PURPOSE: To mass-produce L-tryptophan, by cultivating bacteria of the genus Escherichia, obtained by transforming a plasmid having the genetic information regulating the formation of the tryptophan, and deficient in tryptophanase in a culture medium.
CONSTITUTION: A plasmid DNA (the wild-type trp, wild-type trp-ser, variant type trp, variant type trp-serB and a plasmid free from the attenuator attenuator range) is transformed and incorporated into bacteria of the genus Escherichia, resistant to tryptophan analogs, and having the genetic deficiency in one or two or more genes of trpR, aroP, tyrA and pheA as host bacteria by the calcium shock method, and the bacteria are then cultivated in a culture medium aerobically to prepare L-tryptophan.
KURAUSU EMU HAAMAN
RONARUDO ERU SOMAABUIRU
J.GEN.MICROBIOL.=1979
APPL.ENVIRON.MICROBIOL.,=1979
MOLEC.GEN.GENET.,=1978
PROC.NATL.ACAD.SCI.U.S.A.,=1974
J.GEN.MICROBIOL.,=1979
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