L-lysine prodn. useful in animal nutrition - by fermenting new selena:lysine resistant mutants of Brevibacterium or Corynebacterium, providing high yield

摘要

Prodn. comprises culturing in a nutrient medium, a mutant (L-lysine) (I)-producing strain of Brevibacterium or Corynebacterium which is resistant to selenalysine (II). (I) is accumulated in, then recovered from, the culture broth. The mutant strains are themselves claimed. Culture is pref. carried out at 30-35 deg.C for 40-100 hrs. with pH kept at 6.5-7 during the initial stages and during fermentation. Pref. microorganisms accummulate (I) to at least 2.21 g/dl. Specified are B. lactofermentation AJ 12564 (FERM BP-3554) and AJ12566(BP-3556); C. acetoacidophilum AJ 12565 (BP-3555), B. flavum AJ 12568 (BP-3557) or C. glutamicum AJ 12579 (BP-3559). These strains are prepd. by exposing a starting strain to mutagenic treatment (exposure to UV light or to a chemical mutagen, e.g. N-methyl-N-nitro- N-nitrosoquanidine (NG) or HN03) then selection for resistance to (II) at a concn. which inhibits the starting strain. USE/ADVANTAGE - (I) is an essential amino acid used e.g. in feeding pigs and poultry. It can be now produced more cheaply and efficiently than by known methods.