Table 1 Strains and plasmids used in the study
Strain or plasmid | Characteristics or purpose | Reference |
|---|---|---|
Strains | ||
 E. coli EC135 | Knockout vectors construction | Chinese Academy of Science |
 E. coli EC135 pM.Bam | Plasmid DNA methylation modification | Chinese Academy of Science |
 B. licheniformis 2709 | Wild strain | CICC |
 B. licheniformis 2709 Δupp (BL Δupp) | Parent host | [23] |
 B. licheniformis Δapr (BL ΔA) | ΔaprE, aprE gene deletion | This work |
 B. licheniformis Δeps (BL ΔEP) | Δeps, eps cluster deletion | This work |
 B. licheniformis Δlch (BL ΔS) | ΔlchAC, lchAC gene deletion | This work |
 B. licheniformis Capr (BL CA) | aprE gene complementation | This work |
 B. licheniformis Clch (BL CS) | lchAC gene complementation | This work |
 B. licheniformis ΔepsΔlch (BL ΔES) | Δeps, ΔlchAC | This work |
 B. licheniformis ΔepsΔlchΔapr (BL ΔESA) | Δeps, ΔlchAC, ΔaprE | This work |
 BL ΔESA-pWHA | Recombinant strain with pWHA of BL ΔESA | This work |
 BL ΔESA-pWH1520 | BL ΔESA harboring pWH1520, control | This work |
 BL ΔESA-pLYA | Recombinant strain with pLYA of BL ΔESA | This work |
 BL ΔESA-pLY-3 | BL ΔESA harboring pLY-3, control | This work |
 B. licheniformis I1 (BL I1) | Integration expression of aprE in site1 in BL ΔESA | This work |
 B. licheniformis I2 (BL 12) | Integration expression of aprE in site2 in BL ΔESA | This work |
 B. licheniformis I3 (BL I3) | Integration expression of aprE in site3 in BL ΔESA | This work |
Plasmids | ||
 pWH1520 | Shuttle expression vector, Ampr (E. coli) and Tetr (Bacillus): MCS | Nankai University |
 pLY-3 | Shuttle expression vector, Kanar (E. coli) and Cmr (Bacillus): MCS | Lab collection |
 pKSVT | Temperature-sensitive shuttle plasmid, Kanar | Hubei University |
 pTU | pKSVT, upp gene | This work |
 pTUA | Knockout vector, aprE gene deletion | This work |
 pTUE | Knockout vector, eps cluster deletion | This work |
 pTUS | Knockout vector, lchAC gene deletion | This work |
 pTUCA | Backcrossed vector, aprE gene complementation | This work |
 pTUCS | Backcrossed vector, lchAC gene complementation | This work |
 pTUAI 1 | pTU, integrating aprE expression cassette into site 1 | This work |
 pTUAI 2 | pTU, integrating aprE expression cassette into site 2 | This work |
 pTUAI 3 | pTU, integrating aprE expression cassette into site 3 | This work |
 pWHA | pWH1520, aprE expression cassette | This work |
 pLYA | pLY-3, aprE expression cassette | This work |