PT  - JOURNAL ARTICLE
AU  - Intikhab Alam
AU  - Nojood Aalismail
AU  - Cecilia Martin
AU  - Allan Kamau
AU  - Francisco J. Guzmán-Vega
AU  - Tahira Jamil
AU  - Afaque A. Momin
AU  - Silvia G. Acinas
AU  - Josep M. Gasol
AU  - Stefan T. Arold
AU  - Takashi Gojobori
AU  - Susana Agusti
AU  - Carlos M. Duarte
TI  - Rapid Evolution of Plastic-degrading Enzymes Prevalent in the Global Ocean
AID  - 10.1101/2020.09.07.285692
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.09.07.285692
4099  - http://biorxiv.org/content/early/2020/09/09/2020.09.07.285692.short
4100  - http://biorxiv.org/content/early/2020/09/09/2020.09.07.285692.full
AB  - Estimates of marine plastic stocks, a major threat to marine life (1), are far lower than expected from exponentially-increasing litter inputs, suggesting important loss factors (2, 3). These may involve microbial degradation, as the plastic-degrading polyethylene terephthalate enzyme (PETase) has been reported in marine microbial communities (4). An assessment of 416 metagenomes of planktonic communities across the global ocean identifies 68 oceanic PETase variants (oPETase) that evolved from ancestral enzymes degrading polycyclic aromatic hydrocarbons. Twenty oPETases show predicted efficiencies comparable to those of laboratory-optimized PETases, suggesting strong selective pressures directing the evolution of these enzymes. We found oPETases in 90.1% of samples across all oceans and depths, particularly abundant at 1,000 m depth, with a strong dominance of Pseudomonadales containing putative highly-efficient oPETase variants in the dark ocean. Enzymatic degradation may be removing plastic from the marine environment while providing a carbon source for bathypelagic microbial communities.