Molecular breeding of a biotin-hyperproducing Serratia marcescens strain.
We previously reported that an acidomycin-resistant mutant of Serratia marcescens Sr41, SB304, and a mutant that was derived from SB304 and was resistant to a higher concentration of acidomycin, SB412, produced 5 and 20 mg of D-biotin, respectively, per liter of a medium containing sucrose and urea (N. Sakurai, Y. Imai, M. Masuda, S. Komatsubara, and T. Tosa, Appl. Environ. Microbiol. 59:2857-2863, 1993). In order to increase the productivity of D-biotin, the biotin (bio) operons were cloned from strains SB412, SB304, and 8000 (wild-type strain), and pLGM412, pLGM304, and pLGW101, respectively, were obtained through subcloning. These plasmids harbored 7.2-kb DNA fragments coding for the bioABFCD genes on a low-copy-number vector and were introduced into SB304, SB412, and 8000. Among the resulting recombinant strains, SB412(pLGM304) exhibited the highest D-biotin production (200 mg/liter) in the production medium. The plasmid was stably maintained in cells. Unexpectedly, SB412(pLGM412) grew very slowly, and the D-biotin productivity of this recombinant strain was not evaluated because pLGM412 was unstable.
Sakurai
N
N
Research Laboratory of Applied Biochemistry, Tanabe Seiyaku Co., Ltd., Osaka, Japan.
Imai
Y
Y
Masuda
M
M
Komatsubara
S
S
Tosa
T
T
D001710:Biotin / Q000096:biosynthesis* / Q000235:genetics; D019731:Carbon-Nitrogen Ligases; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005798:Genes, Bacterial; D005818:Genetic Engineering; D008025:Ligases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009876:Operon; D010957:Plasmids / Q000235:genetics; D011995:Recombination, Genetic; D012706:Serratia marcescens / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D000637:Transaminases / Q000235:genetics / Q000378:metabolism
D001710:Biotin; C020029:7,8-diaminopelargonic acid aminotransferase; D000637:Transaminases; D008025:Ligases; D019731:Carbon-Nitrogen Ligases; C020024:dethiobiotin synthetase