Non-ionic detergent-based screening method for poly (butylene adipate-co-terephthalate) (PBAT)-degrading...

With the growing use of bioplastics due to their low environmental impact, interest in bioplastic-degrading microorganisms has also increased. To screen for such microorganisms, a clear zone test using plates containing bioplastic emulsions with detergents has been widely used as a key method for rapid and accurate identification. Although emulsifying detergents affect the hydrolytic activity of microbes, their effects have not been thoroughly evaluated across different detergent candidates. In this study, eight different detergents were evaluated for their effectiveness in screening poly(butylene adipate-co-terephthalate) (PBAT)-degrading strains. The anionic detergents N-Lauroylsarcosine sodium salt (Sarkosyl NL), sodium dodecyl sulfate (SDS), and non-ionic polysorbate 20 (Tween 20) enhanced clear zone formation. Among them, the non-ionic detergent Tween 20-based clear zone test system was the most effective for screening PBAT-degrading strains, showing rapid and distinct clear zone formation. This method was also applicable to polybutylene succinate (PBS), polycaprolactone (PCL), and polylactic acid (PLA). Using the Tween 20-based method, Bacillus sp. Y4 was isolated and exhibited a high PBAT degradation rate of 52 % over 14 days. Overall, this study demonstrated that the Tween 20-based clear zone assay offered a reliable and biologically stable screening platform.