The FUNGI FILTER Project

In view of the urgent issue of water contamination—affecting rivers, lakes, oceans, and groundwater—our experimental, research-based work focuses on examining water remediation using the remarkable properties of mycelium. This experimentation explores how mycelium can play a vital role in restoring water quality and supporting the life cycles of soil and aquatic ecosystems within the water industry.

We addressed some key questions:

Can the breakdown and filtering properties of live mycelium be visible in water – outside of its natural habitat?

How can we demonstrate this bioremediation process?

How can we contribute to assist and embrace this breakdown process?

MYCELIUM

Mycelium, the vegetative part of fungi, is vital in ecosystems, particularly for decomposing organic material and remediating toxins.

Key points include:

Decomposition: Mycelium breaks down organic matter into simpler compounds for plant absorption, essential for nutrient cycling.
Bioremediation: Some fungi can degrade hazardous substances like heavy metals and pesticides, transforming them into less harmful compounds.
Enzymatic Action: Mycelium secretes enzymes that decompose complex organic materials, aiding both nutrient cycling and bioremediation.
Soil Health: It enhances soil structure, water retention, and nutrient availability, promoting plant growth and ecosystem resilience.
Symbiotic Relationships: Mycelium often forms mycorrhizal associations with plants, improving nutrient uptake and stress resilience.

Active mycelium continuously adsorbs and transforms pollutants, reducing their concentrations over time. In contrast, dead mycelium retains limited adsorption capabilities, emphasizing the need to maintain active mycelial populations for effective bioremediation.

PREPARATION

We began by researching the feasibility of our project, reaching out to local mushroom farms in London for various mycelium strains. Our team tackled the challenges of using mycelium for bioremediation and water filtration.

Shichen proposed the idea, managed equipment purchases, and documented mycelium growth at home. He also imported lab testing equipment from China and acquired substrates.

Last semester, we consulted Dr. Kailash Ramlaul the RCA lab manager for valuable articles and data support. A key part of our methodology was establishing a control group for comparative experiments. We achieved a significant breakthrough when we were granted permission to access the RCA Natural Matters Bio Lab.

Our goal is to show that commercially available mycelium can effectively break down pollutants. Inspired by an article from Nature Africa, we based our theoretical framework on the adaptability and heavy metal tolerance of large fungi, especially Pleurotus species. We aim to validate oyster mushrooms (Pleurotus) through negative control experiments with various substrate materials.

The methodology we used:

Preparation of Samples: Noting the quantities and types of substrates used, as well as the conditions under which the polluted water samples were prepared.
Initial Observations: Recording the filtration properties of each substrate during preliminary tests to understand their effectiveness.
Cultivation Process: Keeping detailed notes on the growth of the Blue Oyster mycelium, including any contamination incidents and the adjustments made, such as acquiring a new strain.
Maturation and Transfer: Documenting the timeline for maturation and the conditions under which the mycelium was transferred to filtration columns.
Contamination Monitoring: Logging any instances of bacterial contamination and the impact on our substrate options.
Filtration Testing: Recording the results of TESPERT water strip tests, including contamination levels before and after filtration, and noting the time intervals for evaluations.
Meticulously documenting each step of the process.

Identifying our water source: Collection and Analysis

We focused on addressing heavy metal pollution in water sources by collecting samples from river water, rainwater, and artificially contaminated water to test our hypothesis. Initially, we created an in-lab sample of polluted water containing 1 mg of iron, 1 mg of copper, and 1 mg of Pro Grow fertilizer mixed with 100 ml of lab water. However, we realized this concentration was too high for effective testing.

To resolve this, we refined our formula by filtering the sample and diluting it with additional water and sodium bicarbonate, ensuring that the mycelium would not be overwhelmed or damaged during the experiment. This careful calibration was crucial for accurately evaluating the mycelium’s ability to remediate heavy metal pollutants.

Turning Mycelium into a sustainable filtration solution and a positive cycle for nature

Inspired by our group’s Asian cultural background, we learned about the origins of rain chains in Japan, originally crafted from hemp ropes extending from teahouse roofs to the ground, allowing rainwater to flow alongside the ropes and effectively serving as a drainage system.

During our initial water collection, we observed that the rainwater exhibited various shades of yellow, likely due to metal elements found in car exhaust. Our experiments, combined with existing literature, suggest that mycelium can decompose heavy metals and bacteria present in water sources. We aimed to utilize the filtering properties of mycelium within a rain chain system, allowing rainwater to flow through the mycelium and absorb pollutants before returning purified water to nature.

LAB WORK

During our experiments in the lab, we meticulously documented each step of the process. This included: preparing the samples, initial observation, cultivation process, maturation and transfer, contamination monitoring and filtration testing.

We focused on the edible Blue Oyster strain of fungi and narrowed our substrate options to five: rice husk, wood chips, pine bark, straw, and a mixed substrate. The conditions at the RCA Natural Matters lab allowed us to prepare polluted water samples and autoclave our substrates in beakers.

Initial tests revealed that the substrates lacked effective filtration properties, informing our subsequent experiments. We cultivated a mother plate of Blue Oyster mycelium but encountered contamination issues during the petri dish cultivation and transplantation stages, necessitating a new strain.

After inoculating the mycelium into the substrates in beakers and allowing a week for maturation, we transferred it into filtration columns maintained at 25 degrees Celsius. Unfortunately, the mixed substrate was eliminated due to bacterial contamination, reducing our total to four viable substrates.

This entire process took longer than expected.

For the filtration testing we used TESPERT water strip tests to test levels before and after filtration with our in-lab polluted water samples noting the time intervals for evaluations.

The filtration effectiveness of the mycelium experiment was assessed after 30 minutes and 48 hours of contact with the polluted water sample.

OUTCOME: It’s still Alive!

Our findings reveal a significant breakdown of copper and zinc in the filters after 48 hours, with the mycelium remaining alive in the filters.

We still must determine if this effect persists after six days and whether further breakdown is observable and if the mycelium will survive the time in these conditions. Will it stay alive and for how long?

We observed that live mycelium can effectively break down certain pollutants and heavy metals, thereby improving water quality. While this process does not meet drinking water standards, it could be valuable in other applications, particularly in local outdoor household scenarios where pollution is absorbed.

We can speculate that water remediation using mycelium could be scaled up within standardised norms and conditions, potentially serving as a method for bioremediation in the future, particularly in wetlands.

INTEGRATING MYCELIUM INTO A RAIN CHAIN

These results further advanced our bio-design concept. Rather than functioning as a typical water filter, we integrated the environmental conditions essential for mycelium growth, emphasizing oxygen exposure and human-nature interaction within an outdoor setting. This approach guided our design toward a rain chain structure, showcasing the future potential of environmental bioremediation and sustainable filtration products made from mycelium.

We explored the fascinating evolutionary process of mycelium, drawing inspiration from its microscopic details while directly observing changes in water colour to produce a rain chain.

Due to time constraints, the mycelium and straw substrate are still growing in their moulds in the lab. While we aimed to produce a rain chain but, we will only know if this has matured properly in a couple of days.

The bio remedial properties of mycelium were tangible in our collaborative networking as a team as well as for our individual projects at the RCA. The way mushrooms and mycelium networks connect underground processes with above-ground life emphasizes the intricate relationships in ecosystems.