Non-aseptic growth of anaerobic fungi in vitro for organic acid production
- Institute
- University of York
Summary:
Organic acids (OAs) (e.g. acetic, lactic, formic) are valuable industrial products, serving as precursors for fuel, bioplastics, food additives, pharmaceuticals and other chemicals. Anaerobic fungi (AF) of the genus Neocallimastix are microorganisms which naturally occur in the digestive tract of ruminant herbivores (e.g. cows, goats, sheep) and can perform a process called dark fermentation to produce H2 fuel and OAs from renewable cereal straw biomass (e.g. wheat straw). Cereal straws are an attractive feedstock for dark fermentation because they are produced in large quantities as a by-product of arable farming both in the UK (≈15 million tonnes) and globally (≈2500 million tonnes).
The natural ability of AF to break down and convert globally abundant straw materials into sustainable industrial products makes them attractive for exploitation. However, exploitation of AF faces some challenges which must be overcome to enable their industrial use. Currently, AF viability during laboratory growth is susceptible to contamination from organisms indigenous to the feedstock materials. Specifically, the presence and proliferation of common anaerobic bacteria is detrimental to growth of AF. Hence, a key challenge is to achieve economical and sustainable growth of AF in vitro (i.e. outside of their host organism) without the financial expense or environmental risks associated with sterilisation of feedstock and equipment by using heat or antibiotics to kill bacterial cells. Replicating AF’s ability to thrive in their natural environment, within a complex community and under non-sterile conditions, remains a current knowledge gap. This project aims to develop a novel process which enables targeted culturing of AF for the production of industrial products without the need for substrate sterilisation or addition of antibiotics.
Aims:
The aim of the project was to develop a novel bioreactor system capable of growing anaerobic fungi on wheat straw material. We sought to demonstrate the potential of anaerobic fungi for exploitation in vitro to generate large yields of organic acid feedstocks for industrial processes.
Objectives:
The project developed an innovative fermentation solution that employs lower-cost preparation of a growth medium that can support anaerobic fungal growth on lignocellulosic biomass. The developed approach reduces anaerobic fungi fermentation expenses while maintaining effective conversion of wheat straw biomass to organic acids.
Outcomes:
The new fermentation approach enables efficient conversion of agricultural residues into valuable organic acid feedstocks which have potential for use in the sustainable industrial production of fuels and materials.
Academic partner: Dr. Matthew Reilly, University of York
Industrial partner: Mike Mason, Carbonovia Ltd.
