Due to biocompatibility and
biodegradability of biologically-produced PHA for possible uses as
plastics with promising physical and chemical characteristics (e.g.,
can be changed by blending and/or modifying the surface), PHAs
could be applicable to be biodegradable polymers for green technology
of sustainable development [2].
As a matter of fact, several
naturally-occurring microbes were reported to have capabilities
of PHA biosynthesis (e.g., Azotobacter vinelandii [3], Pseudomonas
sp. [4] and Aeromonas sp. [5]).
The reason
why these PHA-generating bacteria could own such promising
capabilities of producing PHA and associated monomers was due
to induced expression of their DNA sequences for PHA synthesis
(e.g., PhaA, PhaB, PhaC; [8]).
In fact, the expression of these
genes interacted with each other and could be induced at nutrient
limiting conditions to synthesize specific monomers and polymers
of PHAs. Moreover, several naturally-occurring microorganisms
have capabilities for synthesis of PHAs at conditions of physiological
stress (e.g., nitrogen, magnesium limiting conditions; [9]).