Authors: Federico Cerrone, Santosh K Choudhari, Reeta Davis, Denise Cysneiros, Vincent O’Flaherty, Gearoid Duane, Eoin Casey, Maciej W Guzik, Shane T Kenny, Ramesh P Babu, Kevin O’Connor
Publication Date: 01/2014
Journal: Applied microbiology and biotechnology
Volume: 98
Pages: 611-620
Publisher: Springer Berlin Heidelberg
A two step biological process for the conversion of grass biomass to the biodegradable polymer medium chain length polyhydroxyalkanoate (mcl-PHA) was achieved through the use of anaerobic and aerobic microbial processes. Anaerobic digestion (mixed culture) of ensiled grass was achieved with a recirculated leach bed bioreactor resulting in the production of a leachate, containing 15.3 g/l of volatile fatty acids (VFAs) ranging from acetic to valeric acid with butyric acid predominating (12.8 g/l). The VFA mixture was concentrated to 732.5 g/l with a 93.3 % yield of butyric acid (643.9 g/l). Three individual Pseudomonas putida strains, KT2440, CA-3 and GO16 (single pure cultures), differed in their ability to grow and accumulate PHA from VFAs. P. putida CA-3 achieved the highest biomass and PHA on average with individual fatty acids, exhibited the greatest tolerance to higher concentrations of butyric
