Table 1 Strains and plasmids used in this study
Strain or plasmid | Characteristics | Reference or source |
|---|---|---|
Strains | ||
 E. coli DH5α | F– endA1 glnV44 thi-1 recA1 relA1 gyrA96 deoR nupG purB20 ϕ80dlacZΔM15 Δ(lacZYAargF) U169, hsdR17(rK–mK +), λ– | Solgent |
 M. alcaliphilum 20Z | Wild-type strain 20Z | DMSZ |
 20ZE | Evolved putrescine-tolerant strain M. alcaliphilum 20Z | This study |
  20ZES1 | Evolved putrescine-tolerant strain ΔspeE1 | This study |
  20ZE3 | Evolved putrescine-tolerant strain ΔldhΔackΔspeE1 | This study |
  20ZE4A | Evolved putrescine-tolerant strain ΔldhΔackΔspeE1::argDJ | This study |
Plasmid | ||
 pAWP89 | pAWP78 containing dTomato driven by pTac promoter | [49] |
 pCM433KanT | A broad host-range sacB-based vector for unmarked allelic exchange, Kmr | [13] |
 pCSE1 | pCM433kanT containing the deletion construct of speE1 | This study |
 pCM433ldh | pCM433kanT containing the deletion construct of ldh | [16] |
 pCM433ack | pCM433kanT containing the deletion construct of ack | [16] |
 pCM351 | pCM184 with aaaC1 from pCM350; allelic exchange vector | [50] |
 pCAR2 | pCM351 containing two flanking regions to replace the speE2 by pTac-argDJ fragment | This study |
 pACE | pAWP89 carrying speC (E. coli) and potE driven by tac promoter | This study |
 pACO | pAWP89 carrying speC (M. trichosporium OB3b) driven by tac promoter | This study |