Catalytic molecularly imprinted polymers for suppression and control of quorum sensing:
Quorum sensing (QS) is a signalling mechanism used by bacteria so sense their population density by the secretion and detection of the concentration of small signal molecules in the environment. At a concentration of the signalling molecule exceeding a particular threshold, a change in gene suppression in the micro-organism is triggered which promotes responses such as biofilm formation and expression of virulence factors associated with infection and toxicity of the organisms. This pathway is therefore a promising target for control of bacteria without running the risk of engendering antibiotic resistance. A major class of QS signal molecules, secreted by Gram-negative organisms, are the acylated homoserine lactones (AHLs). We have shown that polymers capable of sequestering (binding) AHLs are effective at suppressing quorum sensing in a number of model organisms. Sequestration however, is not the ideal solution to this problem as the polymers will have a finite capacity to absorb the signalling molecules. A much better solution is to deactivation or destruction of the AHLs.
Project Aim: The aim of the proposed project is to develop new molecularly imprinted polymers (MIPs) with catalytic activity for cleavage of AHLs at two possible sites (side chain amide linkage and lactone bond). Imprinting of transition state analogues (TSAs) based on the AHL structure with catalytically active monomer compositions will be carried out, and the ability of the materials to cleave AHLs and influence quorum sensing will be tested.
Recovery of high-value pharmaceutical ingredients from food and agricultural waste:
The mass processing of food and agricultural products results in the creation of large quantities of low grade waste material which is used for animal feed, anaerobic digestion, incinerated, sent to landfill or discharged to waste water treatment. This waste material may still contain ingredients, potentially of high value to the cosmetic and pharmaceutical sectors, including vitamins, bioactives, steroids, proteins, flavours, colouring matter, polysaccharides etc. Much of this material is not recovered because it is not economically feasible to do so. New methods for the economic isolation of these ingredients can supply new markets and stimulate new product development. A recent example is the market for cholesterol-lowering spreads, yoghurts and other foodstuffs based on sterol esters, the raw materials for which were originally obtained as a by-product of the wood pulping industry.
Project Aim: The aim of the proposed study is to investigate the utility of a range of functional polymeric adsorbents for the recovery of useful ingredients form typical waste matter and biomass. The polymer development will include the application of the molecular modelling for optimisation of composition of polymeric adsorbents using software package SYBYL 7.3 (Tripos Inc., St. Louis, Missouri, USA). New high efficient adsorbents and separation protocols will be developed for biotechnology (separation and extraction) applications.
The candidate will receive training in analytical chemistry, molecular modelling and modern polymer chemistry.
We are an equal opportunities employer and particularly welcome applications for Ph.D. places from women, minority ethnic and other under-represented groups.
Self funded students
Related to 'Catalytic molecularly imprinted polymers for suppression and control of quorum sensing':
Piletska, E. V.; Stavroulakis, G.; Karim, K.; Whitcombe, M. J.; Chianella, I.; Sharma, A.; Eboigbodin, K. E.; Robinson, G. K.; Piletsky, S. A. Attenuation of Vibrio fischeri Quorum Sensing Using Rationally Designed Polymers. Biomacromolecules 2010, 11 (4), 975-980.
Wulff, G. Enzyme-like catalysis by molecularly imprinted polymers. Chem. Rev. 2002, 102 (1), 1-27.
Related to 'Recovery of high-value pharmaceutical ingredients from food and agricultural waste':
Thompson, G.R.; Grundy, S.M. History and development of plant sterol and stanol esters for cholesterol-lowering purposes, Am. J. Cardiology 2005, 96 (1, Suppl. S), 3D-9D.