Chemical and Biological Assay for The Degradation of Microwave Synthesized-Hyperbranched Poly (Urethane-Urea) By Local Bacterial Isolates

Ultra-fast recently Microwave-synthesized Hyperbranched Poly (urethane-urea) (MW-HBPU), is a polymer with a unique morphological structure and different applications in many fields as textile printing and coating. Because Polyurethanes (PUs) have excellent chemical and physical properties, their bio-decomposition and decay are difficult and time consuming. Therefore, MW-HBPU biodegradation by five bacterial isolates isolated from different local garbage sites has been studied. The highest activity was observed in three isolates (H1, H2 and H3), that were identified by morphology, physiology, biochemical and molecular biology (16S rRNA). Achromobacter sp. strain NRC2018, Bacillus subtilis strain NRC2018 and Bordetella petrii strain NRC2018, respectively. By determination of Carboxylesterase and acetylcholineesterase activity for the three strains. Achromobacter sp. strain NRC 2018 showed high activity give 91.2 and 526.4 U/ml for Carboxylesterase and acetylcholineesterase, respectively. The change in the characteristic functional groups reflected in the ATR-FTIR spectra of MW-HBPU after incubation with these bacteria showed attack at certain sites in the MW-HBPU structure and pointed to structural changes. SEM images clearly showed degradation in the MW-HBPU network. Additionally, a notable change in weight after incubation with isolated bacteria was also used to demonstrate the ability of these strains to effectively biodegrade MW-HBPU.