Developing a scalable model of recombinant protein yield from Pichia pastoris:the influence of culture conditions, biomass and induction regime

Background The optimisation and scale-up of process conditions leading to high yields of recombinant proteins is an enduring bottleneck in the post-genomic sciences. Typical experiments rely on varying selected parameters through repeated rounds of trial-and-error optimisation. To rationalise this, several groups have recently adopted the 'design of experiments' (DoE) approach frequently used in industry. Studies have focused on parameters such as medium composition, nutrient feed rates and induction of expression in shake flasks or bioreactors, as well as oxygen transfer rates in micro-well plates. In this study we wanted to generate a predictive model that described small-scale screens and to test its scalability to bioreactors. Results Here we demonstrate how the use of a DoE approach in a multi-well mini-bioreactor permitted the rapid establishment of high yielding production phase conditions that could be transferred to a 7 L bioreactor. Using green fluorescent protein secreted from Pichia pastoris, we derived a predictive model of protein yield as a function of the three most commonly-varied process parameters: temperature, pH and the percentage of dissolved oxygen in the culture medium. Importantly, when yield was normalised to culture volume and density, the model was scalable from mL to L working volumes. By increasing pre-induction biomass accumulation, model-predicted yields were further improved. Yield improvement was most significant, however, on varying the fed-batch induction regime to minimise methanol accumulation so that the productivity of the culture increased throughout the whole induction period. These findings suggest the importance of matching the rate of protein production with the host metabolism. Conclusion We demonstrate how a rational, stepwise approach to recombinant protein production screens can reduce process development time.

Training and development needs of PCT strategic level pharmacists

Poster session - The aim of the study was to produce an analysis of the perceived training and professional development needs of strategic level pharmacists in primary care trusts - A survey was carried out in five areas in England of the training needs of PCT strategic level pharmacists on behalf of a West Midlands Workforce Confederation - The results show an increasing recognition by PCT pharmacists of the importance of business and management training - Several key topics of direct relevance to current heath policy were not highly rated by respondents - This study identified gaps in current training provision

Undergraduate research training and employability

Formal opportunities for Psychology undergraduates to carry out research training are starting to emerge. In spite of the fact that such training programmes would have a high authentic learning component little is known of undergraduate expectations and attitudes towards such programmes. Here 108 undergraduate participants were surveyed in two experiments that recorded both the prospective and retrospective attitudes towards research training participation. Questionnaires and focus groups were employed and the data were triangulated together to converge on an understanding of student expectations towards authentic learning programmes. It was found that while Psychology undergraduates expect to be trained in contemporary research techniques it is the sense of community development that is the prime motivator for participation. These findings are placed within the context of increasing the employability profile of the undergraduate cohort.