An environmentally benign microbial production process, converting a renewable carbon source into adipic acid appears highly desirable. However, adipic acid is no natural metabolic product. Here, we propose a non-natural metabolic pathway for the direct production of adipic acid by microorganisms.
The pathway is based on the accumulation of volatile fatty acids - among them hexanoic acid – by the rumen bacterium Megasphaera elsdenii. While short chain fatty acids are highly toxic for most microorganisms, M. elsdeniiis remarkably resistant and therefore an ideal candidate as microbial cell factory for organic acids.
M. elsdenii accumulates short chain fatty acids to high amounts. Subsequent oxidation of hexanoic acid in omega position by described enzyme systems from different sources leads to the accumulation of adipic acid.