Purification and characterisation of the cardenolide-specificβ-glucohydrolase CGH II from Digitalis lanata leaves

A cardenolide-hydrolysing β-D-glucosidase was isolated from young leaves of Digitalis lanata. Since this enzyme differs from the cardenolide glucohydrolase (CGH) described and characterised previously, it was termed cardenolide glucohydrolase II (CGH II). CGH II was detected in various Digitalis tissue cultures as well as in young leaves of D. lanata. The latter source was used as the starting material for the isolation and purification of CGH II. The specific enzyme activity reached about 15 pkat·mg^–1 protein in buffered leaf extracts. Optimal CGH II activity was seen at around pH 6.0 and 50 °C. CGH II was purified about 600-fold by anion exchange chromatography, size exclusion chromatography and hydroxyapatite chromatography. The apparent molecular mass of CGH II was 65 kDa as determined by SDS-PAGE. CGH II exhibited a high substrate specificity towards cardenolide disaccharides, especially to those with a 1-4-β-linked glucose-digitoxose moiety such as glucoevatromonoside. The K_m- and V_max-values for this particular substrate were calculated to be 101 μM and 19.8 nkat·mg^–1 protein, respectively.     

Elevated spring temperature stimulates growth, but not smolt development, in anadromous Arctic charr

Parr–smolt transformation and growth were studied in captive offspring of anadromous Arctic charr (Salvelinus alpinus) from the Hals watercourse in northern Norway (70°N), held either at a natural temperature (< 1 °C until May) or at a temperature elevated to 6 °C in late March. In mid-May, 5 weeks after the increase in photoperiod from 8:16 h light:dark to continuous light, gill Na⁺, K⁺-ATPase activity started to increase in both temperature groups, concurrent with the final development of full seawater tolerance. Temperature had no effect on the development of gill Na⁺, K⁺-ATPase activity, or on hypoosmoregulatory ability. The fish in both treatments resumed growth in mid-May, but from then on growth was faster in the elevated than in the ambient temperature group. In the former group, fish mass doubled in 6 weeks (from 65 to 137 g), and growth ceased at the time when the fish were about to complete their parr–smolt transformation. These findings show that an early vernal temperature increase advances the seasonal growth cycle, but not the parr–smolt transformation, in anadromous Arctic charr.     

Synthesis, structural analysis and anticonvulsant activity of a ternary Cu(II) mononuclear complex containing 1,10-phenanthroline and the leading antiepileptic drug valproic acid

The synthesis and characterization of the binary complex of copper(II) with the antiepileptic drug valproic acid sodium salt (Valp) and the related ternary complex with 1,10-phenanthroline (phen) are reported, as well as the anticonvulsant properties of the latter. The characterization was carried out by means of elemental analyses, infrared (IR), UV–visible (UV–vis) spectrophotometry and Electron Paramagnetic Resonance (EPR). The X-ray crystal structure of the mononuclear complex bis(2-propylpentanoate)(1,10-phenanthroline)copper(II) [Cu(Valp)₂phen] is showed for the first time. It crystallized in C2/c space group with unit cell dimensions of a = 14.939(1) Å, b = 19.280(1) Å, c = 9.726(1) Å, β = 97.27(2)°, V = 2778.8(4) Å ³ and Z = 8. The carboxylates bond in an asymmetric chelating mode and the copper atom adopts a highly distorted octahedral coordination, characterized by the sum of the angles of 365.9° around Cu(II) and its nearest atoms in the CuN₂O₂ + O₂ chromophore instead of the expected 360° for a basal square planar geometry found in most Cu(II) complexes. Molecules assemble three by three through slipped π–π stacking of the aromatic phen with respectively 3.519 and 3.527 Å distances, in a head-to-tail arrangement. Studies of the anticonvulsant properties of this bioligand chelate evidenced its lack of efficacy in preventing MES-induced seizures. Interestingly, complex 4 protected mice against the Minimal Clonic seizures at doses that do not cause Rotorod toxicity, with an ED₅₀ documenting very potent anticonvulsant activity in this model of seizure, a particularly useful pharmacological profile of activity for the treatment of Petit Mal seizures.     

Anatomical basis of the change in leaf mass per area and nitrogen investment with relative irradiance within the canopy of eight temperate tree species

Changes in leaf mass per area (LMA), nitrogen content on a mass-basis (N_m) and on an area basis (N_a) with relative irradiance were assessed in leaves of eight temperate species harvested at different depths in a canopy. Relative irradiance (GSF) at the points of leaf sampling was estimated by hemispheric photographs. There was a strong species-dependent positive relationship between LMA and GSF for all species. Shade-tolerant species such as Fagus sylvatica showed lower LMA for the same GSF than less tolerant species as Quercus pyrenaica or Quercus petraea. The only evergreen species in the study, Ilex aquifollium, had the highest LMA, independent of light environment, with minimum values much higher than the rest of the broad-leaved species studied. There was no relation between N_m and GSF for most species studied and only a very weak relation for the relative shade-intolerant species Q. pyrenaica. Within each species, the pattern of N_a investment with regard to GSF was linked mainly to LMA. At the same relative irradiance, differences in N_a among species were conditioned both by the LMA–GSF relationship and by the species N_m value. The lowest N_m value was measured in I. aquifollium (14.3 ± 0.6 mg g^–1); intermediate values in Crataegus monogyna (16.9 ± 0.6 mg g^–1) and Prunus avium (19.1 ± 0.6 mg g^–1) and higher values, all in a narrow range (21.3 ± 0.6 to 23 ± 0.6 mg g^–1), were measured for the other five species. Changes in LMA with the relative irradiance were linked both to lamina thickness (LT) and to palisade/spongy parenchyma ratio (PP/SP). In the second case, the LMA changes may be related to an increase in lamina density as palisade parenchyma involves higher cell packing than spongy parenchyma. However, since PP/SP ratio showed a weak species-specific relationship with LMA, the increase in LT should be the main cause of LMA variation.     

Optical and EPR characterizations of oxygen-evolving Photosystem II subchloroplast fragments isolated from the thermophilic blue-green alga Phormidium laminosum

An oxygen-evolving, Photosystem II particle was isolated from the thermophilic, blue-green alga, Phormidium laminosum, according to the procedure of Stewart and Bendall (Stewart, A.C. and Bendall, D. (1979) FEBS Lett. 107, 308–312). Our particle has an oxygen-evolution activity of 1500–1600 μmol O₂/mg chlorophyll per h. The oxygen-evolution activity has a pH optimum at 5–6, and is abolished at pH 9. Maximum oxygen evolution occurs at approx. 47°C in whole cells, but at 29°C in the particles. The activity decreases to 50% when the cells are heated for 30 min at 55°C; with the particles, 50% inactivation occurred at 47°C for the same heating time of 30 min. Flash excitation of the particle at 100 K produced absorbance changes whose difference spectrum in the ultraviolet-to-near infrared region shows photochemical charge separation and recombination of P-680⁺ and Q⁻ in the dark with of 1.75 ms. An EPR spectrum for the P-680⁺ free radical, with g 2.0027 and ΔH_pp = 8 G, was constructed from flash-induced EPR changes under conditions identical to those used for obtaining P-680 absorbance changes. The actinic light-induced variable fluorescence yield is 5-fold that induced by the weak probing beam alone. Addition of dithionite to the particle brings the fluorescence to the same maximum level. Under the reducing condition, strong actinic light caused the fluorescence to decrease. This observation is consistent with the notion that variable fluorescence yield in Photosystem II originates, as in green-plant chloroplasts, from recombination luminescence, the attenuation of which corresponds to photoaccumulation of reduced pheophytin under these conditions. Broad segments (300 nm) of the difference spectrum for pheophytin photoreduction were recorded by an intensified photodiode array in conjunction with a phosphoroscopic photometer. Kinetic spectrophotometric assays together with chemical analysis showed a rather clean and simple stoichiometry in these particles, namely, 1 P-680:1 Ph:1 Q:4 Mn:44 Chl. Initial investigation failed to reveal the doublet EPR spectrum previously observed for Ph⁻·Q⁻ Fe in spinach subchloroplast particles (Klimov, V.V., Dolan, E. and Ke, B. (1980). FEBS Lett. 118, 97–100). A hyperfine EPR spectrum consisting of 16–20 lines and presumably associated with the manganese clusters in the oxygen-evolving protein has been confirmed in these particles. Tris washing but not washing with EDTA eliminates this signal. Active oxygen-evolving particles also yield the II_vf signal with a of approx. 800 μs. Upon Tris washing, the II_f signal appears which decays in 23.5 ms.     

Clean conversion of cellulose into fermentable glucose

We studied the process of conversion of microcrystalline-cellulose into fermentable glucose in the formic acid reaction system using cross polarization/magic angle spinning ¹³C-nuclear magnetic resonance, X-ray diffraction and Fourier transform infrared spectroscopy. The results indicated that formic acid as an active agent was able to effectively penetrate into the interior space of the cellulose molecules, thus collapsing the rigid crystalline structure and allowing hydrolysis to occur easily in the amorphous zone as well as in the crystalline zone. The microcrystalline-cellulose was hydrolyzed using formic acid and 4% hydrochloric acid under mild conditions. The effects of hydrochloric acid concentration, the ratio of solid to liquid, temperature (55–75 °C) and retention time (0–9 h), and the concentration of glucose were analyzed. The hydrolysis velocities of microcrystalline-cellulose were 6.14 × 10^− 3 h^− 1 at 55 °C, 2.94 × 10^− 2 h^− 1 at 65 °C, and 6.84 × 10^− 2 h^− 1 at 75 °C. The degradation velocities of glucose were 0.01 h^− 1 at 55 °C, 0.14 h^− 1 at 65 °C, 0.34 h^− 1 at 75 °C. The activation energy of microcrystalline-cellulose hydrolysis was 105.61 kJ/mol, and the activation energy of glucose degradation was 131.37 kJ/mol.     

Storage reserve mobilization during low temperature germination and early seedling growth in Brassica napus

In western Canada, oilseed rape (Brassica napus L. var. oleifera cv. Westar) is seeded during the early months of spring, when ambient temperatures are well below the optimum. This can result in poor seedling emergence. The objectives of the present study were to determine which developmental stages are sensitive to low temperature and whether the effects are thermal or developmental in nature. Seed was germinated at 22, 10 and 6 °C. Fresh weight changes and seedling growth were assessed on the basis of equal accumulated heat units, and the mobilization of storage reserves was assessed by employing antibodies against isocitrate lyase (ICL; EC 4.1.3.1), oleosin and cruciferin. Additionally, de novo protein synthesis was determined by quantifying the incorporation of methionine via in vivo labelling. Low temperature resulted in poor germination and early seedling growth with phase II of germination being most sensitive. At 10 °C, there was a temporal delay in germination that did not affect the overall success of germination. This was a thermal effect as seed at the lower temperatures required the equivalent of 16–24 degree days before germination occurred. Also, seedling growth at 10 °C was lower in comparison to seedlings grown at 22 °C. Seed at 6 °C displayed slow and incomplete germination and poor seedling growth as a result of both thermal and developmental effects.     

Molecular cloning and characterization of Mn-superoxide dismutase from disk abalone (Haliotis discus discus)

The mitochondrial enzyme manganese superoxide dismutase (mitMn-SOD) is one of the antioxidant enzymes involved in cellular defense against oxidative stress and catalyzes the conversion of O₂⁻ into the stabler H₂O₂. In this study, a putative gene encoding Mn-SOD from disk abalone (Haliotis discus discus, aMn-SOD) was cloned, sequenced, expressed in Escherichia coli K12(TB1) and the protein was purified using pMAL protein purification system. Sequencing resulted ORF of 681 bp, which corresponded to 226 amino acids. The protein was expressed in soluble form with molecular weight of 68 kDa including maltose binding protein and pI value of 6.5. The fusion protein had 2781 U/mg activity. The optimum temperature of the enzyme was 37 °C and it was active in a range of acidic pH (from 3.5 to 6.5). The enzyme activity was reduced to 50% at 50 °C and completely heat inactivated at 80 °C. The alignment of aMn-SOD amino acid sequence with Mn-SODs available in NCBI revealed that the enzyme is conserved among animals with higher than 30% identity. In comparison with human mitMn-SOD, all manganese-binding sites are also conserved in aMn-SOD (H28, H100, D185 and H189). aMn-SOD amino acid sequence was closer to that of Biomphalaria glabrata in phylogenetic analysis.     

Using a chelate-buffered nutrient solution to establish the critical solution activity of Mn2+ required by barley (Hordeum vulgare L.)

Relatively little is known about the responses of plants to micronutrients when these nutrients are maintained at the very low levels found in soils of low fertility. We have determined the requirement of barley (Hordeum vulgare L. cv Herta) for ionic Mn²⁺ in plant culture solutions using the chelating agent HEDTA as a buffer for micronutrient metal ions. The chemical activity of Mn²⁺ was varied approximately 10,000-fold from log(Mn²⁺)=–10.8 to –6.8 (pMn 10.8 to pMn 6.8), while holding constant the activities of the other micronutrient cations. Growth, appearance, and composition of Herta barley indicated that log(Mn²⁺) of approximately –8.3 would permit optimal dry matter production and normal plant development. The specific accumulation rate of Mn by 15 to 23 day old seedlings was a linear function of the Mn²⁺ activity in solution. At log(Mn²⁺) of about –9.8 or below, barley seedlings were unable to accumulate significant amounts of Mn, and at some harvests, suffered a net loss of Mn to solution. Seedlings younger than 11 days old were ineffective accumulators of several cations, including Mn, Fe, Zn, Cu, Mg, and Ca. Differences in Mn availability did not influence uptake of other cations, except that Cu uptake by roots increased with increasing Mn uptake.Abbreviations MES 2-(N-morpholino)-ethanesulphonic acid - HEDTA N-(2-hydroxyethyl)ethylene-dinitrilotriacetic acid - DTPA diethylenetrinitrilopentaacetic acid     

Biosorption of acid violet dye from aqueous solutions using native biomass of a new isolate of Penicillium sp.

Laboratory investigation of the potential use of Penicillium sp. as biosorbent for the removal of acid violet dye from aqueous solution was studied with respect to pH, temperature, biosorbent, initial dye concentrations. Penicillium sp. decolourizes acid violet (30 mg l⁻¹) within 12 h agitation of 150 rpm at pH 5.7 and temperature of 35 °C. The pellets exhibited a high dye adsorption capacity (5.88 mg g⁻¹) for acid violet dye over a pH range (4–9); the maximum adsorption was obtained at pH 5.7. The increase of temperature favored biosorption for acid violet, but the optimum temperature was 35 °C. Adsorption kinetic data were tested using pseudo-first-order, pseudo-second-order and kinetic studies showed that the biosorption process follows pseudo-first-order rate kinetics with an average rate constant of 0.312 min⁻¹. Isotherm experiments were conducted to determine the sorbent–desorption behavior of examined dye from aqueous solutions using Langmuir and Freundlich equations. Langmuir parameter indicated a maximum adsorption capacity of 4.32 mg g⁻¹ for acid violet and R_L value of 0.377. Linear plot of log q_e vs log C_e shows that applicability of Freundlich adsorption isotherm model. These results suggest that this fungus can be used in biotreatment process as biosorbent for acid dyes.     

Antagonism of Aeromonas hydrophila by propolis and its effect on the performance of Nile tilapia, Oreochromis niloticus

Propolis, a resinous substance collected by Apis mellifera bees from various plant sources and mixed with secreted beeswax, is a multifunctional material used by bees in the construction, maintenance, and protection of their hives. The collected propolis sample, from High Egypt, was dark-green with olive-odor. The minimal inhibition concentration (MIC) of propolis-ethanolic-extract, against Aeromonas hydrophila, was 80 μg Propolis-ethanolic-extract and crude propolis (1%) were added to artificial basal diet with (30% crude protein) to evaluate their efficacy on the fish growth-performance, immunostimulation and resistance to A. hydrophila. Two hundred and twenty-five Oreochromis niloticus (8 ± 0.45 g/fish) were divided into three equal treatments (T) of triplet replicates. The fish of T₁ were fed on basal diet (control). The fish of T₂ were given the basal diet, containing propolis-ethanolic-extract. The fish of T₃ were given the basal diet containing crude propolis for 28 day. The fish were intraperitoneally challenged by A. hydrophila (0.2 × 10⁷ cells ml⁻¹) at the end of the feeding period and kept for 15 more days.The best growth rate and feed conversion ratio were obtained with T_2. The increase in the average daily gain, specific growth rate and feed efficiency ratio were highly significances in T₂ followed by T₃ when compared with the control group. The HCT-level and monocyte-counts were increased (T₂). No significant change, in the large lymphocytic-count was found among the three treatments (28–27–28%), while the neutrophil-count was significantly decreased (7%) with T₂ and increased (13.11%) with the control. A significant increase in serum lysozyme and serum bactericidal activities was found with T₂. The RLP against A. hydrophila was high with T₂ and T₃.The propolis-ethanolic-extract enhanced the growth, immunity and resistance of O. niloticus against A. hydrophila more than the crude propolis.     

Early changes in adenosine A1 receptors in cerebral cortex slices submitted to in vitro ischemia

The effects of brain ischemia on the maximum binding capacity (B_max) and affinity (K_d) of A₁ receptors were studied in the rat cerebral cortex, with an in vitro approach. The results were correlated with changes in ³H-adenosine release, studied under identical experimental conditions. Fifteen minutes of in vitro ‘ischemia’ (hypoxic, glucose-free medium) induced a significant increase in both B_max (2398±132 fmol/mg protein, 151% of the control, P<0.05) and in K_d (2.43±0.12 nM, 161% of the control, P<0.01). At the same time, an increase in tritium efflux from [³H]-adenosine labeled cerebral cortex slices to 324% of the control was observed. A trend toward normalization was evident 5–15 min after ‘reoxygenation’ (restoring normal medium), but the binding parameters were still altered after 60 min (B_max 2110±82 fmol/mg protein, K_d 2.26±0.14 nM, P<0.01 vs the corresponding control) as was adenosine release (196% of the control). These findings suggest that the increased availability of adenosine and its receptors may be a defense mechanism against ischemic injury, while the reduced affinity of A₁ receptors, possibly due to desensitization, may be a sign of ischemia-induced cellular damage.     

Photosynthetic electron transport in thylakoids from cotton cultivars (Gossypium sp.) differing in tolerance to prometryn

A method to determine photosynthetic electron transport in thylakoid membranes is described for Gossypium barbadense (cv. Pima S-7) and G. hirsutum (cv. DP 5415). These cultivars differed markedly in tolerance to prometryn, a PS II inhibitor. The rates of photosynthetic electron transport obtained were 245 mole oxygen mg^–1 chl h¹. Plant age and leaf size influenced the activity of the thylakoid preparations. Thylakoids from leaves of plants 24 to 37 d and 50–70 mm in diameter had the highest activities; thylakoids from cotyledons, fully expanded leaves and young leaves had low activity. Thylakoids from both species had similar photosynthetic activities and I₅₀'s for prometryn, atrazine and diuron. Thus, tolerance to prometryn was not due to differential binding at D1 protein.Abbreviations PSII photosystem II - DAP day after planting - DQ duroquinone - DBMIB dibromothymoquinone - DMBQ 2,5-dimethyl-p-benzoquinone - I₅₀ concentration to inhibit reaction by 50% - Q_A quinone A - Q_B quinone B     

Diet and physiological responses of Spondyliosoma cantharus (Linnaeus, 1758) to the Caulerpa racemosa var. cylindracea invasion

Marine invasions are a worldwide problem that involves changes in communities and the acclimation of organisms to them. The invasive Chlorophyte Caulerpa racemosa var. cylindracea is widespread in the Mediterranean and colonises large areas from 0 to 70 m in depth. The omnivorous fish Spondyliosoma cantharus presents a high frequency of occurrence of C. racemosa in the stomach contents at invaded areas (76.3%) while no presence of C. racemosa was detected in control areas. The isotopic composition of muscle differed significantly between invaded and non-invaded sites for δ¹³C (− 16.67‰ ± 0.09 and − 17.67‰ ± 0.08, respectively), δ¹⁵N (10.22‰ ± 0.22 and 9.32‰ ± 0.18, respectively) and the C:N ratio (2.01 ± 0.0002 and 1.96 ± 0.009, respectively). Despite the high frequency of occurrence of C. racemosa in the stomach contents of S. cantharus and its important contribution to the δ¹³C source (20.7% ± 16.2), the contribution of C. racemosa to the δ¹⁵N in S. cantharus food sources was very low (6.6% ± 5.8). Other invertebrate prey such as decapods and polychaetes were more important contributors to the δ¹⁵N source at both invaded and non-invaded sites. Activation of enzymatic pathways (catalase, superoxide dismutase, glutathione-s-tranferase, 7-ethoxy resorufin O-de-ethylase) but not a significant increase in lipid peroxidation MDA (0.49 ± 0.01 nmol/mg prot at non-invaded and 0.53 ± 0.01 nmol/mg prot at invaded sites) was observed in S. cantharus individuals living in C. racemosa-invaded sites compared with control specimens. The low δ¹⁵N contribution values of C. racemosa by S. cantharus together with the toxicity demonstrated by the activation of the antioxidant defences and the important contribution of invertebrate prey to the δ¹⁵N could mean that the ingestion of C. racemosa by S. cantharus might be unintentional during the predation of invertebrate preys living underneath the entanglement of the C. racemosa fronds and stolons mats.     

Thin layer chromatographic analysis of glucose and maltose in estivated Biomphalaria glabrata snails and those infected with Schistosoma mansoni

Thin layer chromatography was used to analyze the glucose and maltose concentrations of the digestive gland–gonad complex (DGG) of uninfected-estivated Biomphalaria glabrata snails and estivated B. glabrata patently infected with Schistosoma mansoni. All snails were estivated in a most chamber at a relative humidity of 98 ± 1% and a temperature of 23 ± 1 °C for 14 days. Carbohydrates were extracted from the DGG with 70% aqueous ethanol, and extracts were analyzed on silica gel preadsorbent plates using ethyl acetate–glacial acetic acid–methanol–water (60:15:15:10) mobile phase, α-naphthol–sulfuric acid detection reagent, and quantification by densitometry. The concentrations of glucose and maltose were significantly reduced in both uninfected-estivated snails and infected-estivated snails.     

Nitrogen fertilizers promote plant growth and assist in manganese (Mn) accumulation by Polygonum pubescens Blume cultured in Mn tailings soil

Abstract

This study examined how different nitrogen (N) forms and application levels promote plant growth and assist in manganese (Mn) remediation of Polygonum pubescens Blume (P. pubescens) cultured in soil with a high Mn level. The effects of ammonium chloride (a) and urea (u), at three application levels (10, 20, and 30?mg L^?1 N) and control (no N addition, CK) on the growth, Mn accumulation, and enzymatic anti-oxidative defenses of P. pubescens were examined. In general, both ammonium-N and urea-N promoted the plant mass and height of P. pubescens. The total Mn amount of roots, stems, and leaves in N treatments were higher (p?<?0.05) than that of CK. The ammonium-N treatments showed greater plant biomass and Mn accumulation compared to the urea-N ones. In general, the accumulations of Mn, Cr, Zn, and Cu were significantly lower (p?<?0.05) in the N fertilizer treatment than those in the control; while the accumulations of Pb were higher (p?<?0.05) in P. pubescens across all N fertilizer treatments than those in the control. The N addition decreased the contents of O₂^? and H₂O₂ in the leaves of P. pubescens, while increasing the activities of enzymatic anti-oxidative defenses.     

Growth and protein synthesis of barramundi, Lates calcarifer, fed lupin as a partial protein replacement

Protein synthesis is an essential growth process in all animals. Little information is available on post-prandial protein synthesis and even less where different protein sources are compared. Protein synthesis was measured at 4 and 24 h after feeding juvenile barramundi in order to determine the effect of using lupin as a partial protein replacement for fish meal on the post-prandial protein metabolism. Juvenile barramundi (4.3 ±0.6 g) were held in a recirculation system (27 °C, salinity 10‰ and 24 h light) for 15 days. Fish were fed one of two isonitrogenous isoenergetic diets (40% crude protein, 16% lipid and 18.5 GE MJ kg^− 1). One diet was formulated with 100% fish meal as the protein source while the other had 45% of the protein replaced with lupin ingredients (lupin kernel meal (Lupinus angustifolius) and lupin protein concentrate). All fish were fed a ration of 6%·d^− 1 and feed intake was not significantly different between the two diets. Specific growth rate (SGR) and growth efficiency (in relation to protein (PPV) and energy (PEV)) were 6.5 ± 0.14%·d^− 1, 43.8 ± 2.72% and 38.31 ± 1.56%, respectively, and were not significantly different between the two diets. There was no significant difference in protein synthesis between the two diets at 4 and 24 h after feeding, however protein synthesis was significantly higher 4 h after feeding than at 24 h (p = 0.02). Neither growth performance nor protein metabolism was altered by replacing 45% of the protein with lupin protein and indicated this to be a suitable protein source for barramundi feeds.     

A novel anti-plant viral protein from coelomic fluid of the earthworm Eisenia foetida: purification, characterization and its identification as a serine protease

A novel protein showing strong antiviral activities against cucumber mosaic virus (CMV) and tomato mosaic virus (TMV) was purified from the coelomic fluid of the earthworm Eisenia foetida. The protein was characterized as a cold-adapted serine protease. Its molecular weight was estimated to be 27,000 by SDS-PAGE. The enzyme was most active at pH 9.5 and 40–50 °C. The protease activity at 4 °C was 60% of that obtained at the optimal temperature. The activity was suppressed by various serine protease inhibitors. Partial N-terminal amino acid sequence of the enzyme showed homology with serine proteases of earthworms, E. foetida and Lumbricus rubellus previously studied. Our results suggest that the enzyme can be applicable as a potential antiviral factor against CMV, TMV, and other plant viruses.     

Testosterone metabolism in Neomysis integer following exposure to benzo(a)pyrene

Cytochromes P450 (CYPs) are important enzymes involved in the regulation of hormone synthesis and in the detoxification and/or activation of xenobiotics. CYPs are found in virtually all organisms, from archae, and eubacteria to eukaryota. A number of endocrine disruptors are suspected of exerting their effects through disruption of normal CYP function. Consequently, alterations in steroid hormone metabolism through changes in CYP could provide an important tool to evaluate potential effects of endocrine disruptors. The aim of this study was to investigate the potential effects of the known CYP modulator, benzo(a)pyrene (B(a)P), on the testosterone metabolism in the invertebrate Neomysis integer (Crustacea; Mysidacea). N. integer were exposed for 96 h to 0.43, 2.39, 28.83, 339.00 and 1682.86 μg B(a)P L^− 1 and a solvent control, and subsequently their ability to metabolize testosterone was assessed. Identification and quantification of the produced phase I and phase II testosterone metabolites was performed using liquid chromatography coupled with multiple mass spectrometry (LC–MS²). Significant changes were observed in the overall ability of N. integer to metabolize testosterone when exposed to 2.39, 28.83, 339.00 and 1682.86 μg B(a)P L^− 1 as compared to the control animals.     

Manganese deficiency in maize affects pollen viability

Maize (Zea mays L. cv. G2) was grown with 0.55 mg L^–1 (sufficient), or 0.0055 mg L^–1 (deficient) manganese in sand. Manganese-deficient plants developed visible deficiency symptoms and showed poor tasseling and delayed anther development. Compared to Mn-sufficient plants, Mn-deficient plants produced fewer and smaller pollen grains with reduced cytoplasmic contents. Manganese deficiency reduced in vitro germination of pollen grains significantly. Ovule fertility was not significantly affected by Mn. But in Mn-deficient plants seed-setting and development was reduced significantly.