTC 92920T = NBRC 114902T). Furthermore, based on the taxonomic data, 'Achromobacter panacis' is proposed to be reclassified as Zwartia panacis comb. nov. [ABSTRACT FROM AUTHOR]

Cutaneous wound healing is a complex biological process involving a series of well-coordinated events aimed at restoring skin integrity and function. Various experimental models have been developed to study the mechanisms underlying skin wound repair and to evaluate potential therapeutic interventions. This review explores the diverse array of skin wound healing models utilized in research, ranging from rodent excisional wounds to advanced tissue engineering constructs and microfluidic platforms. More importantly, the influence of lipids on the wound healing process is examined, emphasizing their role in enhancing barrier function restoration, modulating inflammation, promoting cell proliferation, and promoting remodeling. Lipids, such as phospholipids, sphingolipids, and ceramides, play crucial roles in membrane structure, cell signaling, and tissue repair. Understanding the interplay between lipids and the wound microenvironment provides valuable insights into the development of novel therapeutic strategies for promoting efficient wound healing and tissue regeneration. This review highlights the significance of investigating skin wound healing models and elucidating the intricate involvement of lipids in the healing process, offering potential avenues for improving clinical outcomes in wound management.

Objective: To establish a method for the determination of hydrogenated soybean phosphatidylcholine(HSPC) and phosphatidylglycerol(DSPG) in amphotericin B liposomes(L-AMB) by HPLC and electrospray detector(CAD). Methods: Venusil XBP C 8(4.6 mm×250 mm, 5 μm) column was used. The column temperature was 30℃. Using methanol-water as mobile phase; Spray pressure: 56.4 psi, spray temperature: 55℃; Gradient elution at flow rate of 1.0 m L·min-1. Results: L-AMB phospholipids had a good linear relationship with peak area in 5～60 mg·m L-1. The average recovery of HSPC was 100.06%, and the average RSDS were 0.42. The average recovery of DSPG was 100.03%, and the average RSDS were 0.55. HSPC and DSPG contents in L-AMB were 1497.66 mg·L-1and4710.93 mg·L-1, respectively, and no lysophospholipids were detected by HPLC-CAD. HSPC and DSPG contents were 1495.28 mg·L-1and4712.71 mg·L-1, respectively. HSPC and DSPG contents by HPLC-ELSD method were consistent. Conclusion: Determination of HSPC and DSPG in L-AMB by HPLC-CAD is simple and accurate, and can accurately determine the quality of liposome in L-AMB. [ABSTRACT FROM AUTHOR]

Recently, phosphatidylglycerol (PG) focused on its important role in chloroplast photosynthesis, mitochondrial function of the sperm, an inhibitory effect on SARS-CoV-2 ability to infect naïve cells, and reducing lung inflammation caused by coronavirus disease 2019. To develop an enzymatic PG determination method as the high-throughput analysis of PG, a PG-specific phospholipase C (PG-PLC) was found in the culture supernatant of Amycolatopsis sp. NT115. PG-PLC (54 kDa by SDS-PAGE ) achieved the maximal activity at pH 6.0 and 55°C and was inhibited by detergents, such as Briji35, Tween 80, and sodium cholate, but not by EDTA and metal ions, except for Zn2+. The open reading frame of the PG-PLC gene consisted of 1620 bp encoding 515-amino-acid residues containing the preceding 25-amino-acid residues (Tat signal peptide sequence). The putative amino acid sequence of PG-PLC was highly similar to those of metallophosphoesterases; however, its substrate specificity was completely different from those of known PLCs. [ABSTRACT FROM AUTHOR]

A small receptor molecule composed of a porphyrin core with tetrakis-ammonium glycine pickets (liptin 3e) appears to target anionic phosphatidylglycerol (PG) lipid head groups through multifunctional binding-pocket complementarity. Although a major component of bacterial cell membranes, PG is not widely found in animal cells, making PG potentially selective for bacterial targeting. Growth of microbial isolates was monitored in liquid cultures treated with liptin 3e by dilution plate counts and turbidity. Inhibition of growth by liptin 3e was observed for the ESKAPE human pathogens (Enterobacter aerogenes, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterococcus faecium), Escherichia coli, Mycobacterium smegmatis, Streptococcus sobrinus, and methicillin-resistant S. aureus (MRSA), with certain species suppressed at <1 μg/mL (sub-μM) concentrations. Prolonged lag phases were observed, although cell viability was mainly unaffected, suggesting that liptin treatment caused bacteriostasis. Cultures treated with liptin 3e eventually recovered, resumed growth, and reached the same final densities as untreated cultures. Growth of the fungus Candida albicans was not appreciably inhibited by liptin 3e. If liptins exhibit bacteriostasis through broad extracellular binding to PG head groups, thereby disrupting cellular processes, liptins may be considered for development into preclinical drug candidates or be useful as a targeting system for molecular beacons or antibacterial drugs. [ABSTRACT FROM AUTHOR]

Cardiolipin is a hallmark phospholipid of mitochondrial membranes. Despite established significance of cardiolipin in supporting respiratory supercomplex organization, a mechanistic understanding of this lipid-protein interaction is still lacking. To address the essential role of cardiolipin in supercomplex organization, we report cryo-EM structures of a wild type supercomplex (IV1III2IV1) and a supercomplex (III2IV1) isolated from a cardiolipin-lacking Saccharomyces cerevisiae mutant at 3.2-Å and 3.3-Å resolution, respectively, and demonstrate that phosphatidylglycerol in III2IV1 occupies similar positions as cardiolipin in IV1III2IV1. Lipid-protein interactions within these complexes differ, which conceivably underlies the reduced level of IV1III2IV1 and high levels of III2IV1 and free III2 and IV in mutant mitochondria. Here we show that anionic phospholipids interact with positive amino acids and appear to nucleate a phospholipid domain at the interface between the individual complexes, which dampen charge repulsion and further stabilize interaction, respectively, between individual complexes. Whether anionic phospholipids required for respiratory supercomplex (SC) formation is unclear. Here authors resolve SCs from a wild type and cardiolipin-deficient yeast strain at 3.2- 3.3 Å resolution to show that cardiolipin can be replaced by phosphatidylglycerol. [ABSTRACT FROM AUTHOR]

This review proposes the use of dioleoylphosphatidylglycerol (DOPG) to enhance diabetic wound healing. Initially, the characteristics of diabetic wounds are examined, focusing on the epidermis. Hyperglycemia accompanying diabetes results in enhanced inflammation and oxidative stress in part through the generation of advanced glycation end-products (AGEs), in which glucose is conjugated to macromolecules. These AGEs activate inflammatory pathways; oxidative stress results from increased reactive oxygen species generation by mitochondria rendered dysfunctional by hyperglycemia. These factors work together to reduce the ability of keratinocytes to restore epidermal integrity, contributing to chronic diabetic wounds. DOPG has a pro-proliferative action on keratinocytes (through an unclear mechanism) and exerts an anti-inflammatory effect on keratinocytes and the innate immune system by inhibiting the activation of Toll-like receptors. DOPG has also been found to enhance macrophage mitochondrial function. Since these DOPG effects would be expected to counteract the increased oxidative stress (attributable in part to mitochondrial dysfunction), decreased keratinocyte proliferation, and enhanced inflammation that characterize chronic diabetic wounds, DOPG may be useful in stimulating wound healing. To date, efficacious therapies to promote the healing of chronic diabetic wounds are largely lacking; thus, DOPG may be added to the armamentarium of drugs to enhance diabetic wound healing. [ABSTRACT FROM AUTHOR]

SUMMARY: Cytidine diphosphate diacylglycerol (CDP‐DAG), an important intermediate for glycerolipid biosynthesis, is synthesized under the catalytic activity of CDP‐DAG synthase (CDS) to produce anionic phosphoglycerolipids such as phosphatidylglycerol (PG) and cardiolipin (CL). Previous studies showed that Arabidopsis CDSs are encoded by a small gene family, termed CDS1–CDS5, the members of which are integral membrane proteins in endoplasmic reticulum (ER) and in plastids. However, the details on how CDP‐DAG is provided for mitochondrial membrane‐specific phosphoglycerolipids are missing. Here we present the identification of a mitochondrion‐specific CDS, designated CDS6. Enzymatic activity of CDS6 was demonstrated by the complementation of CL synthesis in the yeast CDS‐deficient tam41Δ mutant. The Arabidopsis cds6 mutant lacking CDS6 activity showed decreased mitochondrial PG and CL biosynthesis capacity, a severe growth deficiency finally leading to plant death. These defects were rescued partly by complementation with CDS6 or supplementation with PG and CL. The ultrastructure of mitochondria in cds6 was abnormal, missing the structures of cristae. The degradation of triacylglycerol (TAG) in lipid droplets and starch in chloroplasts in the cds6 mutant was impaired. The expression of most differentially expressed genes involved in the mitochondrial electron transport chain was upregulated, suggesting an energy‐demanding stage in cds6. Furthermore, the contents of polar glycerolipids in cds6 were dramatically altered. In addition, cds6 seedlings lost the capacity for cell proliferation and showed a higher oxidase activity. Thus, CDS6 is indispensable for the biosynthesis of PG and CL in mitochondria, which is critical for establishing mitochondrial structure, TAG degradation, energy production and seedling development. Significance Statement: The Arabidopsis mitochondrial CDP‐DAG synthase, CDS6, differs from the previously identified CDS1–CDS5. CDS6 is indispensable for the biosynthesis of PG and CL in mitochondria, which is critical for establishing the cristae structure of the mitochondrial inner envelope. The Arabidopsis cds6 mutant lacking CDS6 activity showed decreased capacity for TAG degradation and energy production and severe growth deficiency, finally leading to plant death. [ABSTRACT FROM AUTHOR]

Two novel aerobic, gram-negative, rod-shaped bacterial strains designated strains REN5T and REN5-1, were isolated from pit mud of Baijiu in Sichuan province, China. Based on the 16S rRNA gene sequence similarity, both strains belonged to the genus Sphingomonas. Strains REN5T and REN5-1 showed the highest similarity with S. aquatilis (97.9–98.0%). The DNA G+C content of REN5T and REN5-1 were 67.62 and 67.57 mol %, respectively. The DNA-DNA relatedness values between strains REN5T and S. aquatilis, REN5-1 and S. aquatilis were 22.8 and 22.6%, respectively. The main isoprenoid quinone of REN5T was Q-10, the major fatty acids were C18:1ω7c, C16:0 and C14:0 2-OH, and the main are polar lipids were DPG (diphosphatidylglycerol), SGL (sphingoglycolipid), PG (phosphatidylglycerol), PC (phosphatidylcholine), PE (phosphatidylethanolamine), UPL (unidentified phospholipid) and UL (unidentified polar lipid). The polyphasic taxonomic data showed that strains REN5T and REN5-1 represented a novel species within the genus Sphingomonas, for which the name Sphingomonas beigongshangi sp. nov. is proposed, with the type strain REN5T (=GDMCC1.2211T = JCM 34404T). [ABSTRACT FROM AUTHOR]

Our previous work shows that dioleoylphosphatidylglycerol (DOPG) accelerates corneal epithelial healing in vitro and in vivo by unknown mechanisms. Prior data demonstrate that DOPG inhibits toll-like receptor (TLR) activation and inflammation induced by microbial components (pathogen-associated molecular patterns, PAMPs) and by endogenous molecules upregulated in psoriatic skin, which act as danger-associated molecular patterns (DAMPs) to activate TLRs and promote inflammation. In the injured cornea, sterile inflammation can result from the release of the DAMP molecule, heat shock protein B4 (HSPB4), to contribute to delayed wound healing. Here, we show in vitro that DOPG inhibits TLR2 activation induced in response to HSPB4, as well as DAMPs that are elevated in diabetes, a disease that also slows corneal wound healing. Further, we show that the co-receptor, cluster of differentiation-14 (CD14), is necessary for PAMP/DAMP-induced activation of TLR2, as well as of TLR4. Finally, we simulated the high-glucose environment of diabetes to show that elevated glucose levels enhance TLR4 activation by a DAMP known to be upregulated in diabetes. Together, our results demonstrate the anti-inflammatory actions of DOPG and support further investigation into its development as a possible therapy for corneal injury, especially in diabetic patients at high risk of vision-threatening complications. [ABSTRACT FROM AUTHOR]

A unique feature of plastid phosphatidylglycerol (PG) is a trans-double bond specifically at the sn-2 position of 16C fatty acid (16:1t- PG), which is catalyzed by FATTY ACID DESATURASE 4 (FAD4). To offer additional insights about the in vivo roles of FAD4 and its product 16:1t-PG, FAD4 overexpression lines (OX-FAD4s) were generated in Arabidopsis thaliana Columbia ecotype. When grown under continuous light condition, the fad4-2 and OX-FAD4s plants exhibited higher growth rates compared to WT control. Total lipids were isolated from Col, fad4-2, and OX-FAD4_2 plants, and polar lipids quantified by lipidomic profiling. We found that disrupting FAD4 expression altered prokaryotic and eukaryotic PG content and composition. Prokaryotic and eukaryotic monogalactosyl diacylglycerol (MGDG) was up-regulated in OX-FAD4 plants but not in fad4-2 mutant. We propose that 16:1t-PG homeostasis in plastid envelope membranes may coordinate plant growth and stress response by restricting photoassimilate export from the chloroplast. [ABSTRACT FROM AUTHOR]

In this article, we used molecular dynamics (MD), one of the most common methods for simulations of membranes, to study the interaction of fluorescent membranotropic biological probe 10-N-nonyl acridine orange (NAO) with the bilayer, mimicking a plasma membrane of Gram-negative bacteria. Fluorescent probes serve as an effective tool to study the localization of different components in biological membranes. Revealing the molecular details of their interaction with membrane phospholipids is important both for the interpretation of experimental results and future design of lipid-specific stains. By means of coarse-grained (CG) MD, we studied the interactions of NAO with a model membrane, imitating the plasma membrane of Gram-negative bacteria. In our simulations, we detected different NAO forms: monomers, dimers, and stacks. NAO dimers had the central cardiolipin (CL) molecule in a sandwich-like structure. The stacks were formed by NAO molecules interlayered with anionic lipids, predominantly CL. Use of the CG approach allowed to confirm the ability of NAO to bind to both major negatively charged phospholipids, phosphatidylglycerol (PG) and CL, and to shed light on the exact structure of previously proposed NAO–lipid complexes. Thus, CG modeling can be useful for the development of new effective and highly specific molecular probes. [ABSTRACT FROM AUTHOR]

A Gram-negative, strictly aerobic, motile, and rod-shaped bacterial strain G4R7T was isolated from the roots of moso bamboo (Phyllostachys edulis) in Zhejiang, Hangzhou Province, China. After comparing 16S rRNA gene sequences, strain G4R7T exhibited the highest similarities with Massilia neuiana PTW21T (98.3%), followed by M. agri K-3-1T (98.3%), M. consociate CCUG 58010T (97.7%), M. niastensis 5516S-1T (97.7%) and M. yuzhufengensis ZD1-4T (97.6%). The phylogenetic analysis revealed that strain G4R7T belonged to the genus Massilia. The draft genome of strain G4R7T was 5.81 Mb, and the G+C content was 64.4%. The average nucleotide identity values between G4R7T and another related member of the genus Massilia ranged from 76.6 to 87.2%, and the digital DNA–DNA hybridization ranged from 20.7 to 27.9%. Strain G4R7T grew at 15–37 °C (optimum 25–30 °C) and pH 6.0–9.0 (optimum pH 7.0) in the presence of 0–3% (w/v) NaCl (optimum 0%). The respiratory quinone was Q-8, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and aminophospholipid. The major cellular fatty acids were C10:0 3OH, C12:0, C12:0 2OH, and C16:0, summed feature 3 (C16:1ω6c and/or C16:1ω7c). As per the data from chemotaxonomic, phylogenetic, and phenotypic evidence, strain G4R7T represents a new species of genus Massilia, for which the name Massilia phyllostachyos sp. nov. is proposed. The type strain is G4R7T (=ACCC 61911T=GDMCC 1.2961T=JCM 35225T). [ABSTRACT FROM AUTHOR]

A gram-stain-negative, aerobic, rod-shaped and motile bacterium, designated Alg18-2.2T, was isolated from a bottom sediment of the highly alkaline-saline lake in Buryatia, Russia. The isolate is facultatively alkaliphilic, growing at pH 7.0–12.0 (optimum at 9.0–9.5), and salt-tolerant up to 7% NaCl (w/v; optimum, 1%, w/v). Phylogenetic analysis based on the 16S rRNA gene sequence showed that strain Alg18-2.2T formed a distinct monophyletic lineage within the family Lysobacteraceae. Strain Alg18-2.2T had highest sequence similarity to Lysobacter concretionis Ko07T (95.0%), Lysobacter maris KMU-14T (95.0%), Coralloluteibacterium stylophorae Sty a-1T (94.9%) and Lysobacter psychrotolerans ZS60T (94.8%). The ANI values between Alg18-2.2T and representatives of genera within order Lysobacterales were 66.4–76.5%, which is below of the statistical threshold for the delineation of the species. The AAI values between the strain and representatives of genera within order Lysobacterales were 52.2–66.4%, which is consistent with the data intra-order AAI values for Lysobacterales. The quinone system consisted of ubiquinone 8 (Q-8). Diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids were presented as major lipids in the polar lipid profile. The major cellular fatty acids were 9-Methyl C16:0 (23.9%), iso-C15:0 (22.4%), iso-C16:0 (16.3%) and iso-C17:0 (14.6%). The genome has a G+C content of 68.7 mol % and a total assembly size of 3,025,752 bases. Based on polyphasic results including phylogenomic data, we propose a new genus and species Alkalisalibacterium limincola gen. nov., sp. nov. with the type strain Alg18-2.2T (=CPCC 101300Т = DSM 110880T = VKM B-3394T). [ABSTRACT FROM AUTHOR]

Catechins have been shown to display a great variety of biological activities, prominent among them are their chemo preventive and chemotherapeutic properties against several types of cancer. The amphiphilic nature of catechins points to the membrane as a potential target for their actions. 3,4,5-Trimethoxybenzoate of catechin (TMBC) is a modified structural analog of catechin that shows significant antiproliferative activity against melanoma and breast cancer cells. Phosphatidylglycerol is an anionic membrane phospholipid with important physical and biochemical characteristics that make it biologically relevant. In addition, phosphatidylglycerol is a preeminent component of bacterial membranes. Using biomimetic membranes, we examined the effects of TMBC on the structural and dynamic properties of phosphatidylglycerol bilayers by means of biophysical techniques such as differential scanning calorimetry, X-ray diffraction and infrared spectroscopy, together with an analysis through molecular dynamics simulation. We found that TMBC perturbs the thermotropic gel to liquid-crystalline phase transition and promotes immiscibility in both phospholipid phases. The modified catechin decreases the thickness of the bilayer and is able to form hydrogen bonds with the carbonyl groups of the phospholipid. Experimental data support the simulated data that locate TMBC as mostly forming clusters in the middle region of each monolayer approaching the carbonyl moiety of the phospholipid. The presence of TMBC modifies the structural and dynamic properties of the phosphatidylglycerol bilayer. The decrease in membrane thickness and the change of the hydrogen bonding pattern in the interfacial region of the bilayer elicited by the catechin might contribute to the alteration of the events taking place in the membrane and might help to understand the mechanism of action of the diverse effects displayed by catechins. [ABSTRACT FROM AUTHOR]

A novel strain, Streptomyces griseiviridis MUM 136JT was recovered from a mangrove forest soil in Malaysia. The Gram-positive bacterium forms strong yellow aerial mycelium and moderate yellow substrate mycelium on ISP 2 agar. A polyphasic approach was used to determine the taxonomy status of strain MUM 136JT . The strain showed a spectrum of phylogenetic and chemotaxonomic properties consistent with those of the members of the genus Streptomyces. The cell wall peptidoglycan was determined to contain LL-diaminopimelic acid. The predominant menaquinones were identified as MK-9(H8) and MK-9(H6), while the identified polar lipids consisted of lipid, aminolipid, phospholipid, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylinositolmannoside. The cell wall sugars consist of ribose, mannose, and galactose. The predominant cellular fatty acids (>10.0 %) were identified as iso-C16:0 (31.6 %), anteiso-C15:0 (14.8 %), iso-C15:0 (12.0 %), and anteiso-C17:0 (11.1 %). Phylogenetic analysis identified that closely related strains for MUM 136JT are Streptomyces leeuwenhoekii DSM 42122T (98.9 %), Streptomyces erythrogriseus JCM 9650T (98.4 %), Streptomyces griseoincarnatus JCM 4381T (98.5 %). The DNA-DNA relatedness values between MUM 136 JT and closely related type strains ranged from 13.3 ± 1.5 % to 17.4 ± 2.0 %. The name Streptomyces griseiviridis sp. nov. is proposed, and the type strain is MUM 136JT (= NBRC 114249T = MCCC 1K04199T ). [ABSTRACT FROM AUTHOR]

[Display omitted] By direct deposition of the drug at the local site of action, injectable depot formulations – intended for treatment of a local disease or for local intervention – are designed to limit the immediate exposure of the active principle at a systemic level and to reduce the frequency of administration. To overcome known drawbacks in the production of some marketed phospholipid-based depots, here we propose to manufacture drug-loaded negatively charged liposomes through conventional technologies and to control their aggregation mixing a solution of divalent cations prior to administration. We identified phosphatidylglycerol (PG) as the most suitable phospholipid for controlled aggregation of the liposomes and to modulate the release of the anesthetic bupivacaine (BUP) from liposomal depots. In vivo imaging of the fluorescently-labelled liposomes showed a significantly higher retention of the PG liposomes at the injection site with respect to zwitterionic ones. In situ mixing of PG liposomes with calcium salts significantly extended the area under the curve of BUP in plasma compared to the non-depot system. Overall, controlling the aggregation of negatively charged liposomes with divalent cations not only modulated the particle clearance from the injection site but also the release in vivo of a small amphipathic drug such as BUP. [ABSTRACT FROM AUTHOR]

The strain designated as AN120528T was isolated from farmland soil in South Korea. This strain grows well on R2A medium at 28 °C. The cells are an off-white colour and have no hyphae. The phylogenetic analysis indicated that the strain is a member of the genus Shimazuella with a 98.11% similarity to Shimazuella alba KC615T and a 97.05% similarity to S. kribbensis KCTC 9933T, respectively. The strain AN120528T shares common chemotaxonomic features with the other two type strains in the genus. It has MK-9 (H4) and MK-10 (H4) as its predominant menaquinones. The major fatty acids are iso-C14:0, iso-C15:0, anteiso-C15:0 and iso-C16:0. Diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), lipids (L), and aminolipids (AL) were identified as the major cellular polar lipids. Analysis of the peptidoglycan showed the presence of meso-diaminopimelic acid. Whole-genome sequencing revealed that the genome of the strain is approximately 3.3 Mbp in size. The strain showed a 77.5% average nucleotide identity (ANI) with S. alba KC615T. The genomic DNA (gDNA) G + C content is 39.0%. Based on polyphasic taxonomy analysis, it is proposed that this strain, AN120528T, represents a novel species in the genus Shimazuella, designated as Shimazuella soli sp. nov. The type stain is AN120528T (=KCTC 39810T = DSM 103571T). Furthermore, shimazuellin I, a new 15-amino-acid peptide, was discovered in the AN120528T through genome mining; it has the features of a lasso peptide, containing eight amino acids (-G-Q-G-G-S-N-N-D-) that form a macrolactam ring and seven amino acids (-D-G-W-Y-H-S-K-) that form a tail. [ABSTRACT FROM AUTHOR]

Corneal wounds resulting from injury, surgeries, or other intrusions not only cause pain, but also can predispose an individual to infection. While some inflammation may be beneficial to protect against microbial infection of wounds, the inflammatory process, if excessive, may delay corneal wound healing. An examination of the literature on the effect of inflammation on corneal wound healing suggests that manipulations that result in reductions in severe or chronic inflammation lead to better outcomes in terms of corneal clarity, thickness, and healing. However, some acute inflammation is necessary to allow efficient bacterial and fungal clearance and prevent corneal infection. This inflammation can be triggered by microbial components that activate the innate immune system through toll-like receptor (TLR) pathways. In particular, TLR2 and TLR4 activation leads to pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) activation. Similarly, endogenous molecules released from disrupted cells, known as damage-associated molecular patterns (DAMPs), can also activate TLR2, TLR4 and NFκB, with the resultant inflammation worsening the outcome of corneal wound healing. In sterile keratitis without infection, inflammation can occur though TLRs to impact corneal wound healing and reduce corneal transparency. This review demonstrates the need for acute inflammation to prevent pathogenic infiltration, while supporting the idea that a reduction in chronic and/or excessive inflammation will allow for improved wound healing. [ABSTRACT FROM AUTHOR]

• Phosphatidylglycerol (PG) and phosphatidylcholine (PC) are used in drug delivery. • PG forms inter- and intramolecular hydrogen bonds. • The type and amount of hydrogen bonding depends on the conformation of PG. • PC/PG mixtures exhibit non-linear properties due to changes in hydrogen bonding. Phosphatidylglycerol (PG) is an anionic phospholipid, a constituent of biomembranes and an important component of drug delivery formulations and modern vaccines. Its mixtures with phosphatidylcholine (PC) exhibit non-linear properties, which are usually attributed to the molecular immiscibility of PG and PC. Here, using a combination of spectroscopic (FTIR, fluorescence) and computational (quantum chemistry, molecular dynamics) approaches, we show that the nonlinear properties of PG/PC mixtures are caused by hydrogen bonding between PG molecules. The latter are able to change their conformation to either form or break intermolecular hydrogen bonds. [ABSTRACT FROM AUTHOR]

ABSTRACT The absence of Isc1, the yeast homologue of mammalian neutral sphingomyelinase type 2, leads to severe mitochondrial dysfunction. We show that the deletion of another type C phospholipase, the phosphatidylglycerol (PG)-specific phospholipase Pgc1, rescues this defect. Phosphatidylethanolamine (PE) levels and cytochrome c oxidase activity, which were reduced in isc1Δ cells, were restored to wild-type levels in the pgc1Δ isc1Δ mutant. The Pgc1 substrate PG inhibited the in vitro activities of Isc1 and the phosphatidylserine decarboxylase Psd1, an enzyme crucial for PE biosynthesis. We also identify a mechanism by which the balance between the current demand for PG and its consumption is controlled. We document that the product of PG hydrolysis, diacylglycerol, competes with the substrate of PG-phosphate synthase, Pgs1, and thereby inhibits the biosynthesis of excess PG. This feedback loop does not work in the absence of Pgc1, which catalyzes PG degradation. Finally, Pgc1 activity is partially inhibited by products of Isc1-mediated hydrolysis. The described functional interconnection of the two phospholipases contributes significantly to lipid homeostasis throughout the cellular architecture. IMPORTANCE In eukaryotic cells, mitochondria are constantly adapting to changes in the biological activity of the cell, i.e., changes in nutrient availability and environmental stresses. We propose a model in which this adaptation is mediated by lipids. Specifically, we show that mitochondrial phospholipids regulate the biosynthesis of cellular sphingolipids and vice versa. To do this, lipids move by free diffusion, which does not require energy and works under any condition. This model represents a simple way for the cell to coordinate mitochondrial structure and performance with the actual needs of overall cellular metabolism. Its simplicity makes it a universally applicable principle of cellular regulation.

Pentameric ligand-gated ion channels (pLGICs) mediate synaptic transmission and are sensitive to their lipid environment. The mechanism of phospholipid modulation of any pLGIC is not well understood. We demonstrate that the model pLGIC, ELIC (Erwinia ligand-gated ion channel), is positively modulated by the anionic phospholipid, phosphatidylglycerol, from the outer leaflet of the membrane. To explore the mechanism of phosphatidylglycerol modulation, we determine a structure of ELIC in an open-channel conformation. The structure shows a bound phospholipid in an outer leaflet site, and structural changes in the phospholipid binding site unique to the open-channel. In combination with streamlined alchemical free energy perturbation calculations and functional measurements in asymmetric liposomes, the data support a mechanism by which an anionic phospholipid stabilizes the activated, open-channel state of a pLGIC by specific, state-dependent binding to this site. Pentameric ligand-gated ion channels are modulated by anionic phospholipids. Here, by capturing an open-channel conformation of ELIC, the authors demonstrate the structural details of channel activation and a leaflet-specific mechanism for modulation by phosphatidylglycerol. [ABSTRACT FROM AUTHOR]

The aims of this study were to develop topical liposomal hydrogels based on thermal waters (TWs) acquired in the region of Biskra (Northeast Algeria) and also to investigate their rheological properties. Liposomes containing two highly mineralized thermal waters, Baraka (BTW) and Salhine (STW), were prepared by probe sonication using phosphatidylcholine (PC) and cholesterol (Chol), plain or mixed with phosphatidylglycerol (PG). Based on their lipid composition, obtained liposomes presented vesicle sizes of 60 nm, a low polydispersity index, and various negative zeta potentials. It was noted that with increasing counterions charge in TWs the zeta potential of liposomes decreased toward neutral values. Carbopol (1%, w/w) hydrogels prepared with BTW, STW, and also demineralized water (placebo hydrogel) showed a non-Newtonian behavior, pseudoplastic fluid adjusted to Carreau model. The composition of thermal waters influenced highly the rheological properties of Carbopol hydrogels. Liposomal hydrogels were prepared by dispersing liposomes in hydrogels formulated with the same encapsulated thermal water. Regardless of composition or lipid concentration of added liposomes, the viscosity and viscoelastic parameters of Carbopol hydrogels changed negligibly. Indeed, liposome composition and lipid concentration seemed to have no effect on the rheological properties of Carbopol hydrogel in the presence of an important charge of cations. Hence, hydrogels and liposomal hydrogels based on thermal waters had suitable rheological properties for topical application and delivery of minerals in the skin. [ABSTRACT FROM AUTHOR]

Daptomycin is a calcium-dependent cyclic lipodepsipeptide antibiotic that is used in the clinic for treating serious infections caused by Gram-positive bacteria. In this account, I present a summary of the research that has been conducted in my group on daptomycin's total chemical synthesis, its structure–activity relationships, and its mechanism of action, since we began our studies a decade ago. 1 Introduction 2 Solid-Phase Synthesis of Daptomycin by an On-Resin Cyclization 3 α-Azido Acids and Alternative Routes to Daptomycin by On-Resin Cyclization 4 Synthesis of Daptomycin by an Off-Resin Cyclization 5 SAR Studies on Daptomycin 6 Oligomerization of Daptomycin on Membranes 7 The Chiral Target of Daptomycin 8 SAR Studies on Phosphatidylglycerol 9 Conclusions [ABSTRACT FROM AUTHOR]

With the aim of isolating clopyralid-degrading bacterial species for potential bioremediation, a pale-yellow, Gram-negative, rod-shaped, and non-motile designated as Clo-40T was isolated from soil which was about 10 years use of clopyralid in Zaozhuang city, Shandong province. Growth occurred within the ranges from 10 to 40 °C and 0–2.5% (w/v) NaCl. Strain could completely degrade 50 mg/L clopyralid within 2 days after induction and formed 3, 6-hydroxypicolinic acid, a major clopyralid metabolite, hydrolyze esculin, and reduce nitrates to nitrites, but could not hydrolyze gelatin. Based on phylogenetic analysis, strain clustered within the genus Xinfangfangia clade and branched with Xinfangfangia humi IMT-291T (97.6%) and Xinfangfangia soli ZQBWT (96.9%). Genome sequencing revealed a genome size of 4.41 Mbp and G + C content of 67.3%. The average nucleotide ANI values of strain with respect to X. humi IMT-291T and X. soli ZQBWT were 77.5% and 76.9%, respectively. The DDH estimated values between strain Clo-40T and X. humi IMT-291T and X. soli ZQBWT were 20.5% and 20.0%, respectively. The predominant fatty acids (> 5% of the total fatty acids) were C18:1w7c (42.9%), C16:0 (28.8%), C17:0 cyclo (13.0%), and C14:0 (7.0%). The major polar lipids were identified as phosphatidylethanolamine, phosphatidylglycerol, unidentified phospholipid, unidentified glycolipid, and unidentified lipids. The predominant respiratory quinone was Q-10. Based on data from phenotypic, chemotaxonomic, and genotypic analyses in this study, strain Clo-40T represent a novel species in the genus of Xinfangfangia, for which the name Xinfangfangia pollutisoli sp. nov. is proposed. The type strain is Clo-40T (= KCTC 92089T = GDMCC 1.2845T). [ABSTRACT FROM AUTHOR]

Niemann-Pick type C (NPC) disease, caused by mutations in the NPC1 or NPC2 genes, leads to abnormal intracellular cholesterol accumulation in late endosomes/lysosomes (LE/LY). Exogenous enrichment with lysobisphosphatidic acid (LBPA), also known as bis-monoacylglycerol phosphate or BMP, either directly or via the LBPA precursor phosphatidylglycerol (PG), has been investigated as a therapeutic intervention to reduce cholesterol accumulation in NPC disease. Here we report the effects of stereoisomer configuration and acyl chain composition of LBPA on cholesterol clearance in NPC1-deficient cells. We find that S,R, S,S, and S,R LBPA stereoisomers behaved similarly, with all 3 compounds leading to comparable reductions in filipin staining in two NPC1-deficient human fibroblast cell lines. Examination of several LBPA molecular species containing one or two mono- or polyunsaturated acyl chains showed that all LBPA species containing one 18:1 chain significantly reduced cholesterol accumulation, whereas the shorter chain species di-14:0 LBPA had little effect on cholesterol clearance in NPC1 deficient cells. Since cholesterol accumulation in NPC1 deficient cells can also be cleared by PG incubation, we used non-hydrolyzable PG analogues to determine whether conversion to LBPA is required for sterol clearance, or whether PG itself is effective. The results showed that non-hydrolyzable PG species were not appreciably converted to LBPA and showed virtually no cholesterol clearance efficacy in NPC1 deficient cells, supporting the notion that LBPA is the active agent promoting LE/LY cholesterol clearance. Overall these studies are helping to define the molecular requirements for potential therapeutic use of LBPA as an option for addressing NPC disease., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Tomatoes (Solanum lycopersicum L.) are sensitive to chilling temperatures between 0 °C and 12 °C owing to their tropical origin. SlHSP17.7, a cytoplasmic heat shock protein, interacts with cation/calcium exchanger 1-like (SlCCX1-like) protein and promotes chilling tolerance in tomato fruits (Zhang, et al., Plant Sci., 2020, 298, 1–12). The overexpression of SlHSP17.7 can also promote cold tolerance in tomato plants, but its specific mechanism remains unclear. In this study, we show that the overexpression of SlHSP17.7 in tomato plants enhances chilling tolerance with better activity of photosystem II (PSII). Metabolic analyses revealed that SlHSP17.7 improved membrane fluidity by raising the levels of polyunsaturated fatty acids. Transcriptome analyses showed that SlHSP17.7 activated Ca2+ signaling and induced the expression of C-repeat binding factor (CBF) genes, which in turn inhibited the production of reactive oxygen species (ROS). The gene coexpression network analysis showed that SlHSP17.7 is coexpressed with SlMED26b. SlMED26b silencing significantly lowered OE-HSP17.7 plants' chilling tolerance. Thus, SlHSP17.7 modulates tolerance to chilling via both membrane fluidity and Ca2+-mediated CBF pathway in tomato plants. [ABSTRACT FROM AUTHOR]

Using a population of recombinant inbred lines (RILs) cowpea (Vigna unguiculata. L. Walp), we tested for co‐linkages between lipid contents and chilling responses of photosynthesis. Under low‐temperature conditions (19°C/13°C, day/night), we observed co‐linkages between quantitative trait loci intervals for photosynthetic light reactions and specific fatty acids, most strikingly, the thylakoid‐specific fatty acid 16:1Δ3trans found exclusively in phosphatidylglycerol (PG 16:1t). By contrast, we did not observe co‐associations with bulk polyunsaturated fatty acids or high‐melting‐point‐PG (sum of PG 16:0, PG 18:0 and PG 16:1t) previously thought to be involved in chilling sensitivity. These results suggest that in cowpea, chilling sensitivity is modulated by specific lipid interactions rather than bulk properties. We were able to recapitulate the predicted impact of PG 16:1t levels on photosynthetic responses at low temperature using mutants and transgenic Arabidopsis lines. Because PG 16:1t synthesis requires the activity of peroxiredoxin‐Q, which is activated by H2O2 and known to be involved in redox signalling, we hypothesise that the accumulation of PG 16:1t occurs as a result of upstream effects on photosynthesis that alter redox status and production of reactive oxygen species. Summary Statement: Analyses of natural variation in lipid contents suggest that natural variations in chilling photosynthetic responses in cowpea are modulated by specific fatty acid species, especially the thylakoid‐specific phosphatidylglycerol 16:1Δ3trans, rather than bulk lipid properties. [ABSTRACT FROM AUTHOR]

A Gram-reaction-negative, facultatively aerobic, motile, non-spore-forming, rod-shaped, and denitrifying bacterium, designated dN18-1T, was isolated from activated sludge, Republic of Korea. This bacterium was investigated via a polyphasic approach to reveal its taxonomic position. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain dN18-1T belongs to the genus Paludibacterium and is most closely related to P. purpuratum KCTC 42852T (96.2% sequence similarity), P. yongneupense KACC 11601T (96.1%), and P. paludis BCRC 80514T (95.2%). The average nucleotide identity values and digital DNA-DNA hybridization values calculated between strain dN18-1T and the closely related strains were 72.5–73.1% and 19.0–19.6%. The genome comprises of 3,347,996 bp with a G + C content of 57.3 mol%. Strain dN18-1T possesses ubiquinone Q-8 as a predominant respiratory quinone, and summed feature 3 (C16:1ω6c and/or C16:1ω7c), summed feature 8 (C18:1ω6c/C18:1ω7c), C16:0 and C12:0, as its major fatty acids (>5%). The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and four unidentified aminophospholipids. The results of ANI calculation, digital DNA-DNA hybridization, physiological and biochemical tests allowed phenotypic differentiation of strain dN18-1T from rephrase other genus Paludibacterium species with validly published names. Therefore, this isolate represents a novel species, for which the name Paludibacterium denitrificans sp. nov. (type strain dN18-1T = KACC 19537T = CGMCC 1.16961T) is proposed. [ABSTRACT FROM AUTHOR]

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Abstract In plant cells, phosphatidylglycerol (PG) in the chloroplast has a characteristic trans‐∆3‐hexadecenoic acid (t16:1) at the sn‐2 position. The t16:1 content in wheat leaf tissues decreases during cold treatment, but the significance of this fatty acid compositional change and the underlying biochemical mechanism remains poorly understood. Using a large collection of wheat cultivars displaying a varying capacity of freezing tolerance, we show for the first time under field conditions that this low temperature induced t16:1 change is associated with winter hardiness. To explore the metabolic mechanism responsible for the reduction of t16:1, we performed detailed lipid analysis and comparative transcriptome study with four selected wheat lines under cold acclimation. Our results show that wheat leaf tissues experience a gradual decrease in chloroplast lipid pathway activity during cold acclimation and that the decline in chloroplast lipid synthesis manifests itself in the decrease of t16:1 in PG. Comparative RNA‐seq analyses with leaf tissues further reveal concerted transcriptome shifts indicating a rebalancing of chloroplast and cytosolic lipid synthesis during cold acclimation. Our study, thus, provides mechanistic understanding on chloroplast lipid adjustments as a “molecular ideotype” and the t16:1 change as a specific metabolite marker for screening freezing tolerance in wheat.