Roseobacter weihaiensis sp. nov., a cellulose-degrading bacterium isolated from intestinal content of Nipponacmea schrenckii collected from golden beach in Weihai, China.

A Gram-staining-negative, dark pink, rod-shaped, amastigote and cellulose-degrading strain, designated H9T, was isolated from intestinal contents of Nipponacmea schrenckii. The isolate was able to grow at 4-42 °C (optimum, 25 °C), at pH 6.5-9.0 (optimum, pH 7.0), and with 0.0-11.0% (w/v) NaCl (optimum, 3.0-5.0%). Phylogenetic analysis of the 16S rRNA gene sequence suggested that isolate H9T belongs to the genus Roseobacter, neighboring Roseobacter insulae YSTF-M11T, Roseobacter cerasinus AI77T and Roseobacter ponti MM-7 T, and the pairwise sequence showed the highest similarity of 99.1% to Roseobacter insulae YSTF-M11T. The major fatty acid was summed feature 8 (C18:1ω7c and/or C18:1ω6c; 81.08%). The predominant respiratory quinone was Q-10. The polar lipids consisted of phosphatidylcholine, phosphatidylglycerol, an unknown lipid, and a small amount of an unknown phospholipid. The genome of strain H9T was 5,351,685 bp in length, and the DNA G + C content was 59.8%. The average amino acid identity (AAI), average nucleotide identity (ANI), and digital DNA hybridization (dDDH) values between strain H9T and closely related strains were 63.4-76.8%, 74.7-78.8%, and 13.4-19.7%, respectively. On the basis of the phenotypic, chemical taxonomic, and phylogenetic data, it is suggested that strain H9T should represent a novel species in the genus Roseobacter, for which the name Roseobacter weihaiensis sp. nov. is proposed. The type strain is H9T (= KCTC 82507 T = MCCC 1K04354T).

Jeotgalibacillus aurantiacus sp. nov., a novel orange-pigmented species with a carotenoid biosynthetic gene cluster, isolated from wetland soil.

A Gram-stain-positive, orange-pigmented, rod-shaped and flagellated bacterial strain T12T was isolated from wetland soil in Kunyu Mountain Wetland in Yantai, China. The strain was able to grow at 15-40 °C (optimum 37 °C), at 0.0-9.0% NaCl (optimum 2%, w/v) and at pH 5.5-9.0 (optimum 8.5). A phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain T12T is a member of the family Planococcaceae, sharing 97.6% and 97.1% sequence similarity with the type strains of Jeotgalibacillus salarius and Jeotgalibacillus marinus, respectively. Genome-based analyses revealed a genome size of 3,506,682 bp and a DNA G + C content of 43.7%. Besides, the genome sequence led to 55.0-74.6% average amino acid identity values and 67.8-74.7% average nucleotide identity values between strain T12T and the current closest relatives. Digital DNA-DNA hybridization of strain T12T with the type strains of Jeotgalibacillus proteolyticus and J. marinus demonstrated 19.0% and 20.3% relatedness, respectively. The chemotaxonomic analysis showed that the sole quinone was MK-7. The predominant cellular fatty acids were iso-C15:0, anteiso-C15:0, C16:1ω7c alcohol and iso-C14:0. The polar lipids consisted of an unidentified aminolipid, phosphatidylglycerol, diphosphatidylglycerol and two unidentified phospholipids. Based on the polyphasic characterization, strain T12T is considered to represent a novel species, for which the name Jeotgalibacillus aurantiacus sp. nov. is proposed. The type strain is T12T (= KCTC 43296 T = MCCC 1K07171T).

Insights into the Influence of Signal Peptide on the Enzymatic Properties of Alginate Lyase AlyI1 with Removal Effect on Pseudomonas aeruginosa Biofilm.

Most reports on signal peptides focus on their ability to affect the normal folding of proteins, thereby affecting their secreted expression, while few studies on its effects on enzymatic properties were published. Therefore, biochemical characterization and comparison of alginate lyase rALYI1/rALYI1-1 (rALYI1: without signal peptides; rALYI1-1:with signal peptides) were conducted in our study, and the results showed that the signal peptide affected the biochemical properties, especially in temperature and pH. rALYI1 (32.15 kDa) belonging to polysaccharide lyase family 7 was cloned from sea-cucumber-gut bacterium Tamlana sp. I1. The optimum temperature of both rALYI1 and rALYI1-1 was 40 °C, but the former had a wider optimum temperature range and better thermal stability. The optimum pH of rALYI1 and rALYI1-1 were 7.6 and 8.6, respectively. The former was more stable and acid resistant. Noticeably, rALYI1 was a salt-activated enzyme and displayed remarkable salt tolerance. Alginate, an essential polysaccharide in algae and Pseudomonas aeruginosa biofilms, is composed of α-L-guluronate and ß-D-mannuronate. It is also found in our study that rALYI1 is also effective in removing mature biofilms compared with controls. In conclusion, the signal peptide affects several biochemical properties of the enzyme, and alginate lyase rALYI1 may be an effective method for inhibiting biofilm formation of Pseudomonas aeruginosa.

Oceaniglobus trochenteri sp. nov., isolated from the gut microflora of top shell (Trochus maculatus Linnaeus).

A Gram-stain negative, non-flagellated, beige-pigmented, circular, catalase-positive, oxidase-positive bacterium, designated G4T, was isolated from gut microflora of top shell (Trochus maculatus Linnaeus) collected from Diwanggong market, Weihai, People's Republic of China. The novel isolate was able to grow at 4-42 °C (optimum 25-33 °C), pH 7.0-9.0 (optimum 6.5-7.0) and with 0.0-11.0% NaCl (optimum 2.0-3.0%, w/v). Analysis of 16S rRNA gene sequence revealed that strain G4T shared the highest 16S rRNA gene sequence similarities with Oceaniglobus ichthyenteri YLY08T (96.6%), followed by Oceaniglobus indicus 1-19bT (95.3%). The genome of strain G4T, with 32 assembled contigs, was 4.5 Mb long with a G+C content of 65.3 mol%. DNA-DNA hybridization values of the isolate against the closely related type strains were far below the 70% limit for species delineation. The average amino acid identity, average nucleotide identity and digital DNA-DNA genome hybridization relatedness between strain G4T and the closely related members of the genus Oceaniglobus, Oceaniglobus indicus1-19bT and Oceaniglobus ichthyenteri YLY08T were 71.3, 76.4 and 20.0%, and 75.0, 76.3 and 19.4%. The major cellular fatty acid was summed feature 8 (C18:1ω7c and/or C18:1ω6c). The sole respiratory quinone was Q-10. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and phosphatidyldimethylethanolamine. The results of phenotypical, phylogenetic and biochemical analyses indicated that strain G4T represents a novel species in genus Oceaniglobus within the family Rhodobacteraceae, for which the name Oceaniglobus trochenteri sp. nov. is proposed. The type strain is G4T (= MCCC 1K04356T = KCTC 82506T).

Pseudaestuariivita rosea sp. nov., isolated from Acmaea sp., a marine mollusk.

A Gram-stain-negative, pink-pigmented, aerobic, non-motile and rod-shaped bacterium, designated as strain H15T, was isolated from Acmaea sp., collected from Weihai, Shandong Province, China. The novel isolate was able to grow at 4-37 °C (optimum 33 °C), pH 5.5-9.0 (optimum 7.0) and with 0.0-7.0% NaCl (optimum 4%, w/v). Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that the strain belonged to the family Rhodobacteraceae and was associated to the type strain of Pseudaestuariivita atlantica (96.7%). Genome analysis showed that the genome size was 3,893,398 bp and the DNA G + C content obtained from the draft genome sequence was 56.7%. The secondary metabolites predicated that the strain H15T contained one cluster of lasso peptide, one cluster of bacteriocin, two clusters of terpene production, two clusters of homoserine lactone and one cluster of beta lactone. The average amino acid identity, average nucleotide identity and digital DNA-DNA hybridization values between genome sequences of strain H15T and all the related strains compared were lower than 63.1, 72.0 and 19.7%, respectively. Based on the analysis of chemical components, the predominant cellular fatty acids were summed featured 8 (C18:1ω7c/ω6c, 46.1%), C20:1 ω7c (17.1%), the major polar lipids contained phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine and an unidentified lipid and the predominant menaquinone was Q10. Therefore, the combined chemotaxonomic, phenotypic and phylogenetic data indicated that the strain was considered to represent a novel species of the genus Pseudaestuariivita and the name Pseudaestuariivita rosea sp. nov. was proposed for strain H15T (MCCC 1K04420T = KCTC 82505T).

Williamsia soli sp. nov., an actinobacterium isolated from soil at a thermal power plant in Yantai, China.

Strain C17T, a novel strain belonging to the phylum Actinobacteria, was isolated from a thermal power plant in Yantai, Shandong Province, China. Cells of strain C17T were Gram stain positive, aerobic, pink, non-motile and round with neat edges, showing optimum growth at 28 °C. Phylogenetically, strain C17T was a member of the class Actinobacteria, order Mycobacteriales, family Gordoniaceae. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that the related strains were Williamsia faeni JCM 17784 T and Williamsia limnetica KCTC 19981 T with pairwise sequence similarity of 98.5% for both strains. According to the draft genome sequence, the DNA G + C content was 64.7%. The average amino acid identity (AAI), average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between genome sequences of strain C17T and the closest type strain W. faeni JCM 17784 T were 77.5, 77.9, and 20.7%, respectively. Predominant fatty acids were C16:0 (31.7%) and C18:1ω9c (26.8%). The major menaquinone was MK-9. The diagnostic phospholipids were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), and phosphatidylinositol (PI). Therefore, the combined phenotypic, chemotaxonomic and phylogenetic data indicated that strain C17T was considered to represent a novel species of the genus Williamsia. Williamsia soli sp. nov. was proposed for strain C17T (= KCTC 49567 T = MCCC 1K04355T).

MnCaCs-Biomineralized Oncolytic Virus for Bimodal Imaging-Guided and Synergistically Enhanced Anticancer Therapy.

Oncolytic adenovirus (OA) is an ideal candidate for clinical anticancer treatment, because it can specifically replicate in tumor cells with high titer. However, its systemic administration is still hindered, because of severely compromised antitumor efficacy. Herein, an engineered OA was innovatively developed by enwrapping OA with calcium and manganese carbonates (MnCaCs) biomineral shell, which could protect the virus from removal of the host immune system and prolong its in vivo circulation. Upon accumulating in tumor sites, MnCaCs readily dissolved under the acidic microenvironment, releasing Mn2+ that could convert endogenous H2O2 into oxygen (O2) and then enhance the duplication ability of OA, thus significantly increased the antitumor efficacy. Meanwhile, Mn2+ and the increased O2 individually endowed the T1 modal magnetic resonance imaging (MRI) and photoacoustic imaging (PAI) feasibility, providing real-time monitoring information for the therapy. This versatile engineered OA demonstrated its promise for visible and efficient oncolytic virotherapy by systemic administration.

Spatial transcriptomics: recent developments and insights in respiratory research.

The respiratory system's complex cellular heterogeneity presents unique challenges to researchers in this field. Although bulk RNA sequencing and single-cell RNA sequencing (scRNA-seq) have provided insights into cell types and heterogeneity in the respiratory system, the relevant specific spatial localization and cellular interactions have not been clearly elucidated. Spatial transcriptomics (ST) has filled this gap and has been widely used in respiratory studies. This review focuses on the latest iterative technology of ST in recent years, summarizing how ST can be applied to the physiological and pathological processes of the respiratory system, with emphasis on the lungs. Finally, the current challenges and potential development directions are proposed, including high-throughput full-length transcriptome, integration of multi-omics, temporal and spatial omics, bioinformatics analysis, etc. These viewpoints are expected to advance the study of systematic mechanisms, including respiratory studies.

Theoretical studies on the structural and spectroscopic properties of an iminocoumarin-based probe and its metal complexation: an implication for a fluorescence probe.

To understand the sensing behaviors of molecular fluorescent probes, an N,N-di(picolyl)aminoethyl-iminocoumarin probe (L) and its complexation with metal(II) ions (ML, M = Mg, Ca, Zn, Cd and Hg) were examined by relativistic density functional theory (DFT). Four stable conformational isomers (labeled as g1, g2, a1 and a2) for each of them have been optimized, except for CaL having only three without the g2 isomer. All of these structures have been confirmed by frequency calculations. In the aqueous solution, the a2 isomer of the L probe was calculated to be the most stable, while the g1 isomer turns out to be energetically favorable upon binding with metal ions. At these isomeric geometries, the experimentally obtained absorption was well reproduced by calculations of time-dependent DFT (TD-DFT) and a conductor-like polarized continuum model (CPCM). A slight red-shifting from L (508 nm) to ML (516-528 nm) was found. This is due to the metal affinity that stabilizes the LUMOs of ML greater than the HOMOs. Singlet excited-state structures of L and ML (M = Zn, Cd and Hg) were fully optimized using the TD-DFT approach, giving more relaxed geometries than their respective ground-state ones. Their fluorescent emissions in the aqueous solution were calculated to be 543 and 551-560 nm, respectively, agreeing with experimental values of 543 nm for L and 558 nm for ZnL. The present study also presents theoretical support for a sensing mechanism of photo-induced charge transfer of the L probe that was proposed in the previous experiment.

Using the optokinetic response to study visual function of zebrafish.

Optokinetic response (OKR) is a behavior that an animal vibrates its eyes to follow a rotating grating around it. It has been widely used to assess the visual functions of larval zebrafish. Nevertheless, the standard protocol for larval fish is not yet readily applicable in adult zebrafish. Here, we introduce how to measure the OKR of adult zebrafish with our simple custom-built apparatus using a new protocol which is established in our lab. Both our apparatus and step-by-step procedure of OKR in adult zebrafish are illustrated in this video. In addition, the measurements of the larval OKR, as well as the optomotor response (OMR) test of adult zebrafish, are also demonstrated in this video. This OKR assay of adult zebrafish in our experiment may last for up to 4 hours. Such OKR test applied in adult fish will benefit to visual function investigation more efficiently when the adult fish vision system is manipulated.