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肝素钠粗品工业化高效生产工艺的探讨 总被引:1,自引:0,他引:1
本文从原料的选用、工艺的综合应用和后产品的处理等方面对肝素钠粗品的生产进行了探讨。结果显示,二次盐解可提高收率16.5%,二次吸附提高19.3%,三次洗脱增加13.0%,4℃沉淀和冷冻干燥分别减少活性损失1.4%和1.0%,在沉淀剂YNB99-1和Na2SO3的保护下,后产品肝素钠的酸化处理收率达98%。 相似文献
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1,6—二磷酸果糖产生菌的筛选及最佳培养条件的研究 总被引:1,自引:0,他引:1
1,6-二磷酸果糖(FDP)广泛应用于治疗心血管疾病。本文进行了1,6-二磷酸果糖产生菌的筛选和最佳条件的研究。筛选出菌株HY2具有较高的产1,6-二磷酸果糖酶活力,高达160mgFDP/g wet cells,菌体生长的最适培养条件为:麦芽汁培养基糖度为12柏林,培养温度为28℃,pH6.0 ̄6.5,菌体收率达7.0%左右。 相似文献
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盐酸胍浓度对变性溶菌酶复性的影响 总被引:5,自引:0,他引:5
研究了复性液中盐酸胍浓度对变性溶菌酶复性的影响。变性酶的复性收率与复性液中盐酸胍度浓度紧密相关,获得高复性收率所需的盐酸胍浓度随酶浓度提高而增大。当酶浓度较低时(0.06-0.21g/L),0.7mol/L的盐酸胍即可溶菌酶完全复性;当酶浓度较高时(0.6-1.05g/L),提高盐酸胍浓度至1.0-1.5mol/L才可使复性收率达到95%以上。另外,酶的复性速率随盐酸胍浓度增大而下降。因此,根据酶浓度选择最佳盐酸胍浓度是提高蛋白质复性收率的关键。 相似文献
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梨头霉11α—羟基化制备16β—甲基—11α,17α21—三烃基孕甾—1, … 总被引:1,自引:2,他引:1
选育到一株对16β-甲基-17α,21-二羟基孕甾-1,4=-二烯-3,20-二酮(Ⅱa)11α-羟基化活性强的梨头霉A28菌株,并发现底物21-乙酰化(Ⅱb)可明显提高11α-羟工 能力。在适宜的转化条件下,11b投料浓度0.5%,产物16β-基11α,17α,21-三羟基孕甾-1,4-二烯-3,20-二酮(Ⅲ)收率为73%,结构经波谱分析确认。 相似文献
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本文采用回归分析法研究了超速离心纯化时,固定一次溴化钾密度梯度比例,选择不同的二次溴化钾梯度比例对下一步SepharoseCL-4B柱层析纯化收率的影响。结果表明:回归分析不仅能揭示纯化的最佳条件,即,二次溴化钾超速离心时溶液由240ml(1.04g/ml):800m1(1.28g/ml):600ml(1.32g/ml):50ml(1.34g/ml)构成时柱层析收率最高。而且还能解释层析纯化中出现的异常结果。 相似文献
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微生物发酵合成L—缬氨酸—15N 总被引:1,自引:0,他引:1
采用含有稳定同位素15N-硫铵为主要氮源的专用发酵培养液配方和相应的工艺条件,在国内首次微生物直接发酵研制成L-缬氨酸-15N高丰度精制产品。产品15N丰度97.68%,反比原料15N-硫铵丰度下降0.53%,L-缬氨酸-15N产酸率最高达4%以上(未校正)。每克15N-硫可得到1克以上的L-缬氨酸-15N(分析值)提取精制收率平均为80-90%(单程),最高达到95%以上(二次提取)。实际每克1 相似文献
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In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980. 相似文献
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N. P. Vesselkin Yu. V. Natochin 《Journal of Evolutionary Biochemistry and Physiology》2010,46(6):592-603
Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms.
The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal
mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization
followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The
mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction
of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms
are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning
of physiological systems and organs of the living organism 相似文献