Vegetable Plant Part Relationships. III. Modification of Carrot (Daucus carota L.) Root and Shoot Weights by Gibberellic Acid and Daminozide

Aqueous foliar sprays of N-dimethylaminosuccinamic acid (daminozide)at 2000 p.p.m. and gibberellic acid (GA) at 100 p.p.m. wereapplied 45, 59, 82 and 100 days after sowing to Chantenay carrotswith population densities of 244, 495 and 883 plants m^–2.The plants were harvested on ten approximately weekly occasions;fresh weights were determined and d. wt estimates were obtainedfor the separated shoots (s) and roots (r). Allometric linearregressions of the logarithm of s on that of r at each harvestseparately, clearly showed that GA always increased shoot: rootratio and reduced root yield (by approximately 35 per cent)but could sometimes also increase whole-plant weight. Daminozideincreased root yield (by approximately 7 per cent from 80 tonnesha^–1) and tended to have effects opposite to those ofGA. Daucus carota L., carrot, root weight, shoot weight, N-dimethylaminosuccinamic acid (daminozide), gibberellic acid     

OBSERVATIONS ON THE EFFECT OF ADDED HYPOCHLORITE ON THE NUMBERS AND KINDS OF BACTERIA IN MILK

SUMMARY: In an investigation of the effect of added hypochlorite on the bacterial flora and bacterial numbers of milk no bactericidal action was apparent within 15 min of adding the disinfectant unless at least 500 p/m available chlorine had been added. After 24 hr storage at atmospheric temperature a reduction in numbers was found with 10 p/m available chlorine and this became more pronounced with increased concentrations. Micrococci seemed more susceptible to the bactericidal effect than streptococci, which formed, after 24 hr storage, the predominant residual flora where 250 and 500 p/m available chlorine had been added. Acid production by lactic streptococci was retarded at concentrations greater than 50 p/m available chlorine in a 5 hr incubation period at 30°, but after a 24 hr incubation the decrease in acid production was only apparent when 500 or 1,000 p/m available chlorine was present. Little effect on acid production by lactic streptococci was found when less than 50 p/m available chlorine had been added. The residual chlorine content of rinses of equipment sterilized in hypochlorite solutions was negligible.     

CRYSTALLIZATION OF PEPSIN FROM ALCOHOL

1. Pepsin is soluble in 65 per cent alcohol and may be readily crystallized from 20 per cent alcohol. The crystals appear as needles or plates which may be transformed into the usual hexagonal bipyramids by recrystallization from water. The different crystals are probably two crystalline forms of the same chemical substance. 2. The enzyme is quite stable in 20 per cent alcohol at pH 2.0 but is inactivated by high concentrations of alcohol. 3. The enzyme is stable for several hours in 65 per cent alcohol at pH 4.0 to 5.0 but is rapidly inactivated in more acid solution. 4. No increase in activity could be noted after treatment with hydrogen peroxide. 5. No proteolytic activity either before or after treatment with hydrogen peroxide could be found in trichloracetic acid filtrates, butyl alcohol extracts of pepsin preparations, or oxidized phenylhydrazine solutions.     

Optimization of poly(β-hydroxybutyric acid) recovery from Alcaligenes latus: combined mechanical and chemical treatments

Recovery of the intracellular bioplastic poly(β-hydroxybutyric acid) or PHB from fed-batch cultured Alcaligenes latus, ATCC 29713, was examined using combinations of chemical and mechanical treatments to disrupt the cells. Chemical pretreatments used sodium chloride and sodium hydroxide. For salt pretreatment the cells were exposed to NaCl (8?kg?m^?3) and heat (60?°C, 1 h), cooled to 4?°C, and mechanically disrupted. For alkaline treatments, the cells were exposed to sodium hydroxide (0.025–0.8 kg?NaOH per kg biomass) and mechanically disrupted at ambient temperature. A combined treatment with sodium chloride (8 kg m^?3), heat (60?°C, 1 h), and alkaline pH shock (pH 11.5, 1?min) was also tested. Mechanical disruption employed a continuous flow bead mill (2,800 rpm agitation speed, 90?ml?min^?1 slurry flow rate, 512 m mean bead diameter, bead loadings of 80% or 85% of chamber volume). Disruption was quantified by protein release. Over most of the disruption period, the release of PHB was approximately proportional to protein release. Regardless of the pretreatment or bead load, the disruption obeyed first order kinetics; hence, the rate of protein release was directly proportional to the amount of unreleased protein. Relative to untreated biomass, pretreatment always produced earlier protein release during milling. Pretreatment with a minimum of 0.12?kg NaOH per kg biomass was necessary to enable complete disruption within three passes (85% bead load). Untreated biomass required more than twice as many passes. Irrespective of the chemical pretreatment, the bead loading strongly influenced the disruption rate which was higher at the higher loading. Alkaline hydrolysis associated PHB loss was observed, but it could be limited to insignificant levels by immediate neutralization of disrupted homogenates.     

Effects of Salinity and Temperature on Seed Germination in a Japanese Endangered Halophyte Triglochin maritimum (Juncaginaceae)

Triglochin maritimum (Juncaginaceae). Germination tests were carried out at three salinity levels (0,200,400 mM NaCl in which seeds were exposed to increasing- or decreasing temperatures. Effects of moist-chilling pretreatment (stratification) in 0,200 and 400 mM NaCl on seed germination at 0,200 and 400 mM NaCl, respectively, were also examined. Under the highest salinity condition (400 mM NaCl), no germination was observed. The seeds germinated very well (88%) in fresh-water after 5-month moist-chilling pretreatment. Longer moist-chilling pretreatment resulted in higher germination percentages. Moist chilling pretreatment in 0,200 and 400 mM NaCl for 5 month enhanced germination percentages to 10% (in 400 mM NaCl) –88% (in 0 mM NaCl). Received 10 December 1998/ Accepted in revised form 8 October 1999     

Dynamic of black-grass populations depending on the sowing time of winter wheat

Currently, economic, agronomic and environmental concerns, lead to reduce use of herbicides. This reduction can be help by cultural measures like delay of the sowing date. Four sowing dates of winter wheat from 15th of October to 26th of November were tested. Dynamic of black-grass (Alopecurus myosuroides Huds.) populations and their reproduction rate were assessed as well as dynamic of winter wheat for each date. Delay of sowing could significantly reduce reproduction rate of black-grass. It was shown that the emergence rate (pl/m2), but also number of ears per plant and number of seeds per ear of black-grass decreased significantly with the sowing date. This reduction of seeds production already is from sixty per cent for a delay of two weeks sowing.     

Carbon Assimilation at Low Carbon Dioxide Levels: I. APPARATUS AND TECHNIQUE

The construction and operation of a versatile apparatus forthe measurement of CO₂ exchange of detached plant parts is described. CO₂ concenteration was measured with an accuracy of about ±3per cent using a commercial infra-red gas analyser; measurementswere made at ambient CO₂ levels between 10 and 10,000 p.p.m.(0.001 per cent. and 1.0 per cent. by volume), at leaf temperaturesbetween 5°C. and 40°C. (±0.1°C.) and at lightintensities up to 2,000 foot candles. The measurements were made on either a fixed volume of gas repeatedlypassed over the leaf, or on a stream of gas passing over theleaf once only, or with any desired combination of these two. Rates of gas flow (up to 801./hr.) could be controlled to finelimits independent of changes in flow resistance and measuredwith an accuracy of at least ±1 per cent., if required.     

Extracellular release of free fatty acids by rat T lymphocytes is stimulus-dependent and is affected by dietary lipid manipulation

[(3)H]-Arachidonic acid-labelled rat T lymphocytes released radioactivity extracellularly when stimulated by the calcium ionophore A23187 or by monoclonal antibodies to some cell surface structures (CD2, CD5, CD11a, CD18, CD54, T-cell receptor) but not to others (CD49d, CD62L); release was greater with the calcium ionophore. Almost all of the radioactivity released from anti-CD2-stimulated lymphocytes was recovered in the free fatty acid fraction, whereas only about 50 per cent of that released after A23187 stimulation was recovered in this fraction. A23187 stimulation resulted in release of arachidonic acid from a variety of phospholipids (phosphatidylinositol, phosphatidylcholine and perhaps phosphatidylethanolamine), while the monoclonal antibody stimulation released arachidonic acid from phosphatidylinositol and perhaps phosphatidylcholine. Unstimulated lymphocytes released a range of fatty acids extracellularly, with palmitic acid accounting for 35-40 per cent and arachidonic acid for 5 per cent of released fatty acid. Stimulation of lymphocytes with either anti-CD2 or A23187 increased total fatty acid release 1.5- to 1.8-fold. In both cases palmitic acid remained the most predominant fatty acid released but the contribution of arachidonic acid increased. The type of lipid fed to the rats significantly influenced the amount and type of fatty acid released. Fish oil feeding significantly reduced extracellular fatty acid release by stimulated lymphocytes.     

Inhibitory effects of calcium ionophore pretreatment of porcine oocytes on polyspermic fertilization

The present study examined the inhibitory effects of various pretreatment concentrations (0-100 microM) of the calcium ionophore A23187 on polyspermic fertilization and then examined the effect of the maturation period and the time between calcium ionophore treatment and fertilization on the inhibitory effect of calcium ionophore on polyspermic fertilization. In experiment 1, a high concentration of calcium ionophore (100 microM) increased the rate of activated oocytes, but the rate of fertilization declined. On the other hand, when oocytes were treated with a low concentration of calcium ionophore (10 microM), monospermic fertilization was significantly increased (10 microM; 31.3%) (p < 0.05). In experiment 2, oocytes were cultured for various times (0, 0.5, 3, 6 h) after calcium ionophore treatment (10 microM) before fertilization. The highest rate of monospermic fertilization was detected in the oocytes cultured for 6 h after calcium ionophore treatment before fertilization. In experiments 3 and 4, we examined the effect of the maturation period (40 h or 44 h) on the rate of fertilization and blastulation of oocytes pretreated with calcium ionophore. The treatment of oocytes with calcium ionophore significantly decreased the rate of polyspermic fertilization regardless of the maturation period (44 h: with calcium ionophore 26.25% vs without 78.8%; 40 h: with calcium ionophore 37.5% vs without 77.5%); however, calcium ionophore treatment increased the rates of monospermic fertilization and blastulation of the oocytes matured for 44 h, but not those matured for 40 h. In conclusion, activation with a low concentration of calcium ionophore (10 microM) and a further 6 h of culture before fertilization improved the rate of monospermic fertilization and blastulation.     

ON THE CHEMICAL COMPOSITION OF THE AXOPLASM OF SQUID GIANT NERVE FIBERS WITH PARTICULAR REFERENCE TO ITS ION PATTERN

Investigations dealing with the determination of the major chemical constituents of the axoplasm of the giant nerve fiber of the squid are described. Particular emphasis has been placed on determining the components involved in acid-base balance. It was found that 72 per cent of the total solids of axoplasm, representing 13.5 per cent of the wet material, are of relatively low molecular weight (dialyzable) and consist mainly of charged ionic or dipolar constituents. Of the 520 micromoles per gm. of total base, 72 per cent are balanced by organic acids: aspartic acid (65 micro equivalents per gm.), glutamic acid (10 micro equivalents), fumaric and succinic acids (15 micro equivalents), a new polycarboxylic acid (35 micro equivalents), and isethionic acid, a biologically novel sulfonic acid (220 micro equivalents). Besides potassium, sodium, small amounts of calcium, and magnesium there is a considerable fraction of organic (nitrogenous) base. Other features of the chemical composition of squid axoplasm include a relatively high concentration of taurine (100 micro equivalents) and an ultraviolet absorbing substance possibly identical with N-methylpicolinic acid. The distribution of the phosphates, especially the concentration of ATP, has been investigated. Specific techniques elaborated in connection with this study have been described and the biochemical implications of the analytical results are discussed.     

Morphological and chemical studies of the spores and parasporal bodies of Bacillus laterosporus

Spores of Bacillus laterosporus were studied to determine the chemical and morphological nature of their basophilic canoe-shaped parasporal bodies. An unusually high phosphorus content of these spores compared to other Bacillus species appeared to be associated with the parasporal body. Preparations of these "canoes" still attached to the spore coats were indeed high in phosphorus, but also in nitrogen. They were free of lipide-soluble and nucleic acid phosphorus and stained for protein. Some 50 per cent of the total nitrogen, but only 6 to 10 per cent of the total P were liberated by extraction with alkali-thioglycollate (pH 11.5) or alkali alone (pH 12.2-12.5). Proteinaceous material was recovered from these alkaline extracts and electron microscopy indicated that there had been a marked loss of "canoe" substance. Extraction with acid, removed some 80 per cent of the phosphorus associated with the "canoes" as orthophosphate. Chromatographic analyses for amino acids indicated some 14 ninhydrin-positive spots in the canoe-coat preparations whereas the whole spores contained at least 16.     

The growth and resistance to sodium hypochlorite of Listeria monocytogenes in a steady-state multispecies biofilm

A constant-depth film fermenter (CDFF) was used to culture a steady-state multispecies biofilm consisting of one strain each of Listeria monocytogenes, Pseudomonas fragi and Staphylococcus xylosus. These bacteria were initially grown together in a conventional chemostat to achieve a steady state before being inoculated into the CDFF over an 18-h period. A dilute tryptone soya broth (TSB) medium was supplied to the CDFF and the biofilm allowed to develop over a 28-d period. This mature biofilm was then subjected to increasing levels of sodium hypochlorite solution to measure any antimicrobial effect. The three organisms were seen to reach a steady state after 6 d in the chemostat before being transferred to the CDFF where the mature multispecies biofilm reached steady state at 17 d. Listeria monocytogenes in both planktonic and biofilm growth stabilized at 1. 8 and 1.5%, respectively, of the total plate counts, while Ps. fragi and Staph. xylosus were the predominant organisms in the biofilm at 59% and 39.5%, respectively, of the total microbial population. Steady-state biofilms in the CDFF were exposed to increasing strengths of sodium hypochlorite; 200, 500 and 1000 p.p.m. free chlorine, but a substantial two-log cycle drop in bacterial numbers was only achieved at 1000 p.p.m. free chlorine. In planktonic culture all three organisms were completely eliminated when exposed to 10 p.p.m. free chlorine for a 30-s period.     

On phytin phosphorus in the soil

Summary Phytin was isolated from a diluvial sand which has been cultivated for about 800 years. Various investigations of the organic phosphoric compounds isolated made it probable that the substance was phytin.A method for a quantitative determination of phytin phosphorus in soil was worked out. In the heath soil in question 163 p.p.m. phytin phosphorus was found to correspond to 46 per cent. of the total content of organically held phosphorus.In acid soils phytin is presumably found as ferric phytate and in basic soils possibly as calcium phytate.     

Pilot plant scale extraction of alginates from Macrocystis pyrifera 3. Precipitation, bleaching and conversion of calcium alginate to alginic acid

Three steps of the alginate production process were studied at pilot plantlevel. The effect of the amount of calcium chloride used during theprecipitation was measured in terms of filtration time of the precipitatedcalcium alginate. Three different proportions of calcium chloride per gramof alginate were tested. The best proportion used was 2.2 parts ofcalcium chloride per one part of alginate, yielding a filtration rate of 97.9L min^-1 on a screen area of 1.32 m². The method ofadding the solutions and the degree of mixing are discussed as other factorsaffecting the precipitation step. The effect of bleaching the calciumalginate with sodium hypochlorite (5%) was studied. Seven proportions,ranging from 0 to 0.77 mL of sodium hypochlorite per gram of sodiumalginate were tested. The effect of hypochlorite was compared foralginates with three different viscosities. Using alginates with mediumviscosity (300–500 mPa s), the best proportion was 0.4 mL hypochloriteper gram of alginate, yielding an alginate of light cream color with 20%less viscosity than the control. Alginates with lower viscosity showed asmaller loss of viscosity. The effect of pH during conversion of calciumalginate to alginic acid was determined using four combinations of pH,ranging from 2.2 to 1.6, in three acid washings. The extent of conversionwas determined by measuring the percent reduction of the alginate viscosity(RV) in 1% solution before and after adding a sequestrant of calcium. When a pH 1.8 or 1.6 was used for each washing, only two washings werenecessary to produce a RV lower than 40% (maximum recommended). The use of pH 2 required three acid washings to produce the same effect. The pH 2.2 did not remove enough calcium, even with three washings,the RV of the resulting sodium alginate being greater that 40%. Theresults of these experiments provide the information that producers needwhen deciding the best parameters to obtain a product with the desiredcharacteristics.     

Morphological and Chemical Studies of the Spores and Parasporal Bodies of Bacillus laterosporus

Spores of Bacillus laterosporus were studied to determine the chemical and morphological nature of their basophilic canoe-shaped parasporal bodies. An unusually high phosphorus content of these spores compared to other Bacillus species appeared to be associated with the parasporal body. Preparations of these "canoes" still attached to the spore coats were indeed high in phosphorus, but also in nitrogen. They were free of lipide-soluble and nucleic acid phosphorus and stained for protein. Some 50 per cent of the total nitrogen, but only 6 to 10 per cent of the total P were liberated by extraction with alkali-thioglycollate (pH 11.5) or alkali alone (pH 12.2–12.5). Proteinaceous material was recovered from these alkaline extracts and electron microscopy indicated that there had been a marked loss of "canoe" substance. Extraction with acid, removed some 80 per cent of the phosphorus associated with the "canoes" as orthophosphate. Chromatographic analyses for amino acids indicated some 14 ninhydrin-positive spots in the canoe-coat preparations whereas the whole spores contained at least 16.     

Germination responses to temperature responsible for the seedling emergence seasonality ofPrimula sieboldii E. Morren in its natural habitat

Temperature requirements for the breaking of seed dormancy and germination inPrimula sieboldii E. Morren and the annual surface-soil temperature regime in one of its natural habitats were investigated in order to clarify the germination responses determining the seedling emergence seasonality of the species. In a grassland nature reserve in an abandoned flood plain of the Arakawa River, natural seedling emergence of the species was shown to be restricted to mid- to late-spring before the closure of seasonal vegetational gaps, when the daily mean soil surface temperature reached about 15°C, accompanied by large daily fluctuations of about 10°C. Mature seeds collected in late June were never able to germinate at any constant temperature in the range of 8–40°C unless they had been previously subjected to moist-chilling treatment. The proportion of seeds which were released from dormancy increased with increasing duration of the moist-chilling treatment at 2°C, 70–85% of seeds becoming germinable at 16–28°C after 12 weeks of pretreatment at 2°C. The thermal time required for the germination of the thus-pretreated seed population was 905–1690 Kh with a base temperature of around 5°C. Fluctuating temperatures between 24°C and 16 or 12°C had a remarkable dormancy-breaking effect, inducing considerably quick germination in most of the seeds previously subjected to 2°C moist-chilling for 8 weeks.     

Influence of S-ethyl Dipropylthiocarbamate on Atrazine Absorption by Wheat

Wheat (Triticum sativum L. cv. Nisu) grown in 0·5 Hoaglandssolution containing sub-toxic concentrations of S-ethyl dipropylthiocarbamate(EPTQ (0,0·0625,0·125,0·25, and 0·5p.p.m.w.) were exposed to ¹⁴C-ring labelled-2-chloro-4-ethylamino-6-isopropylamino-s-triazine(atrazine). Total ¹⁴C-atrazine absorption was increased to 182per cent in wheat treated with 0•5 p.p.m.w. EPTC when comparedto the EPTC untreated wheat. Detoxification and metabolism ofEPTC were not appreciably altered by EPTC pretreatment. Thisresulted in an increased atrazine content in the wheat leavespretreated with 0·5 p.p.m.w. EPTC that amounted to 370per cent of the unchanged atrazine present in the leaves ofEPTC untreated wheat.     

Formulation of Bacillus amyloliquefaciens B190 for Control of Lily Grey Mould (Botrytis elliptica)

Calcium hydroxide (0.1%) significantly increased the growth of Bacillus amyloliquefaciens B190, inhibited completely the germination of Botrytis elliptica, and decreased the disease severity caused by B. elliptica on lily. Spraying B. amyloliquefaciens B190 mixed with either 0.025% calcium hydroxide, 0.05% sodium carbonate or 0.025% ammonium nitrate decreased the grey mould disease on lily leaves. B. amyloliquefaciens B190 mixed with 0.025% calcium hydroxide and 0.05% sodium carbonate, or mixed with 0.025% calcium hydroxide and 0.025% ammonium nitrate controlled lily grey mould completely. When the concentration of tested adjuvants was below 0.1% (v/v), adhesive adjuvant, i.e. carboxymethyl cellulose and spreader, i.e. Tween 80 were equally effective to assist B. amyloliquefaciens B190 to control lily grey mould. Calcium hydroxide (0.025%) and 0.05% sodium carbonate mixed with 0.1% Tween 80 significantly controlled lily grey mould. B. amyloliquefaciens B190 mixed with 0.025% calcium hydroxide and 0.05% sodium carbonate, and these two chemicals plus or without 0.1% Tween 80 and 0.05% mineral oil (i.e. emulsion and wettable powder, respectively) was consistently able to control grey mould on lily as well as 100 p.p.m. flusilazole in greenhouse and field trials, respectively.     

REVIVAL OF MAMMALIAN SPERM AFTER IMMERSION IN LIQUID NITROGEN

1. A wide variety of procedures was used to test the motility of mammalian sperm after plunging them into liquid nitrogen at –195°C. and later rapidly warming them to 35°C. by plunging them into a suitable balanced and isotonic medium. 2. Using seminal fluid sperm from the same human donor, maximal numbers of motile sperm survived vitrification when the samples were (a) very fresh, (b) untreated with plasmolysing solutions, (c) plunged into the refrigerant in the form of a foam. The maximum yield of motile human sperm recoverable from the liquid nitrogen was 50 per cent. Since in this sample only 75 per cent of the sperm were alive before immersion, 67 per cent of the living sperm survived vitrification. 3. Experiments with sperm from 31 rabbits were made with a variety of conditions of pretreatment to obtain maximal yields of recoverable, motile sperm after vitrification by liquid nitrogen. (a) A consistent recoverable yield of about 0.5 per cent was obtained when the untreated suspension of sperm was smeared on cellophane and partially dried in air before immersing in liquid nitrogen. (b) On a few out of many occasions plasmolysis for several minutes with hypertonic Ringer solution gave a recoverable yield of 0.1 per cent as did (c) pretreatment with hypertonic Ringer and butyric acid.     

Assessment of genotoxicity of 14 chemical agents used in dental practice: ability to induce chromosome aberrations in Syrian hamster embryo cells

To assess the genotoxicity of 14 chemical agents used as locally applied agents in dental practice, the ability of these agents to elicit chromosome aberrations was examined using Syrian hamster embryo (SHE) cells. Chromosome aberrations in SHE cells were induced by treatment with three of eight chemical agents used as endodontic medicaments, i.e. ethylenediaminetetraacetic acid (EDTA), formocresol (a mixture of formalin and tricresol), and sodium arsenite. The other five chemical agents, i.e. chloramphenicol, p-chlorophenol, p-phenolsulfonic acid, sodium hypochlorite, and tetracycline hydrochloride exhibited a negative response for chromosome aberrations. Assessment of three dyes used for disclosing dental plaque showed chromosome aberrations induced by basic fuchsin but not by acid fuchsin and erythrosine B. Three local anesthetics, lidocaine hydrochloride, prilocaine hydrochloride, and procaine hydrochloride, were negative for chromosome aberrations. Among the ten chemical agents that exhibited a negative response in the assay, p-chlorophenol, sodium hypochlorite, and erythrosine B induced chromosome aberrations in SHE cells when treated in the presence of exogenous metabolic activation. The percentages of cells with polyploidy or endoreduplication were enhanced by formocresol, sodium arsenite, p-chlorophenol, p-phenolsulfonic acid, sodium hypochlorite, erythrosine B, prilocaine hydrochloride, and procaine hydrochloride in the absence or presence of exogenous metabolic activation. Our results indicate that the chemical agents that had a positive response in the present study are potentially genotoxic to mammalian cells.