and bacteria, which live in mutualistic symbiosis with entomopathogenic nematodes, are currently recognised as an important source of bioactive compounds. During their extraordinary life cycle, these bacteria are capable of fine regulation of mutualism and pathogenesis towards two different hosts, a nematode and a wide range of insect species, respectively. Consequently, survival in a specific ecological niche favours the richness of biosynthetic gene clusters and respective metabolites with a specific structure and function, providing templates for uncovering new agrochemicals and therapeutics.
View Article and Find Full Text PDFPolycyclic aromatic hydrocarbons (PAHs) are common xenobiotics that are detrimental to the environment and human health. Bacterial endophytes, having the capacity to degrade PAHs, and plant growth promotion (PGP) may facilitate their biodegradation. In this study, phenanthrene (PHE) utilization of a newly isolated PGP endophytic strain of 23aP and factors affecting the process were evaluated.
View Article and Find Full Text PDFMultilamellar bodies (MLBs) are membrane-bound cytoplasmic organelles of lysosomal origin. In some protozoa, they were considered as lipid storage secretory organelles and feasible participants in cell-to-cell communication. However, for , similar vesicles were indicated only as possible transmission vectors of several pathogenic bacteria without attributing them biological roles and activities.
View Article and Find Full Text PDFAnthropogenic activities generate a high quantity of organic pollutants, which have an impact on human health and cause adverse environmental effects. Monitoring of many hazardous contaminations is subject to legal regulations, but some substances such as therapeutic agents, personal care products, hormones, and derivatives of common organic compounds are currently not included in these regulations. Classical methods of removal of organic pollutants involve economically challenging processes.
View Article and Find Full Text PDFLipopolysaccharide (LPS) is the major glycolipid and virulence factor of Gram-negative bacteria, including spp. The O-specific polysaccharide (O-PS, O-chain, O-antigen), i.e.
View Article and Find Full Text PDFInnate immunity is an evolutionarily ancient form of host defense that serves to limit infection. The invading microorganisms are detected by the innate immune system through germline-encoded PRRs. Different classes of PRRs, including TLRs and cytoplasmic receptors, recognize distinct microbial components known collectively as PAMPs.
View Article and Find Full Text PDFIn our previous report, we had shown that the free-living amoeba influenced the abundance, competiveness, and virulence of NZP2213, the microsymbiont of agriculturally important plants of the genus . The molecular basis of this phenomenon; however, had not been explored. In the present study, we demonstrated that , the -acetyltransferase encoding gene located in the lipopolysaccharide (LPS) synthesis cluster of , was responsible for maintaining the protective capacity of the bacterial cell envelope, necessary for the bacteria to fight environmental stress and survive inside amoeba cells.
View Article and Find Full Text PDFThe O-specific polysaccharide (OPS) was isolated from the lipopolysaccharide of Aeromonas hydrophila strain K691 and studied by chemical methods and H and C NMR spectroscopy, including 2D H,H COSY, TOCSY, NOESY, H-detected heteronuclear H,C HSQC, and HMBC experiments. It was found that the O-specific polysaccharide was built up of pentasaccharide repeating units composed of β-GlcpNAc, 2-O-acetylated α-Rhap, and β-Quip4NAc residues. The following structure of the OPS was established: →3)-α-l-Rha2OAc-(1→3)-β-d-GlcNAc-(1→3)-α-l-Rha2OAc-(1→3)-β-d-GlcNAc-(1→2)-β-d-Qui4NAc-(1→.
View Article and Find Full Text PDFThe outer core oligosaccharide (OS) was isolated from the lipopolysaccharide (LPS) of Rhizobium leguminosarum bv. trifolii strain 24 after Smith degradation and then studied by sugar and methylation analyses along with NMR and mass spectrometry methods. Negative-ion electrospray (ESI-MS) mass spectrum showed two molecular ions at m/z 686.
View Article and Find Full Text PDFThe importance of protozoa as environmental reservoirs of pathogens is well recognized, while their impact on survival and symbiotic properties of rhizobia has not been explored. The possible survival of free-living rhizobia inside amoebae could influence bacterial abundance in the rhizosphere of legume plants and the nodulation competitiveness of microsymbionts. Two well-characterized strains of Mesorhizobium: Mesorhizobium loti NZP2213 and Mesorhizobium huakuii symbiovar loti MAFF303099 were assayed for their growth ability within the Neff strain of Acanthamoeba castellanii.
View Article and Find Full Text PDFEther lipids were identified among components liberated with HF and nitrous acid deamination from Acanthamoeba rhysodes whole cells and its membrane glycoinositolphospholipids (GIPL). Liberated ether glycerols were converted to various derivatives that served characterization thereof. These included TMS and isopropylidene derivatives, oxidation with sodium periodate to aldehyde followed by reduction with NaBH4 to alcohol, and reaction of the alcohol with acetic anhydrite to form acetate derivatives.
View Article and Find Full Text PDFThe polymer called lipophosphonoglycan (LPG) was isolated from Acanthamoeba castellanii membranes after exhaustive delipidation and butanol extraction. A novel extremely long phytosphingosine was revealed in glycoinositolphosphosphingolipid (GIPSL). All data obtained by gas-liquid chromatography coupled with MS analyses of products liberated during acid methanolysis and products of sodium metaperiodate and permanganate-periodate oxidations showed an unusual pattern of long chain bases (LCB) with branched bases (anteiso-C₂₄, anteiso-C₂₅, anteiso-C₂₆, iso-C₂₆, anteiso-C₂₇, and anteiso-C28) and normal ones (C₂₄, C₂₅, C₂₆, C₂₇).
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