Microbial-Enzymatic Combinatorial Approach to Capture and Release Microplastics

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

5 Scopus Citations
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Author(s)

  • Shepherd Yuen Chan
  • Max Wang-Tang Wong
  • Bonnie Tsz Ching Kwan
  • James Kar-Hei Fang
  • Song Lin Chua

Detail(s)

Original languageEnglish
Pages (from-to)975–982
Journal / PublicationEnvironmental Science and Technology Letters
Volume9
Issue number11
Online published12 Oct 2022
Publication statusPublished - 8 Nov 2022

Abstract

Difficult-to-remove microplastic pollution poses serious risks to ecosystems and human health. Sewage treatment plants also cannot remove microplastics completely with filters or harsh chemical treatments. It is imperative to develop biotechnologies that aggregate microplastics into larger sizes for rapid removal from polluted waters. Using experimental evolution, we generated microplastic aggregators (MAGs) from the environmentally prevalent Pseudomonas aeruginosa, which are evolved to aggregate microplastics into sizable aggregates via biofilm formation. This is mediated by upregulation of a cyclic-di-GMP (c-di-GMP) secondary messenger signaling system found in most bacterial species. Comparative genomic analysis of MAGs revealed mutations in the yfiR gene, which is the repressor of tpbB, a c-di-GMP synthesizing diguanylate cyclase (DGC). Derepression of tpbB conferred MAGs with high intracellular c-di-GMP content and production of a CdrA biofilm matrix protein, resulting in higher biofilm formation and aggregation of microplastics with various sizes and materials. To release microplastics from the aggregates for downstream resource recovery, we employed protease (trypsin) to degrade CdrA and disrupt the biofilm matrix. As a proof-of-concept method, we demonstrated that a capture-then-release approach could mitigate microplastic pollution in seawater samples collected in the vicinity of a sewage outfall. Hence, our work provides insights into efficient biological removal of other micropollutants or biofilm-enabled catalysis of microparticles.

Research Area(s)

  • Bacteria, Biofilm, Evolution, Microplastics, Recovery

Citation Format(s)

Microbial-Enzymatic Combinatorial Approach to Capture and Release Microplastics. / Chan, Shepherd Yuen; Wong, Max Wang-Tang; Kwan, Bonnie Tsz Ching et al.
In: Environmental Science and Technology Letters, Vol. 9, No. 11, 08.11.2022, p. 975–982.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review