The highest biodegradability observed during soil incubation
was reported for PHA (70%); a polyhydroxyalkanoate-based plastic.
This was similar in magnitude to the extent of mineralization of the
cellulose positive control (cellulose paper). Bacterial polyhydroxyalkanoates
are intracellular aliphatic polyesters of various
chain lengths [34]. Several studies have been conducted to study
the biodegradability of aliphatic polyesters under different conditions
[35e38]. Mineralization of these polymers is mainly achieved
by cleavage of the ester bonds which occurs due to both enzymatic
and chemical hydrolysis [39].