Mycoprotein 2.0

Lead Research Organisation: National Institute of Agricultural Botany
Department Name: Centre for Research

Abstract

As prosperity rises, demand for meat increases as it is a rich source of protein. This in turn places demand on water resources, changes land use (in a manner highly dependent upon how the animal is fed) and leads to an increase in anthropogenic GHG emissions. This has been determined to be unsustainable by a number of international bodies, with some estimates predicting a 70% rise from current levels of 11% of total GHG emissions by 2050. However, demand for protein can also be met by crop-based sources (e.g. soy and pulses) and by mycoprotein, produced by fermentation of crop-derived glucose into biomass, which is harvested and processed into high quality protein.

Mycoprotein remains a relatively under-exploited resource worldwide but offers great promise for year-round production of high quality protein, a vital requirement for future food security and human nutrition.

The most significant challenge to production is the reliance on a single carbon source, a wheat-derived glucose, which requires special processing before it is suitable for use. Our recent work has revealed that while the fungus used to produce mycoprotein is grown on this glucose substrate, production of a number of essential vitamins is inhibited. Our recent work has revealed that expression of vitamins in some other carbon sources, for example beet derived sucrose syrup is observed. In some, but not all cases, this is coupled to an increase in other deleterious secondary metabolites. This leads to the question, how is the fungus regulating secondary metabolism in relation to carbon source?

To expand both the nutritional value of mycoprotein and the range of carbon sources that can be utilised (enabling production to move to other regions of the world) we will use the latest DNA sequencing techniques to reveal the structure of the genome of Fusarium venenatum and study the regions of the genome that contain secondary metabolite genes. From work carried out in other related fungi it is known that control of secondary metabolism (SM) is regulated by the position of SM cluster in the genome, and by specific regulatory factors. Utilising the latest sequencing techniques will allow us to positionally resolve SM location and determine the underlying mechanisms regulating responses to different carbon sources.

Through a series of controlled batch and continuous culture experiments we will develop techniques to selectively induce vitamin biosynthesis across a range of carbon sources, without inducing the expression of deleterious SM genes, providing both an understanding of the control of SM and an enhanced product for future product development.

Building on our existing work we will expand the toolbox of molecular techniques in order to edit the genome of F. venenatum to remove deleterious secondary metabolite gene clusters and their regulatory factors which are induced in response to different carbon sources.

As a result of this work, mycoprotein will be able to be produced using a larger range of carbon sources drawing upon a wider range of UK agricultural sources (maize, barley, rice) and even shift to sucrose-based production of mycoprotein (a carbon source that has currently been completely inaccessible), utilising UK sources of sucrose such as sugar beet. Furthermore, the ability to enhance the complement of micronutrients in mycoprotein will broaden its utility as an important component of global diets and offers a more sustainable and flexible alternative to meat.

Technical Summary

Work is proposed to elucidate the complex regulation of metabolism by different carbon sources and the effect upon the nutritional status of mycoprotein. In this proposal we will improve the ~1000 contig draft genome of Fusarium venenatum using Pacbio and sequencing followed by scaffolding with Bionano optical mapping. We will annotate the genome using orthology anlaysis, reading over information from the plant pathogen Fusarium graminearum. Using bioinformatics analysis of the improved genome, physically clustered and environmentally co-regulated genes that respond to differences in primary carbon source will be idenfied using both existing RNAseq data and new RNAseq data from further deletion lines. The construction of reporter lines using rapid modular cloning techniques, along with optimisation of CRIPSR-Cas9 mediated expression modulation, mutagenesis and deletion will allow a range of screens to be undertaken to identify global and specific signalling components modulating both deleterious secondary metabolite biosynthesis and the upregulation advantageous vitamin precursors which affect the end nutritional status of mycoprotein. Targeted knockout of pathway-specific regulators and screening for enhanced growth conditions will improve the metabolic profile of mycoprotein and advance our fundamental understanding of how this important microbe can be manipulated for enhanced industrial production. EMS mutagensis and subsequent TILLING by either Illumina or MinION sequencing will identify mutants that can be used for downstream commercial production.

Planned Impact

The formation of this collaboration allows a company (Marlow Foods) that has previously not worked on research of this nature to, in time, realise new market opportunities as a result of developments in basic bioscience and ensures that the UK maintains its leading position in the production of high quality mycoprotein. MF will gain further competititive advantages by gaining additional buying power for raw materials and would have the capacity to broaden its horizons for production in areas where wheat glucose is not an economic source of production. This grant will have a global impact, both on the research field internationally and on the international industry, especially the UK industry. Through full engagement with industry stakeholders, maximum translation of this research will be ensured, driving forward the UK food industry in a globally competitive market. NIAB EMR and MF will develop an exploitation plan for any IP that arises as a result of the project.

Direct beneficiaries:

1. Commercial private sector
The impact of releasing the constraints on production of mycoprotein using only unrefined wheat-derived glucose (available from only 1 supplier) is enormous. Production costs could immediately be lowered and MF would be able to source carbon sources from a larger range of suppliers and from a wider range of sources (maize, barley, rice) and even shift to sucrose-based production of mycoprotein, utilising UK sources of sucrose such as sugar beet, benefiting primary agriculture. It is estimated that in the short term production costs for MF could be reduced by at least £250k per annum. Simplification of the production process would allow more rapid growth of production, growing market share in the UK and worldwide which at its current rate is already growing MF turnover by approximately £12M per annum. Widening the possibilities for mycoprotein production from a range of carbon sources, could lead to large benefits in the wider supply chain and for consumers. A low carbon, sustainable source of protein, could fulfil multiple roles in the national supply chain, as demand for meat increases and lead to longer term sustainable production of nutritionally balanced food. This could have particular application in developing 'giant economies' and has significant potential for further growth of a UK business.

Indirect beneficiaries
Companies focused on enhancing secondary metabolism will benefit through the knowledge gained in this project about the link between carbon source and the control of secondary metabolism. This could aid in development of enhanced strains for production of valuable biomaterials.

Government, public and policy benefits
There are opportunities to deploy novel technologies to enhance the nutritional value of Quorn, which would allow overall dietary consumption to be altered and potentially expand the range of applications for mycoprotein.

Production improvements in mycoprotein will have benefit for the long term sustainabilty of mycoprotein and contribute to a resilient food supply for the consumer in the UK and beyond. Technologies deployed in this proposal will also be instrumental in improving the nutritional quality of Quorn, broadening its applicability.

CO2e (equivalent CO2) emissions from Quorn production compare favourably with chicken production (the most efficient mass-consumed meat source defined by feed-conversion ratio), with 2.6t of CO2e per tonne of mycoprotein coming from primary production. There are significant opportunities to lower production costs, CO2e production and energy consumption through improved utilisation of a range of technologies e.g., utilisation of a broader range of substrates, longer production runs, more efficient biomass conversion, waste stream recovery etc.

Publications

10 25 50
 
Description This work is still onging, but key inital findings:

1. There is a complex interaction between Carbon and Nitrogen source and levels that differentially impacts secondary metabolite expression
2. CRISPR editing has been developed in Fusarium, but is more challenging than other species.

2020 update
1. A large and complex experiment has been carried out to dissect C:N relationships on secondary metabolism.
2. CRISPR has been developed and is working well and is now being used to generate edits. Cas9 expressed at too high levels is toxic so very careful work to select promoters for cas9 and the sgRNA were both required.
3. Fluorescent reporters have now been developed and now work- some standard fungal promoters do not work well.
4. Plasmid based expression has been developed, again a non-trivial development

The project is extended through covid funding due to severe staff issues in 2020.

2021 update
Staff issues continued during 2021 and a severe loss of capability due to covid-related issues. However, we have managed to move forward on the bioinformatics analysis and two publications are now under development reporting the outcomes of our large C:N experiment described in point 1 above. These will both be published during 2022 and have provided useful insights into regulation of primary and secondary metabolism. However, we were not able to use our developed CRIPSR method to test candidate genes due to staffing issues, nor were we able to use EMSA analysis as planned to validate motif binding. However, tools remain to analyse candidates should further funding become available.
Exploitation Route Our industry partner is keen to understand how to regulate secondary metabolism, depending on C:N sources and ratios
Sectors Manufacturing, including Industrial Biotechology

 
Description Data from our large C:N experiment has been taken forward by our industrial partner and has led to confidential process changes in their fermentation methodologies.
First Year Of Impact 2021
Sector Manufacturing, including Industrial Biotechology
Impact Types Economic

 
Description Article for Microbiology society 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Developed an article with Rob Johnson at Marlow Foods talking about future opporutnities and technology led approaches for novel protein production.
Year(s) Of Engagement Activity 2018