Biodegradation of untreated plasticizers-free linear low-density polyethylene films by marine bacteria
Kejvin Bajo, Roberta Romanò, Boris A. Kolvenbach, Seyed Amirabbas Nazemi, Patrick Shahgaldian, Philippe F.-X. Corvini, Fabio Fava, Noura Raddadi
Abstract
Polyethylene significantly contributes to marine plastic pollution. This study focuses on isolating bacteria from sea water and microplastic samples collected from the Tyrrhenian Sea and evaluating their ability to degrade virgin plasticizers-free linear low-density polyethylene (LLDPE) films. The isolates grew on the plastic film under aerobic conditions in shaken flasks leading to LLDPE mass losses of up to 2.597 ± 0.971 % after 60 days incubation. Biofilm formation on the film surface was confirmed by adhered protein quantification while film surface erosion and appearance of functional groups were revealed using SEM and FTIR analyses confirming biodegradation capabilities especially for isolates Bacillus velezensis MT9, Vreelandella venusta MT1 and Vreelandella titanicae MT11. This is the first report on the biodegradation of plasticizers-free non pretreated LLDPE films by marine Bacillus sp. and Vreelandella sp.; most of the LLDPE biodegradation studies have been so far performed on plasticizer containing, pre-treated, or naturally weathered films. • Untreated plasticizers-free LLDPE films biodegradation by marine bacteria assessed • Bacillus sp. and Vreelandella sp. grow and form biofilm on LLDPE film surface. • Highest mass loss (2.597 ± 0.971 %) recorded with B. velezensis MT9 after 60 days • Film biodegradation supported by FTIR and SEM analyses