Tetrahydrofolate-dependent vanillate and syringateO-demethylation links tightly to one-carbon metabolic pathway associated with amino acid synthesis and DNA methylation in the lignin metabolism ofSphingomonas paucimobilis SYK-6

Sphingomonas paucimobilis SYK-6 strain can degrade various lignin-related compounds. In the lignin metabolic pathway of this bacterium, vanillate and syringate are demethylated by the tetrahydrofolate (THF)-dependentO-demethylation system, which requires the enzymatic function of LigH. Upstream of theligH gene is the 5,10-methylene-THF reductase gene. Its gene product was essential for one-carbon metabolism involved in the amino acid synthesis and DNA methylation in all organisms. When themetF gene was inactivated in the genome of SYK-6, the resultant mutant, DLmetF, could not grow on vanillate and syringate as a sole carbon source. Furthermore, DLmetF showed significant accumulation of methyl-THF as a result of vanillate and syringateO-demethylation. We report here that THF-dependent vanillate and syringateO-demethylation links tightly to the one-carbon metabolic pathway that is associated with amino acid synthesis and DNA methylation, and the methyl group is the sole one-carbon source inS. paucimobilis SYK-6.     

促性腺激素(LH,FSH)对鸡卵泡孕酮分泌的影响

摘出垂体12 h 后的卵泡孕酮(P_4)浓度显著下降.单独添加 LH 时第一卵泡(F_1)的P_4浓度显著增加,同时添加 LH 和 FSH 时,所有卵泡的颗粒层 P_4浓度恢复到对照的水平.但是单独添加 FSH 时无促进作用.LH 和 FSH 的处理对卵泡的卵泡膜 P_4浓度影响极小.在细胞培养液中添加 LH 和 FSH 可以促进颗粒层的 P_4合成,这种反应以 F_1最为明显.LH 和 FSH同时添加时对颗粒层 P_4合成有显著效果,但是对卵泡膜 P_4合成无明显促进作用.表明 P_4在 LH和 FSH 的协同调控下,主要在 F_1的颗粒层中合成.     

Offstream water and trace mineral salt as management strategies for improved cattle distribution

The objective of this study was to test the combined effect of offstream water and trace mineral salt on cattle distribution in a riparian meadow and its adjacent uplands. From July 15 to August 26, 1996 and 1997, three treatments were each randomly assigned to one pasture in each of three blocks. Sixty cow/calf pairs were then randomly allotted to the grazed pastures. The treatments included 1) stream access and access to offstream water and trace-mineral salt (off-stream), 2) stream access and no access to offstream water or trace-mineral salt (no-offstream), and 3) ungrazed control. The response of cattle was measured through visual observations of cattle distribution, grazing activity and travel distance, cow/calf performance, and fecal deposit distribution. Distribution patterns of the cattle, measured as the distance of cattle from the stream, was characterized by a time of day x treatment x time in grazing period x year interaction (P < 0.05). No-offstream cattle began the day further from the stream than offstream cattle but consistently moved closer to the stream after the morning grazing period (0600 to 0900). Differences in distribution patterns between the two treatments were more pronounced early in the grazing period than late in the grazing period. Grazing activity, fecal deposit distribution, and travel distance of cattle were not affected by the presence of offstream water and trace-mineral salt. Cows and calves with offstream water and trace-mineral salt gained 11.5 kg and 0.14 kg/d more, respectively, than no-offstream cows and calves averaged across years (P < 0.05). Overall, cattle distribution patterns and cow/calf performance were influenced by the presence of offstream water and trace-mineral salt. Changes in distribution were most pronounced early in the grazing season.     

Immunolocalization of steroidogenic enzymes in equine fetal adrenal glands during mid-late gestation

To elucidate the relationship between steroidogenic hormones and developing adrenal glands, we investigated the immunolocalization of steroidogenic enzymes in equine fetal adrenal glands during mid-late gestation. Fetal adrenal glands were obtained from three horses at 217, 225 and 235 days of gestation. Steroidogenic enzymes were immunolocalized using polyclonal antisera raised against bovine adrenal cholesterol side-chain cleavage cytochrome P450 (P450scc), human placental 3beta-hydroxysteroid dehydrogenase (3betaHSD), porcine testicular 17alpha-hydroxylase cytochrome P450 (P450c17) and human placental aromatase cytochrome P450 (P450arom). Histologically, cortex and medulla cells were clearly observed in the three fetal adrenal gland tissue samples. P450scc and P450c17 were identified in cortex cells close to medulla cells and in some medulla cells in the fetal adrenal glands. P450arom was present in both cortex and medulla cells in the fetal adrenal glands. However, 3betaHSD was not found in any of the equine fetal adrenal gland tissue samples. These results suggest that equine fetal adrenal glands have the ability to synthesize androgen and estrogen, which may play an important physiological role in the development of equine fetal adrenal glands.     

Nutrio-physiological studies on the tomato plant II. Translocation of photosynthates

The percentage translocation from the leaf is low in the tomato; it is as low as 16 per cent in some cases and the maximum value observed is 62 per cent.

The ability of a leaf to act as the sink for the photosynthates of other leaves becomes very low with age, but it serves as a sink for its own photosynthates for a long period.

The photosynthates of a leaf may be translocated to any alnk, but the major translocation stream under ordinary conditions is determined by the growth stage of the plant and the position of the source leaf. In this sense thero are source-sink partnerships between certain leaves and organs: The major sinks of L₅, L₉, L₁₁, L₁₄, and L₁₆ are the roots, T-1, T-Il, T-III, and T-III, respectively, although the partnerships are weak and flexible.     

Enhanced Growth and nodule occupancy of red kidney bean and soybean inoculated with soil aggregate-based inoculant

Volcanic ash soil, which is widely distributed in Japan, contains a large amount of well-structured soil aggregates. By using these aggregates as carrier materials, we prepared (brady)rhizobial inoculants for red kidney bean (Phaseolus vulgaris) and soybean (Glycine max). Autoclaved soil aggregates were inoculated with Rhizobium tropici CIATS99R or Bradyrhizobium japonicum USDA110R, incubated for 15 or 21 d at 30°C, slowly air-dried at 20°C to prepare the aggregate-based inoculants, and stored at various temperatures. The populations of CIATS99R and USDA110R in the aggregate-based inoculants were maintained during several months of storage at 20°C. When the aggregate-based inoculants were mixed with soil, CIATS99R and USDA110R cells showed a remarkably improved survival in soils compared with those mixed with soil without carrier material. The effect of the aggregate-based inoculants on the growth of red kidney bean and soybean was examined in pot experiments. By placing a small amount of the inoculant just beneath the seeds at the time of sowing, plant growth was significantly enhanced compared with the use of traditional peat-based inoculant. In addition, nodule formation on the upper part of soybean roots and nodule occupancy by the inoculated strain were remarkably enhanced by the aggregate-based inoculant. It is suggested that soil aggregates might be suitable carrier materials for preparing cheap and effective (brady)rhizobial inoculants.     

Quantitation of curcuminoids in curcuma rhizome by near-infrared spectroscopic analysis

This study investigated a nondestructive and rapid quantitation method for the curcuminoids, including curcumin, demethoxycurcumin, and bisdemethoxycurcumin, present in turmeric using near-infrared (NIR) spectroscopy and multivariate statistics. In the second derivatives of the NIR spectra of turmeric samples, two characteristic absorptions of curcuminoids were detected around 1700 and 2300-2320 nm. Partial least-squares regression (PLS-R) analysis was applied to the NIR spectra obtained from 34 turmeric samples, and PLS models for the quantitation of curcumin, demethoxycurcumin, bisdemethoxycurcumin, and total curcuminoid contents in the pulverized turmeric samples were constructed. Combination usage of the Standard Normal Variate (SNV) and second derivatives was obviously superior to other preprocessing methods. The lowest root mean squared error of cross-validation (RMSECV) values were detected at 6, 6, 6, and 6 PLS factors, for the quantitative subjects curcumin, demethoxycurcumin, bisdemethoxycurcumin, and total curcuminoid contents. It was clarified that the prediction of the composition by PLS-R analysis showed high correlation with the results of HPLC quantitations.     

A proposed method to determine adequate amount of fertilizers to be applied to crops

To determine the adequate amounts of fertilizers to be applied to crops is one of the most important problems in the field of soil science.     

Analysis of volatile compounds released during the grinding of roasted coffee beans using solid-phase microextraction

A dynamic solid-phase microextraction (SPME) method to sample fresh headspace volatile compounds released during the grinding of roasted coffee beans was described and the analytical results using gas chromatography/mass spectrometry (GC/MS) and GC/olfactometry (GC/O) were compared to those of the conventional static SPME sampling methods using ground coffee. Volatile compounds released during the grinding of roasted coffee beans (150 g) were obtained by exposing the SPME fiber (poly(dimethylsiloxane)/divinylbenzene, PDMS/ DVB) for 8 min to nitrogen gas (600 mL/min) discharged from a glass vessel in which the electronic coffee grinder was enclosed. Identification and characterization of volatile compounds thus obtained were achieved by GC/MS and GC/O. Peak areas of 47 typical coffee volatile compounds, separated on total ion chromatogram (TIC), obtained by the dynamic SPME method, showed coefficients of variation less than 5% (n = 3) and the gas chromatographic profile of volatile compounds thus obtained was similar to that of the solvent extract of ground coffee, except for highly volatile compounds such as 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 4-ethenyl-2-methoxyphenol. Also, SPME dilution analysis of volatile compounds released during the grinding of roasted coffee beans showed linear plots of peak area versus exposed fiber length (R (2) > 0.89). Compared with those of the headspace volatile compounds of ground coffee using GC/MS and GC/O, the volatile compounds generated during the grinding of roasted coffee beans were rich in nutty- and smoke-roast aromas.