Using genetics to improve straw digestibility and reduce the carbon footprint of whiskey production

Grains from cereal crops such as wheat and barley are widely used in the food and biotechnology industries for drink (beer, whisky and malt) and biofuel or bioethanol production.

As a result, millions of tons of these crops are produced yearly across the world with Europe producing over 60% of global barley yield.

The industrial scale processing of barley generates a large amount of other potentially under-utilised co-products including straw (the dry stalks/stems of the cereal plant following the harvest of the grain), chaff (the grain husks) and distilling by-products. .

Making industrial processes such as distilling truly carbon neutral will be assisted by recovering and using as much of the barley plant as possible, not just the grain. .

However, the exploitation of lignocellulosic biomass (straw, chaff) has been greatly hampered by the resistance of the straw cell wall to degradation, partly contributed by its high lignin content and its degree of cross-linking/interaction with other components of the cell wall..

This research aims to investigate different genetic varieties or cultivars of the barley plant to understand the impact of their genetic differences on barley cell wall integrity, structure and consequently chemical and microbial digestibility under aerobic and anaerobic conditions.

The goal is to identify genetic determinants that control important properties of the plant cell wall that could be exploited to make industrial use easier.

The project will also develop an in-house anaerobic model culture systems that mimic rumen or bioreactor microbial consortia to study anaerobic digestion of straw cell wall carbohydrates as well investigate the genetic and enzymatic basis of microbiota degradation of straw-derived lignocellulosic biomass.

Residues could have further use as fertilizer contributing to a fully circular process.

The project will be carried out in collaboration with our industrial partners William Grant & Sons Distillers Ltd whom the candidate will also have the opportunity to interact with on practical level and hence also gain both industrial experience alongside expertise on plant processing and genetic analyses, microbial culture, bioinformatics and genetics.

These studies will ensure that we maximise the amount of value that can be derived from these important by products, minimise the waste generated and enhance the overall cost and carbon efficiency of barley processing.