The biodegradability of different bio-based materials including
cellulose and starch [49,50] has been investigated previously under
anaerobic conditions [51,52]. Yagi et al. [53] studied the biodegradability
of cellulose powder under mesophilic (35 C) and
thermophilic (55 C) AD conditions. Cellulose powder reached a
cumulative conversion of 80% under both temperature conditions.
Other authors have also studied the anaerobic mineralization of
aliphatic polyesters. Abou-Zeid et al. [54] conducted a study to
determine the biodegradability of the natural polyesters poly(bhydroxybutyrate)
(PHB), poly(b-hydroxybutyrate-co-11.6%-bhydroxyvalerate)
(PHBV) and the synthetic polyester poly(ocaprolactone)
(PCL) using different anaerobic sludges and individual
strains. Biodegradability of the powdered materials was
measured as the percent of weight loss. They found that almost all
the PHB was converted in 9 days, but only 60 and 30% weight loss