The procedure for the construction of the strain is described in the paper entitled "Cloning, sequencing, and disruption of the Bacillus subtilispsd gene coding for phosphatidylserine decarboxylase" (J. Bacteriol.(1998)180, 100-106). The psd gene was interrupted at the unique PstI site with neo.
Matsumoto K, Okada M, Horikoshi Y, Matsuzaki H, Kishi T, Itaya M, Shibuya I.
Cloning, sequencing, and disruption of the Bacillus subtilis psd gene coding for phosphatidylserine decarboxylase.
100-6 [PubMed ID = 9422599]