Nowadays, the dependence that our society has to non-biodegradable plastics derived
from petroleum has created the necessity to develop an economically viable alternative.
Biopolymers seem to be an attractive alternative to common plastics. Among all them,
Polyhydroxyalkanoates (PHA) represent one of the most studied and important source of
biopolymers. These biopolymers are produced naturally by various microorganism that use
different nutrient sources to conduct the production. Many studies are focusing their efforts in
the utilization of alternative substrates to reduce the final cost of the whole process. Besides,
the utilization of transgenic organisms (obtained through genetic engineering techniques) for
biopolymers production seems to be the path to follow for a higher PHA production and to
diminish the cost of the whole biosynthesis.
Bearing in mind all this information, in the present thesis, a work to study all the
different aspects that involve the obtaining of PHB through fermentation in Ralstonia eutropha
was carried out.
Hence, the thesis pretends to evaluate experimentally the obtaining, isolation and
characterization of PHB in Ralstonia eutropha using different configurations and systems. All
these experimental stages were carried out in Terrassa and Barcelona (UPC). Besides, this
study includes a theoretical part where all the aspects referred to PHB are analyzed and
supports the experimental work carried out.
During the experimental part, three different fermentations with Ralstonia eutropha
were conducted. The main aim of these fermentations was to see the effect of time and
glucose dosage in a fermentative process considering an initial medium –according to
literature- as standard.
In all these processes, an extraction method with chloroform was used to isolate the
final biopolymer. Afterward, a characterization of the product obtained by means of FTIR, NMR
and GPC analysis was carried out. All these results are presented in the corresponding section.
Besides, in the thesis, an economic study is included in the appendix section. This study
comprises the economic cost that is required to develop the PHB process described in the
experimental part. Thus, the economic cost, the income and the budget of all the different
aspects of the process are considered. |