POS9-0880
Degradation Behavior of PLA, PHA, PBS, and PBAT by Marine Tidal Flat-Derived Marinobacterium maritimum
Topic
S9. Polymer Technology for Sustainability
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Jihyeon Jung (Incheon National University)
Co-Author(s)
Abstract
Biodegradable plastics, including poly(lactic acid) (PLA), polyhydroxyalkanoate (PHA), poly(butylene succinate) (PBS), and poly(butylene adipate-co-terephthalate) (PBAT), are increasingly used as sustainable materials; however, their degradation in marine environments remains uncertain. Low temperature, salinity, and nutrient limitation may reduce microbial abundance and activity, restricting polymer degradation. Thus, marine microbial resources capable of degrading these polymers are needed to evaluate environmental degradability. In this study, plastic-accumulating tidal flat sediment was used to isolate a marine-derived bacterium with biodegradable polymer-degrading potential, and its degradation of PLA, PHA, PBS, and PBAT was compared.
The isolate was selected by clear-zone formation on PLA-, PHA-, PBS-, and PBAT-sprayed agar plates and identified as Marinobacterium maritimum by 16S rRNA gene sequencing. Film-based cultivation was performed using PLA, PHA, PBS, and PBAT films, and degradation was evaluated at 0, 30, and 60 days by weight loss, GPC, SEM, water contact angle, and FTIR. After 60 days, PLA showed the highest weight loss (6.19%), while PHA, PBS, and PBAT showed measurable losses of 1.09–1.24%. GPC revealed molecular-weight reduction in all polymers; PBAT showed the largest decreases in Mn and Mw (25.0% and 19.8%), and all plastics showed at least 10.5% and 11.2% decreases in Mn and Mw, respectively, indicating polymer chain scission. Water contact angle decreased by 18.3–29.2% compared with neat films, suggesting increased surface hydrophilicity. SEM and FTIR confirmed polymer-dependent surface erosion and functional-group changes, while lipase, amylase, and protease activities supported possible enzyme-mediated degradation.
This study demonstrates that tidal flat-derived M. maritimum can degrade multiple biodegradable plastics and provides evidence for understanding their degradability and environmental fate in marine environments.
The isolate was selected by clear-zone formation on PLA-, PHA-, PBS-, and PBAT-sprayed agar plates and identified as Marinobacterium maritimum by 16S rRNA gene sequencing. Film-based cultivation was performed using PLA, PHA, PBS, and PBAT films, and degradation was evaluated at 0, 30, and 60 days by weight loss, GPC, SEM, water contact angle, and FTIR. After 60 days, PLA showed the highest weight loss (6.19%), while PHA, PBS, and PBAT showed measurable losses of 1.09–1.24%. GPC revealed molecular-weight reduction in all polymers; PBAT showed the largest decreases in Mn and Mw (25.0% and 19.8%), and all plastics showed at least 10.5% and 11.2% decreases in Mn and Mw, respectively, indicating polymer chain scission. Water contact angle decreased by 18.3–29.2% compared with neat films, suggesting increased surface hydrophilicity. SEM and FTIR confirmed polymer-dependent surface erosion and functional-group changes, while lipase, amylase, and protease activities supported possible enzyme-mediated degradation.
This study demonstrates that tidal flat-derived M. maritimum can degrade multiple biodegradable plastics and provides evidence for understanding their degradability and environmental fate in marine environments.
