Expression, purification, and basic properties of a novel domain structure possessing chitinase from Escherichia coli carrying the family 18 chitinase gene of Bacillus velezensis strain RB.IBE29.

Background: Bacillus velezensis possesses numerous chitinolytic enzymes; however, not much is known about the role of its chitinase molecules.

Methods And Results: In this study, the chiA gene, which encodes a novel domain structure possessing family 18 chitinase from B. velezensis RB.IBE29, was expressed successfully in Escherichia coli BL21-CodonPlus (DE3)-RIPL using the pColdII expression vector. The recombinant protein, rBvChiA, was purified using the HisTrap FF column. Purified rBvChiA showed hydrolytic activity against insoluble chitin and bound to chitinous substrates. In addition, the purified recombinant enzyme displayed remarkable inhibition effects on the spore germination of Fusarium falciforme and the egg hatch of root-knot nematodes (Meloidogyne spp.), which are the main causes of black pepper diseases in the Central Highlands region, Vietnam.

Conclusion: The current work results might enable further studies to develop novel chitinase A and strain RB.IBE29 as a natural fungicide and nematicide for sustainable black pepper production and other crops in the Central Highlands, Vietnam. This is the second report describing chitinase from B. velezensis based on the experimental data.