Search Results (7)

Lipid peroxidation plays a crucial role in living organisms. On the one hand, it contributes to the biosynthesis of several hormones; on the other, it can damage cellular structures, induce cell death, and participate in the pathogenesis of numerous human diseases. Therefore, the development of methods for real-time monitoring of lipid peroxidation, particularly within living systems, represents a highly relevant scientific goal. We previously demonstrated that peroxides of polyunsaturated fatty acids (PUFAs) or PUFA-containing lipids serve as substrates for Chaetopterus luciferase. Further studies revealed that the luminescence of this enzyme results from the decomposition products of PUFA peroxides or related lipids. Moreover, analogous luminescence-inducing products are generated during both enzymatic and chemical peroxidation of PUFAs or PUFA-containing lipids. Collectively, these findings indicate that Chaetopterus luciferase is a promising tool for online detection of lipid peroxidation. Full article

The tubes of polychaetes of the genus Chaetopterus (Annelida: Chaetopteridae) provide habitat for cryptic, symbiotic organisms that are often overlooked when examining diversity. Our study employed molecular phylogenetics to examine the diversity of symbiont species associated with Chaetopterus djiboutiensis stat. nov., collected from the Gulf of Tadjoura, Djibouti. A total of 15 Chaetopterus hosts and their associated symbionts were collected from nine coastal sites. Four genetic regions were targeted for PCR amplification: the mitochondrial cytochrome oxidase subunit I and 16S rDNA and the nuclear 18S rDNA and Histone H3. Chaetopterus djiboutiensis was redescribed from topotypic material and elevated to species rank, and a neotype specimen was designated. Phylogenetic and morphological analysis confirmed five species associated with C. djiboutiensis in Djibouti: two porcelain crabs, Polyonyx pedalis and Polyonyx socialis; one nudibranch, Tenellia chaetopterana; one fish, Onuxodon sp.; and one amphipod, Leucothoe sp. A. As only the fourth comprehensive study on Chaetopterus symbionts, our study highlights the diversity and community patterns of symbionts associated with these unique tubicolous marine polychaetes. Full article

Two novel strains, CB1-14^T and CB2-10, were isolated from the marine polychaetes Chaetopterus cautus from the Sea of Japan. Phylogenetic analysis based on the 16S rRNA sequences revealed that the two strains belong to the genus Vibrio, sharing 98.96% identity with Vibrio hangzhouensis CN 83^T. MLSA using five protein-coding genes (ftsZ, gyrA, gyrB, mreB, and rpoA) showed that CB1-14^T and CB2-10 are closely related to the members of the Mediterranei clade, namely Vibrio mediterranei CECT 621^T, Vibrio barjaei 3062^T, Vibrio thalassae CECT 8203^T, Vibrio hangzhouensis CGMCC 1.7062^T, Vibrio maritimus CAIM 1455^T, and Vibrio variabilis CAIM 1454^T. Based on both MLST neighbor-net phylogenetic network and phylogenomic tree results, they fell into the subclade formed by V. maritimus CAIM 1455^T and V. variabilis CAIM 1454^T. Both new strains CB1-14^T and CB2-10 showed the highest ANI/AAI values of 91.3%/92.7% with V. variabilis CAIM 1454^T and 90.3%/93.1% with V. maritimus CAIM 1455^T. The dDDH values between strain CB1-14^T and the members of the Mediterranei clade ranged from 20.9% to 45.7%. Major fatty acids were C_16:1ω9c, C_16:1ω7c, and C_18:1ω9c, followed by C_16:0 and C_18:1ω7c. The genome of CB1-14^T is 5,591,686 bp in size, with DNA G+C content of 46.1%. It consists of two circular chromosomes (3,497,892 and 1,804,652 bp) and one plasmid (241,015 bp) and comprises 4782 protein-coding genes and 10 rrn operons. The CB1-14^T and CB2-10 genomes were enriched in CAZyme-encoding genes of the following families: GH1, GH3, GH13, GH23, GH43, GH94, PL17, and CE4, indicating the potential to catabolize alginate, xylan, and chitin, common polysaccharides in marine ecosystems. Based on the combined phylogenomic analyses and phenotypic properties, a new species, Vibrio chaetopteri sp. nov., is proposed, with CB1-14^T = (KMM 8419^T = KCTC 92790^T) as the type strain. Full article

Vibrio sp. KMM 8419 (=CB1-14) is a Gram-negative bacterium isolated from a food-net mucus sample of marine polychaete Chaetopterus cautus collected in the Sea of Japan. Here, we report the structure and biosynthetic gene cluster of the capsular polysaccharide (CPS) from strain KMM 8419. The CPS was isolated and studied by one- and two-dimensional ¹H and ¹³C nuclear magnetic resonance (NMR) spectroscopy. The molecular weight of the CPS was about 254 kDa. The CPS consisted of disaccharide repeating units of D-glucose and sulfated and acetylated L-rhamnose established as →2)-α-L-Rhap3S4Ac-(1→6)-α-D-Glcp-(1→. To identify the genes responsible for CPS biosynthesis, whole-genome sequencing of KMM 8419 was carried out. Based on the genome annotations together with the Interproscan, UniProt and AntiSMASH results, a CPS-related gene cluster of 80 genes was found on chromosome 1. This cluster contained sets of genes encoding for the nucleotide sugar biosynthesis (UDP-Glc and dTDP-Rha), assembly (glycosyltransferases (GT)), transport (ABC transporter) and sulfation (PAPS biosynthesis and sulfotransferases) of the sulfated CPS. A hypothetical model for the assembly and transportation of the sulfated CPS was also proposed. In addition, this locus included genes for O-antigen biosynthesis. Further studies of biological activity, the structure–activity relationship in the new sulfated polysaccharide and its biosynthesis are necessary for the development of potent anticancer agents or drug delivery systems. Full article

Biochemistry of bioluminescence of the marine parchment tubeworm Chaetopterus has been in research focus for over a century; however, the results obtained by various groups contradict each other. Here, we report the isolation and structural elucidation of three compounds from Chaetomorpha linum algae, which demonstrate bioluminescence activity with Chaetopterus luciferase in the presence of Fe²⁺ ions. These compounds are derivatives of polyunsaturated fatty acid peroxides. We have also obtained their structural analogues and demonstrated their activity in the bioluminescence reaction, thus confirming the broad substrate specificity of the luciferase. Full article

Twenty-three bacterial strains were isolated from the secreted mucus trapping net of the marine polychaete Chaetopterus variopedatus (phylum Annelida) and twenty strains were identified using 16S rRNA gene analysis. Strain CB1-14 was recognized as a new species of the genus Vibrio using the eight-gene multilocus sequence analysis (MLSA) and genome sequences of nineteen type Vibrio strains. This Vibrio sp. was cultured, and 6-epi-monanchorin (2), previously isolated from the polychaete and two sponge species, was found in the cells and culture broth. The presence of the 6-epi-monanchorin was confirmed by its isolation followed by ¹H NMR and HRESIMS analysis. These results showed the microbial origin of the bicyclic guanidine alkaloid 2 in C. variopedatus. Full article

Lectins including flowering plant lectins, algal lectins, cyanobacterial lectins, actinomycete lectin, worm lectins, and the nonpeptidic lectin mimics pradimicins and benanomicins, exhibit anti-HIV activity. The anti-HIV plant lectins include Artocarpus heterophyllus (jacalin) lectin, concanavalin A, Galanthus nivalis (snowdrop) agglutinin-related lectins, Musa acuminata (banana) lectin, Myrianthus holstii lectin, Narcissus pseudonarcissus lectin, and Urtica diocia agglutinin. The anti-HIV algal lectins comprise Boodlea coacta lectin, Griffithsin, Oscillatoria agardhii agglutinin. The anti-HIV cyanobacterial lectins are cyanovirin-N, scytovirin, Microcystis viridis lectin, and microvirin. Actinohivin is an anti-HIV actinomycete lectin. The anti-HIV worm lectins include Chaetopterus variopedatus polychaete marine worm lectin, Serpula vermicularis sea worm lectin, and C-type lectin Mermaid from nematode (Laxus oneistus). The anti-HIV nonpeptidic lectin mimics comprise pradimicins and benanomicins. Their anti-HIV mechanisms are discussed. Full article