Biodegradation of Nitrile Gloves as Sole Carbon Source of Pseudomonas aeruginosa in Liquid Culture

Abstract

Nitrile gloves have become a significant environmental pollutant after the COVID-19 pandemic due to their single-use design. This study examines the capability of P. aeruginosa to use nitrile gloves as its sole carbon energy source. Biodegradation was determined by P. aeruginosa adapting to increasing nitrile glove concentrations at 1%, 3%, and 5% (w/v). The growth kinetics of P. aeruginosa were evaluated, as well as the polymer weight loss. Topographic changes on the glove surfaces were examined using SEM, and FT-IR was used to evaluate the biodegradation products of the nitrile gloves. Following the establishment of a biofilm on the glove surface, the nitrile toxicity was minimized via biodegradation. The result of the average weight loss of nitrile gloves was 2.25%. FT-IR analysis revealed the presence of aldehydes and aliphatic amines associated with biodegradation. SEM showed P. aeruginosa immersed in the EPS matrix, causing the formation of cracks, scales, protrusions, and the presence of semi-spherical particles. We conclude that P. aeruginosa has the capability to use nitrile gloves as its sole carbon source, even up to 5%, through biofilm formation, demonstrating the potential of P. aeruginosa for the degradation of nitrile gloves.

Keywords: COVID-19; EPS matrix; NBR; Pseudomonas aeruginosa; SEM; biofilm; nitrile gloves; plastic biodegradation; plastic pollution.

Figure 1

Growth changes in ln (CFUmL⁻¹) of P. aeruginosa during biodegradation with 5% nitrile gloves in Luria broth over 7 days. Data are represented as mean values ± SD (n = 3).

Figure 2

Comparison of initial and final OD values with different percentages of nitrile gloves as the sole carbon source: adaptation of 1% after 9 days, biodegradation of 3% after 14 days, and biodegradation of 5% after 7 days. Results are presented as mean values ± SD (n = 3). The control was utilized as a baseline for comparison.

Figure 3

Optical density changes in P. aeruginosa during biodegradation with 5% nitrile gloves in Luria broth over 7 days. Data represented as mean values ± SD (n = 3). The control served as the baseline for comparison.

Figure 4

Weight loss of nitrile gloves caused by P. aeruginosa during biodegradation at 5% after 7 days. The mean % weight loss ± SD of the nitrile gloves was 2.25% ± 0.81%, and for the control samples, it was 0.59% ± 0.04% (n = 3).

Figure 5

The FT-IR spectra of the nitrile gloves degraded by P. aeruginosa with different percentages of polymer in LB: (a) FT-IR spectrum of control at initial stage and final stage after 7 days; (b) FT-IR spectrum of degraded nitrile gloves with adaptation at 1% after 9 days, biodegradation at 3% after 14 days, and biodegradation at 5% after 7 days.

Figure 6

Surface changes caused by P. aeruginosa on nitrile gloves in different percentages (w/v) at the end of each bioprocess: (a) adaptation of P. aeruginosa at 1%; (b) biodegradation at 3%; (c) biodegradation at 5%; (d) nitrile glove control (no bacteria). Nitrile gloves were observed by Motic^® BA310 LED Digital, 10× magnification.

Figure 7

Biodegradation of nitrile gloves by P. aeruginosa viewed with SEM: (a) adaptation at 1%; (b) biodegradation at 3%; (c) biodegradation at 5%; (d) control (nitrile gloves without treatment). Magnification 1.5 k× and 8.5 k×.

Figure 8

Biofilm of P. aeruginosa on surface of nitrile gloves viewed with SEM at 15 k×: (a) biodegradation at 5% and (b) control (nitrile gloves without treatment).