Because of their tiny particle size, microplastics are easily ingested and accumulated by organisms in mangrove ecosystems. These mi- croplastics may then be passed through the food chain, affecting the health of higher-level organ- isms and may even end up in the human food chain, posing a po- tential threat to human health.
Accumulation of microplastics in the soil alters the health and pro- ductivity of the soil and negatively affects the growth of mangrove plants by impeding root develop- ment and reducing photosynthe- tic efficiency.
Mangrove forests are complex ecosystems in which various or- ganisms and environmental fac- tors are interdependent and inter- act with each other. Microplastics can upset this balance, interfere with the normal functioning of the ecosystem, alter the processes of nutrient cycling and energy flow in mangrove wetlands, and affect the diversity and stability of bio- logical communities.
PE plastics
PP plastics
PET plastics
PS plastics
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The translated peptide traverses the Sec channel, then folds in the periplasm.
This protein is anchored to the outer cell membrane, helps the bacteria bind and depolymerize the PE plastic.
P. aeruginosa degrades plastic into CO2, which
is converted to bicarbonate and passed on to
R. palustris.
CO2 converts to cellulose through the CBB cycle.
In mangrove forests, the two engineered bacteria work together as PE & CO2 hunters to achieve PE degradation and CO2 fixation.
*In certain specific regions' mangrove ecosystems, the content of polyethylene (PE) microplastics exhibits a higher proportion compared to other types of microplastics. However, this is not a universal phenomenon across all mangrove forests globally, as each mangrove region possesses unique environmental conditions, leading to significant differences in the distribution and composition of microplastics. In summary, PE plastics have emerged as a particularly prominent and difficult-to-degrade source of pollution in mangrove environments, posing a major challenge to these ecosystems.
Reference: Yu, L. et al. Distribution, characteristics, and human exposure to microplastics in mangroves within the Guangdong-Hong Kong-Macao Greater Bay Area. Marine Pollution Bulletin 175, 113395 (2022).
