Degradability of poly(ether-urethanes) and poly(ether-urethane)/acrylic hybrids by bacterial consortia of soil.

An enrichment culture strategy was used to obtain natural consortia from soil in order to study the biodegradability of poly(ether-urethanes) (PUE). PUE were synthesized with different aliphatic diisocyanate group, termed PUIPDI and PUHMDI. In addition, PUE/acrylic hybrids, termed PUH 90 :DEA 10 and PUH 70 :DEA 30 consisted of PUHMDI and increasing ratio of 2-(diethylamino)ethyl methacrylate (DEA) were tested. PUIPDI was biodeteriorated through urea-bond hydrolysis by a consortium dominated by Acinetobacter. A higher biodeterioration rate was demonstrated for PUHMDI, which exhibited large surface holes and a greater weight loss. The hydrolysis of ester-urethane bonds and the oxidation of soft-segment ether bonds were the key reactions identified, possibly by Acinetobacter , Mycobacterium , Sphingopyxis and Pseudomonas , which were present in this consortium. Diverse metabolic functions were also predicted. The addition of DEA favored the biodegradability of PUH:DEA hybrids demonstrated by the increased weight loss, swelling degree and the hydrolysis of DEA-ester bond. Urethane and ether bonds degradation were also detected. PUH:DEA hybrids selected even bacterial consortia, most likely by allowing better access to the nutrients. Pseudomonadaceae and Bradyrhizobiaceae families got relevance in these consortia and their outstanding features were cell mobility and quorum sensing. This work has provided a deeper insight into PUE biodegradation by proposing the chemical mechanisms, bacterial taxa and functions that could be implicated. • Polymers were used as the sole carbon and energy source by the consortium of bacteria. • PUH 70 :DEA 30 was the most biodegradable polymer, and IPDI content decreased the PUE biodegradability. • In each polymer a distinctive chemical attack by the microorganism was observed. • A number of taxa, unreported until now, were identified as key players involved in PUE degradation. • Specific bacterial functions were predicted and correlated with PUE and PUE/acrylic hybrid chemical attack. [ABSTRACT FROM AUTHOR]