共查询到16条相似文献,搜索用时 92 毫秒
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不同添加物对D-核糖产量的影响 总被引:3,自引:0,他引:3
采用短小芽孢杆菌转酮酶缺陷突变株 ,通过先后向培养基中添加适量的葡萄糖酸钠、Mn2 + ,直接或间接地影响D 核糖的生物合成途径 ,最终影响D 核糖的产量。此外向培养基中添加芳香族氨基酸中的酪氨酸 ,有机酸中的山梨酸可以促进D 核糖的生物合成 ,使其产量达 6 4.2 g/L。 相似文献
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使用转酮醇酶变异株-枯草芽孢杆菌C1-B941进行了D-核糖发酵中间试验。3000L发酵罐试验结果表明,发酵培养基中的葡萄糖浓度为18%时,发酵周期约为64h,发酵转化率达36.84%,发酵液经离子交换树脂纯化后,可以直接用于生产VB2合成的中间体-N-D-核糖醇基-3,4-二甲苯胺。 相似文献
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D-核糖发酵过程参数的研究与控制 总被引:5,自引:0,他引:5
以7L自控发酵罐进行D-核糖发酵实验,对D-核糖发酵过程参数进行优化,发现对数生长后期接种,溶氧控制在40%左右,以葡萄糖酸补料并调节pH值在7.2左右,可使罐的发酵单位由45g/L提高至65g/L左右。 相似文献
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目的:筛选出莽草酸、转酮醇酶双重营养缺陷型的D-核糖生产菌枯草芽胞杆菌,以提高D-核糖的产量。方法:采用化学诱变剂乙基磺酸甲烷(EMS)对野生型D-核糖生产菌的原生质体进行诱变,并从D-核糖合成途径对发酵培养基进行优化设计。结果:摇瓶发酵D-核糖平均产量为52.2g/L;获得的B.sems-10菌株具有良好的遗传稳定性,D-核糖产量高达67.5g/L。结论:通过对D-核糖生产菌原生质体的EMS诱变,筛选出了高产、遗传性状稳定的营养缺陷型B.sems-10菌株,为进一步提高产量奠定了基础。 相似文献
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环腺苷二磷酸核糖(cADPR)──一种新发现的胞内信使分子胡国渊,(中国科学院上海药物研究所新药研究国家重点实验室200031)胡桦(上海医科大学临床医学系200032)多种激素、递质和细胞膜表面对应的受体结合后能引起细胞内钙释放,从而使细胞内游离钙... 相似文献
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金属离子对枯草芽孢杆菌转酮酶缺失突变株合成D-核糖的影响 总被引:1,自引:0,他引:1
研究了金属离子Mn2 +、Fe2 +、Zn2 +对枯草芽孢杆菌 (Bacillussubtilis)转酮酶 (EC 2 .2 .1 .1 )缺失突变株FBL0 4 531D 核糖合成的影响。发现Mn2 +对该突变株合成D 核糖和形成芽孢具有非常显著的影响。 相似文献
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Aim: To investigate the effects of Bacillus subtilis , Bacillus licheniformis and Bacillus megaterium in terms of toxin and growth of pathogenic Vibrio harveyi .
Methods and Results: Three Bacillus probionts were isolated from probiotic BZT aquaculture and identified using a 16S rDNA sequence. Growth inhibition assay showed that supernatants from the 24-h culture of three Bacillus species were able to inhibit the growth of V. harveyi (LMG 4044); B. subtilis was the most effective based on the well diffusion method. Results of a liquid culture model showed that B. subtilis was also widely effective in inhibiting three strains of V. harveyi (isolated from Thailand, the Philippines and LMG 4044), and that both B. licheniformis and B. megaterium inhibit the growth of V. harveyi isolated from the Philippines. Moreover, a haemolytic activity assay demonstrated that V. harveyi (IFO 15634) was significantly decreased by the addition of B. licheniformis or B. megaterium supernatant.
Conclusions: Bacillus subtilis inhibited Vibrio growth, and both B. licheniformis and B. megaterium suppressed haemolytic activity in Vibrio .
Significance and Impact of the Study: The cell-free supernatants produced by Bacillus probionts inhibit Vibrio disease, and Bacillus probionts might have an influence on Vibrio cell-to-cell communications. 相似文献
Methods and Results: Three Bacillus probionts were isolated from probiotic BZT aquaculture and identified using a 16S rDNA sequence. Growth inhibition assay showed that supernatants from the 24-h culture of three Bacillus species were able to inhibit the growth of V. harveyi (LMG 4044); B. subtilis was the most effective based on the well diffusion method. Results of a liquid culture model showed that B. subtilis was also widely effective in inhibiting three strains of V. harveyi (isolated from Thailand, the Philippines and LMG 4044), and that both B. licheniformis and B. megaterium inhibit the growth of V. harveyi isolated from the Philippines. Moreover, a haemolytic activity assay demonstrated that V. harveyi (IFO 15634) was significantly decreased by the addition of B. licheniformis or B. megaterium supernatant.
Conclusions: Bacillus subtilis inhibited Vibrio growth, and both B. licheniformis and B. megaterium suppressed haemolytic activity in Vibrio .
Significance and Impact of the Study: The cell-free supernatants produced by Bacillus probionts inhibit Vibrio disease, and Bacillus probionts might have an influence on Vibrio cell-to-cell communications. 相似文献