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D-Xylose isomerase, induced in the mycelial cells of Streptomyces griseus grown on D-xylose, was partially purified and the properties of the enzyme studied. The enzyme was not inhibited by low concentrations of sulfhydryl group binding reagents. Complete inactivation which occurred after dialysis against versene was reversed by addition of Co~(++), Mg~(++) or Mn~(++).The inducer for D-Xylose isomerase synthesis was not restricted to the substrate of the enzyme; D-ribose was also effective.Investigations on... D-Xylose isomerase, induced in the mycelial cells of Streptomyces griseus grown on D-xylose, was partially purified and the properties of the enzyme studied. The enzyme was not inhibited by low concentrations of sulfhydryl group binding reagents. Complete inactivation which occurred after dialysis against versene was reversed by addition of Co~(++), Mg~(++) or Mn~(++).The inducer for D-Xylose isomerase synthesis was not restricted to the substrate of the enzyme; D-ribose was also effective.Investigations on the distribution of D-Xylose isomerase in organisms of the order Actinomycetales were carried out. Seven strains representing four Genera of the order Actinomycetales so far tested, were invariably shown to be capable of producing this enzyme when grown on D-Xylose or other appropriate pentoses. 链霉菌细胞能诱导形成D-木糖异构酶。将D-木糖异构酶进行提纯,研究它的特性,发现与细菌来源的木糖异构酶基本上性质相似。试验金属离子对经过透析后的酶的活力作用,发现除Mg~(++)与Mn~(++)能恢复因透析而失去的酶的活力外,Co~(++)同样有这个作用,而且效应甚为显著。D-木糖异构酶的诱导物并非只限于其作用底物,D-核糖也同样具有诱导作用。观察了木糖异构酶在放线菌目的分布。在链丝菌属、小单孢菌属、放丝菌属及分枝杆菌属的7个种内,发现都具有木糖异构酶,但缺少木糖还原酶,说明这类微生物对木糖的最初代谢步骤是与细菌同一类型。 By means of the gradiant technique, 93 different kinds of chemicals were tested for the induction of lysogenie bacteria to liberate phages in E. coli K12 W1177 and W1485 his~- system. The chemicals used included those known to be mutagenic, tumoricidal, carcinogenic, anti-radiation and/or anti-metabolite.There were found 15 chemicals that gave about 5% induction (about 25 times spontaneous liberation), and 3 chemicals that gave at least 45% induction. Among these effective chemicals, at least 60% were known... By means of the gradiant technique, 93 different kinds of chemicals were tested for the induction of lysogenie bacteria to liberate phages in E. coli K12 W1177 and W1485 his~- system. The chemicals used included those known to be mutagenic, tumoricidal, carcinogenic, anti-radiation and/or anti-metabolite.There were found 15 chemicals that gave about 5% induction (about 25 times spontaneous liberation), and 3 chemicals that gave at least 45% induction. Among these effective chemicals, at least 60% were known to be mutagenic agents. Of the 6 chemicals that were found to be inhibitory to the spontaneous liberation of phages, 4 were uracil analogues.The results are briefly discussed in connection with the relationship between the bactericidal and the induction potency of these chemicals, and with the possible mechanism of the action of such base analogues as 5-bromodeoxyuridine, diazouracil and 2-thiouracil. 应用浓度梯度培养皿的方法,在Escherichia coli K12 W1177和K12 W1485 his~-系统中测定了93种药物对于溶源性细菌释放噬菌体的诱导能力.这些药物包括已知的基因诱变剂、抗肿瘤药物、致癌药物、辐射防护剂以及代谢抑制剂等.诱导量达到5%(约25倍于自发释放量)的药物共15种,诱导量在45%以上的有3种.在具有诱导作用的药物中至少有60%的药物对于基因有诱变作用.有6种药物对于自发释放有抑制作用,其中尿嘧啶的结构类似物占4种.实验表明许多同时具有致癌和抗肿瘤作用及诱变作用的药物都具有诱导作用.文中简单地讨论了药物的杀菌作用和诱导作用之间的关系,以及5-溴脱氧尿核苷和重氮尿嘧啶及2-硫尿嘧啶等天然碱基结构类似物的可能作用机制. The formation of cellulase in washed mycelia of T. pseudokoningii EA_3-867 was markedly induced by sophorose. The cellulase activity, after shaking the mycelial suspension with sophorose, approached maximum within 24 hour culture with a lag period of about 3 hours. The washed mycelia of various species of Trichoderma and that of T. pseudokoningii EA_3-867 with various ages were all able to produce cellulase in which C_1 Cx-cellulase was Predominantly extracellular, whereas cellobiase wes intracellular. The formation... The formation of cellulase in washed mycelia of T. pseudokoningii EA_3-867 was markedly induced by sophorose. The cellulase activity, after shaking the mycelial suspension with sophorose, approached maximum within 24 hour culture with a lag period of about 3 hours. The washed mycelia of various species of Trichoderma and that of T. pseudokoningii EA_3-867 with various ages were all able to produce cellulase in which C_1 Cx-cellulase was Predominantly extracellular, whereas cellobiase wes intracellular. The formation of cellulase was affected by the inducer, mineral elements (nitrogen, phosphorus, iron and manganese) temperature, pH, aeration, and the physiological conditions of the mycelial cells. The optimal concentration of sophorose was 10~3—10~5 M, optimal temperature was 30℃. the range of pH used for induction was 3-6, and optimal pH was 5. The production of cellulase was stimulated by O_2, but strongly repressed by inhibitors of respiration, such as iodoacetate fluoride, malonate, azide and 2, 4,-dinitrophenol. The induction of cellulase in washed mycelia was inhibited also by actidione, 5-fluouraeil and 6-azauracil greatly, but inhibited by actinomycin D only slightly. Furthermore, various sugars, sugar phosphates, glycerol, organic acids. NAD, NADP and ATP all repressed the inductive cellulase formation. The catabolite repression of glucose could not be overcome by c-AMP added to the medium. From these results it is obvious that the induction of cellulase formation is closely related to the respiration and nucleic acid metabolism of fungus. The mode of cellulase synthesis in this microorganism was discussed. 槐糖对拟康氏木酶(Trichoderma pseudokoningii Rifai)EA_3—867洗涤菌丝体的纤维素酶形成有强力的诱导作用,经过3小时左右的延迟期,24小时后,纤维素酶便达到高峰。各种木霉菌种和EA_3—867不同菌令的菌丝体都能被槐糖诱导形成纤维素酶,c_1、c_x酶主要分布在胞外,纤维二糖酶分布在胞内。菌丝体诱导形成纤维素酶需要诱导剂;无机盐(氮、磷、铁、锰盐);适宜的温度、pH和通气;以及菌丝体细胞活跃的代谢。槐糖的最适浓度是10~(-3)~10~(-5)M,诱导的最适温度为30℃,适宜的pH范围3~6,最适pH为5。O_2能刺激纤维素酶的形成,而呼吸抑制剂碘乙酸、氟化钠、丙二酸、迭氮化钠和3,5-二硝基苯酚能强烈抑制菌丝产酶。槐糖对菌丝体纤维素酶的诱导形成能不同程度地被核酸代谢抑制剂如放线菌酮、5-氟尿嘧啶、6-氮杂尿嘧啶和放线菌素D抑制。葡萄糖、甘油、各种糖类、糖磷酸酯、有机酸、辅酶NAD、NADP及ATP~(**)均能阻遏槐糖对菌丝体纤维素酶的诱导作用。葡萄糖对纤维素酶形成的阻遏作用不能被c—AMP介除。
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