POLYHYDROXYALKANOATES IN SYNTHETIC MICROBIAL COMMUNITIES OF ANTARCTIC ENDOPHYTIC BACTERIA

Abstract

This study investigates the accumulation dynamics of polyhydroxyalkanoates (PHA) in synthetic microbial communities formed by Antarctic endophytic bacteria isolated from Deschampsia antarctica and Colobanthus quitensis. We evaluated the influence of biofilm architecture (air-liquid-solid [ALS] vs. liquid-solid [LS]) and wide temperature range (4, 15, 25, 37, and 42 °C) on PHA biosynthesis. Quantitative gravimetric analysis and confocal laser scanning microscopy (CLSM) demonstrated that PHA accumulation is significantly enhanced in ALS multi-species biofilms compared to monocultures, peaking at 4 °C. Higher temperatures led to rapid depletion of energy reserves. Oxygen availability and spatial organization within the biofilm matrix are critical drivers of carbon allocation toward PHA storage in cold-adapted microbial communities.