Oyster Mushroom Soil Cleanup Study

ISEF Category: Environmental Engineering

Subcategory: Bioremediation  ·  Difficulty: Advanced  ·  Setup: School Lab  ·  Time: Full Year

The Hook

Used motor oil can linger in soil for years. Fungi can help break down oily pollutants, like a living cleanup crew. Oyster mushrooms are one of the best-known candidate species for this job. You can test how well they work across different contamination levels.

What Is It?

Mycoremediation means using fungi to help clean polluted soil or water. Fungi grow thread-like networks called mycelium, and those networks release enzymes that can break large, messy molecules into smaller pieces. In this project, you would test oyster mushroom substrate, which is the material the fungus grows on, in soil mixed with motor oil.

Think of the fungus like a sponge mixed with a chemistry kit. The sponge part spreads through the soil, and the chemistry part helps break down hydrocarbons, which are the carbon-rich compounds in oil. You would not just ask, “Does it work?” You would measure how much cleanup happens at different contamination levels and compare that with how well the fungus grows.

That gives you two linked signals. One is soil chemistry, which you can track with a colorimetric kit for hydrocarbons or oil-related compounds. The other is fungal growth, which you can estimate from visible spread, biomass, or another consistent growth measure. Together, they help you see whether the fungus performs better in lightly or heavily contaminated soil.

Why This Is a Good Topic

This makes a strong science fair topic because you can test a real environmental problem with a clear variable, a measurable outcome, and a live biological system. Oil-contaminated soil is a real cleanup challenge, and fungi give you a low-cost way to study bioremediation. You can also build real research skills, like setting controls, making concentration curves, and comparing chemical data with growth data.

Research Questions

• How does motor-oil concentration affect the ability of oyster mushroom substrate to reduce hydrocarbon signals in soil?
• What is the effect of oyster mushroom substrate on fungal growth rate across increasing motor-oil contamination levels?
• Does pre-colonized oyster mushroom substrate remove more hydrocarbons than uncolonized substrate in contaminated soil?
• To what extent does soil moisture change the oil-degradation pattern in oyster mushroom treatments?
• Which contamination level produces the highest balance between fungal growth and hydrocarbon reduction?
• How does the response of treated soil compare with untreated control soil over the same contamination range?

Basic Materials

• Motor oil or used motor oil collected safely and legally
• Garden soil with a consistent texture
• Oyster mushroom substrate or spawn from a legal source
• Plastic or glass containers with lids
• Digital kitchen scale with 0.1 g accuracy
• Measuring spoons or graduated cylinders
• Disposable gloves
• Safety goggles
• pH strips or a soil pH kit
• Colorimetric hydrocarbon test kit or oil test strips
• Labels and waterproof marker
• Camera or smartphone for image tracking
• Ruler or calipers for visible growth measurements
• Notebook or spreadsheet for data logging.

Advanced Materials

• Analytical balance
• Soil core sampler or consistent soil coring tools
• Autoclave or pressure cooker for sterilizing materials if needed
• Incubator or controlled-temperature chamber
• UV-visible spectrophotometer if your hydrocarbon assay uses absorbance
• Gas chromatography-mass spectrometry for hydrocarbon profiling
• Soil respiration chamber or CO2 sensor
• Moisture meter for soil water content
• Petri dishes, agar media, and sterile transfer tools for fungal culture checks
• Image analysis setup with fixed lighting and calibration target
• Centrifuge and filtration supplies for sample prep
• Laboratory-grade extraction solvents approved by your lab supervisor.

Software & Tools

• Google Sheets: Organizes treatment groups, calculates averages, and plots growth and cleanup data.
• ImageJ: Measures fungal spread, colony area, or soil-surface coverage from consistent photos.
• Python: Helps you fit curves, compare treatments, and run basic statistics on repeated trials.
• RStudio: Supports cleaner statistical analysis, including regression, ANOVA, and confidence intervals.
• GraphPad Prism: Creates publication-style graphs and helps compare dose-response patterns.

Experiment Steps

1. Define one contamination gradient, one fungal treatment, and one untreated control so your comparison stays clear.
2. Choose the main response you will quantify, then decide how you will turn color or absorbance into a cleanup metric.
3. Plan a way to measure fungal growth the same way every time, such as image area, biomass, or another repeatable proxy.
4. Build a calibration curve for your hydrocarbon assay so your readings become comparable across samples.
5. Set up replicates and controls that separate fungal activity from natural soil changes, evaporation, and background color.
6. Map out your analysis before you collect data, including how you will compare trends across contamination levels.

Common Pitfalls

• Using soil from different sources, which changes texture and nutrient content between treatments.
• Mixing motor oil unevenly into the soil, which creates hot spots and makes your results noisy.
• Measuring cleanup with changing light or dirty containers, which distorts colorimetric readings.
• Assuming mushroom growth means oil breakdown, which can hide cases where the fungus grows but does not remove much hydrocarbon.
• Skipping untreated and substrate-only controls, which makes it hard to prove that the fungus caused the cleanup.

What Makes This Competitive

A strong version of this project does more than show that fungi can grow in oily soil. It compares several contamination levels, uses a real calibration curve, and separates fungal growth from actual hydrocarbon removal. You can make it stronger by testing whether performance changes with soil moisture, substrate dose, or pre-colonized versus fresh material. Careful replication and clear statistics will matter a lot here.

Project Variations

• Test how oyster mushroom substrate performs in diesel-contaminated soil instead of motor-oil-contaminated soil.
• Compare oyster mushroom substrate with another fungi-based treatment, such as spent mushroom substrate from a different species.
• Analyze cleanup using image-based soil darkening or fluorescence instead of a colorimetric hydrocarbon kit.

Learn More

• US EPA Bioremediation resources: Search the EPA site for overviews of bioremediation and soil cleanup methods.
• NIH PubMed: Search review articles on mycoremediation, Pleurotus ostreatus, and hydrocarbon degradation.
• USGS Water Science School: Find background on petroleum hydrocarbons and environmental contamination.
• NCBI Bookshelf: Look for free textbook chapters on environmental microbiology and fungal metabolism.
• MIT OpenCourseWare: Search for environmental engineering or microbiology course materials that explain pollutant fate and biodegradation.
• NOAA Marine Debris and Pollution resources: Use as background on hydrocarbon pollution impacts and environmental monitoring.