Table 1 Strains and plasmids.

B. subtilis 168 derivative, laboratory strain; trpC degQ⁰ sfp⁰; Srf– Pps–

Chester Price’ lab (UCDavis, USA)

B. subtilis pB2 derivative with a P43-sfp⁺-degQ⁺ cassette inserted at the amyE locus; producing plipastain (Pps⁺) and surfactin (Srf⁺); Cm^R

Constructed and characterized in our lab, stored in CGMCC (No. 11723)

B. subtilis pB2-L derivative with TE domain fused at end of the 7^th T domain; Pps− Srf⁺ Cm^R

This study

B. subtilis pB2-L derivative with TE domain fused at end of the 8^th T domain; Pps− Srf⁺ Cm^R

This study

B. subtilis pB2-L derivative with TE domain fused at end of the 9^th T domain; Pps− Srf⁺ Cm^R

This study

B. subtilis pB2-L derivative with TE_Long domain fused at end of the 7^th T domain; producing heptapeptide; Pps− Srf⁺ Cm^R

This study

B. subtilis pB2-L derivative with TE_Long domain fused at end of the 8^th T domain; producing octapeptide; Pps− Srf⁺ Cm^R

This study

B. subtilis pB2-L derivative with TE_Long domain fused at end of the 9^th T domain; producing octapeptide and nonapeptide; Pps− Srf⁺ Cm^R

This study

recA1, endA1, lacZΔM15

Vazyme (Nanjing, China)

F’,traD36 proA⁺B⁺ lacI^q lacZΔM15/dam dcm supE44 hsdR17 thi leu thr rpsL lacY galK galT ara tonA tsxΔ (lac-proAB)

Transgen Biolabs (Beijing, China)

TA cloning vector; Ap^R

TaKaRa (Dalian, China)

Thermosensitive vector; Kan^R, Erm^R

22

7ProTlinker-TE fragment inserted into pKS2, Kan^R, Erm^R

This study

8GlnTlinker-TE fragment inserted into pKS2, Kan^R, Erm^R

This study

9TyrTlinker-TE fragment inserted into pKS2, Kan^R, Erm^R

This study

7ProTTE_Long fragment inserted into pKS2, Kan^R, Erm^R

This study

8GlnTTE_Long fragment inserted into pKS2, Kan^R, Erm^R

This study

9TyrTTE_Long fragment inserted into pKS2, Kan^R, Erm^R

This study