1. Biosynthesis of poly(epsilon-L-lysine)s in two newly isolated strains of Streptomyces sp.
- Author
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Hirohara H, Takehara M, Saimura M, Ikezaki A, and Miyamoto M
- Subjects
- Cations, Chemistry, Organic methods, Glycerol chemistry, Hydrogen-Ion Concentration, Lysine chemistry, Magnetic Resonance Spectroscopy, Models, Chemical, Molecular Conformation, Nitrogen chemistry, Peptides chemistry, Polymers chemistry, Biotechnology methods, Polylysine chemistry, Streptomyces metabolism
- Abstract
The biosynthesis of poly(epsilon-L-lysine) (epsilon-PL) in the two newly isolated strains of Streptomyces lydicus USE-11 (USE-11) and Streptomyces sp. USE-51 (USE-51) was studied by a newly developed two-stage culture method of cell growth at pH 6.8 and epsilon-PL production at pH 4.5. USE-11 synthesized epsilon-PL consisting of about 28 residues at a high production level, whereas USE-51 did the polymer with 15 ones at a low level. The secreted epsilon-PLs in culture media were digested in a neutral pH range with a peptide hydrolase(s) produced by the epsilon-PL producers. The optimum production levels were presumed to be dependent upon the inherent epsilon-PL synthesis machinery of each producer. The production in USE-51 was sharply dependent upon cell density as was often observed in the production of antibiotics, whereas that in USE-11 was scarcely affected by the density. The SO(4)(2-) was found to be essential for the epsilon-PL production in both strains. This might suggest the involvement of a thiol group in the polymerization reactions including the activation of L-lysine. This study indicates that USE-11 is a most suitable strain for the exploration of the epsilon-PL biosynthesis at the molecular level as well as for the technical applications.
- Published
- 2006
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