Brackish Groundwaters Contain Plastic- and Cellulose-Degrading Bacteria

Area of Science:

• Microbiology
• Environmental Science
• Biotechnology

Background:

• Groundwater contamination by microplastics is a growing global concern.
• Subterranean ecosystems are underexplored sources of microorganisms with biotechnological potential.
• Previous research has not traditionally focused on screening groundwater bacteria for plastic and cellulose degradation.

Purpose of the Study:

• To isolate and identify plastic- and lignocellulose-degrading bacteria from Serbian brackish groundwater.
• To assess the enzymatic potential of these bacterial isolates.
• To explore the possibility of using these bacteria for bioremediation of contaminated groundwater.

Main Methods:

• Sampling of brackish groundwater from geotectonic regions in western Serbia.
• Isolation and identification of bacteria using next-generation 16S sequencing.
• Screening of bacterial isolates for degradation activity on plastic (Impranil® DLN-SD, bis(2-hydroxyethyl)terephthalate) and lignocellulosic (carboxymethyl cellulose) substrates.
• Identification of degrading isolates using 16S rDNA sequencing.

Main Results:

• 85.3% of bacterial isolates showed growth or degradation activity on at least one tested substrate.
• 27.8% of isolates degraded the plastic substrate Impranil® DLN-SD.
• Specific bacterial genera, including Stenotrophomonas, Flavobacterium, Rhizobium, and Shewanella, were identified as capable of degrading plastics or cellulose.

Conclusions:

• All investigated brackish groundwaters contain bacteria with the potential to degrade plastics and cellulose.
• The identified plastic-degrading bacteria offer promising avenues for bioremediation strategies targeting microplastic-polluted groundwater.
• Subterranean environments warrant further investigation as reservoirs for novel enzymes and microorganisms relevant to biodegradation processes.