Starch Nitrate Research Articles

Heterogeneous O -Nitration of Carboxy Starch

The effect of various factors on preparation of carboxy starch nitrate esters was examined. The ester samples were characterized by IR spectroscopy and chemical analysis.

Influence of nitrogen fertilization on water relations, photosynthesis, carbohydrate and nitrogen metabolism of diverse pearl millet genotypes under arid conditions

Effects of nitrogen fertilization (80 kg N/ha) were studied on pearl millet (Pennisetum glaucum) genotypes including hybrids (MH-179 and HHB-67), composites (CZ-IC-923 and CZP-9604) and land races (Barmer population and CZ-IC-718) grown for 2 consecutive years (1997 and 1998) under rainfed conditions of the Indian arid zone. Nitrogen application significantly increased the grain and stover yields in all the genotypes, particularly in the hybrids during both the years but more so in 1997, characterized by late onset of rains followed by adequate precipitation (299·5 mm). Notwithstanding lower plant water potential and leaf relative water content, N fertilized plants displayed significantly higher photosynthetic rates, leaf area, levels of total chlorophyll, starch, reducing sugars, soluble protein and free amino acids and nitrate reductase activity as compared with unfertilized control plants in all the genotypes during both the years.Genotypes HHB-67 and Barmer population during 1997 and HHB-67 and CZ-IC-718 during 1998 provided significantly higher grain yields than other genotypes whereas dry matter production was highest in cv. Barmer population during both the years. These genotypes generally maintained higher rates of photosynthesis, more efficient carbohydrate metabolism and higher nitrate reductase activity leading to better performance. Relatively higher yields of land races than composites and comparable with those of hybrids indicated adaptation of these cultivars to arid conditions and maintenance of several characteristics for their superior performance which could be further augmented by N application.Fertility induced improvement of metabolic efficiency, coupled with higher photosynthesis and nitrate reductase activity for efficient N utilization seem to be the control mechanisms, for enhanced growth and yield of diverse pearl millet genotypes under limited water conditions.

Influence of Water Stress on Water Relations, Photosynthetic Parameters and Nitrogen Metabolism of Moth Bean Genotypes

Effects of water stress at pre-flowering stage were studied in three genotypes (RMO-40, Maru moth and CZM-32 E) of moth bean [Vigna aconitifolia (Jacq.) Marechal]. Increasing water stress progressively decreased plant water potential, leaf area, net photosynthetic rate, starch and soluble protein contents and nitrate reductase activity while contents of reducing sugars, total soluble sugar, free amino acids and free proline progressively increased. Significant genotypic differences were observed and genotype CZM-32-E displayed a better drought tolerance than other genotypes.

Isolation and enumeration of marine actinomycetes from seawater and sediments in Alexandria.

Actinomycetes were isolated from near-shore marine sediments and water at four different sites in Alexandria. Statistical analysis revealed that variation in temperature, pH, and dissolved phosphate were of insignificant values, but that variation in total nitrogen and organic matter were significant. The treatment of sediments and water samples by heat resulted in a selective reduction of the nonactinomycetal heterotrophic microflora. Four selective culture media were used for counting actinomycetes in marine water and sediments. The starch nitrate medium favored the growth of these microorganisms. The diversity and counts of actinomycetes varied with the seasonal variation, and the highest counts were detected in dry warm seasons. The numbers of this bacterial group in sediments exceeded by far their numbers in seawater. A positive correlation was found between population size and location. Actinomycetes were found in the highest numbers in the upper layers (0-20 cm depth). In a few cases, the counts of actinomycetes showed bimodal maxima 0-20 and 60-100 cm deep. Sediments were the best source of marine actinomycetes, and their distribution varied depending on the depth from which samples were collected. The ratio of actinomycetes to the total microflora ranged from 0.48 to 2.29, depending on location.

Optimization of culture conditions for indole-3-pyruvic acid production by Streptomyces griseoflavus

Thirty strains of actinomycetes were isolated from fertile soils in Egypt on starch–nitrate agar. The isolated organisms were recognized as spore formers with aerial mycelia containing L-DAP (diaminopimelic acid) and glycine. The inability of the vegetative mycelia to fragment into bacillary or coccoid forms and the presence of spores borne on sporophores, placed these organisms in the family Streptomycetaceae. The isolates also proved to be aerobic and Gram positive. The absence of DL-DAP and the presence of L-DAP in their cell hydrolysates, and the production of a wide range of pigments in the aerial and substrate mycelia, assigned these isolates to the genus Streptomyces. The isolated organisms were screened for production of plant growth regulators, and the most active producer of indole-3-pyruvic acid was examined further. Using the described morphological, physiological, and biochemical criteria for identification, this organism was identified as Streptomyces griseoflavus. The optimal culture conditions for maximal production of both cellular and extracellular indole-3-pyruvic acid by S. griseoflavus were investigated and shown to be as follows: a culture medium composed of (g∙100 mL−1) NH4NO3, 0.55; DL-tryptophan, 0.4; NaCl, 0.7; at pH 7 (buffered); with an incubation period of 6 days at 28 °C in the dark and under shaking conditions.Key words: actinomycetes, plant growth regulators, Streptomyces griseoflavus, indole-3-pyruvic acid, culture conditions.

Nutrient effects on growth and the production of 5-hydroxy-4-oxonorvaline by Streptomyces akiyoshiensis

5-Hydroxy-4-oxonorvaline (HON) was produced optimally by Streptomyces akiyoshiensis in media containing starch and casein supplemented with high concentrations of phosphate and magnesium sulfate; cultures grown at initial pH values between 6.3 and 6.6 yielded HON titres of 13-14 mM. Physiological analysis of HON production provided evidence that the excess inorganic constituents in this medium played an important role in optimizing production. In simple defined media buffered at pH 5.5-6.0 and inoculated with either a spore suspension or washed vegetative mycelium, formation of HON was less than one-third the amount produced in the starch-casein-salts medium. Production was markedly affected by the carbon and nitrogen sources used; media containing starch and potassium nitrate or aspartate supported the highest yields of HON. In starch-nitrate media, production was suppressed by excess nitrogen source, and the HON titre decreased 3-fold as the phosphate content was increased from 0.5 to 5 mM; growth was not appreciably altered. The results suggest that the high level of HON production in the complex starch-casein-salts medium is associated with sequestration of metabolic ammonium and reduced availability of phosphate through formation of the poorly soluble magnesium ammonium phosphate.

Deuterium heterogeneity in starch and cellulose nitrate of cam and C 3 plants

Starch and cellulose were extracted and nitrated from well illuminated photosynthetic tissues of seven C 3 species and nine CAM species. Results show that (i) δD values of cellulose nitrate from CAM species are on average 73%ο higher than cellulose nitrate of C 3 plants; (ii) δD values of nitrated cellulose from C 3 and CAM species are significantly higher than their respective nitrated starch and (iii) the lower the δD value of starch the higher the difference between δD of nitrated cellulose and starch, with CAM plants showing a greater enrichment. These results confirm the model that deuterium enrichment occurs during carbohydrate metabolism in the cytoplasm, and are consistent with the hypothesis that deuterium enrichment of the cytoplasmic carbohydrate pool occurs to a greater extent in CAM plants.

An Evaluation of Cassava Starch as a Gelling Material for Electrochemical Salt Bridges

AbstractCassava starch was investigated for its potential use as a gelling material for electrochemical salt bridges. Different electrolytes, KCl, NH4 and NH4NO3, were mixed with the starch and the resulting voltage of a Zn–Cu Cell in which it is used as a salt bridge was measured. The observed voltage agreed with the theoretical voltage within 3.6% error. It was observed that the starch and ammonium nitrate electrolyte produced a better blend, gave more reproducible values and has the lowest resistance of all the other electrolyte‐starch mixtures.

Starch Nitrate

The nitrate ester is the oldest known derivative of starch. Since the beginning of this century, it has been, industrially, by far the most important, high-substituted starch derivative. Possibly the first chemist to experiment with the making of starch nitrate by the modern practice of using mixed nitric and sulfuric acids was Hugo Reinsch in 1849. He used equal parts of nitric acid and sulfuric acid and added 5–9 parts of this mixture to starch, forming slurry instead of a colloid. Commercial starch nitrate has an average nitrogen content of about 13.2%. Its efficiency as an explosive is a direct function of the nitrogen content; but the cost of making it also rises with the proportion of nitrogen, and the “happy medium” seems to be about 13.2 %. For civil uses, the properties of starch nitrate as a high explosive are competitive with those of other types employed; and, for military uses, it has been proved to be an exceptionally good substitute for 1,3,5-trinitrotoluene (TNT).

STUDIES ON THE PHYSIOLOGY OF ELSINOE VENETA

A study was made of the effect of certain nutritional and environmental factors on the growth and pigmentation of the mycelium, the sporulation, and the germination of the conidia of a "convoluted" isolate of Elsinoe veneta (Burkh.) Jenkins, the fungus responsible for the anthracnose disease of raspberries. This isolate utilized with varying degrees of efficiency various mono-, oligo-, and polysaccharides as well as certain organic alcohols as its sole source of carbon for growth. Either a nitrate, ammonium, amino, or imidazole nitrogen compound supported the fungus in culture. Maximum growth of the mycelium occurred in the presence of soluble starch and asparagine, whereas optimum sporulation of the conidia was obtained on media containing potato starch and sodium nitrate. In general, the production of conidia was markedly reduced on media favorable for excessive vegetative growth. Both a decrease in the volume of the medium and in the concentration of either a specific nutrient or of total nutrients adversely influenced the production of mycelium. Temperatures above 30 °C. and below 21 °C. decreased the percentage germination of conidia and restricted the growth of the fungus. Growth and sporulation occurred over a wide range of pH values. The optimum initial pH for both growth and sporulation was 4.0. E. veneta produced conidia and grew as well in continuous darkness as in alternate diffuse light and darkness. Young potted raspberry plants growing in the greenhouse, when inoculated with conidia produced in culture, developed typical anthracnose lesions on the canes.

STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: LXIII. THE STABILITY OF MALTOSE AND CELLOBIOSE OCTANITRATES

Cellobiose and maltose were nitrated and their properties studied to note the effect of the difference in glycosidic linkage (β- and α-respectively). Cellobiose octanitrate is more stable than maltose octanitrate as measured by the Abel test, and both are less stable than cellulose and starch nitrates. Neither of the octanitrates is sufficiently stable to permit of the application of the Bergmann–Junk test. If the stability of the cellulose nitrate building unit, namely, cellobiose octanitrate, carries over into its polymeric form, it would be expected that cellulose nitrate (characterized by 1,4-β-glucosidic linkages) should be inherently more stable than starch nitrate (α-1,4-glucosidic linkages).

STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: LXII. EFFECT OF HOT ALKALI ON THE NITRATES OF STARCH, AMYLOSE, AND AMYLOPECTIN

The nitrates of starch, amylose, and amylopectin were treated with hot aqueous sodium hydroxide solution and the effect of this treatment upon each noted. This treatment does not cause appreciable denitration, nor does it result in a usefully stable nitrate. The nitrates of the starches are more resistant to alkali than is cellulose nitrate. Amylose nitrate appears to resemble cellulose nitrate in being more alkali-labile than either whole starch nitrate or amylopectin nitrate; this is consistent with its linear chain structure. The greater stability of amylose nitrate as compared to amylopectin nitrate is paralleled by a greater alkali-lability of the former, which indicates that the inherent instability of starch nitrate is not due to the presence of free terminal aldehyde groups present either in native starch or formed during the nitration process.

STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: LXI. PROPERTIES OF THE FRACTIONATED NITRATES OF TWO FRACTIONS OF CORN STARCH

Corn starch has been separated into two individual components, arbitrarily designated as amylose (linear fraction) and amylopectin (branched-chain fraction) by means of preferential adsorption on cellulose (Tanret–Pacsu method). These components have been nitrated and their nitrates fractionated by dissolution in ethanol. The relative stabilities and nitrogen contents of the nitrated fractions have been studied.Unfractionated amylose nitrate has greater stability than unfractionated amylopectin nitrate as judged by the Bergmann–Junk test. Dissolution methods of fractionation showed a much higher solubility of the amylopectin nitrate, the greater relative stability of the amylose fractions, and the somewhat greater stabilizing action of ethanol in the case of the latter.The widely different solubilities of amylose and amylopectin nitrates in conjunction with the lower ethanol solubility of whole starch nitrate are in accordance with the theory of a branched-chain structure for amylopectin and the linear type for amylose.

STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: LX. STABILIZING ACTION OF ETHANOL ON STARCH NITRATES

Fractional dissolution has been applied to nitrated corn starch with the consequent removal of ethanol-soluble fractions. Hot and cold ethanol-soluble fractions have been removed in this way amounting to from 10 to 25% of the crude nitrate. The ethanol-soluble fractions, consisting of low-molecular weight and low nitrogen-content material, are not stabilized by ethanol. The insoluble portion is greatly stabilized as a result of the ethanol treatment.The insoluble residue left after ethanol treatment of crude starch nitrate possesses good explosive properties, a high nitrogen content, and high stability. The stabilization of starch nitrate by ethanol is shown to be the result of a dual action, namely, (a) removal of highly unstable material of low molecular weight and nitrogen content, and (b) the conferring of increased stability by some, as yet unknown, mechanism on the insoluble portion.