Studies on Biodegradation of Medium Chain Length PHAs by Soil Bacterial Isolates

Abstract

Growing environmental awareness has imposed a paradigm shift from biostable materials to biodegradable ones that are compatible with the environment to ensure an eco-friendly atmosphere. On account of that, in the present study the biodegradation of Polyhydroxyalkanoates was monitored by open window composting method. Under the prevailing condition (pH 6.8-7.2 and temperature 34-37o C) during open window composting it was observed that, 96 % of PHAs disc degradation occurred within 20 days. In toto fifteen aerobic, bacteria were isolated from the soil and surface of PHA discs, of which three observed as depolymerase producers. These depolymerase producing bacterial isolates were grown abundantly by utilizing PHAs as sole carbon source in Minimal salt medium for four days at pH 7 and temperature 37o C. The in-silico analysis revealed, Alcaligenes sp. B1 shown a strong evolutionary closeness with Alcaligenes faecalis which is supported by 99 % bootstrap value during phylogenetic tree construction. The identified bacterium is Alcaligenes sp. B1 (KT784806). Thus, further study is also essential for exploitation of the potent bacterial isolate for biodegradation of biopolymer or bio-based polymer.