Induced Mutation And Selection Of A High Yielding Strain Of Micrococcus Glutamicus For L-Lysine Production

Abstract

The objective of this investigation was to develop a new auxotropic mutant from a regulatory mutant and to examine its potency for L-lysine production. A high L-lysine yielding strain Micrococcus glutamicus AB₂₀₀ was developed from a regulatory mutant Micrococcus glutamicus AB₅ by subsequent mutagenic treatment with UV rays and methyl methane sulfonate respectively.

Treatment of UV rays on the regulatory mutant AB₅ resulted in a mutant strain AB₅₀ gives the maximum yield of L-lysine (5.5mg/mL) than the regulatory mutant (0.9 mg/mL). The mutant strain AB₅₀ on further treatment with a chemical mutagen methyl methane sulfonate resulted to another mutant Micrococcus glutamicus AB₂₀₀ which produced the highest yield of L-lysine (7.2mg/mL) Micrococcus glutamicus AB₂₀₀ was an auxotropic mutant which requires biotin for growth as well as production of L-lysine. The L-lysine producing capacity of auxotropic mutant was tested after maintaining the strain in three different media of which the mutant was stable in a media having the composition of 5% glucose, 0.6% urea, 0.2% K₂HPO₄. 0.025% MgSO₄. 7H₂O, 2µg/mL biotin.