A Review on the Isolation of Facultative Anaerobes from Gut Bacteria with Bioplastic Degradation Potential

The increasing accumulation of bioplastics has become a growing environmental concern, as their degradation under natural of industrial conditions remains inefficient. Gut bacteria, adapted to low-oxygen and enzyme-rich gastrointestinal environments, represent a promising yet underexplored microbial resource for enhancing bioplastic biodegradation. This review synthesizes current knowledge on gut-derived facultative anaerobes and their potential roles in enhancing anaerobic digestion processes. Representative taxa such as Citrobacter koseri, Klebsiella oxytoca, K. pneumoniae, Enterobacter ludwigii, E. sichuanensis and Serratia sp. have been associated with the degradation of various synthetic and bio-based plastics. These findings emphasize the metabolic versatility of gut microorganisms and their potential integration into sustainable waste management systems. Nevertheless, the opportunistic pathogenicity of several taxa necessitates careful biosafety evaluation before practical implementation in biodegradation and bioconversion systems.