The simultaneous determination of muramic acid and glucosamine in soil by high-performance liquid chromatography with precolumn fluorescence derivatization

Summary The optimal release and quantitative estimation of muramic acid and glucosamine were studied simultaneously in soil samples. The effect of hydrolysis conditions, HCl concentration, hydrolysis time, the ratio of soil dry weight to acid, and the recovery of reference substances were investigated. Derivatization of the fluorogenic reagent o-phthalaldehyde, in the presence of 2-mercaptoethanol with the residue of a soil hydrolysate, was achieved by optimizing the relative amounts of o-phthalaldehyde to hydrolysate in the reaction mixture, the pH of both, and the incubation period. A linear relationship was found between the fluorescence response and the concentration of the test substances. The muramic acid, as well as the glucosamine (o-phthalaldehyde) derivatives gave single peaks, and complete separation from interfering substances at the picomol level was achieved in a short time (3 h preparation and 30 min for chromatography) by using high-performance liquid chromatography.     

Use of transmittance near-infrared spectroscopy to predict the mechanical properties of 1- and 2-year-old transgenic aspen

The investigation of genetically modified trees requires rapid and reliable techniques to measure the mechanical properties at an early age in order to give timely feedback to forest geneticists. In this study, transmittance near-infrared (NIR) spectroscopy was used to predict the green mechanical properties of 1- and 2-year-old transgenic and wild-type aspen. Green modulus of elasticity (MOE) in three-point bending and green ultimate compression strength (UCS) parallel to the grain were predicted from the NIR spectra of dry wood meal pellets. Green UCS had strong correlation (R ² = 0.91) and green MOE had good correlation (R ² = 0.78) with the spectra. The latter could be explained by the moderate correlation of MOE with the lignin content of the transgenic samples, suggesting that besides chemical composition MOE also depends on anatomical properties. The ratio of performance to deviation value suggested that the calibration model of both UCS (2.94) and MOE (1.91) could be used for screening.     

Molecular identification of Anaplasma marginale and rickettsial endosymbionts in blood-sucking flies (Diptera: Tabanidae, Muscidae) and hard ticks (Acari: Ixodidae)

In an attempt to identify the main vector and possible transmission routes of Anaplasma spp. in a region of Hungary with high prevalence of ovine and bovine anaplasmosis, DNA was extracted from 316 haematophagous arthropods (individually or in pools), including 4 species of ixodid ticks, 6 species of tabanid flies and hornflies. Midichloria-like organisms were identified with PCR (amplifying a portion of the 16S rRNA gene) and sequencing from Dermacentor marginatus and Ixodes ricinus. Significantly higher 16S positive D. marginatus individuals were collected in March than in April, suggesting earlier questing of ticks that contain rickettsial agents (thus endosymbionts). Midichloria- and Wolbachia-like organisms were also found in randomly caught horse flies (Tabanus bovinus and T. tergestinus) as well as hornflies (Haematobia irritans), respectively, with 97-99% similarity to sequences deposited in the GenBank. Although all ticks were negative in the Anaplasma spp.-specific msp4 PCR, four individuals of T. bovinus collected near to grazing cattle were positive for Anaplasma marginale. The results of the present study provide the first molecular evidence for the potential mechanical vector role of T. bovinus in the transmission of A. marginale, and broaden the range of haematophagous arthropods harbouring Midichloria-like bacteria, for the first time in any Dermacentor or Tabanus species.     

Using Rheological Phenotype Phases to Predict Rheological Features of Wheat Hardness and Milling Potential of Durum Wheat

Predictions about milling, dough making, and baking properties can be made by measuring properties of the wheat grain with different small‐ and medium‐scale equipment. In this study, rheological hardness index (RHI) was shown to separate hexaploid wheats and durums into clearly distinct hardness classes. Earlier work demonstrated the utility of RHI to give new insight about the classification of wheat types, and in this study further use of the rheological phenotype phases (RPPs) to construct combinations of RPPs (cRPPs) is explored. In particular, it is shown how different cRPPs can be used to compare, for various wheat varieties, the elastic, fragmentation, equilibrium, and viscoelastic phases of an average crush response profile. In addition, relationships were obtained, based on selected RPPs from the single‐kernel characterization system, that gave good predictions of the laboratory milling potential of durum wheats. This information could be used as an early generation test to predict milling yield in breeding programs without having to mill the sample. Further validation of these relationships is required by evaluating the prediction across multiple environments.     

Methoden zur relativen Quantifizierung der pilzlichen Biomasse im Boden

Methods for relative quantifying fungi biomass in soils To estimate the mycological contribution in soil microflora, the amount of chitin and ergosterol and the decolorisation of Poly-B-411 dye was measured in three different soils. The tests showed a linear proportionality between the amount of soil and the respective quantities of the substances. Due to the methodic procedure, ergosterol was measured more accurately than chitin. The decolorisation of the Poly-B-411 dye was in wet humidic aerobic soil higher than in soil suspension. The stability of the adsorbance ratio (593/483 nm), which is a measure for the degradation, was obtained between the 5th and 7th day.     

Actinomycin D: inhibition of respiration and glycolysis

Actinomycin D inhibited respiration and anaerobic glycolysis of human leukemic leukocytes and lowered the adenosine triphosphate content of the cells. Inhibitory effects on respiration and on RNA synthesis could not be dissociated from one another over a wide range of drug concentrations. Actinomycin D also impaired protein synthesis, probably by decreasing the availability of adenosine triphosphate and by inhibiting messenger RNA.     

DNA polymerase activities associated with smooth membranes and ribosomes from rat liver and hepatoma cytoplasm

Deoxyribonucleic acid polymerase activity that prefers denatured DNA primer concentrates with the smooth membranes during sucrose gradient centrifugation of rat liver and hepatoma cytoplasmic extracts. The activity in this fraction is eightfold higher in hepatoma tissue. Deoxyribonucleic acid polymerase activity that prefers native DNA primer concentrates with the free ribosome fraction from both tissues.     

不同品种番茄拉秧后未熟果实的成熟动态变化研究

当番茄作物拉秧结束时,大约有10%～15%的潜在产量是未熟果。本试验研究了未成熟收获果实成熟期间的动态变化,提出了一种简单、低成本的熟化方法。结果表明在20～25℃的贮藏温度下,无论经绿熟期、突变期或转色期的番茄果实均可完全成熟,有限生长品种的未熟变化较无限生长品种快,耐贮番茄较普通番茄完全成熟需要更多的时间。