Little is known about the adaptation strategies utilized by photosynthetic microorganisms to cope with salinity changes happening in the environment, and the effects on microbial electrochemical technologies. Herein, bioinformatics analysis revealed a metabolism shift in Rhodobacter capsulatus resulting from salt stress, with changes in gene expression allowing accumulation of compatible solutes to balance osmotic pressure, together with the up-regulation of the nitrogen fixation cycle, an electron sink of the photosynthetic electron transfer chain. Using the transcriptome evidence of hindered electron transfer in the photosynthetic electron transport chain induced by adaption to salinity, increased understanding of photo-bioelectrocatalysis under salt stress is achieved. Accumulation of glycine-betaine allows immediate tuning of salinity tolerance but does not provide cell stabilization, with a 40 ± 20% loss of photo-bioelectrocatalysis in a 60 min time scale. Conversely, exposure to or inducing the expression of the Rhodobacter capsulatus gene transfer agent tunes salinity tolerance and increases cell stability. This work provides a proof of concept for the combination of bioinformatics and electrochemical tools to investigate microbial electrochemical systems, opening exciting future research opportunities.

中文翻译：

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通过生物信息学和电化学的结合揭示盐度对光生物电催化的影响。

关于光合作用微生物用于应对环境中盐度变化的适应策略及其对微生物电化学技术的影响知之甚少。在此，生物信息学分析显示，盐胁迫导致荚膜红球菌发生代谢转移，基因表达的变化允许相容性溶质的积累以平衡渗透压，同时固氮循环的上调（光合电子的电子吸收）转移链。使用转录组证据表明，由于适应盐分而引起的光合作用电子传输链中的电子转移受阻，可以进一步理解盐胁迫下的光生物电催化作用。甘氨酸-甜菜碱的积累可以立即调节盐度耐受性，但不能提供细胞稳定性，在60分钟的时间内会损失40±20％的光生物电催化作用。相反，暴露或诱导荚膜红细菌基因转移剂的表达可调节盐度耐受性并增加细胞稳定性。这项工作为将生物信息学和电化学工具相结合以研究微生物电化学系统提供了概念验证，从而开启了令人兴奋的未来研究机会。