E-Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2021

Microbial Degradation of Polyurethanes (#345)

Parth Bhavsar 1 , Mrinal Bhave 1 , Hayden Webb 1
  1. Department of Chemistry and Biotechnology, Swinburne University of Technology, Hawthorn, Victoria, Australia

Polyurethanes (PU) have been in use for decades in a wide range of industries, including automobiles, domestic and medical applications, and have posed a major problem when it comes to its disposal.1 PU is highly resistant to natural degradation and accumulates.2 Currently, PU wastes are handled through orthodox disposal techniques, none of which are suitable for prolonged use in the future.3 Thus, biological degradation of polyurethane is a desirable avenue for disposal.3,5 The current knowledge in this field is limited to the microbes that can partially degrade PU with low efficiency and limited versatility. There is also a lack of information on self-sufficient microbial consortia able to convert PU into simple products. This research aims on addressing some of these limitations. Microbes with potential to degrade PU were isolated from landfill soil. These isolates were tested with Impranil®, a polyester PU dispersion. Microbes that have the potential to degrade PU will produce clear zones on the Impranil® plate due to the secretion of PU degrading enzymes such as esterases, lipases etc.4 Numerous microbes produced clear zones on Impranil® media within 7 to 14 days of incubation, suggesting significant potential for practical application. Some isolates produced clear zones faster and were selected for identification through 16S rRNA sequencing for bacteria and ITS sequencing for fungi. Some of the identified fungi were from the genera Aspergillus, Fusarium, Mucor, Riopa and Chlonostachys  and some of the identified bacteria were from Stenotrophomonas, Arthrobacter, Pseudomonas, Streptomyces and Achromobacter. Microbial communities were also incubated with polyester- and polyether-type polyurethane strips as a sole carbon source. Dry weight of the PU strips before and after the assay was measured, polyester PU strips showed substantial weight loss of up to ~18% (n=3)  whereas, only up to ~3.6 % (n=3) was observed for polyether PU after 45 days. These results are promising indicators of the potential of these strains and consortia for development into greener, environmentally sustainable disposal techniques.

  1. LOREDO-TREVIÑO, A., GUTIÉRREZ-SÁNCHEZ, G., RODRÍGUEZ-HERRERA, R. & AGUILAR, C. N. 2012. Microbial Enzymes Involved in Polyurethane Biodegradation: A Review. Journal of Polymers and the Environment, 20, 258-265.
  2. DERRAIK, J. G. B. 2002. The pollution of the marine environment by plastic debris: a review. Marine Pollution Bulletin, 44, 842-852.
  3. YANG, W., DONG, Q., LIU, S., XIE, H., LIU, L. & LI, J. 2012. Recycling and Disposal Methods for Polyurethane Foam Wastes.
  4. BIFFINGER, J. C., BARLOW, D. E., COCKRELL, A. L., CUSICK, K. D., HERVEY, W. J., FITZGERALD, L. A., NADEAU, L. J., HUNG, C. S., CROOKES-GOODSON, W. J. & RUSSELL, J. N. 2015. The applicability of Impranil®DLN for gauging the biodegradation of polyurethanes. Polymer Degradation and Stability, 120, 178-185.
  5. KEMONA, A. & PIOTROWSKA, M. 2020. Polyurethane Recycling and Disposal: Methods and Prospects. Polymers, 12, 1752.