TY - JOUR
TI - Improvement of Lysine Production by Analog-Sensitive and Auxotroph Mutants of the Acetylene-Utilizing Bacterium Gordona bronchialis (Rhodococcus bronchialis)
AU - Kyriacou, A.
AU - Balis, C.
AU - Typas, M.A.
JO - Applied Biochemistry and Biotechnology - Part A Enzyme Engineering and Biotechnology
PY - 1997
VL - 66
TODO - 3
SP - 281-289
PB - Humana Press Inc.
SN - null
TODO - 10.1007/BF02785594
TODO - Bacteria (microorganisms);  Gordonia bronchialis;  Rhodococcus, acetylene;  asparagine;  beta aspartylhydroxamic acid;  beta-aspartylhydroxamic acid;  cysteine;  drug derivative;  lysine;  lysine hydroxamate;  pyruvic acid derivative;  s (2 aminoethyl)cysteine;  S-2-aminoethyl cysteine, antibiotic resistance;  article;  biosynthesis;  metabolism;  mutation;  Rhodococcus, Acetylene;  Asparagine;  Cysteine;  Drug Resistance, Microbial;  Lysine;  Mutation;  Pyruvates;  Rhodococcus
TODO - An acetylene utilizing Gordona (Rhodococcus) bronchialis strain, screened for the production of fine chemicals, was found to be capable of producing small amounts of lysine. Attempts to produce amino-acid analog-resistant and/or sensitive mutants and auxotrophs of this strain with increased lysine production were made following UV-irradiation or N-methyl-N′-nitro-N-nitrosoguanidine (MNNG) treatment. The bacterium exhibited surprisingly high resistance levels to the aforementioned mutagens which is attributed to highly effective inborn-repair systems. Natural resistance to high levels of S-(2-aminoethyl)-L-cysteine (AEC) (2%) was observed, in contrast with D, L-aspartic acid hydroxamate (AAH), L-lysine hydroxamate (LHX) and β-fluoropyruvate (FP). A variety of amino-acid analog-resistant (AAHr, LHXr) or analog-sensitive (FPs) mutants were produced following UV-irradiation or MNNG treatment. Similarly, a large number of auxotrophs (68) of different types were also obtained. From these, one FPs mono-auxotroph and two poly-auxotrophs (with at least one requirement for the aspartic acid family) showed an increased lysine production (∼1.8 g/L) comparable (4 g/L) to that found in other bacteria capable of utilizing long-chain hydrocarbons (1).
ER -