Trypsin inhibitor ofStreptomyces griseus grown in a carbon nutrition medium

Streptomyces griseus grown in beef extractpeptone medium produces trypsin inhibitors which are both peptide and protein in nature. When the strain was grown in carbon nutrition medium, only one trypsin inhibitor was obtained. Similar elution patterns of this inhibitor and the TI-3a inhibitor obtained from the beef extract-peptone medium on Sephadex G-15 and ion-exchange columns and also the R_f values indicate that the inhibitors from both the sources are the same. So, TI-3a is not the breakdown product of the protein inhibitor ofS. griseus.     

Characterization of an extracellular glycoprotein inhibitor of trypsin (TI-23) produced by Streptomyces sp. 23

Summary The production of an extracellular trypsin inhibitor, TI-23, was found to parallel the growth of Streptomyces sp. 23 at different cultivation temperatures, reaching a maximum level at late exponential phase. Although the different temperatures (18°, 28° and 37°C) did not greatly affect the growth of the microorganism, they proved to be an important factor for extracellular inhibitory activity. Maximum specific rates of both cell growth and production of the inhibitor were recorded during the cultivation of Streptomyces sp. 23 at 37°C. TI-23 proved to be a monomeric glycoprotein containing 17% carbohydrate and differing in amino acid composition from the known extracellular proteinase inhibitors of streptomycetes. The molecular mass of the inhibitor was estimated to be about 13 kDa and the isoelectric point 4.3. The inhibition spectrum of TI-23 included trypsin as well as some microbial alkaline proteinases.     

Synthesis of phosphites and phosphates of neuraminic acid and their glycosyl donor properties — convenient synthesis of GM3

The importance and requirements for catalytic activation of sialyl donors are discussed, leading to the acid sensitive phosphite and phosphate moiety, respectively, as leaving group and nitriles as solvent. Therefore, from readily availableN-acetylneuraminic acid, derivative1 with phosphochloridites2a-f and Huenigs' base sialyl phosphites3a-f were prepared and isolated in high yields. Oxidation of3a, c withtert-butyl-hydroperoxide afforded the corresponding phosphates4a, c. As expected, phosphites3 could be activated in acetonitrile by catalytic amounts of TMSOTf; thus, from3a-e as donors and lactose derivatives8A, B as acceptors the ganglioside building blocks9A and9B, respectively, were obtained in good yields. The best results were obtained with diethyl phosphite derivative3a as sialyl donor, which exceeded by far the reults obtained with the corresponding phosphate derivative4a. Trisaccharide9B was transformed into known9A and into the fullyO-acetylated GM₃-trisaccharide10.     

Functional evidence for abnormal maturation within a B-cell subpopulation of NZB mice

NZB mice develop a systemic autoimmune disease and have a subpopulation of B lymphocytes that spontaneously produce excessive amounts of IgM. These abnormal B cells reside within a specific B-cell subset that is affected by the CBA/N defect. In normal mice, this B-cell subset acquires in vitro responsiveness to certain thymus-independent antigens (TI-2) relatively late in ontogeny. We compared the functional development of neonatal B cells from NZB mice to that of normal mice of the same H-2 type. The acquisition of in vitro responsiveness to the TI-1 antigen, TNP-LPS and the TI-2 antigens, TNP-Dextran, TNP-Ficoll, and FITC-Ficoll was examined. TNP-LPS could elicit a response from both normal and NZB neonates. In contrast, responses to the TI-2 antigens were elicited early in life (<1 week) only from or at a higher level from NZB neonates. However, an accelerated appearance of B-cell differentiation antigens was not detected in NZB neonates compared to normal strains. We conclude, therefore, that a maturation or triggering defect occurs in a small B-cell subpopulation of NZB mice very early in life.     

Inheritance of powdery mildew (Erysiphe polygoni DC) resistance in mungbean (Vigna radiata L. Wilczek)

Detached mungbean (Vigna radiata L.Wilczek) leaves were inoculated with a conidial suspension of a local isolate (TI-1) of the powdery mildew pathogen (Erysiphe polygoni DC) under controlled environment conditions. Based on the latent period and severity of the infection, a rating scale of 0–5 was used to classify the host pathogen interactions. Reactions 0, 1 and 2 were considered resistant and referred to as R0, R1 and R2 while 3, 4 and 5 were classified as susceptible (S). RUM lines (resistant to powdery mildew) and their derivatives are crossed with several susceptible (reaction types 3–5) genotypes and the inheritance of the resistance was studied in the F₁, F₂ and F₃ generations. The results showed that powdery mildew resistance in mungbean is governed by two dominant genes designated as Pm-1 and Pm-2. When both Pm-1 and Pm-2 were present, an R0 reaction was observed after inoculation with TI-1. The resistant reaction was R1 when only Pm-1 was present and R2 in the presence of Pm-2. In the absence of both Pm-1 and Pm-2, susceptible reactions 3, 4 and 5 were observed.     

Effects of nitrogen supply and irradiance on growth and nitrogen status in the moss Dicranum majus from differently polluted areas

Abstract

A growth experiment was undertaken to study the effects of nitrogen supply and irradiance on growth and nitrogen status in the moss Dicranum majus Sm. from two areas receiving different amounts of atmospheric nitrogen deposition. Intact samples of D. majus carpets were taken from two Picea abies forests, one located in southern Norway (high-N site) and the other in central Norway (low-N site). The moss carpets were grown for 120 days at three irradiance levels (PPFD: 20,40 or 80 μmol m^?2 s^?l) and sprayed daily with equal amounts of a nutrient solution containing 30, 180 or 330 μM nitrogen as NO₃ - and NH₄ +. Concentrations and total amounts of nitrogen, soluble proteins and chlorophyll were highest in moss plants from the high-N site, both at the start and the end of the experiment. The elongation growth was highest at the lowest irradiance level. As total biomass production did not differ between nitrogen and light treatments, moss growth was presumably limited by other factors, even at the lowest supply rates. Concentrations and total amounts of nitrogen increased with increasing nitrogen supply in moss plants from both sites. Accumulated nitrogen was partly stored as protein and chlorophyll. Recycling of nitrogen from old to young tissues is discussed as a possible explanation for the rather low nitrogen demand in D. majus and the persistently higher nitrogen contents in moss plants from the high-N site.     

Arsenate phytoextraction abilities of one-year-old tree species and its effects on the nutritional element content in plant organs

Abstract

The aim of the study was to evaluate the As phytoextraction potential of four tree species: Acer pseudoplatanus L., Betula pendula Roth., Quercus robur L., and Ulmus laevis Pall. in light of their prospective use in the phytoremediation of arsenate [As(V)] contaminated soils. The content of nutritional elements: B, Ca, K, Mg, Na, Si, P, and S was also analyzed. The trees were grown for 1?month in hydroponic cultures (Knop medium) supplemented with As(V), (1?mM). The results showed that the highest As accumulation efficiency was characterized by B. pendula (BCF = 0.87) and Q. robur (BCF = 0.5). Betula pendula accumulated about 80% of As in its roots (TF = 0.22) whereas Q. robur accumulated more than 60% of As in its shoots (TF = 1.60). The other tree species accumulated significantly lower amounts of As, more than 60% of which collected in their shoots. As(V) phytoextraction led to a significantly lower level of P and S in the roots of all tested tree species. Betula pendula seems promising for phytostabilisation and Q. robur for phytoextraction of As(V) from contaminated soils. The obtained results confirm the accumulation and translocation of As(V), as well as the acquisition of nutritional elements by the selected tree species.     

Growth and Differentiation of Trypanosoma cruzi Cultivated with a Triatoma infestans Embryo Cell Line*

SYNOPSIS. Trypanosoma cruzi strain Peru was cultivated in the presence of an established cell line of Triatoma infestans embryo cells (TI-32). Bloodstream trypomastigotes differentiated into amastigote-like cells (first differentiation phase) which multiplied to form large clusters of cells. Because of their clustering nature, a new term, “staphylomastigotes,” has been proposed for this stage. After 10 days of cultivation, 90% of the staphylomastigotes underwent differentiation (2nd differentiation phase) to trypomastigotes (?98%) or epimastigotes (?2%). Bloodstream trypomastigotes cultivated without TI-32 cells underwent the first, but not the 2nd differentiation phase, although occasional epimastigotes were seen (< 1%). The evidence presented suggests that TI-32 cells produce a labile factor(s) important not only for initiation of the 2nd differentiation phase but also for maintaining the parasites in the trypomastigote stage. The pH of the culture medium was not the initiating factor for the 2nd differentiation phase. Infectivity studies indicated that staphylomastigotes were as infective as bloodstream trypomastigotes, but that metacyclic trypomastigotes isolated from culture after the 2nd differentiation phase were slightly more infective than bloodstream forms. Electromicrographs of styphylomastigotes do not provide any evidence of exchange of genetic material between cells.     

A CHARMm Based Force Field for Carbohydrates Using the CHEAT Approach: Carbohydrate Hydroxyl Groups Represented by Extended Atoms

Abstract

Computational studies of carbohydrates that do not consider explicit solvent molecules suffer from the strong tendency of the carbohydrate pendant hydroxyl groups to form intramolecular hydrogen bonds that are unlikely to be present in protic media. In this paper a novel approach towards molecular modelling of carbohydrates is described. The average effect of intra- and intermolecular hydrogen bonding is introduced into the potential energy function by adding a new (extended) atom type representing a carbohydrate hydroxyl group to the CHARMm force field; we coin the name CHEAT (Carbohydrate Hydroxyls represented by Extended AToms) for the resulting force field. As a training set for the parametrisation of CHEAT we used ethylene glycol, 10 cyclohexanols, 5 inositols, and 12 glycopyranoses for which in total 64 conformational energy differences were estimated using a set of steric interaction energies between hydroxyl and/or methyl groups on six-membered ring compounds as derived by Angyal (Angew. Chem., 8, 172-182, (1969)). The root-mean-square deviation between the estimated energy differences and the corresponding values obtained by our CHEAT approach amounts to 0.37 kcal/mol (n = 64). The CHEAT approach, which is claimed to calculate aqueous state compatible energetical and conformational properties of carbohydrates, is computationally very efficient and facilitates the calculation of nanosecond range MD trajectories as well as systematic conformational searches of oligosaccharides.     

La distribuzione dell'acido l-ascorbico nelle foglie di piante officinali italiane. Aspetti quantitativi e tassonomici

Abstract

Distribution of l-ascorbic acid in leaves of Italian officinal plants. Quantitative and taxonomic aspects.—Fresh samples of 119 Italian officinal plants belonging to 41 families of Angiosperme were assayed for l-ascorbic acid content.

Estimation of data as reported by Seybold and Mehner indicates that relatively high contents are generally found among the Rosaceae, while low amounts are usual within Asteraceae. However, species with leaves rich in l-ascorbic acid may be found at widely different places of the taxonomic system.

Since the vitamin C is widespread in the plant kingdom it has been recommended the indication of the exact amount of vitamin C when a plant is reported as antiscorbutic.

Finally the knowledge of families whose species more frequently show large amounts of vitamin C may facilitate researches of edible wild plants with high content of vitamin C.     

Biomonitoring of heavy metals in the coastal waters of two industrialised bays in southern Spain using the barnacle Balanus amphitrite

Abstract

This paper evaluates the bioavailability of As, Cd, Cu, Mn, Hg, Ni and Zn in the coastal waters of the two most important bays in southern Spain (Cádiz and Algeciras). Concentrations of these metals were measured in the bodies of Balanus amphitrite barnacles in 2005 and 2006. Seawater samples were collected from the same sites as the barnacles to assess metal concentrations and to gain additional information on the environmental conditions. Analysis of variance (ANOVA) showed significant geographic differences in the local bioavailability of metals to the barnacles, as reflected in the concentrations of accumulated metals. Balanus amphitrite accumulates large amounts of metals, with high concentration factors for Zn, Cd, Cu and Mn, in relation to the concentrations in marine waters.     

Stimulation of the Biosynthesis of the Antibiotics Lambertellols by the Mycoparasitic Fungus Lambertella corni-maris under the Acidic Conditions Produced by Its Host Fungus in Vitro

The filamentous fungus, Lambertella corni-maris (L. corni-maris), a mycoparasite on Monilinia fructigena, produces the antibiotics, lambertellols A (1), B (2), and lambertellin (3), in a substantial amounts under acidic conditions, whereas these antibiotics were hardly detected when the fungus was cultured on a potato-sucrose (PS) medium without added acids. Our investigations also revealed that the host, M. fructigena, changed its surroundings into acidic conditions, suggesting that the acidic conditions acted as kairomones that stimulated the production of 1–3.     

Tolerance of Landoltia punctata to arsenate: an evaluation of the potential use in phytoremediation programs

Abstract

Plants used in phytoremediation should accumulate and tolerate a specific pollutant. Here, we aimed at evaluating a possible arsenic (As) accumulation and mechanisms of tolerance against As-induced damage in Landoltia punctata to explore this species for phytoremediation. Plants were subjected to increasing As levels. As absorption was higher with increasing As levels. The activity of superoxide dismutase and glutathione reductase as well as anthocyanin levels increased with As levels. Catalase and peroxidase activities increased in plants subjected to As levels up to 1.0?mg L^?1 and decreased at higher levels. Due to the antioxidant system, higher levels of reactive oxygen species were restrained in plants under low levels of As. However, the levels of superoxide anion, hydrogen peroxide, and lipid peroxidation increased in response to the impaired antioxidant system induced by the highest As levels. Biomass decreased in plants exposed to As and scanning electron microscopy revealed root structural damage in the root cap of plants under 3.0?mg L^?1?As. This work highlights that L. punctata can be considered a hyperaccumulator species and has potential for As phytoremediation when levels are lower than 1.0?mg L^?1—a concentration 100-fold higher than that recommended for drinking water.

Novelty Statement: Landoltia punctata can be considered a hyperaccumulator species and has the potential for arsenic phytoremediation when levels are lower than 1.0?mg L^?1.     

Novel vaccine strategies to T-independent antigens

T cell independent antigens do not require T cell help to induce an immune response, and are characterized by a lack of immunologic memory. These antigens can be divided into two classes, TI-1 or TI-2. TI-1 antigens, such as bacterial lipopolysaccharide, are potent B-cell mitogens, capable of non-specific, polyclonal activation of B cells. In contrast, TI-2 antigens can only activate mature B cells and consist of highly repetitive structures, such as capsular polysaccharides (CPS) from bacteria. Many vaccines currently in use consist of purified capsular polysaccharides from pathogenic bacteria such as Streptococcus pneumoniae and Neisseria meningitidis. These vaccines are efficacious in immune-competent adults, however, due to their TI-2 nature, are not effective in children <2 years of age. Converting polysaccharides into T cell dependent (TD) antigens, allows children, <2, to produce an effective immune response. This review focuses on various strategies used to convert the immune response to polysaccharide antigens from TI-2 to a TD response. Conjugate vaccines, anti-idiotypic antibodies, phage display library technology and DNA vaccines are discussed.     

Endophytic and rhizospheric enterobacteria isolated from sugar cane have different potentials for producing plant growth-promoting substances

Background and aims

Endophytic and rhizospheric environments differ in many respects, leading to the presence of different bacterial communities at each site. However, microorganisms such as enterobacteria can be found both within plants and in the surrounding soil. Bacteria must present differences in the traits that affect such environments in order to successfully colonise them. The present study compared the plant growth-promoting potential of diazotrophic enterobacteria isolated from the rhizosphere and from within surface-disinfected plants.

Methods

A total of 46 diazotrophic enterobacterial strains (21 rhizospheric and 25 putatively endophytic) belonging to the Klebsiella and Enterobacter genera, which are prevalent in sugar cane plantations, were isolated from the rhizosphere and from surface-disinfected plants. Their ability to synthesise amino acids using combined nitrogen obtained from nitrogen fixation, and their ability to synthesise indole-3-acetic acid (IAA) were determined by high performance liquid chromatography. Endogenous ethylene production by the bacteria was measured using gas chromatography, and biocontrol of phytopathogenic fungi was determined qualitatively using a dual culture technique.

Results

The putative endophytes released significantly higher amounts of amino acids than the rhizospheric bacteria, whilst the latter produced higher quantities of ethylene and were more actively antagonistic to fungi. Both types of bacteria released similar amounts of IAA.

Conclusion

Endophytic and rhizospheric bacteria differ in their capacity to release plant growth-promoting substances, which may be a reflection of their adaptations and an indication of their potential impact on their natural environment.

     

Food preferences of Shorelarks Eremophila alpestris,Snow Buntings Plectrophenax nivalis and Twites Carduelis flavirostris wintering in the Wadden Sea

Capsule Seeds of plants from lower salt marsh communities are preferred, with insects less important.

Methods Droppings of Shorelarks Eremophila alpestris, Snow Buntings Plectrophenax nivalis and Twites Carduelis flavirostris sampled in the German Wadden Sea were analysed and compared with food abundance to assess preferences.

Results Shorelarks prefer seeds of Salicornia sp., Suaeda maritima, Atriplex sp., Halimione portulacoides and unidentified small grass seeds. Insects are eaten mainly in periods of seed shortage, but are consumed in smaller amounts during the winter. The food composition of Snow Buntings is very similar, but additionally Triglochin maritimum is commonly eaten. Twites are specialized on seeds of Salicornia sp. and Suaeda maritima and rarely ingest other seeds and insects. All seeds consumed were of plants from lower salt marsh communities. Many halophyte seeds, and especially those that birds feed on, are rich in energy. Large seeds and those which need a long handling time are avoided.

Conclusion Changes in the lower salt marshes of the Wadden Sea by embankments and intensified grazing might have been responsible for the rapid population decline from the 1960s to 1980s.     

Benzoquinones of the Beetles,Tribolium Castaneum Tribolium Confusum

Abstract

Tribolium castaneum T. confusum were washed in HPLC-grade methanol, and the methanolic washes were analyzed by UV spectroscopy, reversed phase HPLC, and GC/MS. The methanolic washes from both species contained methyl-1,4-benzoquinone (MBQ) and ethyl-1,4-benzoquinone (EBQ). The amounts of MBQ recovered from the two species were not significantly different, but the amounts of EBQ and total benzoquinones (MBQ + EBQ) recovered from T. castaneum were significantly greater than for those recovered from T. confusum. The methods described are superior to previous methods for isolating, identifying, and quantifying the benzoquinones in these beetles, since they are relatively simple, fast, do not require handling of the beetles, and are sensitive enough to quantify the benzoquinones of a single beetle.     

A Whole-Plant Microtiter Plate Assay for Drought Stress Tolerance-Inducing Effects

The frequency and intensity of extreme weather events and global temperature are rising, which poses a potential threat to life, specifically crops, and therefore food and bioenergy supply. Reduced water availability has the most severe impact on potential grain yield. Negative effects of transient drought stress (dry spells) can be countered by drought tolerance-inducing chemicals. In search for useful compounds, biochemical assays are fast but limited in scope, whereas whole-plant assays are slow, require large amounts of compounds, and are usually not concentration-related. Here we report the development of a fast, concentration-dependent whole-plant assay using the fast growing duckweed Lemna minor L. 4-Amino-1,8-naphthalimide (1) and the imidacloprid metabolite 6-chloronicotinic acid (2) were affirmed as drought stress tolerance enhancers. Both also reduce oxidative stress-induced cell death in Arabidopsis thaliana (L.) Heynh. cell suspension culture but show differences in their mode of action.     

A Convenient Synthesis of D-Psicofuranosyl Nucleosides1

Abstract

As part of our studies on the synthesis of conformationally restricted nucleosides of types 1 and 2, where X = CH₂, O or S, we required access to differentially substituted D-psicofuranosyl nucleosides such as 3. As shown in the table, we have developed a convenient approach to such compounds that depends on the direct condensation of the 1,2:3,4-di-O-isopropylidene-β-D-psicofuranose derivative 4 with an appropriate silylated purine or pyrimidine base.² Although the α and β anomers of 3 are formed in a 1:1 ratio, the yields of the β anomers are generally comparable with earlier condensation methods that use psicofuranosyl- halide², 2-benzoates⁴ or 2-nitro derivative⁵. However, the present method has the advantage that the starting sugar 4 is more readily accessible. The precursor 6′-alcohol can be prepared in very large amounts from D-fructose using the method of Prisbe et al.⁴     

Speciation of trace element compounds in samples of biota from marine ecosystems

Abstract

The toxicity, mobility, bioavailability and bioaccumulation of metals are dependent on the particular physico-chemical form in which the element occurs in the environment. Special attention has been paid to metals which are essential for the proper functioning of organisms if present in appropriate amounts but are toxic if in excess (i.e. Se, Cr), and also to non-essential elements (i.e. Hg, Pb, Cd, Sn and As). To assess the potential hazard to the health of marine organisms, qualitative and quantitative analyses of metal species accumulating along the food chain needs to be carried out. This paper reviews the available information on the speciation of trace elements in the food chain in marine ecosystems and the analytical tools used for acquiring reliable information in this field. Advantages and limitations of commonly used techniques indicate that all metal species in different samples need diverse extraction, separation and detection conditions. Although not recommending which procedure is the most suitable to determine a given compound, speciation analysis has the potential to be a powerful tool for the identification of trace element species in biological samples.