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Potato spindle tuber viroid can be separated into two fractions by polyacrylamide gelelectrophoresis in the presence of formamide and urea. One fraction contains predominantly circular molecules; the second fraction contains almost exclusively linear molecules. The purity of the fractions was
Potato starch propargyl ethers (PgS) with degrees of substitution (DS) from 0.1 to 2.2 have been prepared by etherification of starch with sodium hydroxide or Li dimsyl in Me(2)SO and propargyl bromide. DS values and substituent distribution were determined after hydrolysis and acetylation by GC-MS.
Potato leafroll virus (PLRV) was purified from infected potato (Solanum tuberosum L.) with yields of 0.4-0.6 mg/kg of foliage. The virus sedimented as a single component of 127 S. An antiserum prepared against purified virus had a maximum titer of 1:1024 in agar gel double diffusion tests. PLRV had
Among isolates of Rhizoctonia solani Kühn collected as sclerotia from potato (Solanum tuberosum L.) tubers harvested from the Toluca Valley in 1995 was one isolate (MexND) of anastomosis group 7 (AG-7). Virulence of this and other isolates of R. solani representing AG-3 (four isolates) or AG-7 (four
The intracellular localization of viroids has been investigated by viroid-specific in situ hybridization and analysis by digital microscopy of the distribution of the fluorescent hybridization signals. Isolated nuclei from green leaf tissue of tomato plants infected with potato spindle tuber viroid
A partially purified potato polyphenol oxidase (PPO) was immobilized in a cross-linked chitosan-SiO2 gel and used to treat phenol solutions. Under optimized conditions (formaldehyde 20 mg/ml, PPO 4 mg/ml and pH 7.0), the activity of immobilized PPO was 1370 U/g and its Km value for catechol was 12
Magnetic porous microspheres composed of Fe3C, MnO and graphitic carbon (Fe3C/MnO/GC) were prepared by a one-pot method. A polycondensate obtained from urea and formaldehyde served as the carbon source and was calcined in the presence of metallic iron and manganese to yield
Two gold immunolabelling techniques using electron microscopy were compared to examine the in situ localization of a luteovirus, potato leafroll virus (PLRV), inside its main aphid vector, Myzus persicae SULZ. With Gildow's technique, virus particles were labelled prior to fixation, embedding by
A rapid and accurate method for measuring low part-per-million levels of free and reversibly-bound sulfites in selected foods by using high-performance liquid chromatography (HPLC) with fluorometric detection was developed. Sulfites were extracted with sodium tetrachloromercurate solution and
A method for isolating transcriptionally competent RNA from fresh, frozen, and lyophilized plant storage tissues containing high levels of starch and phenolics is described. The protocol avoids the use of guanidium salts, which often lead to the formation of a viscous gel during extraction of high
The effect on milk yield and composition of the supplementation of the diets of dairy cows with wheat or potato peelings was studied at three different starch intakes (< 5, 6, and > 7.5 kg/d) for dry matter intakes around 20 kg/d. Starch supply was varied using different dietary concentrations of
In-vitro methods were developed to test fungi for production of metabolites affecting nematode egg hatch and mobility of second-stage juveniles. Separate assays were developed for two nematodes: root-knot nematode (Meloidogyne incognita) and soybean cyst nematode (Heterodera glycines). For egg hatch
OBJECTIVE
The purpose of this study was to determine airborne fungal concentrations in dwellings and to evaluate the relationship between indoor air concentrations of fungi and those of indoor air pollutants, temperature and relative humidity.
METHODS
Indoor and outdoor concentrations of total
Approximately 70% of the cells in a suspension of the amylolytic bacterium Lactobacillus amylovorus bind to cornstarch granules within 30 min at 25 degrees C. More than 60% of the bound bacteria were removed by formaldehyde (2%) or glycine (1 M) at pH 2.0. More than 90% of the bound bacteria were