Phytohabitans maris sp. nov., isolated from marine sediment.

A novel actinobacterium, strain ZYX-F-186T, was isolated from marine sediment sampled on Yongxing Island, Hainan Province, PR China. Based on the results of 16S rRNA gene sequence analysis, strain ZYX-F-186T belongs to the genus Phytohabitans, with high similarity to Phytohabitans kaempferiae KK1-3T (98.3 %), Phytohabitans rumicis K11-0047T (98.1 %), Phytohabitans flavus K09-0627T (98.1 %), Phytohabitans houttuyneae K11-0057T (97.9 %), Phytohabitans suffuscus K07-0523T (97.7 %), and Phytohabitans aurantiacus RD004123T (97.7 %). Phylogenetic analysis of 16S rRNA gene sequences showed that the strain formed a single subclade in the genus Phytohabitans. The novel isolate contained meso-diaminopimelic acid, d-glutamic acid, glycine, d-alanine, and l-lysine in the cell wall. The whole-cell sugars were xylose, arabinose, ribose, and rhamnose. The predominant menaquinones were MK-9(H8), MK-9(H6), and MK-9(H4). The characteristic phospholipids were phosphatidylethanolamine, phosphatidylinositol, phosphatidylmethylethanolamine, phosphatidylglycerol, and an unknown phospholipid. The major fatty acids (>5 %) were iso-C16 : 0, anteiso-C17 : 0, and iso-C18 : 0. Genome sequencing showed a DNA G+C content of 71.9 mol%. Low average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values demonstrated that strain ZYX-F-186T could be readily distinguished from its closely related species. Based on its phylogenetic, chemotaxonomic, and physiological characteristics, strain ZYX-F-186T represents a novel species of the genus Phytohabitans, for which the name Phytohabitans maris sp. nov. is proposed. The type strain is ZYX-F-186T (=CGMCC 4.8025T=CCTCC AA 2023025T=JCM 36507T).

Immuno-modulatory Effects of Inactivated Dietzia Maris on the Selected Aspects of Cellular and Humoral Immune Responses in Mice.

Background: The current study is an attempt to register the alterations in the immunological and histological parameters in mice arising from the administration of Dietza maris (D. maris) in order to confirm its protective properties. Materials and Methods: Mice underwent 7 days of treatment with three doses of D. maris. Then, animals were scrutinized in terms of body weight, relative weight of organs, delayed type of hypersensitivity (DTH) response, and hemagglutination titer (HT). The determination of villus height, villus width, crypt depth, villus/crypt ratio (V/C), Goblet cells, and intestinal epithelial lymphocyte (IEL) density in villi was carried out. Results: A boosted DTH response was observed as a result of bacteria at medium dose. A variation was noted between the hemagglutinin titer of the control group and that of the high-dose group. Crypt depth, villus width, and villus height manifested alterations. High-dose-treated mice demonstrated proliferation of Goblet cells in the villi, whereas both in medium- and high-dose-treated mice, a distribution of IELs in the villus epithelium was noted. Overall, D. maris showed a stimulatory effect on immune functions in mice. Thus, thanks to improved cellular and humoral immunity and the increased quality of intestine function, we believe that D. maris promises novel therapeutic applications in the future. Conclusion: The attained findings lend credence to immuno-stimulatory effects arising from the capacity of D. maris to function as immunological adjuvants and to enhance humoral and cellular immunity as well as the intestinal structure and function.

Actinoplanes maris sp. nov., isolated from marine sediment.

A novel actinobacterium strain (M4I6T) was isolated from marine sediment collected in Megas Gialos, Syros, Greece. On the basis of 16S rRNA gene sequence analysis, strain M4I6T was indicated as belonging to the genus Actinoplanes, with high similarity to 'Actinoplanes solisilvae' LAM7112T (97.9 %), Actinoplanes ferrugineus IFO 15555T (97.6 %), Actinoplanes cibodasensis LIPI11-2-Ac042T (97.2 %) and Actinoplanes bogorensis LIPI11-2-Ac043T (97.2 %). Phylogenetic analysis of the 16S rRNA gene sequence of strain M4I6T showed that the strain formed a stable subclade with 'A. solisilvae' LAM7112T. The cell wall of the novel isolate contained meso-diaminopimelic acid and the whole-cell sugars were xylose, glucose and ribose. The predominant menaquinones were MK-9(H4), MK-9(H2) and MK-9(H8). The phospholipid profile comprised phosphatidylethanolamine, phosphatidylinositol, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannosides and an unknown phospholipid. The major fatty acids (>5 %) were anteiso-C16 : 0, iso-C17 : 0, 10-methyl-C16 : 0, C15 : 0, iso-C16 : 0 and C17 : 0. Genome sequencing showed a DNA G+C content of 70.9 mol%. However, the low average nucleotide identity value, digital DNA-DNA hybridization and average amino acid identity values demonstrated that strain M4I6T could be readily distinguished from its closest related species. Based on data from this polyphasic study, strain M4I6T represents a novel species of the genus Actinoplanes, for which the name Actinoplanes maris sp. nov. is proposed. The type strain is M4I6T (=DSM 101017T=CGMCC 4.7854T).

Exploring associations between the Modular Assessment of Risk for Imminent Suicide (MARIS) questionnaire and recent suicidal ideation and behavior among patients admitted at an acute psychiatric inpatient department.

PURPOSE: The aim of the present study was to investigate the psychometric validity of the Modular Assessment of Risk for Imminent Suicide (MARIS) questionnaire in relation to recent suicidal ideation and behavior among a sample of patients admitted to an acute psychiatric inpatient department in Norway. METHODS: The MARIS was completed within the first 24 h after admission by 338 patients and their clinicians. Information on recent suicidal ideation and behavior was extracted from patients' medical charts. Two out of four MARIS modules, the Suicide Trigger Scale Short-Form (STS-SF; modified version), and the Therapist Response Questionnaire Short-Form (TRQ-SF) demonstrated good internal consistency. The relationships between the STS-SF, addressing symptoms of the suicide crisis syndrome, and the TRQ-SF, exploring therapist emotional responses, and recent suicidal ideation was investigated by logistic regression analysis. RESULTS: In the logistic regression analysis including pre-selected diagnoses, age, and gender as covariates, both STS-SF and TRQ-SF showed significant associations with recent suicidal ideation (inclusive of suicidal behavior in 27% of the patients with suicidal ideation). CONCLUSION: Both the STS-SF and the TRQ-SF showed concurrent and incremental validity with regard to suicidal ideation. This is the first study showing the cross-cultural validity of the MARIS and supports its clinical utility as a suicide risk assessment tool in inpatient settings. Additionally, this study adds to the literature supporting the value of assessing clinicians' emotional responses to high risk patients.

The use of the IAEA MARIS database in determining the variability of sediment distribution coefficients in the marine environment and potential implications for marine dispersion modelling.

A prototype tool has been developed for deriving sediment distribution coefficients,Kd, in the marine environment by harvesting simultaneous measurements of activity concentrations of radionuclides in seawater and sediments based on the International Atomic Energy Agency's Marine Radioactivity Information System (MARIS). As a case study, theKdvariability in the Baltic Sea was investigated as this region has been extensively monitored by HELCOM since 1984 resulting in a comprehensive dataset with good spatial and temporal coverage and required ancillary parameters. The prototype tool was used to derive a dataset ofin-situapparentKd(a)values derived from measurements of seawater and sediment in quasi-equilibrium conditions from the Baltic Sea over a period of approximately 35 years. For Cs, a comprehensive analysis of the Baltic SeaKd(a)dataset was undertaken, focusing on the temporal trend ofKd(a)and comparing the results toKdvalues derived elsewhere. For Sr and Pu, for which there were fewer data records available a more rudimentary analysis was carried out. The CsKd(a)median values derived from137Cs data in this study were estimated to be 2154 l kg-1for seabed sediment and 10 000 l kg-1for suspended sediment. The value derived for seabed sediment is in good agreement with the previously recommended ocean margin CsKdvalue of 4000 l kg-1. The analysis demonstrated the important distinction in the Baltic Sea betweenKdvalues for seabed sediment and suspended sediments, which differed by an order of magnitude. The analysis also highlighted the dependence ofKdvalues on the variation in both the salinity of seawater and the type of seabed sediment. Such variability can significantly influence outcomes when modelling the behaviour of radionuclides in marine dispersion modelling.

[Improving of the nasal cavity mucous membrane restoration efficiency of the after rhinosurgical interventions]. / Primenenie irrigatsionnoi terapii posle khirurgicheskikh vmeshatel'stv v polosti nosa.

The article discusses aspects of the use of irrigation therapy after surgical interventions on intranasal structures, in particular, the features of using the Aqua Maris Leyka device in comparison with traditional methods of nasal cavity care in this group of patients. The use of the Adriatic Sea salt solution for nasal lavage Aqua Maris using a special device in the postoperative period leads to an earlier subsidence of reactive postoperative changes in the nasal cavity, a decrease in edema, an increase of reparative processes. This is evidenced by the dynamics of clinical signs and the results of cytological examination of smears-prints from the nasal cavity. During the irrigation of the nasal cavity using the Aqua Maris Leyka device, the liquid is supplied by gravity, without additional pressure, ensuring safety and uniform irrigation of all parts of the nasal cavity with saline solution, which is especially important in the presence of reactive changes in the postoperative period.

YAP/TAZ maintain the proliferative capacity and structural organization of radial glial cells during brain development.

The Hippo pathway regulates the development and homeostasis of many tissues and in many species. It controls the activity of two paralogous transcriptional coactivators, YAP and TAZ (YAP/TAZ). Although previous studies have established that aberrant YAP/TAZ activation is detrimental to mammalian brain development, whether and how endogenous levels of YAP/TAZ activity regulate brain development remain unclear. Here, we show that during mammalian cortical development, YAP/TAZ are specifically expressed in apical neural progenitor cells known as radial glial cells (RGCs). The subcellular localization of YAP/TAZ undergoes dynamic changes as corticogenesis proceeds. YAP/TAZ are required for maintaining the proliferative potential and structural organization of RGCs, and their ablation during cortical development reduces the numbers of cortical projection neurons and causes the loss of ependymal cells, resulting in hydrocephaly. Transcriptomic analysis using sorted RGCs reveals gene expression changes in YAP/TAZ-depleted cells that correlate with mutant phenotypes. Thus, our study has uncovered essential functions of YAP/TAZ during mammalian brain development and revealed the transcriptional mechanism of their action.

Harenicola maris gen. nov., sp. nov. isolated from the Sea of Japan shallow sediments.

A Gram-negative, non-motile bacterium КMM 3653T was isolated from a sediment sample from the Sea of Japan seashore, Russia. On the basis of the 16S rRNA gene sequence analysis the strain КMM 3653T was positioned within the family Rhodobacteraceae (class Alphaproteobacteria) forming a distinct lineage with the highest gene sequence similarities to the members of the genera Pacificibacter (95.2-94.7%) and Nioella (95.1-94.5%), respectively. According to the phylogenomic tree based on 400 conserved protein sequences, strain КMM 3653T was placed in the cluster comprising Vannielia litorea, Nioella nitratireducens, Litoreibacter albidus and Pseudoruegeria aquimaris as a separate lineage adjacent to V. litorea KCTC 32083T. The average nucleotide identity values between strain КMM 3653T and V. litorea KCTC 32083T, N. nitratireducens KCTC 32417T, L. albidus KMM 3851T, and P. aquimaris CECT 7680T were 71.1, 70.3, 69.6, and 71.0%, respectively. Strain КMM 3653T contained Q-10 as the predominant ubiquinone and C18:1ω7c as the major fatty acid followed by C16:0. The polar lipids were phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified phospholipid, two unidentified aminolipids, and five unidentified lipids. The DNA G+C content of 61.8% was calculated from the genome sequence. Based on the phylogenetic evidence and distinctive phenotypic characteristics, we proposed strain KMM 3653T (= KCTC 82575T) to be classified as a novel genus and species Harenicola maris gen. nov., sp. nov.

Halomonas maris sp. nov., a moderately halophilic bacterium isolated from sediment in the southwest Indian Ocean.

A halophilic, Gram-staining-negative, rod-shaped, flagellated and motile bacterium, strain QX-1 T, was isolated from deep-sea sediment at a depth of 3332 m in the southwestern Indian Ocean. Strain QX-1 T growth was observed at 4-50 °C (optimum 37 °C), pH 5.0-11.0 (optimum pH 7.0), 3-25% NaCl (w/v; optimum 7%), and it did not grow without NaCl. A phylogenetic analysis based on the 16S rRNA gene placed strain QX-1 T in the genus Halomonas and most closely related to Halomonas sulfidaeris (97.9%), Halomonas zhaodongensis (97.8%), Halomonas songnenensis (97.6%), Halomonas hydrothermalis (97.4%), Halomonas subterranea (97.3%), Halomonas salicampi (97.1%), and Halomonas arcis (97.0%). DNA-DNA hybridization (< 26.5%) and average nucleotide identity values (< 83.5%) between strain QX-1 T and the related type strains meet the accepted criteria for a new species. The principal fatty acids (> 10%) of strain QX-1 T are C16:0 (25.5%), C17:0 cyclo (14.0%), C19:0 cyclo ω8c (18.7%), and summed feature 8 (C18:1 ω7c and/or C18:1 ω6c, 18.1%). The polar lipids of strain QX-1 T are mainly diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid, unidentified aminophospholipid, and five unidentified lipids. The main respiratory quinone is Q-9. The G + C content of its chromosomal DNA is 54.4 mol%. Its fatty acid profile, respiratory quinones, and G + C content also support the placement of QX-1 T in the genus Halomonas. These phylogenetic, phenotypic, and chemotaxonomic analyses indicate that QX-1 T is a novel species, for which the name Halomonas maris is proposed. The type strain is QX-1 T (= MCCC 1A17875T = KCTC 82198 T = NBRC 114670 T).

Enhancement of biomass and total carotenoid content of a UV-resistant strain of Dietzia maris in response to different carbon and nitrogen sources.

In the present study, the effect of various fermentation media on the production of carotenoid pigment in a radiation-resistant strain of Dietzia maris was reported. The biomass and pigment production of this strain was evaluated using various sources of carbon and nitrogen as well as different concentrations of whey medium. The antioxidant and cytotoxic activities of the extracted pigment were also determined using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH), and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assays. The antibacterial activity of the carotenoid pigment was also evaluated. All carbon sources increased the pigment production of D. maris in the following order: glucose > raffinose = starch = xylose > sorbitol > sucrose. However, only glucose, xylose, and sorbitol significantly increased the microbial biomass as compared to the control. Moreover, all organic nitrogen sources and ammonium sulfate enhanced the pigment production of the studied strain by approximately 6-9 folds. The free radical scavenging capacity and FRAP of the D. maris carotenoid extract were reported as half-maximal effective concentration or EC50 = 3.30 mg/ml and EC50 =28.46 µg/ml, respectively. The maximum amount of biomass and carotenoid pigment produced by D. maris was obtained in the fermentation medium containing 1 g/l glucose and 1 g/l yeast extract (18 mg/l). This strain can be considered as a promising biocatalyst for the commercial production of natural carotenoids due to its antioxidant capacity and noncytotoxic activity.

Green synthesis of silver nanoparticles using canthaxanthin from Dietzia maris AURCCBT01 and their cytotoxic properties against human keratinocyte cell line.

AIM: Nano-biotechnologically synthesizing silver nanoparticles via canthaxanthin pigment extracted from Dietzia maris AURCCBT01 and assessing their cytotoxic therapeutic potential against human keratinocyte cell line (HaCaT) were the key objectives of this study. METHODS AND RESULTS: The pigment extracted from D. maris AURCCBT01 was identified as canthaxanthin using UV-VIS spectroscopy, FTIR, NMR (1 H NMR and 13 C NMR) and MS. Canthaxanthin, treated with silver nitrate solution, produced canthaxanthin-mediated silver nanoparticles and they were characterized by UV-VIS spectroscopy, FTIR, XRD, FESEM-EDX and TEM-SAED techniques. UV-VIS spectroscopy pointed out an absorption band at 420 nm, relating to the surface plasmon resonance of silver nanoparticles. FTIR findings suggested that the diverse functional groups of canthaxanthin bio-molecules played a significant task in capping the silver nanoparticles. XRD analysis exhibited 40·20 nm for the crystal size of nanoparticles. FESEM and TEM exhibited that the biosynthesized silver nanoparticles were spherical in shape with crystalline nature and the particle size was 40-50 nm. Moreover, the cytotoxicity assessment of the synthesized nanoparticles in HaCaT revealed significant cytotoxicity in the cultured cells with an IC50 value of 43 µg ml-1 . CONCLUSION: Stable silver nanoparticles synthesized using canthaxanthin from D. maris AURCCBT01 were found effective for application in wound healing activity. SIGNIFICANCE AND IMPACT OF THE STUDY: Biosynthesized silver nanoparticles via canthaxanthin bacterial pigment exhibited their cytotoxicity effect in HaCaT and testified their eventual therapeutic potential in the wound healing activity with no side effects in a cost effective and eco-friendly process.

Additions to the genus Gimesia: description of Gimesia alba sp. nov., Gimesia algae sp. nov., Gimesia aquarii sp. nov., Gimesia aquatilis sp. nov., Gimesia fumaroli sp. nov. and Gimesia panareensis sp. nov., isolated from aquatic habitats of the Northern Hemisphere.

Thirteen novel planctomycetal strains were isolated from five different aquatic sampling locations. These comprise the hydrothermal vent system close to Panarea Island (Italy), a biofilm on the surface of kelp at Monterey Bay (CA, USA), sediment and algae on Mallorca Island (Spain) and Helgoland Island (Germany), as well as a seawater aquarium in Braunschweig, Germany. All strains were shown to belong to the genus Gimesia. Their genomes cover a size range from 7.22 to 8.29 Mb and have a G+C content between 45.1 and 53.7%. All strains are mesophilic (Topt 26-33 °C) with generation times between 12 and 32 h. Analysis of fatty acids yielded palmitic acid (16:0) and a fatty acid with the equivalent chain length of 15.817 as major compounds. While five of the novel strains belong to the already described species Gimesia maris and Gimesia chilikensis, the other strains belong to novel species, for which we propose the names Gimesia alba (type strain Pan241wT = DSM 100744T = LMG 31345T = CECT 9841T = VKM B-3430T), Gimesia algae (type strain Pan161T = CECT 30192T = STH00943T = LMG 29130T), Gimesia aquarii (type strain V144T = DSM 101710T = VKM B-3433T), Gimesia fumaroli (type strain Enr17T = DSM 100710T = VKM B-3429T) and Gimesia panareensis (type strain Enr10T = DSM 100416T = LMG 29082T). STH numbers refer to the Jena Microbial Resource Collection (JMRC).

Parahaliea maris sp. nov., isolated from surface seawater and emended description of the genus Parahaliea.

A Gram-stain-negative strictly aerobic, short-rod-shaped, and non-motile bacterial strain designated HSLHS9T was isolated from surface seawater collected from the South China Sea. Strain HSLHS9T could grow at 15-41°C (optimum 28°C), at pH 5.0-9.0 (optimum 6.0-7.0), and in 0-7% (w/v) NaCl (optimum 2-3%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain HSLHS9T shared high identities with the closely related Parahaliea aestuarii S2-26T (98.6%) and Parahaliea mediterranea 7SM29T (97.8%) and formed a distinct lineage within the genus Parahaliea. Wholegenome sequencing of strain HSLHS9T revealed the size of 4.8 Mbp and DNA G + C content of 61.8 mol%. Strain HSLHS9T shared the digital DNA-DNA hybridization values of 22.4% and 23.0%, and the average nucleotide identities of 79.7% and 79.9%, respectively, with the two type strains above. The predominant cellular fatty acids of the strain were summed feature 8 (C18:1ω6c and/or C18:1ω7c), summed feature 3 (C16:1ω7c and/or C16:1ω6c), C17:1ω8c, and C16:0. The sole isoprenoid quinone was identified as Q-8. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, aminolipid, and two glycolipids. Based on taxonomic data obtained in this study, it is suggested that strain HSLHS9T represents a novel species of the genus Parahaliea, for which the name Parahaliea maris sp. nov. is proposed. The type strain is HSLHS9T (= MCCC 1A06717T = KCTC 52307T). An emended description of the genus Parahaliea is also provided.

Analysis of amino acid residues involved in the thermal properties of isocitrate dehydrogenases from a psychrophilic bacterium, Colwellia maris, and a psychrotrophic bacterium, Pseudomonas psychrophila.

Monomeric NADP+-dependent isocitrate dehydrogenase (IDH) from a psychrophilic bacterium, Colwella maris, (CmIDH) is a cold-adapted enzyme, whereas that of a psychrotrophic bacterium, Pseudomonas psychrophila, (PpIDH) is mesophilic. However, the amino acid sequence identity of the two IDHs is high (67%). To identify the amino acid residues involved in the differences in their thermal properties, such as optimum temperature and thermostability for activity, six amino acid residues located in the corresponding positions of their regions 2 and 3 were substituted by site-directed mutagenesis, and several thermal properties of the mutated IDHs were examined. CmIDH mutants, CmE538L, CmE596L and CmA741S, substituted at Glu538, Glu596 and Ala741 by the corresponding PpIDH residues of Leu, Leu and Ser, respectively, exhibited higher thermostability than wild-type CmIDH (CmWT). Furthermore, the specific activity of CmE596L and CmA741S was higher than that of CmWT. On the other hand, the corresponding mutants of PpIDH PpL536E, PpL594E and PpS739A were more thermolabile than wild-type PpIDH, and PpL594E had a lower specific activity at temperatures over 45°C. These results suggested that these amino acid residues of CmIDH and PpIDH are involved in their thermal properties.

An Evolutionarily Conserved Receptor-like Kinases Signaling Module Controls Cell Wall Integrity During Tip Growth.

Rooting cells and pollen tubes-key adaptative innovations that evolved during the colonization and subsequent radiation of plants on land-expand by tip growth. Tip growth relies on a tight coordination between the protoplast growth and the synthesis/remodeling of the external cell wall. In root hairs and pollen tubes of the seed plant Arabidopsis thaliana, cell wall integrity (CWI) mechanisms monitor this coordination through the Malectin-like receptor kinases (MLRs), such as AtANXUR1 and AtFERONIA, that act upstream of the AtMARIS PTI1-like kinase. Here, we show that rhizoid growth in the early diverging plant, Marchantia polymorpha, is also controlled by an MLR and PTI1-like signaling module. Rhizoids, root hairs, and pollen tubes respond similarly to disruption of MLR and PTI1-like encoding genes. Thus, the MLR and PTI1-like signaling module that controls CWI during tip growth is conserved between M. polymorpha and A. thaliana, suggesting that it was active in the common ancestor of land plants.

Rhizoremediation of cadmium-contaminated soil associated with hydroxamate siderophores isolated from Cd-resistant plant growth-promoting Dietzia maris and Lysinibacillus strains.

In search of multitrait plant growth-promoting (PGP) inoculants, we introduced two cadmium-resistant bacterial strains, C4 (PG), C5 (WB), and their consortium C6 (PG × WB) isolated from metal-contaminated industrial waste-fed canal near West Bengal. The test isolates were biochemically characterized and screened in vitro for siderophore production. The infrared spectra revealed the hydroxamate nature of the siderophore produced. Further in green house, siderophore-based seed inoculation with selected PGP isolates exhibited stimulatory effects on seed germination (up to 85.4%), chlorophyll index (22.9 spad unit), shoot and root length (70% and 62.7%), tiller numbers (38.82%), spikelet numbers (52.2%), straw yield (62.2%), grain yield (76.1%), total dry matter of root and shoot (55.56% and 64.4%, respectively), and grain yields (76.1%) of tested wheat cultivars. The 16S rRNA sequencing identified strain PG and WB as Dietzia maris and Lysinibacillus sp. strains. Furthermore, inoculation of C6 (consortium) in both cultivar UP-2565 and KS-227 showed maximum Cd sorption capacity in roots (38.3% and 67.1%) and shoots (68.4% and 67.5%), respectively. Both the strains and their consortium showed a great potential to increase the growth and yield of wheat cultivars, which can also be utilized for rhizoremediation process.

Comparison of the compatible solute pool of two slightly halophilic planctomycetes species, Gimesia maris and Rubinisphaera brasiliensis.

Gimesia maris and Rubinisphaera brasiliensis are slightly halophilic representatives of the deep-branching phylum Planctomycetes. For osmoadaptation both species accumulated α-glutamate, sucrose, ectoine and hydroxyectoine. A major role was found for ectoine, hydroxyectoine as well as sucrose under hyper-osmotic shock conditions. Nevertheless, the levels of sucrose were up-regulated by the increased salinity levels and also by low nitrogen availability. Additionally, G. maris accumulated glucosylglycerate (GG) as major solute specifically under low nitrogen levels, which prompted us to analyse the transcript abundance of two homologues genes known for the biosynthesis of GG, namely glucosyl-3-phosphoglycerate synthase (GpgS) and glucosyl-3-phosphoglycerate phosphatase (GpgP). By qPCR using a suitable reference gene selected in this study, the transcript abundance of the biosynthetic genes was quantified in G. maris cells under hyper-osmotic shock or under low nitrogen conditions. The gpgS gene was induced under nitrogen-limiting conditions suggesting that GG synthesis is regulated primarily at the transcription level. Moreover, the expression of a gene coding for a putative sucrose-phosphorylase (Spase) located upstream the gpgS and gpgP genes was up-regulated, predicting a metabolic role of Spase probably related to GG synthesis.

Development of Genetic Tools for the Manipulation of the Planctomycetes.

Bacteria belonging to the Planctomycetes, Verrucomicrobia, Chlamydiae (PVC) superphylum are of interest for biotechnology, evolutionary cell biology, ecology, and human health. Some PVC species lack a number of typical bacterial features while others possess characteristics that are usually more associated to eukaryotes or archaea. For example, the Planctomycetes phylum is atypical for the absence of the FtsZ protein and for the presence of a developed endomembrane system. Studies of the cellular and molecular biology of these infrequent characteristics are currently limited due to the lack of genetic tools for most of the species. So far, genetic manipulation in Planctomycetes has been described in Planctopirus limnophila only. Here, we show a simple approach that allows mutagenesis by homologous recombination in three different planctomycetes species (i.e., Gemmata obscuriglobus, Gimesia maris, and Blastopirellula marina), in addition to P. limnophila, thus extending the repertoire of genetically modifiable organisms in this superphylum. Although the Planctomycetes show high resistance to most antibiotics, we have used kanamycin resistance genes in G. obscuriglobus, P. limnophila, and G. maris, and tetracycline resistance genes in B. marina, as markers for mutant selection. In all cases, plasmids were introduced in the strains by mating or electroporation, and the genetic modification was verified by Southern Blotting analysis. In addition, we show that the green fluorescent protein (gfp) is expressed in all four backgrounds from an Escherichia coli promoter. The genetic manipulation achievement in four phylogenetically diverse planctomycetes will enable molecular studies in these strains, and opens the door to developing genetic approaches not only in other planctomycetes but also other species of the superphylum, such as the Lentisphaerae.

Cation Diffusion Facilitator family: Structure and function.

The Cation Diffusion Facilitators (CDFs) form a family of membrane-bound proteins capable of transporting zinc and other heavy metal ions. Involved in metal tolerance/resistance by efflux of ions, CDF proteins share a two-modular architecture consisting of a transmembrane domain (TMD) and C-terminal domain (CTD) that protrudes into the cytoplasm. Discovery of a Zn²âº and Cd²âº CDF transporter from a marine bacterium Maricaulis maris that does not possess the CTD questions current perceptions regarding this family of proteins. This article describes a new, CTD-lacking subfamily of CDFs and our current knowledge about this family of proteins in the view of these findings.

Discovery of a cell wall porin in the mycolic-acid-containing actinomycete Dietzia maris DSM 43672.

The cell wall of the Gram-positive mycolic-acid-containing actinomycete Dietzia maris DSM 43672 was found to contain a pore-forming protein, as observed from reconstitution experiments with artificial lipid bilayer experiments in the presence of cell wall extracts. The cell wall porin was purified to homogeneity using different biochemical methods and had an apparent molecular mass of about 120 kDa on tricine-containing SDS/PAGE. The 120 kDa protein dissociated into subunits with a molecular mass of about 35 kDa when it was heated to 100 °C in 8 m urea. The 120 kDa protein, here named PorADm , formed ion-permeable channels in lipid bilayer membranes with a high single-channel conductance of about 5.8 nS in 1 m KCl. Asymmetric addition of PorADm to lipid bilayer membranes resulted in an asymmetric voltage dependence. Zero-current membrane potential measurements with different salt solutions suggested that the porin of D. maris is cation-selective because of negative charges localized at the channel mouth. Analysis of the single-channel conductance using non-electrolytes with known hydrodynamic radii indicated that the diameter of the cell wall channel is about 2 nm. The channel characteristics of the cell wall porin of D. maris are compared with those of other members of the mycolata. They share some common features because they are composed of small molecular mass subunits and form large and water-filled channels. The porin was subjected to protein analysis by mass spectrometry but its sequence had no significant homology to any known porin sequences.