Digital illustration of Pseudomonas brenneri bacteria remediating chromium in a coal mine environment.

Turning Mining Waste into Green Solutions: The Bacteria That Can Clean Up Chromium

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

"Discover how a novel bacterium, Pseudomonas brenneri, offers a promising eco-friendly approach to remediating chromium-contaminated wastewater from coal mines."

Mining, essential to modern society, leaves a lasting imprint on the environment. Among the most concerning issues is mineral contamination, which affects the well-being of communities and ecosystems. Coal mining, in particular, stands out due to its potential for severe environmental consequences. The elemental effluents released during coal extraction can disrupt the natural mineral balance of surrounding areas, leading to long-term ecological damage.

One of the major problems with coal mining is the creation of acid mine drainage (AMD), a highly acidic effluent loaded with heavy metals like cadmium, zinc, copper, nickel, lead, mercury, and chromium. These metals, non-biodegradable and persistent, can accumulate in living organisms through the food chain, posing a serious threat to human and animal health. The urgent need to address this contamination has led to stricter environmental regulations and a growing demand for effective remediation strategies.

Traditional methods for removing heavy metals from water, such as chemical treatments and membrane filtration, can be costly, generate sludge, and may not be selective enough for certain pollutants. This is where bioremediation, a 'green approach' using microorganisms to clean up contamination, offers a compelling alternative. Bioremediation harnesses the natural abilities of fungi, algae, and bacteria to remove or transform pollutants into less harmful substances. Among these, bacteria and algae show particular promise in altering chromium through oxidation and reduction processes.

Pseudomonas brenneri: A Mining Area Marvel

Digital illustration of Pseudomonas brenneri bacteria remediating chromium in a coal mine environment.

A recent study published in the Journal of Environmental Management has shed light on a novel bacterium, Pseudomonas brenneri, isolated from coal mine wastewater. This bacterium exhibits remarkable potential for chromium (Cr(VI)) remediation. Researchers investigated its Cr(VI) removal capabilities through batch studies, manipulating various parameters such as pH, temperature, initial metal concentration, agitation speed, and substrate concentration. They also explored the bacterium's ability to function in both oxygen-rich and oxygen-deprived conditions, as well as its tolerance to other metals.

The study revealed several key findings about Pseudomonas brenneri's unique properties:

Metal Tolerance: The bacterium can survive in solutions tainted with Cr(VI) concentrations ranging from 1 to 140 mg/L.
Optimal Remediation: Maximum remediation was observed in solutions containing 60 mg/L of Cr(VI).
Versatility: Besides Cr(VI), Pseudomonas brenneri can also tolerate other metals like iron, arsenic, copper, lead, zinc, and manganese.
Mechanism: The bacterium accumulates metal ions both on its cell surface and within its cells during the exponential growth phase.

Further analysis using the Monod equation, a classical model for microbial growth, helped determine the factors governing bacterial growth and removal activity. The bacterium also demonstrated its ability to thrive in bimetallic solutions containing Cr(VI) and other metals, highlighting its potential for treating complex industrial wastewater. Genetic analysis identified the bacterium as Pseudomonas brenneri, confirming its unique role in bioremediation.

The Future of Mining Wastewater Treatment

The discovery of Pseudomonas brenneri offers a beacon of hope for more sustainable mining practices. Its ability to thrive in harsh conditions and effectively remove chromium and other heavy metals makes it an ideal candidate for bioremediation applications. As environmental regulations become increasingly stringent, innovative solutions like Pseudomonas brenneri will play a crucial role in transforming mining wastewater from an environmental hazard into a valuable resource.

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: 10.1016/j.jenvman.2018.12.048, Alternate LINK

Title: Interlining Cr(Vi) Remediation Mechanism By A Novel Bacterium Pseudomonas Brenneri Isolated From Coalmine Wastewater

Subject: Management, Monitoring, Policy and Law

Journal: Journal of Environmental Management

Publisher: Elsevier BV

Authors: Soumya Banerjee, Biswajit Kamila, Sanghamitra Barman, S.R. Joshi, Tamal Mandal, Gopinath Halder

Published: 2019-03-01

Everything You Need To Know

What is acid mine drainage, and why is it such a problem in coal mining environments?

Acid mine drainage (AMD) is a significant environmental issue stemming from coal mining. It's a highly acidic effluent containing heavy metals such as cadmium, zinc, copper, nickel, lead, mercury, and chromium. These metals are non-biodegradable, persist in the environment, and can accumulate in living organisms, posing serious threats to both human and animal health. Addressing AMD is critical for mitigating the lasting environmental impacts of coal mining.

What are the limitations of traditional methods for treating heavy metal contamination, and how does bioremediation offer a different approach?

Traditional methods for treating heavy metal contamination in water, like chemical treatments and membrane filtration, have drawbacks. These methods can be costly, generate sludge, and lack the selectivity needed for certain pollutants. Bioremediation, using microorganisms, offers a compelling alternative by harnessing the natural abilities of fungi, algae, and bacteria to transform pollutants into less harmful substances, avoiding some of the pitfalls of traditional approaches.

What makes Pseudomonas brenneri particularly well-suited for bioremediation of chromium-contaminated wastewater?

Pseudomonas brenneri stands out because it can tolerate high concentrations of chromium (Cr(VI)), ranging from 1 to 140 mg/L, with optimal remediation observed at 60 mg/L. It's also versatile, tolerating other metals like iron, arsenic, copper, lead, zinc, and manganese. This bacterium accumulates metal ions both on its cell surface and within its cells, showcasing a unique mechanism for metal removal. The Monod equation is utilized to analyze and determine the factors governing the bacterium growth and removal activity.

How might the discovery of Pseudomonas brenneri impact the future of mining wastewater treatment and sustainability in mining practices?

The discovery of Pseudomonas brenneri introduces the prospect of more sustainable mining practices. It thrives in harsh conditions and effectively removes chromium and other heavy metals, making it a prime candidate for bioremediation. Pseudomonas brenneri offers the potential to transform mining wastewater from an environmental hazard into a valuable resource, aiding coal mines meet the increasingly stringent environmental regulations. The success of Pseudomonas brenneri also leads to more exploration of novel bacteria that may serve environmental needs.

Given that Pseudomonas brenneri tolerates multiple metals, what are the potential implications for treating complex industrial wastewater?

Pseudomonas brenneri's tolerance to multiple metals beyond just chromium, including iron, arsenic, copper, lead, zinc, and manganese, suggests it could be effective in treating more complex industrial wastewater containing a mix of pollutants. Its ability to thrive in bimetallic solutions highlights its potential for broad application in various industrial settings where multiple heavy metals are present. This adaptability could lead to more efficient and cost-effective wastewater treatment processes.