Background and objective: Burkholderia pseudomallei is a pathogenic bacterium, causing melioidosis, a serious infectious disease. Currently, the best treatment is using antibiotic drugs. However, many clinical strains are now intrinsically resistant to almost all available antibiotic drugs. Previous study indicated that Bacillus amyloliquefaciens KKU14 strongly inhibits B. pseudomallei. In this study, antimicrobial peptide LcI of B. amyloliquefaciens KKU14 was cloned and expressed to test activity against B. pseudomallei.
Materials and Methods: Antimicrobial peptide LcI was searched from GenPept database (NCBI) and amplified from genome of B. amyloliquefaciens KKU14 by PCR and cloned into different cloning vectors. The recombinant clones were induced and their activity against B. pseudomallei strain P37 were tested by agar well diffusion and in-gel overlay.
Results: The recombinant peptide was successfully cloned. However, the expression could be observed only in pQE31 vector. The expressed peptide has the size of approximately 10 kDa. Nevertheless, the recombinant clones exposed no antimicrobial activities against B. pseudomallei strain P37.
Conclusion: The recombinant peptide LcI cloned from B. amyloliquefaciens KKU14 does not inhibit B. pseudomallei strain P37 in this study. This might due to improper folding of the recombinant peptide, or the peptide that was responsible for inhibition of B. pseudomallei might be other peptides, or the inhibition effect might need synergistically work from several peptides together, which has to be further investigated.