<Emphasis Type="Italic">Lutibacter oceani</Emphasis> sp. nov., isolated from marine sediment in South Korea

A novel Gram-negative, non-motile, non-spore forming, facultatively anaerobic and short-rod shaped bacterial strain, designated as 325-5^T, was isolated from marine sediment obtained from a coastal region in South Korea. Phylogenetic analysis based on the 16S rRNA gene sequence of strain 325-5^T showed close similarity to Lutibacter crassostreae (97.8 %). The novel isolate was found to grow optimally at 25 °C and pH 7.0. The major fatty acids identified in the strain were iso C_15:0 and iso C_15:0 3OH, which supports the affiliation of strain 325-5^T to the genus Lutibacter. Menaquinone (MK-6) was identified as the respiratory quinone component. The polar lipid profile was found to contain phosphatidylethanolamine and two unidentified lipids. The G+C molar content of strain 325-5^T was determined to be 33.1 mol%. DNA–DNA hybridization of strain 325-5^T exhibited less than 40 % relatedness to L. crassostreae KCTC 42461^T. Pigment analysis showed the presence of carotenoid pigments. Based on this polyphasic analysis, we propose that strain 325-5^T represents a novel species of the genus Lutibacter, for which the name Lutibacter oceani sp. nov. (type strain 325-5^T = JCM 30924^T = KEMB 7306-529^T) is proposed.     

<Emphasis Type="Italic">Tessaracoccus defluvii</Emphasis> sp. nov., isolated from an aeration tank of a sewage treatment plant

A Gram-positive, non-motile, aerobic, coccus-shaped bacterium, designated strain LNB-140^T, was isolated from a sewage treatment plant in the Republic of Korea and was characterised using a polyphasic taxonomic approach. Comparative 16S rRNA gene sequence analysis showed that strain LNB-140^T belongs to genus Tessaracoccus in the family Propionibacteriaceae of the phylum Actinobacteria. The 16S rRNA gene sequence similarities between strain LNB-140^T and type strains of the genus, Tessaracoccus flavescens SST-39^T and Tessaracoccus rhinocerotis YIM101269^T are 97.8 and 97.4 %, respectively. The chemotaxonomic properties of strain LNB-140^T are consistent with those of members of the genus Tessaracoccus: a quinone system with MK-9(H4) as the predominant menaquinone; anteiso-C_15:0 and iso C_15:0 as the predominant cellular fatty acids; and ll-2,6-diaminopimelic acid as the diagnostic peptidoglycan diamino acid. The major polar lipids were identified as diphosphatidylglycerol and phosphatidylethanolamine. The G+C content of the genomic DNA was determined to be 67.1 mol%. Differential phenotypic properties along with low DNA–DNA relatedness (<30 ± 3.2 %) with closely related type strains show that strain LNB-140^T is distinct from previously described members of the genus Tessaracoccus and represents a novel species in this genus, for which the name Tessaracoccus defluvii sp. nov. is proposed. The type strain is LNB-140^T (=KEMB 5401-076^T = JCM 17540^T).     

Evidence Suggesting a Role of Iron in a Mouse Model of Nephrogenic Systemic Fibrosis

Nephrogenic systemic fibrosis is associated with gadolinium contrast exposure in patients with reduced kidney function and carries high morbidity and mortality. We have previously demonstrated that gadolinium contrast agents induce in vivo systemic iron mobilization and in vitro differentiation of peripheral blood mononuclear cells into ferroportin (iron exporter)-expressing fibrocytic cells. In the present study we examined the role of iron in a mouse model of nephrogenic systemic fibrosis. Chronic kidney disease was induced in 8-week-old male Balb/C mice with a two-step 5/6 nephrectomy surgery. Five groups of mice were studied: control (n = 5), sham surgery control (n = 5), chronic kidney disease control (n = 4), chronic kidney disease injected with 0.5 mmol/kg body weight of Omniscan 3 days per week, for a total of 10 injections (n = 8), and chronic kidney disease with Omniscan plus deferiprone, 125 mg/kg, in drinking water (n = 9). Deferiprone was continued for 16 weeks until the end of the experiment. Mice with chronic kidney disease injected with Omniscan developed skin changes characteristic of nephrogenic systemic fibrosis including hair loss, reddening, ulceration, and skin tightening by 10 to 16 weeks. Histopathological sections demonstrated dermal fibrosis with increased skin thickness (0.25±0.06 mm, sham; 0.34±+0.3 mm, Omniscan-injected). Additionally, we observed an increase in tissue infiltration of ferroportin-expressing, fibrocyte-like cells accompanied by tissue iron accumulation in the skin of the Omniscan-treated mice. The deferiprone-treated group had significantly decreased skin thickness (p<0.05) and significantly decreased dermal fibrosis compared to the Omniscan-only group. In addition, iron chelation prevented tissue infiltration of ferroportin-expressing, fibrocyte-like cells. Our in vitro experiments demonstrated that exposure to Omniscan resulted in the release of catalytic iron and this was prevented by the iron chelator deferiprone. Deferiprone inhibited the differentiation of human peripheral blood mononuclear cells into ferroportin-expressing cells by immunohistochemical staining and western blot analysis. Our studies support an important role of iron in the pathophysiology of gadolinium chelate toxicity and nephrogenic systemic fibrosis.     

Characterization of IAA Production by the Mangrove Cyanobacterium Phormidium sp. MI405019 and Its Influence on Tobacco Seed Germination and Organogenesis

The production of indole-3-acetic acid (IAA) by a mangrove root-associated cyanobacterium, Phormidium sp. MI405019, was demonstrated in this study. The extracellular extract (ECE) of this cyanobacterial culture filtrate was tested on tobacco seed germination and callus differentiation. In ECE treatment, seed germination was increased by 40 % when compared to that of control. In addition, ECE also induced multiple roots from tobacco callus. Further, the factors such as concentration of l-tryptophan and NaCl (salinity) on IAA production were studied. IAA in the medium was initially increased up to a certain period and subsequently decreased in all salinity ranges tested. The amount of IAA production was decreased after 48 h in the culture grown in media amended with 2 % NaCl and without NaCl. However, the IAA concentration was increased up to 96 h in media containing 4 % NaCl. IAA produced by Phormidium sp. MI405019 was extracted from the culture filtrate and its identity was confirmed by thin-layer chromatography and ultra-fast liquid chromatography. To the best of our knowledge, this is the first report of IAA production by cyanobacteria isolated from a mangrove ecosystem. Based on the results in this study, the utilization of Phormidium sp. MI405019 in the aspects of mangrove growth promotion was discussed.     

ISOLATION AND CHARACTERIZATION OF CYANOBACTERIA POSSESSING ANTIMICROBIAL ACTIVITY FROM THE SUNDARBANS,THE WORLD’S LARGEST TIDAL MANGROVE FOREST1

Eight obligately halophilic, euryhaline cyanobacteria from intertidal soil were isolated in artificial seawater nutrients III (ASN‐III) medium. Antimicrobial activity, 16S rRNA gene sequences, phenotypic characters as well as growth and antibiosis in response to variable salinity, temperature, phosphate concentration, and pH were studied. Minimum inhibitory concentrations (MIC) of the extracts against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and multiple drug‐resistant clinical isolates ranged between 0.25 and 0.5 mg · mL⁻¹. Cytotoxicity tests showed 73%–84% human colon adenocarcinoma (HT‐29/C1) cell survival at MIC values, indicating that the extracts were nontoxic. Morphologically, six cyanobacteria were assigned to the Lyngbya‐Phormidium‐Plectonema (LPP) group B, and one each was assigned to Oscillatoria and Synechocystis genera. Glycerol, mannitol, and starch supported better photoheterotrophic growth than simpler mono‐ and disaccharides. No heterocyst formation was observed when grown under nitrogen‐starved conditions. All isolates survived 7‰ salinity, grew at minimum 32‰ salinity, and showed sustained growth throughout 32‰–82‰ salinity but matured poorly in freshwater medium supplemented with 30.0 g · L⁻¹ NaCl. Antimicrobial production occurred only at 32‰ salinity. While four of the eight isolates demonstrated sustained growth at 37°C, maximum antimicrobial activity was obtained at 25°C. All strains showed maximum growth and antimicrobial elaboration at 0.04 g · L⁻¹ phosphate. All isolates thrived at pH 9.5; six grew at pH 4.5, though antimicrobial production occurred only at pH 7.5. Molecular phylogenetic analysis based on 16S rRNA gene sequences of the filamentous isolates validated the previous taxonomic affiliations established on morphological characteristics. This is the first study of antimicrobial‐producing halophilic cyanobacteria from the mangroves.     

The ultrastructure of the striated muscle of the tail of Cercaria chackai Nadakal et al., 1969

The electron microscopic study of the tail of Cercaria chackai reveals that it contains four sets of striated muscle bundles located central to the nonstriated circular and longitudinal muscles. The striated muscle consists of longitudinally oriented lamellar myofibres. Each myofibre contains a single "U" shaped myofibril. The banding pattern is analogous to that of vertebrate striated muscle. The sarcolemma is a simple surface membrane. There are no transverse tubular extensions of sarcolemma. The sarcoplasmic reticulum (SR) is very well developed with cisternae, tubules, and vesicles. SR cisternae form dyadic couplings with the sarcolemma. There is a set of flattened tubules of SR origin traversing the myofibril exactly at the Z region. These tubules are unique to the striated muscle of the cercarian tail and may have functional significance. A diagrammatic reconstruction of the myofibre is presented.     

Conformationally constrained analogues of 2-arachidonoylglycerol

Novel monocyclic analogues of 2-arachidonoylglycerol (2-AG) were designed in order to explore the pharmacophoric conformations of this endocannabinoid ligand at the key cannabinergic proteins. All 2-arachidonoyl esters of 1,2,3-cyclohexanetriol [meso-7 (AM5504), (+/-)-8 (AM5503), and meso-9 (AM5505)] were synthesized by regioselective acylation of 2,3-dihydroxycyclohexanone followed by selective reductions. The optically active isomers (+)-8 (AM4434) and (-)-8 (AM4435) were synthesized from (2S,3S)- and (2R,3R)-2,3-dihydroxycyclohexanone, respectively, via a chemoenzymatic route. These head group constrained and conformationally restricted analogues of 2-AG as well as the 1-keto precursors were evaluated as substrates for the endocannabinoid deactivating hydrolytic enzymes monoacylglycerol lipase (MGL) and fatty acid amide hydrolase (FAAH), and also were tested for their affinities for CB1 and CB2 cannabinoid receptors. The observed biochemical differences between these ligands can help define the conformational requirements for 2-AG activity at each of the above endocannabinoid protein targets.     

A novel promoter from soybean that is active in a complex developmental pattern with and without its proximal 650 base pairs

We report the isolation of a novel soybean gene, Msg, which is highly expressed in developing soybean pods. The gene shows significant homology to a family of fruit- and flower-specific genes, designated the major latex protein (MLP) homologues, so far reported in only a few species and whose functions are unknown. The MLPs are more distantly related to a group of pathogenesis-related proteins (IPR or PR-10) whose functions are likewise unknown. This is the first report of a MLP homologue in a plant for which there is already an IPR-protein reported. We performed an analysis of the Msg promoter with 14 different promoter fragments ranging from 0.65 kb to 2.26 kb, fused to the uidA (GUS) gene. High transient expression was obtained with all the constructs upon particle bombardment in soybean and green bean pods. Stable Arabidopsis transformants were obtained with the Agrobacterium vacuum infiltration method. The promoter is fully active in Arabidopsis only in plants transformed with the 2.26 kb fragment promoter, expressing GUS in nectaries, nodes, short style and in guard cells of the silique, pedicel and stem but not in mature leaves. Surprisingly, the proximal 650 bp TATA-containing region cannot function on its own in Arabidopsis and can be deleted without a change in expression pattern in both Arabidopsis and soybean. Thus, tissue-specific regions of the complex Msg promoter reside in the distal 5 regions upstream of a dispensable TATA box in contrast to many examples of tissue-specific elements that reside much closer to the TATA box.