This study investigates the synthesis of polyhydroxyalkanoate (PHA) by a strain of Pseudomonas aeruginosa isolated from oil-contaminated soil. The research focuses on the metabolic processes involved in PHA production when the bacteria are grown in a nitrogen-limited medium with an excess of carbon source.
Begin with a strain of Pseudomonas aeruginosa bacteria, isolated from oil-contaminated soil, in a medium containing a nitrogen source and an excess of edible oil as the carbon source.
This strain synthesizes polyhydroxyalkanoate (PHA), a long-chain polymer useful in producing bioplastics.
Incubate under agitation to facilitate aeration and promote bacterial growth.
Initially, the medium supplies both carbon and nitrogen sources to support bacterial proliferation and generate high biomass.
After substantial growth, nitrogen depletion in the medium halts further cell division and redirects the excess carbon source toward PHA biosynthesis.
The bacteria secrete lipases that break down the oil into fatty acids, which are metabolized by intracellular enzymes into PHA precursors.
PHA synthase enzyme polymerizes these precursors into PHA.
PHA accumulates inside cytoplasmic granules, known as inclusion bodies, which leads to an increase in cell size.
The PHA-enriched bacterial biomass is now ready for downstream analyses.
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