Using fungi to clean fish farm wastewater: a streamlined approach

Greg Howard
9th December, 2025

Using fungi to clean fish farm wastewater: a streamlined approach

The fungus Ganoderma mbrekobenum, used in the optimization phase of this bioremediation study, is identified through images of its naturally occurring fruiting body (a), its pure mycelial culture (b), and its characteristic microscopic hyphae (c).

Image adapted from: El-Alfy et al. / CC BY (Source)

Key Findings

  • This study, conducted near Lake Burullus in Egypt, found that fungi can effectively clean aquaculture wastewater
  • Specific fungi, Aspergillus niger and Aspergillus flavus, significantly reduced pollutants like nitrogen, phosphorus, and organic matter in the wastewater
  • Adding potassium phosphate and magnesium sulfate boosted the ability of Ganoderma mbrekobenum to remove phosphorus, highlighting key nutrients for optimal fungal performance
Aquaculture, the farming of aquatic organisms, generates substantial wastewater containing high levels of nutrients and organic matter. Untreated, this wastewater can severely damage surrounding ecosystems, causing excessive plant growth (eutrophication) and harming aquatic life. Researchers at the National Institute of Oceanography and Fisheries (NIOF)[1] have been investigating biological methods to clean this wastewater, specifically using fungi. The study focused on wastewater from aquaculture ponds near Lake Burullus in Egypt. The research team tested two common fungi, Aspergillus niger and Aspergillus flavus, for their ability to remove pollutants. They also included Ganoderma mbrekobenum in a more detailed part of the study to understand how to best optimize its pollutant removal capabilities. The initial experiments showed that both Aspergillus species were effective at reducing levels of total protein, phosphorus, nitrogen, organic matter, and chemical oxygen demand (COD) – a measure of organic pollution – in the wastewater. This suggests a significant role for Aspergillus in cleaning nutrient-rich water. The researchers then used a statistical method called Plackett-Burman design (PBD) to pinpoint which factors most influenced the ability of G. mbrekobenum to remove total phosphorus (TP). PBD is a way to efficiently test many variables at once to see which ones have the biggest impact. They found that adding potassium phosphate (KH2PO4) and magnesium sulfate (MgSO4) to the water significantly boosted G. mbrekobenum’s phosphorus removal ability. Interestingly, for a control group without the fungus, peptone and yeast extract had the greatest effect. This indicates that different nutrients are important depending on whether a fungus is present or not. The predictive accuracy of these findings was very high, confirming the reliability of the optimization process. This approach builds on earlier work demonstrating the effectiveness of microorganisms in removing pollutants. For example, studies have shown that Bacillus and Aspergillus species can remove over 95% of nitrogen and phosphorus from beverage industry wastewater[2]. The current study expands on this by focusing specifically on aquaculture wastewater and identifying the key nutrients that enhance fungal performance. Furthermore, the optimization process using PBD mirrors techniques used to improve growth conditions for other microorganisms, such as the shipworm bacterium Teredinobacter turnirae[3], where optimizing the concentrations of manganese chloride, sodium carbonate, and potassium phosphate led to exponential growth. The study also observed that the fungal treatment increased metabolic activity and enzyme production – specifically dehydrogenase and total protein – between 9 and 12 days. Enzymes are biological catalysts that speed up chemical reactions, and their increased production suggests the fungi were actively breaking down pollutants. Another study highlighted the importance of fungal enzymes in breaking down waste, demonstrating that white rot fungi can degrade cellulose-containing waste and produce lignocellulolytic enzymes[4]. The NIOF research reinforces this idea, showing that fungal activity directly contributes to pollutant removal. The research also found that Ganoderma isolates can effectively treat stillage, a residue from ethanol production, removing significant amounts of organic carbon, nitrogen, and phenolic compounds while also producing valuable biomass and metabolites[5]. This demonstrates the broader potential of using fungi to valorize various types of industrial waste. The results of the NIOF study demonstrate that using fungal biomass is a cost-effective and environmentally friendly way to reduce nutrient pollution from aquaculture. This is particularly important for protecting sensitive ecosystems like Lake Burullus, which is vulnerable to the negative effects of agricultural and industrial runoff.

EnvironmentBiotechMycology

References

Main Study

1) Bioremediation of aquaculture wastewater using the fungal biomass integrating Plackett–Burman design

Published 5th December, 2025

https://doi.org/10.1007/s10532-025-10222-5

Related Studies

2) In-situ remediation of nitrogen and phosphorus of beverage industry by potential strains Bacillus sp. (BK1) and Aspergillus sp. (BK2).

https://doi.org/10.1038/s41598-021-91539-y

3) Application of Plackett-Burman design and response surface methodology to achieve exponential growth for aggregated shipworm bacterium.

Journal: Biotechnology and bioengineering, Issue: Vol 85, Issue 6, Mar 2004

4) Biodegradation of screenings from sewage treatment by white rot fungi.

https://doi.org/10.1186/s40694-025-00198-5

5) Conversion of Soluble Compounds in Distillery Wastewater into Fungal Biomass and Metabolites Using Australian Ganoderma Isolates.

https://doi.org/10.3390/jof11060432


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