Can, A.; Baysal, O.

Background: Microorganisms produce a diverse array of enzymes with potential applications in biological control and pest management. Among these enzymes, chitinase stands out due to its safety for non-target organisms and the environment. Chitinase enzymes play a crucial role in breaking down chitin, which serves as a critical component in insect exoskeletons and fungal cell walls. As a result, they emerge as valuable tools for managing both agricultural pests and pathogens. Results: The chiA gene region of Serratia marcescens GBS19 was successfully amplified via PCR and cloned into expression vectors. The resulting chiA protein was expressed and purified through His-tag affinity chromatography. The purified chiA enzyme exhibited optimal activity at 40 {degrees}C and pH 5. The insecticidal properties of the purified chiA enzyme were tested against the agricultural pest Myzus persicae, revealing an LD50 value of 15,804 ppm. Comparative analysis with ref_seq chiA enzymes demonstrated that our purified enzyme shows 98.93% similarity, indicating a high degree of conservation and likely functional similarity. Bioinformatics modelling highlighted a strong binding affinity (-4.10 kcal/mol) between the enzyme and chitin, which was also confirmed with the modelled chitin layer and enzyme interaction. Conclusion: The study underscores the potential of S. marcescens GBS19 chitinase as an effective and environmentally safe biocontrol agent. The chiA enzyme exhibits promising insecticidal properties, specifically against M. persicae, and its strong binding affinity to chitin supports its effectiveness. Given its safety for non-target organisms and the environment, S. marcescens GBS19 chitinase holds significant promise as a tool for integrated pest management, contributing to sustainable agricultural practices.