Bacillus salmalaya bacteria cleaning up a landfill.

Landfill Rescue: How Bacteria Can Help Us Solve Waste Problems

Beau Callahan in Climate & Environment August 2025 • 4 min read.

"Discover how a novel, strongly resistant Bacillus salmalaya strain is revolutionizing landfill leachate treatment, reducing chemical oxygen demand and ammonia nitrogen."

The growing amount of waste we produce is a significant threat to our environment. Finding sustainable ways to deal with this waste is more critical than ever to protect our planet and our health. Bioengineering, using biological systems to solve environmental problems, is becoming a key area of focus.

Landfill leachate, a highly toxic liquid that forms when rainwater filters through waste, poses a serious challenge. It's loaded with ammonia nitrogen and has a high chemical oxygen demand (COD), making it difficult and expensive to treat. Traditional methods often fall short, highlighting the need for new approaches.

Now, a promising solution has emerged from an unexpected source: a resilient bacterium called Bacillus salmalaya strain 139SI. This article dives into the groundbreaking research demonstrating how this novel microbe can significantly reduce ammonia nitrogen and COD levels in landfill leachate, offering a sustainable and efficient way to manage this environmental hazard.

The Power of Bacillus salmalaya: A Natural Solution

Bacillus salmalaya bacteria cleaning up a landfill.

Researchers investigated Bacillus salmalaya strain 139SI, a newly identified bacterium, for its ability to remove ammonia nitrogen from landfill leachate. What makes this strain special is its ability to survive in environments with high concentrations of ammonia nitrogen, a common challenge in landfill leachate treatment. The study explored how different conditions, such as temperature, inoculum dosage (the amount of bacteria used), and pH levels, affected the bacterium's performance.

The results were impressive. Bioaugmentation, the process of adding beneficial bacteria to enhance biodegradation, using Bacillus salmalaya significantly improved the breakdown of pollutants in landfill leachate. The bacterium demonstrated a high capacity for removing both ammonia nitrogen (NH3-N) and chemical oxygen demand (COD), two key indicators of water contamination.

Optimal Conditions: The best results were achieved within 11 days under specific conditions: a 10% v/v inoculant (volume of bacteria relative to the volume of leachate), a pH of 6, and a temperature of 35°C.
Ammonia Removal: Under these optimal conditions, Bacillus salmalaya removed 78% of the ammonia nitrogen.
COD and BOD Reduction: The bacterium also significantly reduced the chemical oxygen demand (by 88%) and biological oxygen demand (by 91.4%).
Visual Evidence: Scanning electron microscopy revealed that ammonia ions were effectively captured on the surface of the Bacillus salmalaya cells.

These findings highlight the potential of Bacillus salmalaya as a powerful tool for bioremediation, offering a cost-effective and environmentally friendly way to treat landfill leachate.

A Cleaner Future with Bacterial Allies

Bacillus salmalaya strain 139SI presents a promising avenue for significantly reducing the levels of harmful pollutants in landfill leachate. Its ability to thrive in harsh conditions and efficiently remove ammonia nitrogen and COD makes it a strong candidate for real-world applications.

This research underscores the potential of bioaugmentation as a sustainable and cost-effective solution for waste management. By harnessing the power of microorganisms, we can develop innovative strategies to protect our environment and build a cleaner future.

Further research and field trials will be essential to optimize the use of Bacillus salmalaya in large-scale leachate treatment. However, these initial findings offer a beacon of hope for more effective and environmentally responsible waste management practices.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1186/s12896-017-0395-9, Alternate LINK

Title: Optimal Reduction Of Chemical Oxygen Demand And Nh3–N From Landfill Leachate Using A Strongly Resistant Novel Bacillus Salmalaya Strain

Subject: Biotechnology

Journal: BMC Biotechnology

Publisher: Springer Science and Business Media LLC

Authors: Arezoo Dadrasnia, Mohd Sofian Azirun, Salmah Binti Ismail

Published: 2017-11-28

Everything You Need To Know

What exactly is Bacillus salmalaya, and what does it do?

Bacillus salmalaya is a newly identified bacterium, specifically strain 139SI, that is capable of removing ammonia nitrogen and reducing chemical oxygen demand (COD) in landfill leachate. This bacterium was investigated for its ability to survive in environments with high concentrations of ammonia nitrogen. The discovery of Bacillus salmalaya offers a sustainable and efficient way to manage the environmental hazard of landfill leachate.

What is landfill leachate, and why is it a problem?

Landfill leachate is a highly toxic liquid that forms when rainwater filters through waste in landfills. It contains high levels of ammonia nitrogen and has a high chemical oxygen demand (COD), making it difficult and expensive to treat with traditional methods. This poses a significant threat to the environment and human health. The implications of untreated leachate include soil and water contamination, potentially affecting ecosystems and posing health risks to nearby communities.

Why is Bacillus salmalaya important in the context of managing waste?

The role of Bacillus salmalaya is significant because it offers a cost-effective and environmentally friendly way to treat landfill leachate. It demonstrates a high capacity for removing both ammonia nitrogen and chemical oxygen demand (COD), which are key indicators of water contamination. By using Bacillus salmalaya, bioaugmentation, the process of adding beneficial bacteria to enhance biodegradation, can significantly improve the breakdown of pollutants in landfill leachate.

What are the optimal conditions for Bacillus salmalaya to function, and why is this important?

The optimal conditions for Bacillus salmalaya to perform effectively in treating landfill leachate include a 10% v/v inoculant, a pH of 6, and a temperature of 35°C. Under these conditions, Bacillus salmalaya removed 78% of the ammonia nitrogen and significantly reduced the chemical oxygen demand (by 88%) and biological oxygen demand (by 91.4%). These findings are important because they indicate how the bacterium can be utilized for the best results, showcasing its practical application in real-world scenarios.

What is bioaugmentation, and what role does Bacillus salmalaya play in this process?

Bioaugmentation is the process of adding beneficial bacteria, like Bacillus salmalaya, to enhance biodegradation in a specific environment, such as landfill leachate. Bacillus salmalaya significantly improved the breakdown of pollutants in landfill leachate. Specifically, the bacterium demonstrated a high capacity for removing both ammonia nitrogen and chemical oxygen demand (COD), which are key indicators of water contamination, making bioaugmentation a promising method for cleaning up waste. The implications of bioaugmentation using Bacillus salmalaya include a reduction in environmental pollution and a sustainable way to treat landfill leachate, which benefits both the environment and human health.