Preparation of Cell Wall Fractions by Various Ways and Activity of Bound Saccharase in Sugar Beet Seedlings

Washed cells of facultative methylotrophs which have the serine pathway showed high activities for l-methionine formation from dl-homocysteine, in the presence of methanol as methyl donor. Strain FM 518, isolated from soil and identified as a bacterium belonging to the genus Pseudomonas, showed the highest activity for l-methionine formation and was used as the parental strain for breeding the l-methionine-producing mutants. An ethionine-resistant mutant, FE 244, derived from strain FM 518, accumulated 0.8 mg/ml l-methionine in a methanol-medium under optimum conditions.     

Case report: a successful pregnancy outcome in a patient with non-mosaic Turner syndrome (45, X) via in vitro fertilization

We describe a successful pregnancy outcome in a patient with non-mosaic Turner syndrome (45, X) via in vitro fertilization. The patient achieved a second pregnancy at 35 years of age. The her blood lymphocyte karyotype was examined by G-band and FISH. Furthermore, cumulus cells and her elbow skin cells were evaluated via FISH. Non-mosaic Turner syndrome was determined by G-banding [100 % (50/50) 45, X]. Lymphocytes were shown as 478/500 (95.6 %) cells of X sex chromosome signal, 15/500 (3.0 %) cells of XXX signal, and 7/500 (1.4 %) cells of XX signal. The cumulus cells were mosaic: 152/260 (58.5 %) were X; 84/260 (32.3 %) were XXX, 20/260 (7.7 %) were XX, and 4/260 (1.5 %) were XY. Moreover, skin cells included a mosaic karyotype [47, XXX(29)/46, XX(1)]. We conclude that the collection of a large number of blood lymphocytes can reveal different mosaic patterns (X, XX and XXX) by FISH in spite of non-mosaic Turner syndrome.     

Supersensitivity to β-Lactam Antibiotics in Escherichia coli Caused by D-Alanine Carboxypeptidase IA Mutation

Escherichia coli cells acquired supersensitivity to various β-lactam antibiotics by dacA mutation, a defect in D-alanine carboxypeptidase IA activity. The mutant cells were rather less sensitive to mecillinam than the dacA⁺ cells. This mutation did not result in either thermosensitivity of cell growth or appreciable increase of the generation times in usual rich media, but the resulting appearance of supersensitivity to β-lactam antibiotics suggests that the cell wall or envelope of this mutant is somewhat abnormal and thus that D-alanine carboxypeptidase IA is involved in cell wall or envelope synthesis.     

Studies on the Biosynthesis of Kanamycins

Streptomyces kanamyceticus produces ¹⁴C-kanamycin and other labeled kanamycin-related compounds in the presence of ¹⁴C-glucose or ¹⁴C-glucosamine. One of the latter is paromamine. In order to find a condition to obtain high incorporation rate of radioactive precursors, the culture phase for the addition of labeled compounds was studied. The maximal incorporation rate was obtained by addition of ¹⁴C-glucosamine in the later phase of the culture and the specific activity of resultant kanamycin A was found to be much higher than in the case of the addition of ¹⁴C-glucose. In some experiments one third of radioactivity of the added ¹⁴C-glucosamine was taken into kanamycin, and the distribution was limited only in 6-amino-6-deoxy-D-glucose moiety of kanamycin A when ¹⁴C-glucosamine was added. In contrast, when ^1JC-glucose was added, approximately equal distribution of radioactivity was observed in each of three moieties of kanamycin A molecule.     

Comparison of Compositions of Odor Components of Natto and Cooked Soybeans

Natto, a traditional Japanese food product, was prepared from cooked soybeans by fermentation and its odor concentrate was obtained with a simultaneous distillation and extraction system. It was compared to those obtained from soybeans cooked for 0 ~ 3, 3 ~ 5.5 and 5.5 ~ 8 hr, respectively, by gas chromatography and gas chromatography-mass spectrometry. In the odor concentrates of the cooked soybeans, hexanal, (E)-2-hexenal and hexanol contributing to the green and grassy odor of soybeans disappeared or decreased while the cooking was in progress. 2-Pentylfuran and 1-octen-3-ol contributing to the beany odor remained even if the soybeans were cooked for 8 hr and were fermented into Natto. In the odor concentrate of Natto, pyrazines and sulfur containing compounds were important contributors to the characteristic odor of Natto. As the beany odor was not detected for Natto, it was concluded that the pyrazines and sulfur containing compounds cause the characteristic odor of Natto and mask the beany odor.     

Studies on the Biosynthesis of Kanamycins

Incorporation of the radioactive degradation products of kanamycin A or related metabolites into kanamycin A by growing cells of Streptomyces kanamyceticus was examined. ³H-Deoxystreptamine was incorporated into deoxystreptamine moiety of kanamycin, but neither ¹⁴C-3-amino-3-deoxy-d-glucose nor ¹⁴C-6-amino-6-deoxy-d-glucose was incorporated. ³H-Kanamycin A added to medium was modified and inactivated.     

Metabolism of Leucine and Alanine in Growing Rats Fed the Diets with Various Protein to Energy Ratios

In order to clarify the nutritional significance of metabolism of the carbon skeleton of individual amino acids, the metabolic fates of l-leucine-U-¹⁴C and l-alanine-U-¹⁴C were investigated in growing rats fed the diets with various protein calories percents (PC%) at 410 kcal of metabolizable energy.

The incorporation of ¹⁴C into body protein in 12 hr after the injection of leucine-¹⁴C was about 73% of the dose in the 0 and 5 PC% groups, though it decreased with increasing the levels of dietary protein from 10 to 30 PC%. The value of ¹⁴C recovery in body protein almost agreed with the net protein utilization (NPU) determined for the whole egg protein in a similar experimental condition. The ¹⁴C recovery in expired CO₂ and body lipid suggested that the carbon skeleton of leucine is well utilized as an energy source when the dietary carbohydrate is extensively replaced by protein.

While, the incorporation of ¹⁴C into body protein from alanine-¹⁴C was less than about 11% of the dose in all the dietary groups, and the majority of ¹⁴C was recovered in expired CO₂ and body lipid in a remarked contrast to leucine.

A similar pattern in urinary excretion of ¹⁴C was obtained for these amino acids, and the refracted rise of ¹⁴C from 10 PC% may give an indication for minimum protein requirements.     

The influence of internal and skin temperatures on active cutaneous vasodilation under different levels of exercise and ambient temperatures in humans

To clarify the influence of internal and skin temperature on the active cutaneous vasodilation during exercise, the body temperature thresholds for the onset of active vasodilation during light or moderate exercise under different ambient temperature conditions were compared. Seven male subjects performed 30 min of a cycling exercise at 20 % or 50 % of peak oxygen uptake in a room maintained at 20, 24, or 28 °C. Esophageal (Tes) and mean skin temperature (Tsk) as measured by a thermocouple, deep thigh temperature (Tdt) by the zero-heat-flow (ZHF) method, and forearm skin blood flow by laser-Doppler flowmetry (LDF) were monitored. The mean arterial pressure (MAP) was also monitored non-invasively, and the cutaneous vascular conductance (CVC) was calculated as the LDF/MAP. Throughout the experiment, the Tsk at ambient temperatures of 20, 24, and 28 °C were approximately 30, 32, and 34 °C, respectively, for both 20 % and 50 % exercise. During 50 % exercise, the Tes or Tdt thresholds for the onset of the increase in CVC were observed to be similar among the 20, 24, and 28 °C ambient conditions. During 20 % exercise, the increase in Tes and Tdt was significantly lower than those found at 50 %, and the onset of the increase in CVC was only observed at 28 °C. These results suggest that the onset of active vasodilation was affected more strongly by the internal or exercising tissue temperatures than by the skin temperatures during exercise performed at a moderate load in comparison to a light load under Tsk variations ranging from 30 °C to 34 °C. Therefore, the modification by skin temperature of the central control on cutaneous vasomotor tone during exercise may differ between different exercise loads.     

Fragmentation of Penicillin-binding Protein-1Bs of Escherichia coli by Proteolytic Enzymes: A Preliminary Study on the Location of the Penicillin-binding Site on the Bifunctional Peptidoglycan Synthetase Protein

The absolute configurations of fenvalerate and other related cyanohydrin esters were studied by circular dichroism (CD) measurements and by high performance liquid chromatography (HPLC). Fenvalerate has UV absorption peaks around 278 nm associated with the ¹L_b phenyl transitions and corresponding positive CD peaks were observed around 281 nm for the enantiomers of (S)-configuration at the cyanohydrin chiral center. Most of the other cyanohydrin esters also gave positive CD peaks for the enantiomers of (S)-configuration. CD spectra in the 180 to 250 nm range were also studied.

By HPLC, the elution order of the diastereoisomers of cyanohydrin esters were closely correlated with their absolute configuration and the (RS,SR)-pair consistently eluted earlier than the (RR,SS)-pair for α-substituted phenylacetic acid esters.