ZurBryotheca europaea

Ohne Zusammenfassung     

Microsatellite analysis of Latial Olea europaea L. cultivars

Olea europaea L. is one of the oldest domesticated tree species. O. europaea varieties cannot be confused because they are very different in morphology, genetics, and secondary metabolite content. It is important to study and establish the genetic structure of vegetal cultivars to better distinguish them, to solve past misclassification, to preserve plant biodiversity, and to increase their use, diffusion, selection, resistance to adversities, marketing, and scientific applications. Five simple sequence repeat loci (DCA-3, DCA-9, UDO99-9, UDO99-35, and EMO-3) were used to differentiate 39 individuals, representing 13 olive cultivars sampled in Latium (Central Italy). The markers showed a high discrimination power and were able to differentiate 39 alleles. Observed heterozygosity ranged from 0.538 at locus UDO99-9 to 1 at locus UDO99-35, with a mean value of 0.784. DCA loci were the most informative ones. Sample clustering, based on their genetic distance and similarity values, produced a phylogenetic network that has shown a unique major group of cultivars, composed of two sub-branches, and two independent taxa.     

盐角草磷酸乙醇胺N-甲基转移酶基因（SePEAMT）启动子的克隆及瞬时表达

磷酸胆碱是合成磷脂酰胆碱和甘氨酸甜菜碱的重要前体,磷酸乙醇胺N-甲基转移酶（PEAMT）是磷酸胆碱合成的关键酶。根据已知的SePEAMT cDNA5'端序列设计两个基因特异的反向引物(PP1,PP2),通过锚定PCR获得了PEAMT起始密码子上游1249bp的序列。RLM-RACE反应确定其转录起始位点A位于起始密码子上游301bp处,由此获得了948bp的SePEAMT启动子序列。PlantCARE和PLACE在线启动子预测工具分析表明：该序列除了含有启动子的基本元件TATA-box和CAAT-box外,还含有一些胁迫诱导元件（如ABRE、HSE、LTR）和花粉特异的激活元件AGAAA。构建了SePEAMT启动子与报告基因GUS 融合的表达载体pPro,并通过农杆菌介导的叶盘法转化烟草,染色结果表明SePEAMT启动子可以有效地驱动GUS基因的瞬时表达。     

Estrone in Olea europaea kernel

The estrogen of the olive kernel and of commercial oils has been investigated. A crystalline estrone has been isolated from olive kernel. An estrogen ester has been assayed in olive oil and a free estrone in corn oil.     

Anaerobic metabolism of Nitrosomonas europaea

Nitrosomonas europaea is capable of maintaining an anaerobic metabolism, using pyruvate as an electron donor and nitrite as an electron acceptor; utilization of nitrite depends upon supply of both pyruvate and ammonia. The role of ammonia in this reaction was not determined. N europaea also assimilates CO₂ anaerobically into cell material in the presence of nitrite (0.5–1.0 mM), pyruvate and ammonia. This reaction was partially inhibited by nitrite which apparently competed with CO₂ for reducing power. Anaerobic nitrite respiration is sensitive to ionophores, FCCP being the most effective.Non-standard-abbreviations TCA trichloroacetic acid - FCCP carbonylcyanide-p-trifluoromethoxyphenylhydrazon     

Ethylene oxidation by Nitrosomonas europaea

Incubation of whole cells of the nitrifying bacterium Nitrosomonas europaea with ethylene led to the formation of ethylene oxide. Ethylene oxide production was prevented by inhibitors of ammonium ion oxidation, and showed properties implying that ethylene is a substrate for the ammonia oxidising enzyme, ammonia monooxygenase. Endogenous substrates, hydroxylamine, hydrazine and ammonium ions were compared as sources of reducing power in terms of rates and stoichiometries of ethylene oxidation. The highest rates of ethylene oxide formation (15 mol h^-1 mg protein^-1) were obtained with hydrazine as donor. The data suggest that at high concentrations of ethylene the rate of oxidation is limited by the rate at which reducing power can be supplied to the monooxygenase, not by an intrinsic V _max. Ethylene had an inhibitory effect on the rate of ammonium ion utilisation; an approximate K _i of 80 M was derived, but the results deviated from simple competitive behaviour. Measurement of relative rates of ethylene oxide formation and ammonium ion utilization led to a k _cat/K _m value for ethylene of 1.1 relative to NH ₄ ⁺ , or 0.04 relative to the true natural substrate, NH₃. The effects of higher concentrations of ethylene oxide on oxygen uptake rates were also investigated. The results imply that ethylene oxide is also a substrate for the monooxygenase, but with a much lower affinity than ethylene.     

Tapetum plastids ofOlea europaea L.

Summary The plastid ontogenesis inOlea europaea tapetum has been studied. Tapetum plastids start their development as proplastids and differentiate into elaioplasts. At the end of their development the tapetal cells degenerate and are substituted by roundish lipidic masses which will later form an exine coating (Pollenkitt). During their ontogenesis the plastids are characteristically associated with membrane outlines of mostly smooth ER, which appear to be correlated with lipid accumulation inside the plastids.     

Energy coupling and respiration inNitrosomonas europaea

Intact cells ofNitrosomonas europaea grown in an ammonium salts medium will oxidise ammonium ions, hydroxylamine and ascorbate-TMPD; there is no oxidation of carbon monoxide, methane or methanol. TheK _m value for ammonia oxidation is highly pH dependent with a minimum value of 0.5 mM above pH 8.0. This suggests that free ammonia is the species crossing the cytoplasmic membrane(s). The measurement of respiration driven proton translocation indicates that there is probably only one proton translocating loop (loop 3) association with hydroxylamine oxidation. The oxidation of endogenous substrates is sometimes associated with more than one proton-translocating loop. These results indicate that during growth hydroxylamine oxidation is probably associated with a maximum P/O ratio of 1.Abbreviations H⁺/O ratio g equiv. H⁺ translocated/g atom O consumed     

Growth of Nitrosomonas europaea on hydroxylamine

Abstract Hydroxylamine is an intermediate in the oxidation of ammonia to nitrite, but until now it has not been possible to grow Nitrosomonas europaea on hydroxylamine. This study demonstrates that cells of N. europaea are capable of growing mixotrophically on ammonia and hydroxylamine. The molar growth yield on hydroxylamine (4.74 g mol⁻¹ at a growth rate of 0.03 h⁻¹) was higher than expected. Aerobically growing cells of N. europaea oxidized ammonia to nitrite with little loss of inorganic nitrogen, while significant inorganic nitrogen losses occurred when cells were growing mixotrophically on ammonia and hydroxylamine. In the absence of oxygen, hydroxylamine was oxidized with nitrite as electron acceptor, while nitrous oxide was produced. Anaerobic growth of N. europaea on ammonium, hydroxylamine and nitrite could not be observed at growth rates of 0.03 h⁻¹ and 0.01 h⁻¹.     

Nutrient reserves of Salicornia europaea seeds

Seeds of Salicornia europaea L. were analyzed for their nutrient reserves. The content of potassium and sodium was 216 and 39 mmol (kg dry seeds)^-1, respectively. Calcium and magnesium accounted for 30 and 138 mmol (kg dry seeds)^-1, respectively. Whereas most of the alkali metals were water soluble, the alkaline earth metals were mostly acid soluble. The acid-soluble calcium plus magnesium corresponded well with the acid-soluble phosphate. Chloride was accumulated to a level equivalent to that of sodium. Carbonate was present at a concentration of 9 mmol (kg dry seeds)^-1. Carbohydrates accounted for 93 g (kg dry seeds)^-1, nearly half of which was derived from sucrose. Fructose and glucose were present only in traces. Total nitrogen was determined to be 55 g (kg dry seeds)^-1, 16% of which was diethylether soluble. The remaining nitrogen was separated into 39 g (kg dry seeds)^-1 ethanol-insoluble and 8 g (kg dry seeds)^-1 ethanol-soluble nitrogen. About 10% of the ethanol-soluble nitrogen were derived from amino acids. Total lipid content was about 280 g (kg dry seeds)^-1. The alcoholic component of the storage lipids was glycerol and the glycerides were calculated from gas chromatography to be 66% of the total lipids. About 90% of the fatty acids consisted of unsaturated acids, linoleic and oleic acid, the majority (77%) of which was linoleic acid.     

Methane oxidation by Nitrosomonas europaea.

Methane inhibited NH4+ utilization by Nitrosomonas europaea with a Ki of 2mM. O2 consumption was not inhibited. In the absence of NH4+, or with hydrazine as reductant, methane caused nearly a doubling in the rate of O2 uptake. The stimulation was abolished by allylthiourea, a sensitive inhibitor of the oxidation of NH4+. Analysis revealed that methanol was being formed in these experiments, with yields approaching 1 mol of methanol per mol of O2 consumed under certain conditions. When cells were incubated with NH4+ under an atmosphere of 50% methane, 50 microM-methanol was generated in 1 h. It is concluded that methane is an alternative substrate for the NH3-oxidizing enzyme (ammonia mono-oxygenase),m albeit with a much lower affinity than for methane mono-oxygenase of methanotrophs.     

Enzyme Immunoassay Detection of Nitrosomonas europaea

An exploratory effort to selectively detect the presence of a nitrifying bacterium, Nitrosomonas europaea, successfully demonstrated the fundamental utility of an enzyme-based immunoassay protocol. The applied polyclonal antibody test seemingly offered a marked improvement over the available analytical options, including plating, activity, and fluorescence immunoassay techniques. Following an initial purification step to enhance overall specificity, this procedure had an apparent lower limit of detection of ~5 × 10⁶ cells per ml. Tests conducted with activated sludge samples exhibited a distinct difference between nitrifying and nonnitrifying mixed liquors, although the highest Nitrosomonas levels observed (i.e., at 1 to 2% of the overall viable cell density) were relatively close to the latter detection boundary.     

Cometabolism of Trihalomethanes by Nitrosomonas europaea

The ammonia-oxidizing bacterium Nitrosomonas europaea (ATCC 19718) was shown to degrade low concentrations (50 to 800 μg/liter) of the four trihalomethanes (trichloromethane [TCM], or chloroform; bromodichloromethane [BDCM]; dibromochloromethane [DBCM]; and tribromomethane [TBM], or bromoform) commonly found in treated drinking water. Individual trihalomethane (THM) rate constants () increased with increasing THM bromine substitution, with TBM > DBCM > BDCM > TCM (0.23, 0.20, 0.15, and 0.10 liters/mg/day, respectively). Degradation kinetics were best described by a reductant model that accounted for two limiting reactants, THMs and ammonia-nitrogen (NH₃-N). A decrease in the temperature resulted in a decrease in both ammonia and THM degradation rates with ammonia rates affected to a greater extent than THM degradation rates. Similarly to the THM degradation rates, product toxicity, measured by transformation capacity (T_c), increased with increasing THM bromine substitution. Because both the rate constants and product toxicities increase with increasing THM bromine substitution, a water's THM speciation will be an important consideration for process implementation during drinking water treatment. Even though a given water sample may be kinetically favored based on THM speciation, the resulting THM product toxicity may not allow stable treatment process performance.     

Cometabolism of trihalomethanes by Nitrosomonas europaea

The ammonia-oxidizing bacterium Nitrosomonas europaea (ATCC 19718) was shown to degrade low concentrations (50 to 800 mug/liter) of the four trihalomethanes (trichloromethane [TCM], or chloroform; bromodichloromethane [BDCM]; dibromochloromethane [DBCM]; and tribromomethane [TBM], or bromoform) commonly found in treated drinking water. Individual trihalomethane (THM) rate constants (k1THM) increased with increasing THM bromine substitution, with TBM > DBCM > BDCM > TCM (0.23, 0.20, 0.15, and 0.10 liters/mg/day, respectively). Degradation kinetics were best described by a reductant model that accounted for two limiting reactants, THMs and ammonia-nitrogen (NH3-N). A decrease in the temperature resulted in a decrease in both ammonia and THM degradation rates with ammonia rates affected to a greater extent than THM degradation rates. Similarly to the THM degradation rates, product toxicity, measured by transformation capacity (Tc), increased with increasing THM bromine substitution. Because both the rate constants and product toxicities increase with increasing THM bromine substitution, a water's THM speciation will be an important consideration for process implementation during drinking water treatment. Even though a given water sample may be kinetically favored based on THM speciation, the resulting THM product toxicity may not allow stable treatment process performance.     

Cytochrome aa3 from Nitrosomonas europaea

Cytochrome c oxidase has been purified from the ammonia oxidizing chemoautotroph Nitrosomonas europaea by ion-exchange chromatography in the presence of Triton X-100. The enzyme has absorption maxima at 420 and 592 nm in the resting state and at 444 and 598 nm in the dithionite-reduced form; optical extinction coefficient (598 nm minus 640 nm) = 21.9 cm-1 nM-1. The enzyme has approximately 11 nmol of heme a and approximately 11 nmol of copper per mg of protein (Lowry procedure). There appear to be three subunits (approximate molecular weights 50,800, 38,400, and 35,500), two heme groups (a and a3), and two copper atoms per minimal unit. The EPR spectra of the resting and partially reduced enzyme are remarkably similar to the corresponding spectra of the mitochondrial cytochrome aa3-type oxidase. Although the enzyme had been previously classified as "cytochrome a1" on the basis of its ferrous alpha absorption maximum (598 nm), its metal content and EPR spectral properties clearly show that it is better classified as a cytochrome aa3. Neither the data reported here nor a review of the literature supports the existence of cytochrome a1 as an entity discrete from cytochrome aa3. The purified enzyme is reduced rapidly by ferrous horse heart cytochrome c or cytochrome c-554 from N. europaea, but not with cytochrome c-552 from N. europaea. The identity of the natural electron donor is as yet unestablished. With horse heart cytochrome c as electron donor, the purified enzyme could account for a significant portion of the terminal oxidase activity in vivo.