Effects of Geldanamycin on Hatching and Juvenile Motility in <Emphasis Type="Italic">Caenorhabditis elegans</Emphasis> and <Emphasis Type="Italic">Heterodera glycines</Emphasis>

Several Streptomyces species are known to produce metabolites that inhibit plant pathogens. One such compound is geldanamycin (GA), a benzoquinone ansamycin originally isolated from Streptomyces hygroscopicus. We examined the effect of geldanamycin on egg hatch and juvenile motility in Caenorhabditis elegans and in two populations of the plant-parasitic nematode Heterodera glycines. When C. elegans eggs were exposed to geldanamycin, both hatch and motility were reduced by GA doses between 2 and 50 μg/ml. The H. glycines inbred populations TN17 and TN18 exhibited low dose stimulation of hatch and motility, whereas levels occurring at higher GA doses were at or below control levels. These experiments represent the first demonstration of geldanamycin effects in C. elegans and H. glycines and suggest that the heat shock chaperone Hsp90, the known molecular target of geldanamycin, may be involved in nematode egg hatch and motility. This study also indicates that geldanamycin-producing strains of Streptomyces may be useful as biocontrol agents for nematodes.     

Pheromone attraction in the soybean cyst nematodeHeterodera glycines race 3

MaleHeterodera glycines responded to female nematodes during in vitro bioassay. The male's response was dosage-dependent and significant with a pheromone source of more than five females. Male responsiveness was influenced by the pheromone diffusion and response times. Males were most responsive at three days after emergence from the host plant, while females were also most attractive at the same age. Light intensities that ranged from dark to bright had no effect on female location by the male, although bioassay in a nitrogen atmosphere eliminated sexual communication. Mate location was not significant below 25 °C and declined slightly at 30 or 33 °C. Bioassay at pHs from 5 to 8.5 showed a bimodal effect, with maximal attraction around pH 6.     

Aqueous solvents for extracting glanded cottonseed protein without gland rupture

The presence of pigment glands has thwarted attempts to extract edible cottonseed protein aqueously from glanded seeds or gland-rich meals, probably because of the widely held belief that glands rupture on contact with aqueous media. We found several aqueous salt solutions in which glands did not rupture. Glands remained intact in saturated (2m) sodium sulfate, but not in saturated 2m or 4m solutions of sulfates, chlorides, and nitrates of other Group IA elements as well as sodium chloride and sodium nitrate. Glands also remained intact in saturated solutions of sulfates of aluminum, ammonium, cadmium, copper, magnesium, nickel, and zinc, and chlorides of calcium, iron, and magnesium. Some of these solutions were diluted to <50% saturation before glands started rupturing. Cottonseed protein in the liquid cyclone underflow fraction (gland-rich fraction) was soluble in sodium sulfate and magnesium sulfate, but not in calcium chloride or sodium phosphate. Its solubility in sodium sulfate was investigated further with the following results: Alkalinity of sodium sulfate solution had no effect on solubility; ratio of solid to solvent had no effect in the range of 1:3.5–1:60 (wt:vol); 80% saturated sodium sulfate was optimal for solubility without gland rupture; the period of contact of meal and solvent had no effect on protein solubility in the range of a few minutes to 2 hr. These results indicate that the extraction of cottonseed protein with aqueous solvents in the presence of pigment glands appears technically feasible. Presented in part in the Symposium entitled “Oliseed Proteins—Food Use Potentials and Problems” at the AOCS Meeting in Dallas, June 1975.     

Evaluation of levels and methods of zinc application to rice in sodic soils

Field experiments were conducted in zinc-deficient sodic soil to study the effect of levels and methods of zinc fertilization on yield, concentration and uptake of zinc by rice. Zinc was incorporated in the soil at the rate of 0, 5.6, 11.2 and 22.4 kg Zn per ha as zinc sulfate; sprayed on the plants at 1% and 2% zinc sulfate solution; and roots of rice seedlings were dipped in 2% and 4% ZnO suspensions in water. Grain yield, zinc content and its uptake increased in all the experiments up to 22.4 kg Zn per ha. Soil applied zinc was significantly correlated with yield of rice (r = 0.80^**) and zinc uptake (r = 0.89^**). Zinc content in 45-day old plants gave a significantly higher correlation with grain yield (r = 0.84^**) than the zinc content of rice straw and grain at maturity. Roots of rice seedlings dipped in 2% or 4% zinc oxide suspension in water were not only comparable with soil application of Zn at 5.6 and 11.2 kg Zn per ha, but also proved to be more economical for sodic soils showing moderate zinc deficiency.     

Effects of urea analogs on egg hatching and movement of unhatched larvae of monogenean parasiteAcanthocotyle lobianchi from skin ofRaja montagui

Rapid hatching in the monogenean parasiteAcanthocotyle lobianchi from the skin ofRaja montagui is stimulated by urea. Structurally similar to the urea molecule, the following analogs of urea provide amino groups, carboxyl groups, or combinations of these, but fail to stimulate hatching at concentrations of 1 mM in seawater: methylurea (MU); 1, 3-dimethylurea (DU); 1, 1, 3, 3-tetramethylurea (TMU); thiourea (TU); 1, 1, 3, 3-tetramethyl-2-thiourea (TMTU); and 1-phenyl-2-thiourea (PTU). All of these analogs except PTU elicit movements of unhatched larvae, and posttreatment of the eggs with urea showed that the ability to hatch is not impaired by initial treatment with any of the urea analogs. Thus the larval chemoreceptor that initiates hatching appears to be highly specific for the urea molecule.     

锌离子对自絮凝酵母乙醇耐性和絮凝颗粒大小的影响

研究了6种金属离子在合成培养基中对摇瓶培养的自絮凝酵母乙醇耐性的影响,发现锌离子对高浓度乙醇冲击下的酵母细胞活性有保护作用,并进一步研究了乙醇连续发酵过程中锌的添加对自絮凝酵母乙醇耐性的影响。发酵培养基中分别添加0.01、0.05 和 0.1 g·L^-1的硫酸锌时,自絮凝酵母颗粒平均粒度减小,同时乙醇耐性和高温耐性都得到明显提高,并且发现细胞活性的提高与酵母细胞内麦角固醇和海藻糖的增加密切相关。对酵母细胞内锌的含量的分析表明,3个添加组胞内锌的积累量基本相似,比对照组均增加了6倍。相关性分析表明,酵母胞内锌含量与酵母细胞的胁迫耐性密切相关并显著影响其胁迫耐性。各添加组的乙醇产量均有提高,其中添加0.05 g·L^-1的硫酸锌时乙醇产量最高,比对照组高8.4%。以上研究结果表明,调控连续乙醇发酵过程中培养基中锌离子浓度,是提高酵母细胞乙醇耐受性、高温度耐受性和乙醇产量的有效途径。     

Influence Of Diet-Related Chemical Cues from Predators on the Hatching of Egg-Carrying Spiders

Previous studies have shown that animals may make adaptive adjustments in response to chemical cues from predators, but hatching responses to diet-related chemical cues from predators have not been previously demonstrated. In the system studied here, the predator is an araneophagic jumping spider (Salticidae), Portia labiata, and the prey organism is a subsocial spitting spider, Scytodes pallida (Scytodidae). The spitting spider carries its eggs in its chelicerae, and carrying eggs is known to make it more vulnerable to predators. It is also known from an earlier study that the prior diet of the predator alters how dangerous the individual predator is to the spitting spider. In the experiments reported here, incubation time was shorter when volatile cues from the predator were present and longer in control tests when no chemical cues from the predator were present. The previous predators diet also influenced incubation time: when in the presence of volatile cues from individuals of P. labiata that had previously fed on individuals of S. pallida, incubation time was shorter than when in the presence of volatile cues from individuals of P. labiatathat had been feeding instead on house flies.     

Role of chemical substances from fish hosts in hatching and host-finding in monogeneans

Hatching responses to chemical stimuli appear to have evolved independently in different kinds of monogenean skin and gill parasites of fishes, particularly in those parasites associated with bottom-dwelling hosts. Some monogeneans, such asEntobdella soleae, have two hatching strategies, responding readily to host skin mucus but hatching spontaneously in small numbers in the absence of the host. Other monogeneans, such asAcanthocotyle lobianchi, have abandoned spontaneous hatching and rely entirely on a sit- and-wait strategy, but improvements in the speed of hatching provide opportunities to take advantage of brief periods of contact between the eggs and the host. This has led to the loss of ciliated epidermal cells and to the inability to swim. Comparison of the eggs and hatching responses of two unrelated monogeneans,Leptocotyle minor andHexabothrium appendiculatum, which share the same dogfish host, reveals evidence of convergence. Small, stable molecules such as urea, excreted by the host, have been implicated as hatching stimulants in monogeneans. There is evidence that host recognition inE. soleae is by chemoperception but, in contrast with the lack of specificity of the chemical hatching stimuli, this appears to be of a specific nature.     

Investigations on the growth ofRhodococcus rubra in relation to the formation of stable biological foams

The growth characteristics of a foam-forming species,Rhodococcus rubra were studied on different substrates. The basic medium contained Czapek (3.34%), yeast extract (0.2%), potassium dihydrogen phosphate (0.12%), dipotassium hydrogen phosphate (0.25%) and ammonium chloride (0.1%). This was supplemented with varying concentrations of glucose (0–2%). The same basic medium was also used to examine the growth ofR. rubra in combination with varying concentration of n-hexadecane (0.0–0.5%) as a source of energy while varying the concentration of ammonium chloride in the range 1–3 gl ⁻¹. Studies based on determining the biomass concentration, the surface activity related to the cell suspensions and measuring the variations in broth pH revealed that glucose encouraged the growth ofR. rubra, compared to the control. However, increasing the glucose concentration from 0.1 to 2.0% had no further effect on growth. The surface activity of the cell suspensions increased with increasing glucose concentration. Results similar to glucose were exhibited by the addition of n-hexadecane, suggesting same degree of growth among different concentrations with higher surface activity increasing with increase in substrate concentration. Results have also shown that the pH of all the culture broths decreased as the ammonium chloride concentration increased, suggesting that there was a production of hydrogen ions during the course of its metabolism.     

Mortality and inhibition ofHelicoverpa zea Egg parasitism rates byTrichogramma in relation to trichome/methyl ketone-mediated insect resistance ofLycopersicon hirsutum f. glabratum,accession PI 134417

The glandular trichome/methyl ketone-mediated insect resistance of the wild tomato,Lycopersicon hirsutum f. glabratum C.H. Mull, accession PI 134417, toManduca sexta (L.) andLeptinotarsa decemlineata (Say) was shown to affect adverselyTrichogramma pretiosum Riley. AdultT. pretiosum were killed by direct contact with PI 134417 foliage and by exposure to its volatiles. This effect was greatly reduced or eliminated by removing the exudate of the glandular trichomes from the foliage. 2-Tridecanone, a principal consituent of the foliar glandular trichomes of PI 134417, was toxic to adultT. pretiosum at concentrations similar to those associated with PI 134417 foliage. Incubation of parasitizedHelicoverpa (=Heliothis) zea (Boddie) eggs on PI 134417 foliage or 2-tridecanone-treated filter paper significantly reduced the proportion of eggs producing adult parasitoids. Similarly, incubation of parasitizedH. zea eggs on filter paper treated with 2-undecanone, another constituent of the glandular trichomes of PI 134417, caused an increase in the percentage of host eggs containing dead parasitoid pupae.     

Partial purification and properties of lipase from germinating seeds of Jatropha curcas L.

Lipase present in the seeds of Jatropha curcas L. was isolated and some of its properties studied. Lipase activity was detected in both dormant and germinating seeds. The lipase was partially purified using a combination of ammonium sulfate precipitation and ultrafiltration, which increased the relative activity of the lipase by 28- and 80-fold, respectively. The lipase hydrolyzed palm kernel, coconut, and olive oils at comparable rates (approximately 5 μg FFA/μg protein/min); palm—Raphia hookeri and Jatropha curcas L.—oils at about twice the rate of the first group of oils; and palm and fish oils at a higher rate than all other oils. The lipase, however, had the highest activity with monoolein. Optimal pH and temperature for maximal lipase activity were 7.5 and 37°C, respectively. The addition of ferric ion (15 mM) to the lipase assay medium caused 90% inhibition of lipase activity, whereas calcium and magnesium ions enhanced lipase activity by 130 and 30%, respectively.     

Toxicity of Aflatoxin B1 to Helicoverpa zea and Bioactivation by Cytochrome P450 Monooxygenases

Infestation of corn (Zea mays) by corn earworm (Helicoverpa zea) predisposes the plant to infection by Aspergillus fungi and concomitant contamination with the carcinogenic mycotoxin aflatoxin B1 (AFB1). Although effects of ingesting AFB1 are well documented in livestock and humans, the effects on insects that naturally encounter this mycotoxin are not as well defined. Toxicity of AFB1 to different stages of H. zea (first, third, and fifth instars) was evaluated with artificial diets containing varying concentrations. Although not acutely toxic at low concentrations (1−20 ng/g), AFB1 had significant chronic effects, including protracted development, increased mortality, decreased pupation rate, and reduced pupal weight. Sensitivity varied with developmental stage; whereas intermediate concentrations (200 ng/g) caused complete mortality in first instars, this same concentration had no detectable adverse effects on larvae encountering AFB1 in fifth instar. Fifth instars consuming AFB1 at higher concentrations (1 μg/g), however, displayed morphological deformities at pupation. That cytochrome P450 monooxygenases (P450s) are involved in the bioactivation of aflatoxin in this species is evidenced by the effects of piperonyl butoxide (PBO), a known P450 inhibitor, on toxicity; whereas no fourth instars pupated in the presence of 1 μg/g AFB1 in the diet, the presence of 0.1% PBO increased the pupation rate to 71.7%. Pupation rates of both fourth and fifth instars on diets containing 1 μg/g AFB1 also increased significantly in the presence of PBO. Effects of phenobarbital, a P450 inducer, on AFB1 toxicity were less dramatic than those of PBO. Collectively, these findings indicate that, as in many other vertebrates and invertebrates, toxicity of AFB1 to H. zea results from P450-mediated metabolic bioactivation.An erratum to this article can be found at     

Male sex pheromone of cockroachEurycotis floridana (walker) (Blattidae,Polyzosteriinae): Role and composition of tergites 2 and 8 secretions

InEurycotis floridana, the male calling behavior is associated with the exposition of epidermal glands located under tergites 2, 7, and 8. 4-Hydroxy-5-methyl-3(2H)-furanone and 4-hydroxy-2,5-dimethyl-3(2H)-furanone were recently identified as the specific components of tergite 7 secretion. Methylene chloride extracts of tergite 7 and its major compound 4-hydroxy-5-methyl-3(2H)-furanone attract the conspecific females at a distance. Methylene chloride extracts of tergite 8 are also attractive at a distance to the females, whereas extracts of tergite 2 had no effect on males and females. Our GC investigations showed the absence of specific compounds in tergite 2 secretions. The GC-MS analyses revealed that the male secretion of the gland under tergite 8 is mainly a mixture of (2R*, 3R*)-butanediol, 1-dodecanol and benzyl 2-hydroxybenzoate. These compounds were tested at different concentrations on their own, or as a mixture. Only (2R*, 3R*)-butanediol and 1-dodecanol were attractive for the females. Their functions, as components of the male sex pheromone, in addition with the two derivatives of the furanone are discussed.     

The role of zinc and sulfuric acid concentrations on zinc electrowinning from industrial sulfate based electrolyte

The effects of varying simultaneously the zinc/acid concentrations at a fixed total sulfate, on the current efficiency, energy requirements, and deposit physical characteristics for the zinc electrowinning, using Kidd Creek zinc electrolyte, were investigated. The electrowinning experiments were conducted using a laboratory scale apparatus, at plating cycles of 24 and 30 h, a current density of 500 A m^–2 and a temperature of 38 °C. These conditions are typical of those applied at the Kidd Creek zinc tankhouse. The reagents presently used at Kidd Creek, namely strontium carbonate, Saponin, Dowfroth 250, antimony and sodium silicate, were also continuously added to the cell electrolyte at levels similar to Kidd Creek practice. Scanning electron microscopy and X-ray diffraction techniques were used to characterize the deposits with respect to morphology and preferred orientation, respectively. Cyclic voltammetry was used to study the effect of the zinc/acid concentrations on the polarization behaviour of the electrolyte. In addition, the electrical conductivity of the Kidd Creek zinc electrolyte was measured and compared with other industrial sulfate-based zinc electrolytes.     

Chelation of chitosan derivatives with zinc ions. I. O,N‐carboxymethyl chitosan

The chelation between O,N‐carboxymethyl chitosan (ONCMCh) and zinc sulfate in aqueous solution was studied by kinetic experiments and characterized by inductively coupled plasma (ICP) and UV spectrophotometry. The experimental data indicated that the chelating processes were greatly controlled by the reaction conditions (i.e., reaction time, temperature, and Zn²⁺ ionic and ligand concentrations). The consequence of chelating Zn²⁺ onto ONCMCh was the formation of complexes with different solubilities. The favorable complexes for ONCMCh‐Zn²⁺ chelate were at the low zinc ionic and ligand concentrations, as well as at the appropriate temperature. The evidence provided by the kinetic parameters and the changes in zinc concentration by ICP analysis further confirmed the plausible complexing mechanisms. While the formation of water‐soluble products was occasioned by the electrostatic attraction mechanism, the water‐insoluble products were predominantly formed by chelation of Zn²⁺ with O,N‐carboxymethyl chitosan. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2246–2253, 2000     

Inhibition of potato cyst nematode hatch by lignans fromBupleurum salicifolium (Unbelliferae)

A series of lignans fromBupleurum salicifolium Soland (Umbelliferae) were tested for nematostatic activity on the cysts and freed secondstage juveniles of the potato cyst nematodesGlobodera rostochiensis andG. pallida. None of the six lignans tested—bursehernin, matairesinol, syringaresinol, the novel product buplerol, guayarol, and a derivative, nortrachelogenin triacetate—showed nematicidal activity in an in vitro analysis with second-stage juveniles, but significant differences were noted when the lignans were assayed for nematostatic activity as cyst hatching inhibitors. Bursehernin and matairesinol showed the greatest activity, at concentrations of 50 ppm. This is the first known instance of a natural product inhibiting the hatch of the nematodeG. pallida. The HID (hatching inhibiting dose) of bursehernin was estimated, and some conclusions were drawn about the structure-activity relationships of the lignans under study.     

制备硫酸钾新方法的研究

利用我国丰富的中、低品位的锌资源，通过硫酸处理制备硫酸锌，再由后者与氯化钾复分解制取硫酸钾     

Purification and removal of Ascaris and Fasciola hepatica eggs from drinking water using roughing filters

The performance of a horizontal roughing filter (HRF) and a downflow roughing filter (DRF) in the removal of Ascaris and Fasciola hepatica eggs was investigated. The experiments were performed at three filtration rates of 0.5, 1.0 and 1.5 m/h and different influent concentrations of Ascaris and Fasciola hepatica eggs. Alteration of the filtration rate in the range of 0.5–1.5 m/h did not have significant influence on the effectiveness of the roughing filters. The HRF had higher efficiency in the removal of both Fasciola hepatica and Ascaris eggs in comparison with the DRF, so that the average efficiencies of the HRF for the removal of Fasciola hepatica and Ascaris eggs at filtration rate of 1.0 m/h were determined to be 89.0 and 57.3%, respectively, whereas the same values of the DRF were 77.2 and 52.5%, respectively. The straining was confirmed to be the main mechanism of helminth eggs removal by the roughing filters, because Fasciola hepatica eggs with larger size were removed more effectively than Ascaris eggs. The results of this study indicate that the roughing filters, especially the HRF, had promising performance in the removal of helminth eggs and could be used for water and secondary effluent treatment.     

碱式硫酸锌在湿法炼锌过程结晶热力学研究

对中国几家湿法炼锌厂净化阶段产生的结晶渣进行X射线衍射分析,确定了湿法炼锌过程产生的碱式硫酸锌的结构是ZnSO₄·3Zn（OH）₂·5H₂O,从而否定了是ZnSO₄·3Zn（OH）₂的传统观点,表明碱式硫酸锌的溶解度与水的活度有关。采用高温硫酸锌溶液中加入氧化锌粉末的方法制得与炼锌厂碱式硫酸锌结晶渣晶型一致的产物。同等硫酸锌浓度、pH条件下,碱式硫酸锌溶解度随着温度的升高而升高。研究表明,在锌质量浓度为168 g/L、pH为5.2的中性浸出液中,碱式硫酸锌析出温度为60.6 ℃±0.4 ℃,80 ℃降到40 ℃的析出量为4.4 g/L。     

Antibacterial Properties of Ester—Cross-Linked Cellulose–Containing Fabrics Post-Treated with Metal Salts

To improve the performance properties of cellulose-containing fabric, ester was cross-linked with polycarboxylic acid in the presence of specific catalysts. Its pendant carboxyl groups were exploited in binding some heavy metals (by reacting with some salts, such as zinc acetate, zinc chloride, zinc sulfate, cupric acetate, cupric chloride, cupric sulfate, and nickel sulfate) capable of imparting their antibacterial activity toward some gram-positive bacteria (viz., B. subtilis, B. mycoides, Sta. aureus) and a gram-negative bacteria (E. coli). Zinc salts impart to the fabric the highest antibacterial activity, followed by cupric acetate. Zinc chloride proved to be the metal salt that yielded the maximum antibacterial activity.