Polyhydroxyalkanoate production by bacteria isolated from Antarctic environments

Polyhydroxyalkanoates (PHAs) are biodegradable and biocompatible biopolymers produced by numerous microorganisms as intracellular carbon and energy storage compounds. The search for novel PHA-producing bacteria adapted to extreme environments is of increasing interest, as these organisms may possess unique metabolic traits and enzymes suitable for sustainable bioplastic production under non-conventional conditions. In this study, bacterial strains were isolated from Antarctic environmental samples, including bulk and rhizospheric soils collected from ice-free areas. The isolates were screened for their ability to accumulate PHAs using selective staining and cultivation under nitrogen-limited conditions. Several strains demonstrated significant intracellular PHA accumulation. Molecular identification based on 16S rRNA gene sequencing revealed that the PHA-producing isolates belonged to diverse bacterial taxa, including psychrotolerant and psychrophilic species. In addition, growth was evaluated in flasks, and the accumulated polymer was analyzed. The results indicate that Antarctic bacteria are capable of accumulating PHAs at low to moderate temperatures, highlighting their potential for energy-efficient bioprocesses. The ability of these microorganisms to thrive and produce biopolymers under extreme environmental conditions suggests they may represent promising candidates for the development of sustainable bioplastic production processes. Overall, this work expands current knowledge on PHA-producing bacteria from polar environments and underscores the biotechnological potential of Antarctic microbial biodiversity.