Engineering of LysR-type regulator DmlR in Paraburkholderia sp. CP01 to enhance its antifungal production

An antifungal compound derived from Paraburkholderia sp. CP01 has shown promise in managing Ganoderma boninense , the agent of oil palm basal stem rot. LysR-type transcriptional regulators (LTTRs) are known to regulate biosynthetic gene clusters involved in antifungal production. In this study, we identified the LTTR dmlR in CP01, which regulates antifungal compound synthesis. Deletion of the dmlR gene led to a complete loss of antifungal activity, while its overexpression resulted in significantly higher antifungal production. RP-HPLC analysis confirmed that the dmlR -overexpressing mutant (WB12) produced higher concentrations of antifungal compounds than the wild type. Whole genome sequencing revealed that dmlR was successfully integrated into chromosome 2 of CP01. These findings underscore the importance of LTTRs in regulating secondary metabolite production and suggest that manipulating LTTRs could enhance the antifungal properties of Paraburkholderia species for future biotechnological applications.