Chronic effects of cadmium on two species of mysid shrimp:Mysidopsis bahia andMysidopsis bigelowi

Two species of mysid shrimp, the sub-tropicalMysidopsis bahia and the northern temperateMysidopsis bigelowi, were exposed simultaneously to cadmium (as CdCl₂) in a continuous-flow bioassay system to determine the effect on survival and reproductive success. Temperature and salinity were maintained at 21 ± 1°C and 30,respectively. The 96-h LC50 was 110 µg ^–1 for both species. The 23-day life cycle LC50 forM. bahia was 19.5 µg ^–1 and forM. bigelowi the 27-day LC-50 was 14.8 µg ^–1. At 10 µg ^–1 a series of morphological aberrations were observed in both species at the onset of sexual maturity. Carapace malformations apparently prevented molting after the release of the initial brood and resulted in death of brooding females. As a result, although the initial reproductive rate at this concentration was successful, successive broods could not be produced. For both species in this study the no observed effect concentration was 5.1 µg ^–1; the effect concentration was 10.0 µg ^–1. Mechanisms were postulated in this study to explain the effect of cadmium on the molting process and on calcification and enzymatic reactions of osmosis.Contribution No. 257 of the U.S. Environmental Protection Agency.Contribution No. 257 of the U.S. Environmental Protection Agency.     

Inactivation of calcium currents in the soma of spinal ganglia by removing the membrane potential depolarization shift

Kinetic and voltage-dependent characteristics of the inactivating action of incoming calcium currents were investigated in the somatic membrane of rat spinal ganglia neurons using an intracellular dialysis technique. It was shown that the "tail" of low-threshold calcium current could be reliably described by one exponent with a time constant of =1.2–1.8 msec at a repolarization potential of –90 mV. The "tail" of the high-threshold calcium current represented the sum of several exponents. The time constant of the main component which expressed inactivation of the high threshold calcium current was ^h=250–350 µsec. It was also shown that and ^h remained virtually unchanged for repolarization potentials in the subthreshold region; they increase, however, if the repolarizing potential is close to those potentials at which the corresponding component of calcium current is initially activated. A dependence was observed between the levels and ^h and duration of the depolarizing shift. Findings are discussed in the context of a three-tier model of calcium channels.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 17, No. 5, pp. 682–691, September–October, 1985.     

Production of ℓ-malic acid by Paecilomyces varioti

Summary Preliminary data for production of -malic acid from calcium acetate byPaecilomyces varioti is presented. Shake flask cultures with free cells and with cells immobilised in calcium alginate beads gave comparable results, acid concentrations of approximately 8 g/l being produced after 5 days from a medium containing 4% w/w of calcium acetate. A packed bed reactor, operated as an extended batch with product recycle, produced maximum acid concentrations of 32.6 g/l, equivalent to 73% of the maximum theoretical yield, after 3 days. Evidence obtained indicated that spores were more active than mycelia in the production of malic acid.     

Effect of oxygen-enriched aeration on regeneration of rice (Oryza sativa L.) cell culture

The effect of the oxygen concentration in the aeration gas on regeneration from rice cells in bioreactor cultures was investigated. The efficiency of regeneration in cultures aerated with over 40% oxygen was higher than that in a flask culture. In the case of a culture in which the dissolved oxygen(DO) was saturated by aeration with air, the efficiency of regeneration was less than the half that of cultures aerated with 40% oxygen. In cultures with the DO levels controlled at 8,10 and 12 mg/, the efficiency of regeneration was highest at 12 mg/. In the oxygenenriched cultures, although cell aggregation was observed and the color of plantlets was relatively pale, more than 90% of them grew into healthy plants.Abbreviations DO dissolved oxygen - 2,4-D 2,4-dichlorophenoxyacetic acid - MES 2-(N-morpholino) ethanesulfonic acid - rpm revolution per minute - NAA 1-naphthaleneacetic acid - vvm volume per volume per minute     

Characterization of wine yeasts for ethanol production

Summary Selected wine yeasts were tested for their ethanol and sugar tolerance, and for their fermentative capacity. Growth () and fermentation rates () were increasingly inhibited by increasing ethanol and glucose concentrations, flor yeasts being the least inhibited. Except in the latter strains, the ethanol production rate was accelerated by adding the glucose stepwise. The best fermenting strains selected in laboratory medium were also the best at fermenting molasses. Invertase activity was not a limiting step in ethanol production, being accelerated by supplementing molasses with ammonia and biotine, and by cell recycle.     

Effects of mine drainage on the river hayle,cornwall a) factors affecting concentrations of copper,zinc and iron in water,sediments and dominant invertebrate fauna

Concentrations of copper, zinc and iron were measured in waters, sediments and invertebrates collected from the River Hayle. In river water at least 70% of copper and iron was associated with the particulate fraction whereas 80% of zinc was in the soluble form. Although total concentrations of zinc in water exceeded those of copper approximately ten fold, copper predominated over zinc in the sediments by a factor of approximately three. Iron was the most abundant metal recorded in both water and sediments.Seasonal differences in total metal content of waters suggested that concentrations of copper, zinc and iron increased during. periods of high flow and decreased during lower flows. Copper concentrations in the sediment, unlike zinc and iron, showed markedly higher values during the summer sampling period when flows were minimal.In the free-living Trichoptera larvae, concentrations of copper and zinc in the tissue appeared to follow copper and zinc levels in the water. Similar relationships in Odonata and Plecoptera larvae were not obtained. Factors affecting animal/metal relationships are discussed with particular reference to adaptation shown by organisms exposed to high concentrations of heavy metals in their environment.Department of Applied Biology, Cambridge     

Synthesis of aspartame precursor by solid thermolysin in organic solvent

Summary The enzymatic synthesis of a peptide compound was carried out successfully in homogeneous organic solvent.Solid Thermolysin was found to catalyze the synthetic reaction of N-benzyloxycarbonyl-L-aspartyl-L-phenylalanine methyl ester (Z-APM; a precursor of sweetner Aspartame) from N-benzyloxycarbonyl-L-aspartic acid (Z-L-Asp) and L-phenylalanine methyl ester (L-PheOMe) in a 98 percent organic medium (ethylacetatebenzenemethanolwater=5029192). The dissolution of enzyme was not observed. The optimal pH shifted to acidic side by 1.0 pH unit, compared with that in aqueous medium. The enzymatic activity of solid thermolysin with an average size of 3.4×9.5 m was determined to be 0.18 moles-product/(mg-solid)·h under the initial concentrations of L-PheOMe of 0.1M and Z-L-Asp of 0.05M, and at pH 6.0 and 40°C.     

Endogenous abscisic acid and 2-trans-abscisic acid in alternate bearing ‘Wilking’ mandarin trees

The relationship of abscisic acid (ABA) and 2-trans-abscisic acid (t-ABA) to alternate bearing has been examined in Wilking mandarin (Citrus reticulata Blanco) trees. Leaves, stems and buds of trees loaded with fruit (on trees) had 4.3, 6.0 and 2.2 fold higher ABA levels than the corresponding organs from off trees. Leaves had higher ABA levels than stems and buds in both on and off trees. t-ABA was non-detectable in Wilking leaf, stem and bud tissue. Amounts of t-ABA not exceeding 40% of the ABA content, were found in Shamouti and Valencia orange buds and in Wilking fruit peel.The elevated levels of ABA in on tree organs may reflect a stress imposed by the fruit overload.     

Effects of midazolam on the contraction and relaxation of segments of thoracic aorta stripped of endothelium and stimulated by adrenaline – experimental study in rabbits

To evaluate the effects of midazolam on the angiokinesis of segments of rabbits' thoracic aorta stripped of endothelium and stimulated by adrenaline.Two groups of aortic rings removed from albinic rabbits anesthetized with thiopental were used (Group I – 6 animals; Group II – 12 animals), stripped of endothelium, studied in an organ chamber, perfused by Krebs-Henseleit solution. The groups were stimulated by adrenaline, recording the maximum contraction and dT/dt at 12, 36, 60 and 120. When the plateau phase was reached, the vessel was washed with perfusion solution, recording relaxation at 2, 4 and 6. When the base values were reached, Group I underwent a new adrenergic stimulus; and Group II was stimulated with midazolam and then with adrenaline, and the same values were recorded. T test was applied as a statistical analysis when two variables were studied. When studying more than two variables the Anova test was used, supplemented by the Tuckey test.Group I did not show any significant difference between the two stimuli. Group II – the midazolam significantly reduced the maximum contraction induced by adrenaline (83.01 ± 4.11%) (p < 0.01). The dT/dt was reduced at 12 (57.06 ± 8.47%), and also at 36 (70.59 ± 5.26%). There was no significance at 60 and 120 (p < 0.01).The relaxation increased significantly at all measurements – at 2-adrenaline 39.31 ± 9.60%; adrenaline/midazolam: 44.06 ± 9.62% (p < 0.05). At 4-adrenaline: 53.08 ± 8.3%; adrenaline/midazolam: 61.68 ± 8.50% (p < 0.01). At 6-adrenaline: 76.26 ± 5.45%; adrenaline/midazolam: 84.20 ± 7.96% (p < 0.01).Midazolam significantly reduced the maximum contraction obtained by the adrenergic stimulus as well as the dT/dt in the initial phases of contraction. The relaxation speed also increased.     

Production of a novel syrup containing neofructo-oligosaccharides by the cells of Penicillium citrinum

A novel syrup containing neofructo-oligosaccharides was produced from sucrose (Brix 70) by whole cells of Penicillium citrinum. The efficiency of fructo-oligosaccharides production was more than 55% and those of the main carbohydrate components, 1-kestose (Fruf 21Fruf 21 Glc), nystose (Fruf 21Fruf 21 Fruf 21 Glc) and neokestose (Fruf 26 Glc12 Fruf), were 22, 14 and 11%, respectively.     

Heterosis among populations of maize (Zea mays L.) with different levels of exotic germplasm

Summary Thirteen maize (Zea mays L.) populations including five adapted, five adapted x exotic, two composites of adapted and exotic, and one exotic selected for adaptability were crossed in a diallel mating system. The parents and 78 crosses and nine check hybrids were evaluated for grain yield and plant height in five environments. The Gardner-Eberhart model Analysis II indicated that additive and nonadditive gene effects accounted for 60 and 40% of the total variation among populations, respectively, for grain yield and 86% and 14% of the total variation, respectively, for plant height. Components of heterosis were significant in the combined analysis for both traits. Adapted Corn Belt populations tended to have higher performance in crosses and greater values of variety heterosis than 50% adapted populations. Nebraska Elite Composite, Corn Belt x Mexican, and Corn Belt x Brazilian showed high mean yields in crosses, however, they were not among those with high estimates of variety heterosis. One exotic population (Tuxpeno x Antigua Grupo 2) and three adapted populations [307 Composite, NB(S₁)C-3, and NK(S₁)C-3] might be combined together to form a high-yielding population. It may be possible to synthesize two useful populations for reciprocal recurrent selection by grouping Tuxpeno x Antiqua Grupo 2, NB(S₁)C-3, and NS(FS)LFW-8 into one population and NK(S₁)C-3, KrugxTabloncillo, and 307 Composite in the other one.Contribution from the Department of Agronomy, University of Nebraska, Lincoln, NE 68583. Published as Paper No. 8011. Journal Series, Nebr. Agric. Exp. Station. Research was conducted under Project 12-049     

Comparative study on the chloroplast,mitochondrial and nuclear genome differentiation in two cultivated rice species,Oryza sativa and O. glaberrima,by RFLP analyses

Summary Restriction fragment length polymorphisms of chloroplast (ct), mitochondrial (mt) and nuclear DNA were investigated using eight cultivars of Oryza sativa and two cultivars of O. glaberrima. Relative variability in the nuclear and cytoplasmic genomes was estimated by a common measure, genetic distance. Based on the average genetic distances among ten cultivars for each genome, the evolutionary variabilities of the mitochondrial and nuclear genomes were found to be almost the same, whereas the variability of the chloroplast genome was less than half that of the other two genomes. Cluster analyses on ct and mt DNA variations revealed that chloroplast and mitochondrial genomes were conservative within a taxon and that their differentiations were well-paralleled with respect to each other. For nuclear DNA variation, an array of different degrees of differentiation was observed in O. sativa, in contrast with little variation in O. glaberrima. As a whole, differentiation between O. sativa and O. glaberrima was clearly observed in all three genomes. In O. sativa, no notable difference was found between the cultivars Japonica and Javanica, whereas a large differentiation was noticed between Japonica (including Javanica) and Indica. In all three genomes, the average genetic distances within Indica were much larger than those within Japonica (including Javanica), and almost similar between Japonica (including Javanica) and Indica. These facts indicate that differentiation in O. sativa was due mainly to Indica.     

Synthesis of N-linked pentasaccharides with isomeric glycosidic linkage

As part of a program to explore the structural requirement of N-glycans in the carbohydrate-mediated biological interactions, N-linked pentasaccharide core structure was stereochemically modified in terms of glycosidic linkage. Three isomers, -D-Man-(13)-[-D-Man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, -D-Man-(13)-[-D-Man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, and -D-Man-(13)-[-D-man-(16)]--D-Man-(14)--D-GlcNAc-(14)--D-GlcNAc-L-Asn, were synthesized. Synthesis of the pentasaccharide with natural linkage is also described.     

The effect of aluminium on Anaerobic digestion

Summary The ability of methanogenic bacteria to adapt to high concentrations of aluminium was investigated using a 9 Upflow Anaerobic Sludge Blanket (UASB) reactor fed semi-continuously with a synthetic waste containing glucose as the organic carbon source. It was found that an influent concentration of 2500 mg/ Al³⁺ could be tolerated by acclimatized methanogenic bacteria. However, if the concentration in the synthetic waste was further increased, inhibition of the methanogens resulted, with a corresponding decrease in digester performance. The aluminium precipitated as Al(OH)₃ and accumulated in the sludge bed of the digester.     

A new metabolic pathway from n-dodecane to α, ω-dodecanedioic acid in a mutant of Candida tropicalis

Summary The metabolic formation of ,-dodecanedioic acid via ,-dodecanediol from n-dodecane using a mutant S76 of Candida tropicalis was studied.It was found that resting cells of S76 produce ,-dodecanediol from n-dodecane. This intermediate was identified by different analytical methods. With n-dodecanol as substrate the quantitative changes in the concentrations of ,-dodecanediol as well as other intermediates, e.g. monoacid, -hydroxy acid and ,-dioic acid produced by resting cells of S76 for different periods of time were determined. With ,-dodecanediol as the sole carbon source, quantitative changes of -hydroxy acid and ,-dioic acid produced by S76 were also recorded.The results confirm the existence of a new metabolic pathway via ,-diol in the course of ,-dioic acid formation from n-alkane in the mutant S76 of C. tropicalis.     

A simple method for maintaining high multiplication of Narcissus shoot cultures in vitro

A simple method for stimulating and maintaining high in vitro multiplication of Narcissus shoot clump cultures was developed. Shoot clumps were subjected either to normal cutting where leaves were trimmed to 20 mm in length at the beginning of each culture passage or to severe cutting where shoot clumps were cut down to the basal plate region removing all green tissue. Severe cutting at the beginning of each culture passage initially doubled the leaf multiplication, compared to normal cutting, but the difference between cutting treatments declined in successive passages. The improvement in leaf multiplication was maintained when shoot clumps were subjected to severe cutting only at every other culture passage, with no cutting in the alternate recovery passages. In vitro multiplication was increased by severe cutting in all seven Narcissus cultivars which were tested.Abbreviations NAA-1 naphthylacetic acid - BAP benzylaminopurine     

High crossability of wild barley (Hordeum spontaneum C. Koch) with bread wheat and the differential elimination of barley chromosomes in the hybrids

Four bread wheat (Triticum aestivum L.) cultivars, Aobakomugi, Chinese Spring, Norin 61 and Shinchunaga, were pollinated with five barley lines/cultivars consisting of three cultivated barley (Hordeum vulgare L.) lines, Betzes, Kinai 5 and OHL089, and two wild barley (Hordeum spontaneum C. Koch) lines, OUH602 and OUH324. Crossability, expressed as the percentage of embryo formation, varied from 0 to 55.4% among the cross combinations. The two wild barley lines generally had a higher crossability than the previously reported best pollinator, Betzes, and some Japanese wheat cultivars were better as the female parent than Chinese Spring. Ninety four hybrid plants were obtained from 250 embryos cultured, and their somatic chromosome numbers ranged from 21 to 36. Eighteen plants were mosaic in chromosome number. Twenty one-chromosome plants appeared most frequently (45.7%) followed by 28-chromosome plants (14.9%). C-banding analysis revealed that elimination of barley chromosomes was mainly responsible for the occurrence of aneuploid plants. In hypoploids derived from Betzes-crosses, chromosome 5 was preferentially eliminated as previously reported, while in hypoploids derived from OUH602-crosses, chromosome 4 was preferentially eliminated. The wild barley line OUH602 may be a useful parent for producing a new wheat-barley addition set because of its high crossability with wheat and a different pattern of chromosome elimination.     

The antitumour activity of the interferon inducer bropirimine is partially mediated by endogenous tumour necrosis factor α

Summary Pyrimidinones, like 2-amino-5-bromo-6-phenyl-4-pyrimidinone (bropirimine), are potent immunomodulators. Natural killer cell activity and macrophage cytotoxicity are increased after bropirimine treatment, an effect exerted through induction of cytokines. Up to now, the interferons have been supposed to be the main mediators but we have found that tumour necrosis factor (TNF) can also be an important mediator of the bropirimine antitumour effects. Increased serum levels of TNF were seen in rats after intraperitoneal administration of 200 mg/kg bropirimine on 2 consecutive days. We also found that the tumour-growth-inhibiting effect of the drug on a colon carcinoma in rats could be reduced about 40% by giving the rats rabbit anti-TNF serum just prior to drug treatment. These results indicate that bropirimine can induce the release of TNF in vivo and that this endogenous TNF may be important as far as the antitumour effect of the drug is concerned.     

Isolation of α and β Brain Tubulin Subunits after Alkaline Treatment of the Protein

We demonstrate here that brain purified tubulin can be dissociated into and subunits at pH > 10 and that the subunits can be separated by using the Triton X-114 phase separation system. After phase partition at pH > 10, tubulin but not tubulin behaves as a hydrophobic compound appearing in the detergent rich phase. After three extractions of the alkaline aqueous phase with Triton X-114, about 90% of the tubulin was recovered in the detergent rich phase. The hydrophobic behavior observed for tubulin after its dissociation at pH 11.5 was not due to an irreversible change of the protein, because when the detergent rich phase containing tubulin was diluted with a buffer solution at pH 7.3 and the solution allowed to partition again, -tubulin is recovered in the aqueous phase. The detergent in the aqueous phase of the and tubulin preparations can be removed up to 90% by 12 h dialysis. The and subunits of tubulin from kidney and liver behave, in this phase separation system, like those of brain tubulin.     

Role of local germplasm and induced mutations in the improvement of the protein content in rice

Summary Ninety local cultivars and 124 induced grain shape mutants were screened for their protein content and the distribution of protein in their endosperm. The protein content varied widely from 4.2 to 12.1% in the local varieties and from 5.5 to 13.7% in the mutants. Some high protein lines like Chinnavadlu, Budumavadlu, etc. with more than 10.0% protein were identified. Protein distribution studies have shown that several mutants, such as IR-8-FG-28, IR-8-FG-33, etc., have a deeper distribution of protein bodies and some local cultivars, like Kakathya and Muchulu, have a relatively more uniform distribution of protein in the endosperm. The protein content at different milling levels revealed that at 12% milling the percentage retention of protein varied from about 79 to 96% irrespective of the percentage of protein, suggesting that the distribution of protein, in addition to the protein content, plays an important role in nutritive value of rice.