Ipsita Roy
T: 020 7911 5000 ext 3567
F: 020 7911 5087
E: I.Roy01@westminster.ac.uk
Background
Ipsita Roy is a microbial biotechnologist and a Senior Lecturer in Biotechnology. She was awarded the prestigious Inlaks Scholarship and the Overseas Research Students Award to study for her Ph.D. at the University of Cambridge. During her time at Cambridge she was awarded the Churchill College Scholarship, the Lundgren Scholarship, Leche Trust Scholarship and the Cambridge University Philosophical Society Fellowship Award. Her PhD at the Department of Biochemistry, University of Cambridge was on a B12-dependent enzyme, methylmalonyl-CoA mutase.
Her postdoctoral work was at the University of Minnesota, USA, at the Bioprocess Technology Institute, where she worked on fatty acid biosynthesis. Dr. Roy taught at the extremely well reputed Indian Institute of Technology, India, for four years as an Assistant Professor. During this time she worked actively on the production of biodegradable polymers from Streptomyces. She had a grant from Du Pont, Delaware, USA to support her research. Dr. Ipsita Roy has been at the University of Westminster since 2000 and leads a large research group comprising of 8 PhD students. She has published over 30 papers in her area and presented her work at numerous international conferences. She leads the only group working on the large scale production of the biodegradable polymers, polyhydroxyalkanoates, in the UK.
Research Interests
Biodegradable polymer production and their application
Tissue engineering
Drug delivery
Molecular Enzymology
Quorum sensing
Elicitation
Bacterial metabolism
Fungal interactions
Carbohydrate biochemistry (emphasis on basidiomycete carbohydrates)
Nanobiotechnology
Systems Biology
Current Research / Ongoing Projects
1. Biodegradable polymers (polyhydroxyalkanoates)
PHAs are polyesters of 3-,4-,5- and 6- hydroxyalkanoic acids produced by a variety of bacterial species under nutrient-limiting conditions with excess carbon. These water-insoluble storage polymers are biodegradable, exhibit thermoplastic properties and can be produced from renewable carbon sources. Thus, there has been considerable interest in the commercial exploitation of these biodegradable polyesters. PHAs are known to be biocompatible and hence have the potential to be used for a range of biomedical applications.
We are currently working on a strain of Bacillus cereus SPV that produces polyhydroxybutyrate, the best-known PHA, at a concentration of 30% dry cell weight. This bacterial strain has been shown to produce a range of different types of PHAs, depending on the carbon source provided. We are further exploring the production of novel PHAs and increasing the yield of PHA production.
We are also working on the production of PHA/Bioglass® and PHA/Bioglass®/CNT composites for tissue engineering applications in collaboration with Dr. A. Boccaccini, Imperial College, London and
Prof. S.R.P. Silva, University of Surrey. This work has led to the production of 2D and 3D scaffolds with potential use in the area of skeletal tissue engineering. Other tissue engineering areas are being explored.
Finally, we are working on the molecular enzymology of the enzymes involved in the biosynthesis of these polymers, i.e. the phaC gene encoding the PHA synthase enzyme involved in the synthesis of the polymer and the phaR gene encoding a protein subunit essential for the activity of the PHA synthase. Currently we are involved in the characterisation of these enzymes which have been successfully overexpressed. The ultimate aim is to understand the mechanism of action of the enzyme. We are collaborating with Dr. Nick Keep, Birkbeck College, University of London, to determine the 3-D structure of the enzyme.
2. A Systems Biology approach to the understanding of biological mechanisms
In collaboration with Dr. A. Bhaskar at the School of Engineering, University of Southampton, we are beginning to explore the area of Systems Biology. We aim to understand the physico-chemical kinetics of polymer production in Bacillus cereus using the systems biology approach. In the future we will like to apply this approach to other problems of biological interest such as quorum sensing.
3. The molecular mechanism of quorum sensing in Fungi
In collaboration with Professor Tajalli Keshavarz, we are looking into the phenomenon of quorum sensing (QS) in Aspergillus nidulans. Currently we are isolating, purifying and characterising various putative QS molecules. Future work will focus on the molecular mechanism of their action. (This work will also be part of a European STREP grant entitled ‘Discovering Quorum Sensing in industrially useful Fungi, a novel approach at molecular level for scaling-up in white biotech’ of which I am part of the Working Committee)
4. The molecular mechanism of the elicitation of metabolite production using oligosaccharides
Elicitation is an increase in the yield of a particular metabolite upon addition of external triggers such as oligosaccharides. This is an extremely interesting phenomenon and can be exploited to increase the yield of commercially important metabolites such as antibiotics. The molecular mechanism of this process is very poorly understood. In collaboration with Professor Tajalli Keshavarz, we are trying to probe into the mechanism using molecular techniques such as Real Time PCR for quantification of the transcriptional levels of various related genes and Expression proteomics to determine the varying levels of expression of the related enzymes. The organisms we are currently studying are, Penicillum chrysogenum (for production of penicillin), Streptomyces coelicolor (for production of actinorhodin), Streptomyces rimosus (for the production of oxytetracycline), Saccharopolyspora erthraea (for production of erythromycin) and Bacillus thuringiensis (for production of bacitracin).
5. The metabolic role of methylmalonyl-CoA mutase in Escherichia coli
Methylmalonyl-CoA mutase is a B12-dependent enzyme, known to catalyse the interconversion of methylmalonyl-CoA and succinyl-CoA. Professor Peter Leadlay’s laboratory at the University of Cambridge first reported the gene responsible for this enzyme in Escherichia coli in 1992. Since then there has been no information about the metabolic role of this enzyme in E. coli. We are using techniques such as RT-PCR, real time PCR and expression proteomics to determine the role of this enzyme in E. coli. Preliminary results indicate the role of the enzyme in the utilisation of unusual carbon sources such as succinate and propionate.
6. Carbohydrates and Carbohydrate Active enzymes in Ganoderma Ganoderma, a type of white rot fungi--have been found to be a source of a large number of medicinal compounds including anticancer compounds. These active compounds are mainly known to be carbohydrates. In collaboration with Professor Emeritus C. Bucke, University of Westminster, we are currently isolating and purifying the carbohydrates from Ganoderma applanatum in order to isolate and characterise the active components. We are simultaneously looking at carbohydrate active enzymes such as glycosidases and glycosyl transferases in Ganoderma adspersum, responsible for the processing of these carbohydrates.
7. The mechanisms of fungal interactions
In collaboration with Professor J. Hedger we are looking into the mechanisms of fungal interactions using the example of a wood decomposer basidiomycete, Stereum hirsutum, with two competitor basidiomycetes, Coprinus disseminatus and Coprinus micaceus. Expression proteomics is being used to probe into the differential expression of proteins under these conditions.
8. A European STREP grant entitled ‘Discovering Quorum Sensing in industrially useful Fungi, a novel approach at molecular level for scaling-up in white biotech’ of which I am part of the Working Committee.
Selected Publications
Valappil, S.P., Misra, S.K., Boccaccini, A.R., Keshavarz, T., Bucke, C., Roy, I. 2007; Journal of Biotechnology DOI: 10.1016/j.jbiotec.2007.03.013
Large scale production and efficient recovery of P(3HB) with improved material properties from a newly isolated Bacillus sp.
Misra S.K.,Valappil S.P.,Nazhat S.N., Moshrefi-Torbati M, Roy I., BoccacciniA.R. 2006 Biomacromolecules: DOI: 10.1021/bm0701954; Fabrication and characterisation of biodegradable poly(3-hydroxybutyrate) composite containing Bioglass® for tissue engineering applications
Valappil, S.P., Boccaccini, A.R., Bucke, C., Roy, I.2007; Antonie van Leeuwenhoek 91(1):1-17 :Polyhydroxyalkanoates in Gram positive bacteria:insights from the genera Bacillus and Streptomyces.
Valappil, S.P., Peiris, D., Langley, G.J., Herniman, J., Boccaccini, A.R., Bucke, C., Roy, I. 2007;Journal of Biotechnology Jan 127(3): 475-487:Polyhydroxyalkanoate (PHA) biosynthesis from structurally unrelated carbon sources by a newly characterized Bacillus spp.
Misra S.K., Watts P.C.P.,Valappil S.P., Silva S.R.P., Roy I., Boccaccini A.R. 2007; Nanotechnology18(7): Art No: 075701 doi:10.1088/0957-4484/18/7/075701:Poly(3-hydroxybutyrate)/Bioglass® composite films containing carbon nanotubes
Philip, S. Keshavarz, T., Roy, I. 2007 Journal of Chemical Technology and Biotechnology: Volume 82(3), 233- Polyhydroxyalkanoates: biodegradable polymers with a range of applications.
Valappil S.P., Misra S.K.,Boccaccini A.R., Roy I. 2006; Expert Review in Medical Devices 3(6): 853-868: Biomedical applications of Polyhydroxyalkanoates (PHAs), an overview of animal testing and in vivo responses. an invited review
Misra, S.K, Valappil, S.P., Roy, I., Boccaccini, A.R. 2006; Biomacromolecules Aug;7(8):2249-58. Polyhydroxyalkanoate (PHA)/inorganic phase composites for tissue engineering applications.
Murphy T., Parra R., Roy I., Keshavarz T. 2006 Enzyme Microbial Technology: Novel application of oligosaccharides as elicitors for overproduction of bacitracin by Bacillus licheniformis. doi:10.1016/j.enzmictec.2006.10.03
Nair R., Radman R., Roy, I., Bucke C., Keshavarz T. 2005; Chemical Engineeering Transactions 6: 989-994: Towards unravelling the elicitation mechanism in Penicillium chrysogenum: Chrysogenin elicitation.
Conference presentations or/and Other publications
Publications in e journals:
Valappil, S.P., Bucke, C., Roy, I. 2004; Biosynthesis of polyhydroxyalkanoic acid by Streptomyces coelicolor, e-polymers
Publications in Conference Proceedings:
Roy, I., Valappil, S.P., Misra, S.K, Boccaccini, A.R. 2006; Proceedings of the International Symposium on Biological Polyesters, Minneapolis, USA. PHA biosynthesis in Bacillus cereus SPV and its applications.
Misra, S.K, Nazhat, S.N., Torbati M.M., Silva S.R.P., Roy I., Boccaccini, A.R. 2006; Proceedings of the International Conference on the Design of Biomaterials, Kanpur, INDIA. From bacteria to tissue engineering applications-usage of polyhydroxyalkanoates for biomedical applications.
Misra, S.K, Valappil, S.P., Nazhat, S.N., Torbati M.M., Roy, I., Boccaccini, A.R. 2006; Proceedings of the 20th European Conference on Biomaterials, European Society of Biomaterials, Nantes, FRANCE. Development of polyhydroxyalkanoates/Bioglass® composite tissue scaffolds for tissue engineering applications.
Misra, S.K, Boccaccini, A.R., Valappil, S.P., Roy, I. 2005; Proceedings of ‘A Forecast of the Future for Biomaterials-Professor Larry L. Hench Retirement Symposium’, London,UK: Natural biodegradable polymers from the Polyhydroxyalkanoate family emerging as a promising material for Biomedical Applications.
Valappil, S.P., Philip S., Odell M., Keshavarz T., Roy I. 2005; Proceedings of Frontiers in Chemical Biology: Mechanistic Enzymology and Biocatalysis Exeter, UK: Polyhydroxyalkanoate synthases - the enzymes involved in biodegradable polymer synthesis.
Valappil, S. P., Bucke, C., Roy, I. 2005; Proceedings of the International Union of Microbiological Societies Congress, IUMS, San Fransisco, USA: Effect of various carbon sources on the production of PHAs from the newly isolated Bacillus sp.
Valappil, S.P., Misra, S.K, Boccaccini, A.R., Bucke, C., Roy, I. 2005; Novel PHA/Bioglass® composites for soft-
tissue and hard-tissue engineering scaffolds. In: EPSRC Workshop, Swansea, UK.
Valappil, S.P., Misra, S.K, Boccaccini, A.R., Bucke, C., Roy, I. 2005; Proceedings of the UKSB annual meeting, Nottingham, UK Effect of recovery process on the physical and mechanical properties of Polyhydroxybutyrate (PHB) extracted from a newly isolated Bacillus sp.
Valappil, S. P., Keshavarz, T., Bucke, C., Roy, I. 2005; Proceedings of the 1st International Conference on Environmental Industrial and Applied Microbiology, Badajoz, Spain: Large scale production of P(3HB) from newly isolated Bacillus sp.
Kannan, S.M., Dwek, M., Bucke, C., Roy, I. 2005; Proceedings of Viteomics: Structure and function of vitamins and cofactors. Cambridge, UK: The metabolic role of methymalonyl CoA mutase in Escherichia coli.
Awards and Grants
Grants:
1. University Exploratory Grant from DuPont, Delaware. Amount awarded: $2000.00 (1997-1998)
2. Grant to support Ph.D.student from the University of Westminster. Amount awarded: £27000 (2001-2004)
3. EPSRC exploratory grant entitled, ‘Novel PHA/Bioglassâ composites for soft-tissue and hard-tissue engineering scaffolds’ April 2005-September 2006. Amount awarded: £100,714
Principal Investigator: Dr. Ipsita Roy; Co-Investigator: Dr. A. Boccaccini
Awards and scholarships:
1.Overseas Research Studentship from the Committee of Vice Chancellors and Principals, UK, 1989-1991
2. The Inlaks Scholarship, INDIA, to study at the Department of Biochemistry, for doctoral studies at Cambridge, 1989-1990
3. Churchill College Scholarship, University of Cambridge, UK, 1991
4. Lundgren Scholarship, University of Cambridge, UK, 1992
5. Leche Trust Scholarship, London, UK, 1992
6. Cambridge University Philosophical Society Fellowship Award, Cambridge, UK, 1992
7. Nominated as a member of the New York Academy of Sciences in the year 1997 in recognition of research activities.
Research Groups / Key Appointments
- Co-ordinator of Applied Biotechnology Research Group
