Aggregability of β(1→4)-linked glucosaminoglucan originating from a sulfur-oxidizing bacterium Thiothrix nivea

ABSTRACT

β-1,4-glucosaminoglucan (GG) was prepared from the sheath of a sulfur-oxidizing bacterium Thiothrix nivea. Recently, GG was found to be adsorbed by cellulose (paper) and is therefore potentially applicable as an aminating agent for cellulose. We attempted to increase the yield of GG using a fed-batch cultivation method. Furthermore, the behavior of GG molecules in water was theoretically and experimentally investigated. NMR analysis in combination with molecular dynamics calculation suggested that GG molecules tend to form soluble aggregates in water. It was experimentally revealed that the self-aggregation is enhanced by the addition of NaCl and reduced temperature. Adsorption of GG onto cellulose via hydrogen bonding was confirmed by molecular dynamics simulation. Adsorption was also promoted in the presence of NaCl but was inhibited by a reduction in temperature. Only 11% of the amino groups in the GG-treated paper was reactive, suggesting that GG molecules adsorbed by the paper were forming aggregates.     

Identification of Thiothrix unzii in two distinct ecosystems

AIMS: Molecular procedures were used to identify Thiothrix spp. in biofilms from sulphide-rich waters in two distinct ecosystems. METHODS AND RESULTS: Biofilm samples were obtained from two groundwater-fed systems in central and northern Florida, including an artesian spring and municipal water tank. The 16S rDNA in each sample was directly amplified by polymerase chain reaction. CONCLUSIONS: Clonal libraries of biofilm 16S rDNA from each site contained rDNA sequences that were 99-99.5% similar to Thiothrix unzii. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of T. unzii in a natural system. Biofilm formation by Thiothrix spp. can cause fouling in groundwater processing equipment, including municipal water-processing facilities, agricultural irrigation systems and spring water bottling plant filters. Biofouling can have severe economic and human health impacts as it will influence flow rates and related water treatments. Characterization of specific fouling bacteria and their molecular ecology is essential for their regulation.     

Chemolithoutotrophic growth of Thiothrix ramosa

Thiothrix has been shown for the first time to be able to grow chemolithoautotrophically with thiosulphate or carbon disulphide as sole energy substrate. Thiosulphate served as the growth-limiting substrate for Thiothrix ramosa in chemostat culture. Maximum growth yield (Y_max) from yields at growth rates between 0.029–0.075 h^-1 was 4.0 g protein/mol thiosulphate oxidized. The key enzyme of the Calvin cycle, ribulose 1,5-bisphosphate carboxylase, was present in these cells, as were rhodanese, adenylyl sulphate (APS) reductase and sulphur-oxidizing enzyme. Thiosulphate-grown cells oxidized thiosulphate, sulphide, tetrathionate and carbon disulphide. Oxidation kinetics for sulphide, thiosulphate and tetrathionate were biphasic: oxygen consumption during the fast first phase of oxidation indicated oxidation of sulphide, and the sulphane moieties of thiosulphate and tetrathionate, to elemental sulphur, before further oxidation to sulphate. Kinetic constants for these four substrates were determined. T. ramosa also grew mixotrophically in batch culture on lactate with a number of organic sulphur compounds: carbon disulphide, methanethiol and diethyl sulphide. Substituted thiophenes were also used as sole substrates. The metabolic versatility of T. ramosa is thus much greater than previously realised.     

Genome sequence of the filamentous, gliding Thiothrix nivea neotype strain (JP2(T))

Thiothrix nivea (Rabenhorst 1865) Winogradsky 1888 (Approved Lists 1980) emend. Larkin and Shinabarger 1983 is the type species of the genus Thiothrix in the family Thiotrichaceae. The species is of interest not only because of its isolated location in the yet to be genomically characterized region of the tree of life, but also because of its life-style with gliding gonidia, the multilayer sheath, rosettes, and the embedded sulfur granules. Strain JP2(T) is the neotype strain of the species which was first observed by Rabenhorst in 1865 and later reclassified by Winogradsky in 1888 into the then novel genus Thiothrix. This is the first completed (improved-high-quality-draft) genome sequence to be published of a member of the family Thiotrichaceae. The genome in its current assembly consists of 15 contigs in four scaffolds with a total of 4,691,711 bp bearing 4,542 protein-coding and 52 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Transient development of filamentous Thiothrix species in a marine sulfide oxidizing, denitrifying fluidized bed reactor

In this study, microscopic and molecular microbial analyses were integrated to characterize rapidly developing white filamentous tufts in a fluidized bed reactor used for nitrate removal from a marine recirculating fish culture system. Formation and rapid elongation of the tufts (often exceeding 50 mm day (-1)) was strongly correlated to transient elevated sulfide concentrations (>50 microM) in the reactor. The dominant bacterial constituents of these tufts were filamentous gram-negative bacteria with densely packed intracellular sulfur granules. Using 16S rRNA gene analysis and fluorescence in situ hybridization it was found that these filamentous bacteria represented a novel Thiothrix phylotype closely related (97% sequence identity) to a previously identified Thiothrix strain endogenous to the marine crustacean Urothoe poseidonis. In addition to filamentous morphotypes, rosette-shaped morphotypes of Thiothrix were also detectable within the tufts.     

Structure and permeability of the fungal sheath in thePisonia mycorrhiza

Summary The tracer Cellufluor has been used to test the apoplastic permeability of the fungal sheath inPisonia grandis R. Br. mycorrhizas. In the tip region in the immediate vicinity of the root cap, where the sheath is not yet fully differentiated, Celluflor penetrates as far as the root epidermal cells. Behind this (i.e. just proximal to it) in differentiated regions, where the ultrastructure of both the root and fungal cells indicates that the mycorrhiza is likely to be functionally active, the sheath is impermeable to Cellufluor. During the development and differentiation of the sheath, the interhyphal spaces become filled with extracellular material. In the outer and middle regions this becomes electron opaque after fixation and staining. It is proposed that the dramatic decrease in apoplastic permeability over a short distance back from the root apex as the fungal sheath differentiates results from secretion of extracellular material by the fungus and its modification by deposition of phenolic substances. The symplastic pathway within the fungus may be very important for radial transfer of materials across the sheath. Blockage of the sheath apoplast could provide a sealed apoplastic compartment at the fungus-root interface, with resulting increase in efficiency of transfer between partners. The implications of these observations are discussed in relation to radial transfer across the sheath and transfer between partners in sheathing mycorrhizas in general.     

In vitro plant regeneration from seedling-derived explants of ramie [Boehmeria nivea (L.) Gaud]

Ramie [Boehmeria nivea (L.) Gaud] is one of the most important perennial fiber crops in China. In vitro tissue culture of ramie could serve as an important means for its improvement through genetic transformation. To improve the regeneration capacity of ramie, the effects on plant regeneration of donor plant age, basal medium, plant growth regulators, and culture conditions were evaluated using explants derived from the cotyledon, hypocotyl, leaf, petiole, and stem of ramie seedlings. Cotyledons and hypocotyls excised from 4-d-old seedlings and leaves and petioles and stems from 15-d-old seedlings were optimal explants. The highest regeneration efficiency was obtained on Murashige and Skoog salts with Gamborg’s B₅ vitamins basal medium containing 2.27 μM thidiazuron (TDZ) and 0.054 μM naphthaleneacetic acid (NAA) for the five explant types tested. A photoperiod of 16:8 h (light/dark) was found to be superior than continuous darkness for regeneration of ramie using TDZ. The regenerated shoots were transferred to hormone-free medium for shoot elongation and successfully rooted on half-strength Murashige and Skoog supplemented with 0.134 μM NAA. The rooted plantlets with four to five leaves were transplanted to greenhouse for further growth.     

High annual variability in reproductive success and survival of an Antarctic seabird,the snow petrel Pagodroma nivea

Demographic parameters were estimated for snow petrels Pagodroma nivea nesting at Pointe Géologie Archipelago, Adélie Land, Antarctica between 1963 and 1990; 21 years of data on adult survival and 27 years of data on breeding success are available. The average age of first return and first breeding were 8.1 and 9.9 years respectively and there was no signifcant difference between the sexes. The overall breeding success averaged 51.3% and was very variable between years (21–80%). Breeding failure was mostly due to incubation failure and annual breeding success was negatively correlated with average snow falls in October–November and October–March. Breeding frequency was very low, averaging 52% of seasons during a reproductive lifetime. Good quality sites, with high occupancy rate and high breeding success were few in the study plots. Poor years in 1966–1967, 1976–1977 and 1983–1984, with low breeding success, very low proportions of nets with breeding attempts and high numbers of non-breeders, occurred 1 year after large-scale El Niño Southern Oscillation (ENSO) events. Snow petrels exhibited very low philopatry. Only 45 birds have been recovered in the study plots from a total of 1115 banded fledglings giving an estimated rate of return of 12.9% between fledging and 3 years old. Annual survival between 3 and 10 years was 91.4%. Annual adult survival (93.4%), though variable, was low during poor years of 1977–1978 and 1983–1984. Adult survival of males (94.7%) was not significantly different from that of females (93.9%). Over the study period, the population of Pointe Géologie was stable. Using the estimated parameters, a Leslie model gave a growth rate of 0.948%, which was probably compensated by immigration (5.7% per year). Restricted numbers of good-quality sites at the place of birth could have led young birds to prospect other colonies and could have selected low philopatry. High adult survival, strong site tenacity and capacity to spread breeding over a long lifetime are probably part of the adaptive strategy of this small fulmarine petrel facing highly variable environmental conditions.     

Wuchsform und Organisation vonMonsonia nivea (Geraniaceae) unter besonderer Berücksichtigung der Blattstieldornen

Monsonia nivea is a hemicryptophyte which shows spiny petioles after the loss of leaf blades. Anthocladial inflorescences and their supporting vegetative parts are spineless. Spines are formed only by vigorous rosettes. Similar spiny petioles can be found in all other genera of the tribeGeranieae.

     

Association and path-coefficient studies on vegetatively propagating and sexually reproducing parts in ramie (Boehmeria nivea L. Gaud.)

Summary In 30 genotypes of ramie (Boehmeria nivea L. Gaud.) there were significant genotypic differences in the weight of reproductive parts (male + female flowers), vegetatively propagating parts (clump and rhizome) and non-propagating vegetative parts (leaf and root). The weight of reproductive parts was significantly and positively associated with the weight of vegetatively propagating parts. Path-coefficient analysis revealed that the selection of genotypes with a high weight of reproductive parts should be based on genotypes with a high weight of vegetatively propagating parts.     

Presence of beta-linked GalNAc residues on N-glycans of human thyroglobulin

Hepatic asialoglycoprotein receptor, which may mediate the clearance of circulating thyroglobulin, is known to have a high affinity for GalNAc. Recently, the receptor has been reported to be present also in the thyroid, implicating interaction with thyroglobulin. Here, mammalian thyroglobulins were analyzed for GalNAc termini by Western blotting with GalNAc-recognizing lectins labeled with peroxidase or (125)I. Wistaria floribunda lectin was found to bind human thyroglobulin and, to some extent, bovine, but not porcine thyroglobulin. After desialylation, the lectin bound all of the thyroglobulins tested. The binding was inhibited by competitive inhibitor GalNAc. Peptide N-glycanase treatment of human desialylated thyroglobulin resulted in the complete loss of reactivity with W. floribunda lectin, indicating that the binding sites are exclusively on N-glycans. The binding sites on human desialylated thyroglobulin were partly sensitive to beta-galactosidase, and the remainder was essentially sensitive to beta-N-acetylhexosaminidase. On the other hand, the binding sites of bovine and porcine desialylated thyroglobulins were totally sensitive to beta-galactosidase. Thus the lectin binds beta-Gal termini, as well as beta-GalNAc. GalNAc-specific Dolichos biflorus lectin also bound human thyroglobulin weakly. In contrast to W. floribunda lectin, desialylation diminished binding, suggesting that these two lectins recognize different GalNAc-terminated structures. Again, the binding was inhibited by GalNAc and by treatment with peptide N-glycanase. These results strongly indicate the presence of distinct GalNAc termini of N-glycans on human thyroglobulin.     

Target Host Finding by Steinernema feltiae and Heterorhabditis bacteriophora in the Presence of a Non-Target Insect Host

The ability of Steinernema feltiae or Heterorhabditis bacteriophora infective juveniles (IJ), when applied to the soil surface, to infect a Galleria mellonella larva at the base of a soil-filled cup (276 cm³) was evaluated in the presence and absence of 100 larvae of a non-target insect, the aphid midge Aphidoletes aphidimyza, near the soil surface. In all four trials with either S. feltiae or H. bacteriophora, A. aphidimyza presence did not affect the number of IJ finding and infecting a G. mellonella larva. Steinernema feltiae and H. bacteriophora IJ movement (as measured by the percentage of IJ aggregating on either side of an experimental arena) in the presence of one or many A. aphidimyza larvae was evaluated in agar- and soil-filled petri dishes, respectively. Infective juvenile movement in the presence of A. aphidimyza did not differ from random, indicating that IJ were not attracted to A. aphidimyza. It is suggested, therefore, that A. aphidimyza does not reduce IJ efficacy when these two forms of biological control agent are present together in a field situation even though it is known that A. aphidimyza is susceptible to IJ of these species.     

Structure of the polysaccharide isolated from the sheath of Sphaerotilus natans

A polysaccharide was isolated from the sheath of a sheathed bacterium, Sphaerotilus natans. The sheath polysaccharide (SPS) was composed of D-glucose and D-(N-acetyl)galactosamine in molar ratios of 1:4. Methylation linkage analysis revealed the presence of the residues of 4-linked glucose, 4-linked (N-acetyl)galactosamine, and 3-linked (N-acetyl)galactosamine in molar ratios of 1:3:1. The oligomer of SPS was prepared with an SPS-specific degrading enzyme from a sheath-degrading bacterium, Paenibacillus koleovorans. The oligomer was derivatized and subjected to fast atom bombardment-mass spectrometry to investigate the monosaccharide sequence of SPS. The structure of SPS was confirmed by nuclear magnetic resonance. The resulting data showed that SPS is a straight-chained basic polysaccharide constructed of a pentasaccharide repeating unit.     

2-O-methyl-d-xylose containing sheath in the cyanobacterium Gloeothece sp. PCC 6501

The sheath of the unicellular cyanobacterium Gloeothece sp. PCC 6501 was isolated from cell homogenates by differential and sucrose gradient centrifugation, followed by lysozyme treatment and hot sodium dodecyl sulfate extraction. The sheath contains a major fraction of carbohydrate consisting of galactose, glucose, mannose, rhamnose, 2-O-methyl-d-xylose, xylose, glucuronic and galacturonic acids, but only traces of fatty acids and phosphate. A protein content of about 2% (of fraction dry weight) could not be removed by the detergent treatment.Abbreviation SDS sodium dodecyl sulfate     

Occurrence of a Thiothrix sp. Attached to Mayfly Larvae and Presence of Parasitic Bacteria in the Thiothrix sp

Larvae of the mayfly (Drunella grandis [Eaton]) from Diamond Fork Creek, Utah, were covered with a heavy growth of the sulfide-oxidizing bacterium Thiothrix. The bacterium did not seem to harm the mayfly, but the Thiothrix trichomes were parasitized by three morphologically distinct bacteria, two of which were cytoplasmic and one of which was probably periplasmic. At least two of the parasites destroyed the cytoplasmic contents of the Thiothrix sp., thus killing the host cell. Attempts to obtain the parasites in pure culture were unsuccessful.     

Structural elucidation of a novel fucogalactan that contains 3-O-methyl rhamnose isolated from the fruiting bodies of the fungus, Hericium erinaceus

A new heteropolysaccharide, HEPF3, was isolated from the fruiting bodies of Hericium erinaceus. HEPF3 has a molecular weight of 1.9 x 10(4) Da and is composed of fucose and galactose in a ratio of 1:4.12. Compositional analysis, methylation analysis, together with 1H and 13C NMR spectroscopy established that HEPF3 consists of a branched pentasaccharide repeating unit with the following structure: [structure: see text]. HEPF3 also contains a minor proportion of 3-O-methylrhamnose that is thought to terminate the polymer main chain.     

Biodegradation of Phenanthrene by Pseudomonas putida and a Bacterial Consortium in the Presence and in the Absence of a Surfactant

This study describes the biodegradation of phenanthrene in aqueous media in the presence and in the absence of a surfactant, Brij 30. Biodegradations were performed using either Pseudomonas putida DSMZ 8368 or a bacterial consortium Pyr01 isolated from one PAHs-polluted site. P. putida degraded phenanthrene to form 1-hydroxy-2-naphthoic acid (1H2Na) as the major metabolite. LC–MS analysis revealed the production of complementary intermediates in the presence of Brij 30, showing intense ions at mass-to-charge ratios (m/z) 97 and 195. Higher phenanthrene biodegradation rate was obtained in the presence of Brij 30. Conversely, in the case of Pyr01consortium, the addition of Brij 30 (0.5 g L⁻¹) had a negative effect on biodegradation: no phenanthrene biodegradation products were detected in the medium, whereas a production of several intermediates (m/z 97, 195 and 293) was obtained without surfactant. New results on phenanthrene metabolism by P. putida DSMZ 8368 and Pyr01 consortium in the presence and in the absence of Brij 30 we obtained. They confirm that the knowledge of the effect of a surfactant on bacterial cultures is crucial for the optimization of surfactant-enhanced PAHs biodegradation.

Electronic supplementary material

The online version of this article (doi:10.1007/s12088-012-0265-z) contains supplementary material, which is available to authorized users.     

Purification and structural investigation of a water-soluble polysaccharide from Flammulina velutipes

A novel water-soluble heteropolysaccharide FVP60-B was extracted from the fruiting bodies of Flammulina velutipes with boiling water and purified by Sephacryl S-300 and S-400, which molecular weight was estimated to be 1.3 × 10⁴ Da by HPLC. It is composed of l-fucose, d-mannose, d-glucose and d-galactose in a ratio of 1.16:0.82:1.00:3.08. Sugar analysis, methylation analysis together with ¹H, ¹³C and 2D NMR spectroscopy disclosed that FVP60-B is consisted of a α-(1 → 6)-d-galactopyranan backbone with a terminal fucosyl, terminal glucosyl and α-(1 → 6)-d-mannopyranan units on O-2 of 2,6-O-substituted-d-galactosyl units.     

Cell wall and sheath constituents of the cyanobacterium Gloeobacter violaceus

Sheaths isolated from Gloeobacter violaceus were found to be composed of a major polysaccharide moiety (glucose, galactose, rhamnose, mannose, arabinose), a protein moiety, and negatively charged components (glucuronic acids, phosphate, sulfate). Outer membrane polypeptide patterns were dominated by two major peptidoglycan-associated proteins (M_r 62,000 and 53,000). Lipopolysaccharide constituents were glucosamine, 3-hydroxy fatty acids (3-OH-14:0, anteiso-3-OH-15:0, 3-OH-16:0, 3-OH-18:0), carbohydrates, and phosphate. A1-type peptidoglycan and non-peptidoglycan components (mannosamine, glucose, mannose, and glucosamine) indicated the presence of a peptidoglycan-polysaccharide complex in the cell walls of Gloeobacter violaceus.Abbreviations A₂pm diaminopimelic acid - ATCC American Type Culture Collection - CE cell envelope - CM cytoplasmic membrane - CW cell wall - dOcla 3-deoxy-d-manno-2-octulosonic acid - GalN galactosamine - GlcN glucosamine - GlcUA glucuronic acid - HF hydrofluoric acid - LPS lipopolysaccharide - ManN mannosamine - M relative molecular mass - MurN muramic acid - MurN-6-P muramic acid-6-phosphate - OMe O-methyl - PAGE polyacrylamide gel electrophoresis - PCC Pasteur Culture Collection - SDS sodium dodecyl sulfate - SH sheath