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961.
Chikahiro Sakazawa Masayuki Shimao Yoshifumi Taniguchi Nobuo Kato 《Applied microbiology》1981,41(1):261-267
Polyvinyl alcohol (PVA)-utilizing cultures were obtained from various sources. They were mixed cultures even after cyclical transfer to liquid and plate media with PVA as a sole source of carbon. Component bacteria were isolated from the several mixed cultures, and it was shown that PVA was utilized symbiotically by two bacterial members which could not utilize PVA in each respective pure culture. From a mixed culture, strains VM15, VM15A (Pseudomonas putida) and VM15C (Pseudomonas sp.) were isolated as members essential for PVA utilization. VM15C was the predominant strain in the mixed-culture population and produced PVA-degrading enzyme. The culture supernatant of VM15A enabled VM15C to grow on PVA. VM15A was presumed to supply VM15C with a unique growth stimulant which was distinct from usual growth factors. 相似文献
962.
The Roles of the Cotyledons and Auxin in the Adventitious Root Formation of Hypocotyl Cuttings of Light-Grown Cucumber Seedlings 总被引:2,自引:0,他引:2
Adventitious root formation in encumber hypocotyl cuttings was studied. Root formation was quantitatively related to the amount of the cotyledons attached to the hypocotyl. Complete removal of the cotyledons diminished root formation entirely. Hut the removal of the apical bud had no effect. Treatment of the hypocotyl with triiodobenzoic acid resulted in the inhibition of root formation. On t he other hand, IAA promoted root formation. Promoting concentration of IAA was 1 mg/1 for the cuttings with intact cotyledons and 10 mg/1 for those with l/8th of the cotyledons. The first two or three days of treatment was most effective. The presence of auxin (IAA-like. substance) in cucumber seedlings was demonstrated by paper chromatography and the pea straight test. It is concluded that the cotyledon is necessary for root formation in cucumber hypocotyl cuttings and that auxin is at least one of the factors supplied from the cotyledons. 相似文献
963.
Investigation of the enzymatic synthesis of sphingomyelin 总被引:4,自引:0,他引:4
964.
965.
966.
Pituitary adenylate cyclase activating polypeptide provokes cultured rat chromaffin cells to secrete adrenaline. 总被引:7,自引:0,他引:7
T Watanabe Y Masuo H Matsumoto N Suzuki T Ohtaki Y Masuda C Kitada M Tsuda M Fujino 《Biochemical and biophysical research communications》1992,182(1):403-411
Pituitary adenylate cyclase activating polypeptide (PACAP) provoked the rat chromaffin cells to secrete adrenaline. Within 20 min, the amount of adrenaline secreted by PACAP (10(-8) M) was as much as that caused by acetylcholine (10(-4) M). PACAP, but not acetylcholine, induced a long-term (over 120 min) increase in secretion of adrenaline. PACAP also activated adenylate cyclase and elevated cytosolic Ca2+ concentration. Furthermore, we found immunoreactive PACAP and PACAP binding sites in the rat adrenal medulla. These results suggest that PACAP has an important role in stimulating secretion of adrenaline in the adrenal medulla. 相似文献
967.
Methylmercury-resistant mutants were obtained from Saccharomyces cerevisiae. They were divided into two complementation groups, met2 (homoserine O-acetyltransferase deficiency) and met15 (enzyme deficiency unknown), as reported previously. It was found that met15 was allelic to met17 (O-acetylserine and O-acetylhomoserine sulfhydrylase deficiency). Methylmercury toxicity was counteracted by exogenously added HS-, and both met2 and met17 (met15) mutants overproduced H2S. On the basis of these results, we conclude that met2 and met17 (met15) cause accumulation of hydrosulfide ions in the cell and that the increased level of hydrosulfide is responsible for detoxification of methylmercury. 相似文献
968.
Fried B. and Fujino T. 1984. Scanning electron microscopy of Echinostoma revolutum (Trematoda) during development in the chick embryo and the domestic chick. International Journal for Parasitology14: 75–81. Scanning electron microscopy (SEM) was used to study the development of chemically excysted metacercariae of Echinostoma revolutum on the chick chorioallantois. SEM studies were also made on preovigerous adults of E. revolutum grown in the domestic chick. During worm development on the chorioallantois the tegument changed from smooth to granular and sensory papillae on the suckers became well-defined. As worms developed on the chorioallantois the cephalic collar spines became thicker and more curved and the tegumentary spines showed marked changes in shape, size and distribution on both ventral and dorsal aspects of the body. Changes in the surface ultrastructure of worms grown on the chorioallantois were essentially similar to those observed in preovigerous worms from chicks. 相似文献
969.
Summary The kinetic behaviour of succinate dehydrogenase [EC 1.3.99.1] in three fibre types of rat gastrocnemius was examined by a quantitative histochemical method without disruption of the cellular structure. 2-(2-Benzothiazolyl)-3-(4-phthalhydrazidyl)-5-styryl-tetrazolium chloride (BPST) and phenazine methosulphate were used as electron acceptors. On measurement of the absorbance value at 530 nm of BPST formazan, produced by the succinate dehydrogenase reaction in sections, it was found that the staining intensity of succinate dehydrogenase was linearly proportional to both the incubation time and the thickness of the slice therefore, the initial velocity of the staining could be calculated. By Michaelis-Menten (1913) treatment of the dependence of the initial velocity on the substrate concentration in the absence and the presence of a competitive inhibitor, malonate, the Km andVmax values for succinate and the Ki value for malonate were obtained. The Km and Ki values of the three fibre types were similar. The ratio of theVmax values of type A, B and C fibres was 1.02.03.3. The temperature dependence of the kinetic parameters was very similar in the three fibre types. These findings confirm that the differences in the staining intensity of the three fibre types reflect differences in the amounts, but not the properties, of succinate dehydrogenase. 相似文献
970.
Nobuo Kato Tomohide Yamagami Masayuki Shimao Chikahiro Sakazawa 《Applied microbiology and biotechnology》1987,25(5):415-418
Summary
N
6-[N-(6-Aminohexyl)carbamoylmethyl]-NAD was covalently bound to formate dehydrogenase. The formate dehydrogenase-NAD complex, which contained 0.2 mol of reactive NAD moiety per subunit, functioned as an NAD(H)-regeneration system for a second coupled reaction involving one of the following enzymes; lactate, malate, alanine and leucine dehydrogenases, whose reductive reactions proceeded stoichiometrically in the absence of exogenous NAD. 相似文献