Isolation of a Rhodobacter sphaeroides mutant with enhanced hydrogen production capacity from transposon mutagenesis by NH4+ nitrogen resource
Isolation of a Rhodobacter sphaeroides mutant with enhanced hydrogen production capacity from transposon mutagenesis by NH4+ nitrogen resource
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DOI：
10.1016/j.ijhydene.2018.01.179
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发表时间：
2018-07-26
影响因子：
7.2
通讯作者：
Guo, Liejin
中科院分区：
文献类型：
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作者：
Wang, Xueqing;Wu, Xiaomin;Guo, Liejin
为了减轻光合细菌中固氮酶的氨抑制效应，我们筛选了一个转座子插入突变体库，该突变体在氨抑制条件下表现出更好的产氢性能，揭示了相关的调控基因。利用转座子质粒pRL27对在氨存在下生长不良的光合细菌cbbR无效突变体进行转座子诱变，并成功分离出具有更好生长特性的突变体。突变体WRR04的产氢率和产氢率分别提高了14.16%和31.38%。 BLAST 分析显示，中断的 DNA 序列编码转录调节因子 trmB。此外，还构建了突变体WTF05（trmB（-））和WTRO6（trmB（-）、cbbR（-）），其H-2产率较野生株分别显着提高了54.72%和41.44%。固氮酶活性的增强表明，trmB 的断裂可以部分解除对球形红细菌受铵抑制的固氮酶活性的抑制。 (C) 2018 年由 Elsevier Ltd 代表 Hydrogen Energy Publications LLC 出版。
In order to mitigate the ammonia-repression effect of nitrogenase in photosynthetic bacteria, we screened a library of transposon insertion mutants that showed better hydrogen production performance under ammonia-repressed conditions, revealing a relevant regulatory gene. The transposon plasmid pRL27 was engaged for transposon mutagenesis in a cbbR nullmutant of photosynthetic bacteria that has poor growth in the presence of ammonia, and mutants with better growth characteristics were successfully isolated. The hydrogen production yield and rate of one mutant (WRR04) were improved by 14.16% and 31.38%, respectively. BLAST analysis revealed that the interrupted DNA sequence encodes trmB, a transcriptional regulator. Additionally, the mutants WTF05 (trmB(-)) and WTRO6 (trmB(-), cbbR(-)) were constructed, and their H-2 production rates were increased remarkably by 54.72% and 41.44% comparing with the wild strain, respectively. The enhancement of nitrogenase activity demonstrates that the rupture of trmB could partly de-repress the activity of nitrogenase inhibited by ammonium for Rhodobacter sphaeroides. (C) 2018 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.