Project Lead(s): Radhakrishnan Mahadevan
Tuberculosis (TB) affects 9 million people and kills 1.4 million annually, mostly in developing countries, and is increasingly resistant to treatment by standard, first-line drugs.
Treatment of resistant TB (MDR-TB) costs upwards of $5,000 per patient.
The goal of the project was to engineer a yeast organism to make TB drugs from glucose.
The process involved applying molecular genetics methodology to transfer all steps of the 2-deoxystreptamine (2-DOS) pathway to S. cerevisiae, thereby constructing new strains of yeast to act as a cell factory for the production of aminoglycosides.
The ability of these strains to produce 2-DOS and kanamycin in batch cultures containing either minimal or complex media with 3% glucose was evaluated by TLC (Thin Layer Chromatography).
The results of the TLC assay demonstrated the ability of both yeast strains to produce 2-DOS and kanamycin in only complex media, as compared with the control.
However, this method is not reproducible or sensitive enough.
In addition, TLC is not a suitable method for quantifying 2-DOS and kanamycin.
The team needs to confirm their experimental results on a larger scale by evaluating their strain in a 500 ml bioreactor under controlled conditions.
There are plans to contact Sanofi Pasteur, which is already working on a yeast-based process for an anti-malarial drug, and then attempt to apply for Phase II Transition To Scale funding.
It is anticipated that $3 million will be required over three years to increase the yield and concentrations to be similar to that of current processes.