The Induction of L-lysine-α-Oxidase from Trichoderma Harzianum Rifai by Metabolic Products of Brevibacterium sp. and the Improvement of Its Isolation and Purification Techniques

Background: The enzyme L-lysine-α-oxidase from Trichoderma harzianum Rifai is a promising anticancer, antifungal and antibacterial agent. Intensive exploring of its physico-chemical properties and possible ways of application requires sufficient amounts of the protein which in turn depends on good techniques of cultivation of the micro-organism producer, enzyme soft isolation and purification, and storage. Methods: An improved method has been suggested for isolation and purification of the enzyme. A specific combination of column sorbents was adapted and gradient elution with sodium chloride was applied to elevate the yield of the enzyme. The inductive influence of Metabolic Products (MP) of the Brevibacterium species, along with fungal metabolites of Ulocladium sp. and Trichoderma sp. was tested. The enzyme activity assay was based on the detection of oxidized dimethylbenzidine in a peroxidase reaction coupled with an L-lysine-α-oxidase reaction. Some enzyme properties were additionally explored. Results: The upgraded technique of isolation and purification resulted in a yield of enzyme of about 79%. All strains of Brevibacterium sp. proved to be potent enhancers of L-lysine-α-oxidase activity and concomitant activities. The induced enzyme appeared to be less specific but more thermostable. Possible application scopes for the enzyme with modified properties are discussed. Phosphate buffer solution (pH=5.6) appeared to be the best one for long-term storage of the enzyme. Conclusion: A significant inducing effect of MP of Brevibacterium sp. on L-lysine-α-oxidase has been detected, and its isolation and purification techniques have been improved.