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121.
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123.
The use of four stereoisomers of isoleucine by Lactobacillus fermenti strain 36 was studied in detail. All four isoleucine isomers were used for growth in the presence of vitamin B(6) compounds, but only l-isoleucine was active in the absence of these vitamins. Of the vitamin B(6) compounds, pyridoxal and pyridoxamine were equally more effective than pyridoxine for the utilization of these isomers. Lowering the initial pH, decreasing the amounts of leucine and valine, and adapting the organism to d-alloisoleucine medium accelerated the use of isoleucine isomers. Thus, the conditions were established under which respective isomers gave the same growth response, and these findings were applied to the separate microbiological assay of l-isoleucine and total isoleucine isomers. 相似文献
124.
Fermentation Studies with Streptomyces griseus: II. Synthetic Media for the Production of Streptomycin 总被引:1,自引:0,他引:1 下载免费PDF全文
Synthetic media for streptomycin fermentation were studied to determine which media gave highest yields of streptomycin. The effect of salts on streptomycin production by Streptomyces griseus was examined, and a suitable combination of salts was established in a glucose-casein medium. This medium yielded 3,000 μg/ml of the antibiotic with an inoculum of 1.6%. Substitution of amino acids for casein was examined. Of 17 amino acids tested, best results were obtaind with sodium aspartate. Substitution of ammonium salts was tried, and an excellent streptomycin yield was obtained with a medium containing ammonium citrate. 相似文献
125.
126.
Makoto Suematsu Shigenari Houzawa Soichiro Miura Hiroshi Nagata Tetsuji Kitahora Tetsuo Morishita Chikara Oshio Masaharu Tsuchiya 《Luminescence》1989,4(1):531-534
Reaction difference of oxyradical generation and luminol-dependent photoemission of zymosan- and phorbol ester-treated neutrophils were investigated using a conventional photomultiplier and ultrasensitive photonic imaging technique. Zymosan-treated cells released a concentrated photonic burst corresponding to the cellular distribution. In contrast, phorbol ester-treated cells produced a negligible level of photoemission, and the additional application of Ca2+ ionophore enhanced the photonic burst, which was gradually spread out into extracellular space. Serine protease inhibitors did not attenuate PMA-induced chemiluminescence but did attenuate zymosan-induced chemiluminescence. This suggests the involvement of serine protease in the respiratory burst of phagocytizing neutrophils. 相似文献
127.
Peter L. Pingerelli Hiroshi Mizukami Monica J. Mooney Alice L. Schlaepfer 《The protein journal》1989,8(2):183-196
S100b is a calcium-binding protein that will bind to many calmodulin target molecules in a Ca2+-dependent manner. In order to study the Ca2+-dependent binding properties of S100b, its interaction with a calmodulin antagonist, trifluoperazine (TFP), was investigated using [19F]- and [1H]-NMR and UV-difference spectroscopy. It was estimated from [19F]-NMR that in the absence of Ca2+, thek 1/2 value of TFP was 130 µM, while itsk 1/2 value decreased to 28 µM in the presence of Ca2+. The addition of KCl was not antagonistic to the Ca2+-dependent interaction of TFP to S100b. The chemical exchange rate of TFP with Ca2+-bound S100b was estimated to be 9×102 sec?1. By comparison with TFP-calmodulin exchange rates, it is suggested that the TFP-binding site on S100b is structurally different from its binding sites on calmodulin. Proton NMR resonance broadening in the range 6.8–7.2 ppm, corresponding to phenylalanine nuclei of S100b, indicates that these residues may be involved in TFP binding. Addition of Ca2+ to a 1:1 mixture of S100b and TFP resulted in a red-shifted UV-difference spectrum, while no significant difference spectrum was detected when Mg2+ was added to a S100b-TFP solution. Thus, we suggest that Ca2+ induces the exposure of a hydrophobic domain on S100b containing one or more phenylalanine residues that will bind TFP but that this domain is different from the hydrophobic domain on calmodulin. 相似文献
128.
Isolated microspores of Chinese cabbage (Brassica campestris ssp. pekinensis) were incubated in modified NN medium containing 10% sucrose in darkness at 33°C for one day followed by culture at 25°C. After 14 days of culture, microspores developed into embryos ranging from globular to cotyledonary stage. Plants were regenerated after transfer of embryos to medium containing 3% sucrose and no plant growth regulators.Abbreviations NN
Nitsch and Nitsch
- MS
Murashige and Skoog
- NAA
naphthaleneacetic acid
- BA
6-benzylaminopurine 相似文献
129.
Hiroshi Koizumi 《Journal of plant research》1989,102(4):521-532
Photosynthetic and respiratory activities and gross production in relation to temperature conditions were investigated in
the population of an evergreen herb,Pyrola japonica, growing on the floor of a deciduous forest in the warm temperate region of central Japan.
Analysis of the temperature-photosynthesis relationship ofP. japonica leaves during the growing season indicated distinct seasonal changes in the temperature optimum for photosynthesis. This
population was found to be acclimatable to ambient air temperatures exceeding 15C, but this acclimation became less pronounced
under thermal conditions below 15 C. This plant possessed narrow photosynthetic optima in the warm season but wide optima
in the cold season. The shape of the temperature-respiration curve did not vary significantly with the months except for April.
The Q10 for respiration between 10 C and 20 C was calculated to be 1.93–2.65. Annual dry matter loss associated with respiration
was estimated to amount to 159.1 g d.w.m−2 based on the measurements of the seasonal changes in the respiratory activity of each organ. Gross production of this population
was estimated to be 219.3 g d.w.m−2 year−1 as the sum total of the net production (60.2 g d.w.m−2year−1) and the respiration. Monthly gross production was high in the early growing season, and low and stable in winter. 相似文献
130.
Hiroshi Yura 《Ecological Research》1989,4(3):351-360
The underlying mechanisms of drought resistance in seedlings ofLarix kaempferi as compared with those inAbies veitchii were investigated. First, seedlings of the two species were desiccated in air of differing water potential, and their survival
rates were compared to detect any difference in desiccation tolerance between them. Contrary to differences in their drought
resistance,A. veitchii showed higher survival. Next, the shoot heights and root depths of the two species were compared to detect any difference
in desiccation avoidance. Although the shoot height differed little between the two species, the roots ofL. kaempferi seedlings were much deeper than those ofA. veitchii seedlings, and the death rate under progressing drought was well correlated with the root extensibility of each species.
It was thus concluded thatL. kaempferi seedlings are able to avoid desiccation by extending their roots in deep soil faster thanA. veitchii seedlings, thereby resisting to drought.
This paper is dedicated to Prof. Toshiro Saeki to mark his fruitful career in plant ecology. 相似文献