Bharathi, P (2015) Characterization of certain Biopolymers produced by Fermentation Process and Evaluation of their Pharmaceutical Applications. Doctoral thesis, The Tamilnadu Dr. M.G.R. Medical University, Chennai.
|
Text
14050302015bharathi.pdf Download (27MB) | Preview |
Abstract
Glucans have remarkable potential for use in various diseases, due to its very low‐to‐negligible toxicity. Over the last decade or so, modern medical research has reached a phase where the basic mechanism of glucan effects are known and the relationship between structure and activity has been outlined rather clearly. It is rather imminent that glucans will finally take the position they deserve in diagnostic and preventive medicine. Glucans ability to activate the host immune system could be attributed to their distribution within microorganisms in which they act as membrane components in addition to the property of not being biosynthesised in mammals. The purified fungal glucans are administered orally for treatment of diseases with minimum side effects. Though glucans are found in all fungi, exocellular glucans are prefered because of this simple downstream processing that could be extrapolated to their industrial production and use. Glucan based polymers could see significant development in the coming years. The promising developments may be possible in the pharmaceutical sector as these polymers have been used for antitumorogenic, immunopotentiator, antiviral, hypercholesterolemia and as agents for stabilisation of glycemic index. The purified fungal glucans have been administered orally for treatment of human diseases with no major adverse effects. We have been successful in identifying new microbial strains for the production of pullulan, curdlan and chitosan (by biotransformation). The strains identified and screened in this research may be used in the polymer industry to produce pullulan and curdlan with simultaneous production of chitosan economically. These strains possess significant advantages over existing strains in the industry. Factors such as fermentation kinetics, pH, temperature, rpm and inoculum size, effect of carbon & nitrogen sources and concentration of carbon source were found to greatly influence pullulan production and yield. The objective of this research was to identify new strains producing larger amounts of pullulan and curdlan than existing strains; new strains identified in this research possessed visible industrial advantages for the production of pullulan. In the case of curdlan the reference strain produced higher amount of curdlan than the new strains identified for the first time, in this research. Chitosan was produced by using the reference strain A.faecalis (commercially used in the curdlan industry) by the biotransformation of the biomass obtained during pullulan production. Bacteria can be readily grown in the laboratory on cheap nutrients and chitosan can be obtained by biotransformation using simple fermentation techniques and effective downstream procedures. These polymers can be produced in a controlled environment all year round, independent of the seasonal shellfish industry required for production of chitosan by conventional method. Bio conversion process of converting chitin to chitosan used in this study is cost effective and reduces environmental pollution. The use of eco-friendly renewable materials, obtained during pullulan production, as biomass, offers tremendous benefits to the pharma industry for the bio-production of chitosan. The isolated polymers were identified and characterized by using various chemical tests and spectroscopic methods. The isolated chitosan with higher degree of deacetylation possessed favourable surface smoothness, hydrophilicity and swelling index. We successfully prepared microspheres using the isolated polymers and compared them with the reference polymers. The prepared microspheres showed efficient drug release. The FT-IR, differential scanning calorimetry, swelling index, particle size, zeta potential and drug release kinetics of the prepared microspheres were comparable to those of the reference polymers. The FT-IR and DSC data indicate no interaction between donepezil HCl and polymers. The isolated polymers may be used in various drug delivery systems. Among the three polymers studied for microsphere preparation, chitosan, due to its inherent cationic potential helping to avoid phagocytosis, could serve as an ideal polymer for various drug delivery systems. The research work published during the last decade showed that, pullulan, curdlan and chitosan are versatile biopolymers having diversified applications in different fields including medical and pharma industries. Innovations in fermentation technology through strain improvement, effective media optimization and cost effective downstream processing could greatly enhance newer ways for utilizing these three biopolymers on an industrial scale. Besides the versatility in applicability with regard to the three polymers studied, they also individually represent distinct class of polymers namely alpha glucan (pullulan), Beta glucan (curdlan) and amino glucan (chitosan). This study would serve as a lead for newer glucan based biopolymer research. The simultaneous production of the three biopolymers studied in this research, namely pullulan, curdlan and chitosan could be judiciously planned as an extremely profitable industrial venture due to the efficient utilization of the biomass generated as waste during pullulan production, which could be used for the bio-production of chitosan using the strain Alcaligenes faecalis NCIM 2444 having the ability to produce curdlan. Finally this work would be an effective alternative for the production of polymers with varied pharmaceutical applications and would help to overcome the disadvantages of traditional production and through the use of economic substrates for production. Microbes identified in this study can be readily grown using simple nutrients and the biopolymers pullulan, curdlan, chitin and chitosan can be recovered easily from fermentation broth by simple downstream processing. These polymers can be economically produced under controlled environment all year round and is independent of seasonal shellfish industry as in case of chitin and chitosan. Bio conversion of chitin containing biomass to chitosan is another method to avoid the environmental concerns faced in the chemical conversion using the strain Alcaligenes faecalis NCIM 2444. As the research on the properties of new microbial polymers continues to grow, there is a need to streamline the commercialization of such compounds against traditional processes, balancing the cost of production and development. Ultimately, the pharmaceutical industry may provide new markets for chemically‐modified glucans and help to develop new generations of polymers with more beneficial biological activities. Natural resources depletion and environmental concerns have triggered new guidelines and rising awareness all over the world which has promoted the use of waste materials and renewable resources to produce polymers. The production of biopolymers like pullulan, curdlan and chitosan using simple nutrients, hyper producing strains and biomass waste could greatly contribute to improved economics and eco-friendly process. The utilization of eco-friendly, simple fermentation medium, new strains with many advantages, renewable materials and possibility of large scale production of the identified polymers gives tremendous benefits to the pharmaceutical industry for various biomedical applications. The orally administered β-glucans for human use are yet to report any major adverse effects. The variation among glucans with respect to their biological activity, may be due to their differential binding ability to the receptor. There is no report that correlates glucans structure with biological activity. Further studies on structure activity relationship would help to understand these biopolymers as biologically active materials. This knowledge once available would help in improved technological production of glucans with optimum structural characters by careful microbial screening or by optimizing cultural conditions. All the three polymers selected in this research are exopolymers (pullulan, curdlan and chitosan) and are suitable for use as carrier for drug delivery. The major limitations seen particularly with regard to pullulan and chitosan production were solved to a great extent making their production economical. In the near future it may be possible to design and produce biopolymers with desirable properties through controlled fermentation system. It is within the realm of possibility that a design based study similar to that available with proteins emerges with regard to the biopolymers.
| Item Type: | Thesis (Doctoral) |
|---|---|
| Uncontrolled Keywords: | Characterization, Biopolymers, Fermentation Process, Evaluation, Pharmaceutical Applications. |
| Subjects: | PHARMACY > Pharmaceutical Biotechnology |
| Depositing User: | Subramani R |
| Date Deposited: | 20 Aug 2017 05:15 |
| Last Modified: | 27 Oct 2022 14:05 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/2722 |
Actions (login required)
 |
View Item |
