Thai Researchers Engineer Pichia pastoris for Isobutanol Production

Microbial production of fuels via bioprocesses has emerged as an attractive alternative to the traditional production of fuels. Wiparat Siripong of the National Center for Genetic Engineering and Biotechnology in Thailand engineered the yeast Pichia pastoris to produce isobutanol from glucose and glycerol. The team diverted the amino acid intermediates to the 2-keto acid degradation pathway for higher alcohol production.

The engineered strain overexpressing the keto-acid degradation pathway produced 284 mg/L of isobutanol when fed with 2-ketoisovalerate. To improve the production of isobutanol, the team overexpressed a part of the amino acid l-valine biosynthetic pathway in the engineered strain. This led to a strain capable of producing 0.89 g/L of isobutanol. Fine-tuning the expression of bottleneck enzymes further improved the production titer of isobutanol by 43 times compared to the original strain.

This work will provide a route to establish P. pastoris as a versatile production platform for fuels and chemicals.