Department of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Gunma, Japan.
Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura-machi, Gunma, Japan.
Biosci Biotechnol Biochem. 2022 Jul 22;86(8):1128-1135. doi: 10.1093/bbb/zbac083.
Improving the organic solvent tolerance of bacteria is beneficial for the bioproduction of various valuable chemicals. In this study, we found that 1,4-dihydroxy-2-naphthoic acid (DHNA), known as a prebiotic, increased organic solvent tolerance in Escherichia coli. The AcrAB-TolC multidrug efflux pump contributes to the intrinsic organic solvent tolerance of E. coli. The addition of DHNA increased this pump's expression level. Transcriptional activators MarA, SoxS, and Rob proteins are known to control the expression of marA/soxS/rob regulon genes, including acrAB and tolC. Evaluation of the organic solvent tolerances of ΔmarA mutant, ΔsoxS mutant, and Δrob mutant showed that ΔmarA mutant and ΔsoxS mutant did not improve organic solvent tolerance by the addition of DHNA. In addition, DHNA increased the promoter activities of both marA and soxS. These results indicated that DHNA induces the AcrAB-TolC pump through both the marRAB system and the soxRS system.
提高细菌对有机溶剂的耐受性有利于各种有价值化学品的生物生产。在这项研究中，我们发现，1,4-二羟基-2-萘甲酸（DHNA），作为一种前体，可提高大肠杆菌对有机溶剂的耐受性。AcrAB-TolC 多药外排泵有助于大肠杆菌的固有有机溶剂耐受性。DHNA 的添加增加了该泵的表达水平。MarA、SoxS 和 Rob 蛋白等转录激活因子已知可控制 marA/soxS/rob 调节基因的表达，包括 acrAB 和 tolC。对 ΔmarA 突变体、ΔsoxS 突变体和 Δrob 突变体的有机溶剂耐受性评估表明，DHNA 的添加并不能提高 ΔmarA 突变体和 ΔsoxS 突变体的有机溶剂耐受性。此外，DHNA 增加了 marA 和 soxS 的启动子活性。这些结果表明，DHNA 通过 marRAB 系统和 soxRS 系统诱导 AcrAB-TolC 泵。
