Addition of exogenous astaxanthin for improving ε-poly-L-lysine (ε-PL) production in Streptomyces griseofuscus was investigated in this study. By this unique strategy, the ε-PL production in shaker-flask fermentation was 2.48 g/L, which was 67.5% higher than the control at the addition dosage of 1.0 g/L, owing to the oxidation resistance of astaxanthin. In fed-batch fermentation, the ε-PL production reached 36.1 g/L, a 36.3% increase compared to the control. Intracellular response for oxidation in S. griseofuscus such as ROS generation and lipid peroxidation was reduced by astaxanthin addition. Illumina RNA deep sequencing (RNA-seq) technology further revealed that S. griseofuscus with astaxanthin addition showed down-regulated transcriptions of genes involved in oxidative stress. This research proved that the beneficial effect of astaxanthin addition was far better than glutathione (GSH) owing to the stronger antioxidant capacity, and provided a novel approach to regulate ε-PL synthesis.

中文翻译：

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通过添加外源虾青素增强灰链霉菌中ε-聚-L-赖氨酸的产生。

在本研究中，研究了添加外源虾青素以改善灰链霉菌中ε-聚-L-赖氨酸（ε-PL）的产生。通过这种独特的策略，由于虾青素的抗氧化性，摇瓶发酵中的ε-PL产量为2.48 g / L，在添加量为1.0 g / L时比对照高67.5％。在分批补料发酵中，ε-PL产量达到36.1 g / L，与对照相比增加了36.3％。加入虾青素后，对红褐葡萄球菌氧化的细胞内反应（如ROS生成和脂质过氧化反应）降低。Illumina RNA深度测序（RNA-seq）技术进一步表明，添加虾青素的灰链霉菌显示出氧化应激相关基因的转录下调。