Enhancing Polyhydroxybutyrate (PHB) Production in Bacillus subtilis via ppk Gene Overexpression for Sustainable Bioplastic Synthesis
Yoonsun Choi
Hankuk Academy of Foreign Studies, Yongin-si, Republic of Korea
Publication date: May 31, 2025
Hankuk Academy of Foreign Studies, Yongin-si, Republic of Korea
Publication date: May 31, 2025
DOI: http://doi.org/10.34614/JIYRC2025I14
ABSTRACT
Bioplastics are emerging as a good alternative to oil-based plastics. PHBs are produced by microorganisms such as bacteria—most commonly Bacillus subtilis—and are known to be very flexible and durable. However, their high production cost makes them one of the most expensive bioplastics. This study aims to increase the efficiency of PHB production in Bacillus subtilis through overexpression of the ppk gene. The ppk gene was cloned into the pHT01 vector and transformed into Bacillus subtilis. Then, they were cultured under various plasmid concentrations, and the amount of PHB and the expression level of the ppk gene were measured using RT-qPCR. As a result, they significantly increased in 3.33 nM plasmid concentration. Minimal changes occurred at lower concentrations, suggesting the existence of an expression threshold. In conclusion, overexpression of the ppk gene effectively enhanced PHB production in Bacillus subtilis, confirming its potential to contribute to sustainable bioplastic synthesis.
Bioplastics are emerging as a good alternative to oil-based plastics. PHBs are produced by microorganisms such as bacteria—most commonly Bacillus subtilis—and are known to be very flexible and durable. However, their high production cost makes them one of the most expensive bioplastics. This study aims to increase the efficiency of PHB production in Bacillus subtilis through overexpression of the ppk gene. The ppk gene was cloned into the pHT01 vector and transformed into Bacillus subtilis. Then, they were cultured under various plasmid concentrations, and the amount of PHB and the expression level of the ppk gene were measured using RT-qPCR. As a result, they significantly increased in 3.33 nM plasmid concentration. Minimal changes occurred at lower concentrations, suggesting the existence of an expression threshold. In conclusion, overexpression of the ppk gene effectively enhanced PHB production in Bacillus subtilis, confirming its potential to contribute to sustainable bioplastic synthesis.
