Algivirga pacifica gen. nov., sp. nov., a Novel Agar-Degrading Marine Bacterium of the Family Flammeovirgaceae Isolated from Micronesia

An aerobic, Gram-negative, coccoid to short rod-shaped and non-flagellated marine bacterial strain S354^T was isolated from seawater of Micronesia. The strain was capable to degrade agar-forming slight depression into agar plate. Growth occurred at a temperature range of 12–44 °C, a pH range of 5–9, and a salinity range of 1–7 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA gene sequences suggested that S354^T belongs to the family Flammeovirgaceae. The novel strain was most closely related to Limibacter armeniacum YM 11-185^T with similarity of 92.5 %. The DNA G+C content was 43.8 mol%. The major fatty acids (>10 %) were iso-C_15:0 and C_16:1 ω5c. The predominant isoprenoid quinone was determined to be MK-7. Polar lipid profile of S354^T consisted of phosphatidylethanolamine, unknown polar lipid, and unknown glycolipids. Based on the phenotypic, phylogenetic, biochemical, and physiological tests conducted in this study, S354^T is proposed to represent a type strain of a novel genus and species. The 16S rRNA gene sequence of S354^T is registered in GenBank under the accession number JQ639084. The type of strain Algivirga pacifica gen. nov., sp. nov. is S354^T (=KCCM 90107^T=JCM 18326^T).     

Comparison of Expression of Inflammatory Cytokines in the Spinal Cord Between Young Adult and Aged Beagle Dogs

Aging is an inevitable process that occurs in the whole body system accompanying with many functional and morphological changes. Inflammation is known as one of age-related factors, and inflammatory changes could enhance mortality risk. In this study, we compared immunoreactivities of inflammatory cytokines, such as interleukin (IL)-2 (a pro-inflammatory cytokine), its receptor (IL-2R), IL-4 (an anti-inflammatory cytokine), and its receptor (IL-4R) in the cervical and lumbar spinal cord of young adult (2–3 years old) and aged (10–12 years old) beagle dogs using immunohistochemistry and western blotting. IL-2 and IL-2R-immunoreactive nerve cells were found throughout the gray matter of the cervical and lumbar spinal cord of young adult and aged dogs. In the spinal cord neurons of the aged dog, immunoreactivity and protein levels were apparently increased compared with those in the young adult dog. Change patterns of IL-4- and IL-4R-immunoreactive cells and their protein levels were also similar to those in IL-2 and IL-2R; however, IL-4 and IL-4R immunoreactivity in the periphery of the neuronal cytoplasm in the aged dog was much stronger than that in the young adult dog. These results indicate that the increase of inflammatory cytokines and their receptors in the aged spinal cord might be related to maintaining a balance of inflammatory reaction in the spinal cord during normal aging.     

Hypoglycemic dipeptide cyclo (His-Pro) significantly altered plasma proteome in streptozocin-induced diabetic rats and genetically-diabetic (ob/ob) mice

The proteins in plasma perform many important functions in the body, and the protein profiles of the plasma vary under different physiological and pathological conditions. In an attempt to identify novel marker proteins for diabetes prognosis, we examined the effect of hypoglycemic dipeptide cyclo (His-Pro) (CHP) on the differential regulation of plasma proteins in streptozocin-induced diabetic rats and genetically-diabetic (ob/ob) mice. The orally-administrated CHP produced an excellent hypoglycemic effect in both animal models, lowering the average plasma glucose level by over 50 %. In the 2-DE analysis of the plasma, a total of 23 spots among 500 visualized spots were found to be differentially regulated, and they were identified by MALDI/TOF mass spectrometry. These proteins include the down-regulation of Apo E and the up-regulation of FGA, Apo A-I, Apo A-IV, and A1M in STZ-induced diabetic rats. Moreover, CHP significantly reduced the plasma protein levels of FGB, FGC, F12, C1QTNF5, and SPA3K, as well as increased the abundance of A1M, A2M, Apo E, and TTR in genetically-diabetic mice. In conclusion, alteration in the regulation of these proteins indicates that this treatment may be successful in overcoming the diabetic state. The present proteomic data can serve as the basis for the development of specific evidence-based interventions allowing for the prevention and treatment of diabetes.     

Spotted fever group rickettsia closely related to Rickettsia monacensis isolated from ticks in South Jeolla province,Korea

Rickettsia monacensis, a spotted fever group rickettsia, was isolated from Ixodes nipponensis ticks collected from live‐captured small mammals in South Jeolla province, Korea in 2006. Homogenates of tick tissues were inoculated into L929 and Vero cell monolayers using shell vial assays. After several passages, Giemsa staining revealed rickettsia‐like organisms in the inoculated Vero cells, but not the L929 cells. Sequencing analysis revealed that the ompA‐small part (25–614 bp region), ompA‐large part (2849–4455 bp region), nearly full‐length ompB (58–4889 bp region) and gltA (196–1236 bp region) of the isolates had similarities of 100%, 99.8%, 99.3% and 99.5%, respectively, to those of R. monacensis. Furthermore, phylogenetic analysis showed that the isolate was grouped into the cluster in the same way as R. monacensis in the trees of all genes examined. These results strongly suggest that the isolate is closely related to R. monacensis. As far as is known, this is the first report of isolation of R. monacensis from ticks in Korea.     

The structure of a shellfish specific GST class glutathione S‐transferase from antarctic bivalve Laternula elliptica reveals novel active site architecture

Glutathione‐S‐transferases have been identified in all the living species examined so far, yet little is known about their function in marine organisms. In a previous report, the recently identified GST from Antarctic bivalve Laternula elliptica (LeGST) was classified into the rho class GST, but there are several unique features of LeGST that may justify reclassification, which could represent specific shellfish GSTs. Here, we determined the crystal structure of LeGST, which is a shellfish specific class of GST. The structural analysis showed that the relatively open and wide hydrophobic H‐site of the LeGST allows this GST to accommodate various substrates. These results suggest that the H‐site of LeGST may be the result of adaptation to their environments as sedentary organisms. Proteins 2013. © 2012 Wiley Periodicals, Inc.     

The Influence of Antimicrobial Peptides and Mucolytics on the Integrity of Biofilms Consisting of Bacteria and Yeasts as Affecting Voice Prosthetic Air Flow Resistances

The integrity of biofilms on voice prostheses used to rehabilitate speech in laryngectomized patients causes unwanted increases in airflow resistance, impeding speech. Biofilm integrity is ensured by extracellular polymeric substances (EPS). This study aimed to determine whether synthetic salivary peptides or mucolytics, including N-acetylcysteine and ascorbic acid, influence the integrity of voice prosthetic biofilms. Biofilms were grown on voice prostheses in an artificial throat model and exposed to synthetic salivary peptides, mucolytics and two different antiseptics (chlorhexidine and Triclosan). Synthetic salivary peptides did not reduce the air flow resistance of voice prostheses after biofilm formation. Although both chlorhexidine and Triclosan reduced microbial numbers on the prostheses, only the Triclosan-containing positive control reduced the air flow resistance. Unlike ascorbic acid, the mucolytic N-acetylcysteine removed most EPS from the biofilms and induced a decrease in air flow resistance.     

Overexpression of the glutamine synthetase gene modulates oxidative stress response in rice after exposure to cadmium stress

Key message

Overexpression of OsGS gene modulates oxidative stress response in rice after exposure to cadmium stress. Our results describe the features of transformants with enhanced tolerance to Cd and abiotic stresses.

Abstract

Glutamine synthetase (GS) (EC 6.3.1.2) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine. Exposure of plants to cadmium (Cd) has been reported to decrease GS activity in maize, pea, bean, and rice. To better understand the function of the GS gene under Cd stress in rice, we constructed a recombinant pART vector carrying the GS gene under the control of the CaMV 35S promoter and OCS terminator and transformed using Agrobacterium tumefaciens. We then investigated GS overexpressing rice lines at the physiological and molecular levels under Cd toxicity and abiotic stress conditions. We observed a decrease in GS enzyme activity and mRNA expression among transgenic and wild-type plants subjected to Cd stress. The decrease, however, was significantly lower in the wild type than in the transgenic plants. This was further validated by the high GS mRNA expression and enzyme activity in most of the transgenic lines. Moreover, after 10 days of exposure to Cd stress, increase in the glutamine reductase activity and low or no malondialdehyde contents were observed. These results showed that overexpression of the GS gene in rice modulated the expression of enzymes responsible for membrane peroxidation that may result in plant death.