Three dimensional typological studies using scanning electron microscopy for characterization of Termitomyces pellets obtained from submerged growth conditions

There are gaps in existing understanding of fungal pellet growth dynamics. We used scanning electron microscopy (SEM) for morphological characterization of the biomass organization of Termitomyces pellets for seven species: T. microcarpus (TMI1), T. albuminosus (TAL1, TAL2), T. striatus (TSTR), T. aurantiacus (TAUR), T. heimii (THE1, THE2), T. globulus (TGLO) and T. clypeatus (TCL1, TCL2, TCL3, TCL4, TCL5). We assessed the utility of SEM for morphological and structural characterization of Termitomyces spp. in three dimensional (3D) pellet form to identify ideal pellet morphology for industrial use. Typological classification of Termitomyces species was based on furrows, isotropy, total motifs and fractal dimensions. The pellets formed were entangled and exhibited highly compacted mycelial mass with microheterogeneity and microporosity. The mean density of furrows of Termitomyces species was between 10,000 and 11,300 cm/cm², percentage isotropy was 30?80 and total motifs varied from 300 to 2500. TGLO exhibited the highest furrow mean density, 11243 cm/cm², which indicated a compact, cerebroid structure with complex ridges and furrows, whereas TAL2 exhibited the lowest furrow density. TMI1a exhibited a high percentage isotropic value, 74.6, TSTR exhibited the lowest, 30.9. Total motif number also was used as a typological classification parameter. Fractal values were 2.64?2.78 for various submerged conditions of Termitomyces species. TAL1 exhibited the highest fractal dimension and TAL2 the lowest, which indicates the complexity of branching patterns. Three-dimensional SEM image analysis can provide insight into pellet micromorphology and is a powerful tool for exploring topographical details of pellets.     

Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload

We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.     

Exclusion of Protein from High Polymer Media: I. Derivation of Probability Distribution for the Number of Fiber Centers Within Any Sphere of Radius r

Ogston's (1958) fiber model based on Poisson's distribution function gives the average number of fibers making contact and no contact inside a sphere of radius r. The probability of penetration of spherical particles within a fibrous network was derived from the moment generating function [Formula: see text] A is the number of particles that intrude into a sphere of radious r. α(μ) is the probability that a particle, whose center is μ units away from the origin, intrudes into a sphere of radius r. A has a Poisson distribution with a mean value E(A) = 4πνα(μ)μ² dμ. The theoretical derivation of the distribution function of A gives Ogston's fiber model.     

Two new myrmecophytic associations from the Malay Peninsula: Ants of the genusCladomyrma (Formicidae,Camponotinae) as partners ofSaraca thaipingensis (Caesalpiniaceae) andCrypteronia griffithii (Crypteroniaceae)

Summary In Peninsular Malaysia the treesSaraca thaipingensis (Caesalpiniaceae) andCrypteronia griffithii (Crypteroniaceae) are inhabited by ants. In the vicinity of Gombak, near Kuala Lumpur, the hollow internodes of youngSaraca thaipingensis plants are colonized mainly by twoCladomyrma species. In larger trees aCrematogaster sp. is also found.Crypteronia griffithii is inhabited by a third species ofCladomyrma. None of these species is conspecific with any of the threeCladomyrma taxa so far described. The colonies are founded by single mated queens, which have a conspicuous, sphecid wasp-like behaviour when searching for host plants and nest sites. They chew holes into the plant internodes and hollow them out to provide nest sites. Coccids and pseudococcids are cultivated within the internodes. The homopterans are not carried by queens on their nuptial flights. They apparently find their way by themselves into the cavities or are perhaps carried there by the worker ants. TheCladomyrma ants onCrypteronia are not aggressive, in contrast to those onSaraca thaipingensis.The relationship ofCrypteronia with ants seems to be obligatory, whereasSaraca was only partly colonized byCladomyrma. The interaction ofSaraca withCrematogaster sp. is loose and facultative, since theCrematogaster sp. also lives on other three species. Our studies have now revealed fourCladomyrma spp. which are regularly associated with plants. The genus therefore seems to have an entirely myrmecophytic way of life.     

Dual Split Protein-Based Fusion Assay Reveals that Mutations to Herpes Simplex Virus (HSV) Glycoprotein gB Alter the Kinetics of Cell-Cell Fusion Induced by HSV Entry Glycoproteins

Herpes simplex virus (HSV) entry and cell-cell fusion require glycoproteins gD, gH/gL, and gB. We propose that receptor-activated changes to gD cause it to activate gH/gL, which then triggers gB into an active form. We employed a dual split-protein (DSP) assay to monitor the kinetics of HSV glycoprotein-induced cell-cell fusion. This assay measures content mixing between two cells, i.e., fusion, within the same cell population in real time (minutes to hours). Titration experiments suggest that both gD and gH/gL act in a catalytic fashion to trigger gB. In fact, fusion rates are governed by the amount of gB on the cell surface. We then used the DSP assay to focus on mutants in two functional regions (FRs) of gB, FR1 and FR3. FR1 contains the fusion loops (FL1 and FL2), and FR3 encompasses the crown at the trimer top. All FL mutants initiated fusion very slowly, if at all. However, the fusion rates caused by some FL2 mutants increased over time, so that total fusion by 8 h looked much like that of the WT. Two distinct kinetic patterns, “slow and fast,” emerged for mutants in the crown of gB (FR3), again showing differences in initiation and ongoing fusion. Of note are the fusion kinetics of the gB syn mutant (LL871/872AA). Although this mutant was originally included as an ongoing high-rate-of-fusion control, its initiation of fusion is so rapid that it appears to be on a “hair trigger.” Thus, the DSP assay affords a unique way to examine the dynamics of HSV glycoprotein-induced cell fusion.     

Vibrio tetraodonis subsp. pristinus subsp. nov., isolated from the coral Acropora cytherea at Palmyra Atoll,and creation and emended description of Vibrio tetraodonis subsp. tetraodonis subsp. nov

Strain OCN044^T was isolated from the homogenised tissue and mucus of an apparently healthy Acropora cytherea coral fragment collected from the western reef terrace of Palmyra Atoll in the Northern Line Islands and was taxonomically evaluated with a polyphasic approach. The morphological and chemotaxonomic properties are consistent with characteristics of the genus Vibrio: Gram-stain-negative rods, oxidase- and catalase-positive, and motile by means of a polar flagellum. Strain OCN044^T can be differentiated as a novel subspecies based on 21 differences among chemotaxonomic features (e.g., fatty acids percentages for C_12:0 and C_18:1 ω7c), enzymatic activities (e.g., DNase and cystine arylamidase), and carbon sources utilized (e.g., L-xylose and D-melezitose) from its nearest genetic relative. Phylogenetic analysis and genomic comparisons show close evolutionary relatedness to Vibrio tetraodonis A511^T but the overall genomic relatedness indices identify strain OCN044^T as a distinct subspecies. Based on a polyphasic characterisation, differences in genomic and taxonomic data, strain OCN044^T represents a novel subspecies of V. tetraodonis A511^T, for which the name Vibrio tetraodonis subsp. pristinus subsp. nov. is proposed. The type strain is OCN044^T (=?LMG 31895^T?=?DSM 111778^T).

     

An iTRAQ-based quantitative analysis to elaborate the proteomic response of Nostoc sp. PCC 7120 under N2 fixing conditions

Nostoc sp. PCC 7120 is an oxygen-evolving photoautotrophic N2 fixing filamentous cyanobacterium. Upon nitrogen starvation, a range of processes are initiated, such as differentiation of the heterocysts, specific cells where N2 fixation takes place. We have characterized and quantified the proteome of the Nostoc sp. PCC 7120 wild-type strain grown under N2 fixing and non-N2 fixing conditions. To assess global proteome changes in response to environmental changes, measurements were made using the quantitative proteomics tool, iTRAQ, on a whole cell digest. From this approach, a total of 486 different proteins was accurately identified across 2 biological replicate experiments, where 226 identifications contained 2 or more distinct peptides. Results of metabolic regulation will be discussed to demonstrate that proteomics represents an important tool for the development of heterocystous cyanobacteria for future biological H2 production.