IAP2-23-070

Grounds for an Equitable Transition

This CASE project aims to provide the scientific foundation for a social enterprise based on the recycling of spent coffee grounds (SCG). It will equip the student with the skills needed to integrate concepts in environmental and human nutritional health in a circular nutrient economy. These include cutting-edge metagenomic analyses, nutrient profiling of foods using GC-MS, and molecular bioinformatics and biophysical characterisation of soil health. They will also be embedded within a team-based with our CASE partner to learn how to translate science into a self-sustaining social enterprise.

The project will build on the “Grounds for Recycling” pilot that was launched to coincide with the 2023 UCI Cycling World Championships. Led by our CASE partners, the Glasgow Chamber of Commerce, together with Glasgow Life and Zero Waste Scotland, the campaign aimed to bring attention to the local and global problem of food waste by presenting a circular economy solution to waste from coffee shops.

The process involves the incorporation of nutritionally dense spent coffee grounds with other organic waste streams to produce an optimal growth medium for the cultivation of high-value oyster mushrooms. This circular nutrient economy prevents waste-to-landfill while creating two value streams to sustain a new social enterprise. Local production of mushrooms in deprived areas of the city has the co-benefit of providing an affordable and highly nutritious food source in these areas.

Our external partner is Chido Govera, a multi-award-winning Zimbabwean-based social entrepreneur, farmer, campaigner, educator, and the founder of The Future of Hope Foundation (https://www.thefutureofhope.org/). She has pioneered the use of mushroom cultivation from food waste to lift communities out of poverty and has established social enterprises in Australia, Tanzania, the Congo, South Africa, India, Colombia, Serbia and China. She will advise on the cultivation methodology and the establishment of the social enterprise.

The proposed project builds on the Glasgow as a Living Lab for Accelerating Novel Transition (GALLANT), a collaboration between the University and Glasgow City Council (GCC) to design and deliver a just transition to net-zero. The PhD project will belong to the GALLANT graduate school – a highly stimulating and multidisciplinary research environment where they will have access to contaminated land, urban greenspace, and community gardens through the GALLANT research and GCC.

Microbiology methods.
Previous research has found that caffeine from SCG delays and inhibits the growth of oyster mushroom fruiting bodies (DOI: 10.1007/s00253-019-09883-z). Bacterial biodegradation is however an efficient, economical and environmentally friendly process to convert caffeine into non-toxic compounds (https://doi.org/10.1016/j.enzmictec.2005.03.004). This project will therefore trial the use of bacterial cultures, before and after mixing SCG into other waste streams, to test the most effective protocol for reducing caffeine content, and optimising mushroom growth.

Nutrient Profiling.
Randomised, block design trials will be run in Y1 with at least 5 replicates per conditions, each incorporating a gradient of SCG. Fruiting bodies will be harvested whole and stored for subsequent analysis, as fresh, freeze-dried or frozen samples.

Fatty acid content of mushroom fruiting bodies has been shown to vary based on compost composition (https://doi.org/10.1371/journal.pone.0255794), and fatty acid analysis will be carried out by GC-MS.

Total phenolic content of the fruiting body grown on compost incorporating a gradient of SCG will be measured using the Folin Ciocalteau assay [https://doi.org/10.1021/jf4003126]; while caffeine and chlorogenic acids will be measured using HPLC with UV detection [DOI: 10.1021/jf200122m].

Biologically active glucans, rich in pleurotus mushrooms, have potential prebiotic activity. Following extraction, total and α-1,4-glucans will be determined enzymatically, and non-starch glucans estimated.

Soil Health
Following mushroom cultivation, the resulting compost will be amended with additional organic waste materials (food waste, straw) and minerals (e.g. clay) to match the needs of the receiving soil (contaminated land, urban green space, community gardens). The impact of compost on the health of the receiving soil is unlikely to be measurable in the timescale of the PhD. However, it is important to create a baseline against which health benefits can be quantified. This will be achieved by combining a set of molecular and physical measures associated with the concept of soil as a composite extended phenotype of the resident microbiome (https://doi.org/10.1038/s41598-020-67631-0) developed by members of the supervisory team. Because of cross-relevance, costs will be shared by existing funded projects amongst collaborators.

Replicate aggregates will be scanned using a Phoenix Nanotom X-ray Computed Tomography system (GE Measurement and Control solution, Wunstorf, Germany) set at 90 kV, a current of 65 μA and at a base resolution of 1.51 μm (voxel volume resolution = 3.4 μm3). Image analysis was performed using ImageJ. Soil community DNA will be extracted using the MoBio PowerSoil DNA isolation kit (Mo Bio Laboratories, Inc. Carlsbad, CA, USA) with three replicates for each soil treatment. Shotgun metagenomic sequencing of DNA will be undertaken by Illumina (Great Abington, UK) using a HiSeq 2000 sequencing platform, generating 150-base, paired-end reads. Metagenome sequences will be associated with both taxa and Kyoto Encyclopaedia of Genes and Genomes (KEGG) functional orthologs and modules using MEGAN Ultimate version 6.10.2.

Placement with the case partner.
The purpose of the placement is to provide experiential learning related to connecting research to the establishment of a social enterprise. The student will learn from case studies of similar enterprises established by the CASE partner and GCC. They will work closely with the enterprise team assigned to the establishment of the mushroom and compost business. The will interact regularly with Chido as a mentor to contribute to the design and implementation of the enterprise in Glasgow.

Year 1

Microbiology.
In year 1 the candidate will perform literature searches and initial laboratory tests to identify bacteria capable of caffeine biodegradation, and to optimise conditions for SCG biodegradation. In year 3 the candidate will consider how to adapt their findings so that SCG treatment can be safely, easily and economically be delivered to the community.

Nutrition profiling.
Fresh samples will be analysed either in Y1 (fresh samples) or in Y2 (stored samples) for fatty acids, phenolic content, caffeine, chlorgenic acids and fibre / glucans.

Soil Health.
Selection of receiving soil plots. Collection of samples for baselining. DNA extraction. Scanning at the University of Nottingham Hounsfield Centre

CASE Partner
1 month placement

Year 2

Microbiology.
In year 2 the candidate will set up microcosms to test a range of protocols for SCG biodegradation that could be adapted for real-world use. These will include the timing of culture introduction and incubation, and the use of different bacterial cultures, substrates, pH, temperature and water contents.

Nutrition profiling.
Mineral analysis to include Vitamins – vit D, thiamine/riboflavin /vit C, folates, niacin, B12.

Soil Health.
Familiarisation with MEGAN and bioinformatics analyses with support from collaborators at Rothamsted Research. Image analysis of CT images

Year 3

Microbiology.
The candidate will consider how to adapt their findings so that SCG treatment can be safely, easily and economically be delivered to the community.

Nutrient profiling.
Analysis of the biological yield, economical yield, willingness to pay (and consumer acceptability) and potential impact on the dietary intake of consumers using dietary modelling analysis.

Soil Health.
Bioinformatics analysis of soil metagenomes including interpretation using MEGAN.

CASE Partner
2 month placement with CASE partner

Year 3.5

Analytical synthesis across all dimensions of the project. Writing up

Microbial ecology, bioinformatics, GC-MS, image analysis, social entrepreneurship.