Related Experiment Video
Updated: Jul 9, 2026
09:33
An Anaerobic Biosensor Assay for the Detection of Mercury and Cadmium
Published on: December 17, 2018
Naphthalene-utilizing and mercury-resistant bacteria isolated from an acidic environment
S Y Dore1, Q E Clancy, S M Rylee
1Department of Biological Sciences and Center for Environmental Science and Technology, University of Notre Dame, Notre Dame, IN 46556, USA.
Applied Microbiology and Biotechnology
|June 27, 2003
Summary
Researchers isolated five bacterial strains from acidic soil near coal storage that can degrade polycyclic aromatic hydrocarbons (PAH). These bacteria, including an Acidocella strain, show unique mercury resistance mechanisms, suggesting novel bioremediation potential.
Area of Science:
- Environmental Microbiology
- Bioremediation
- Acidophile Research
Background:
- Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants.
- Low pH environments pose challenges for microbial degradation of contaminants.
- Coal storage sites can be sources of both PAHs and acidic conditions.
Purpose of the Study:
- To isolate and characterize bacteria capable of degrading PAHs at low pH.
- To investigate novel metabolic pathways for PAH degradation in acidophilic bacteria.
- To explore the mercury resistance mechanisms in isolated bacterial strains.
Main Methods:
- Enrichment culture using naphthalene as the sole carbon source in acidic medium.
- Isolation and cultivation of bacterial strains from soil samples.
- 16S rDNA sequencing for bacterial identification.
- PCR amplification and sequencing of mer operon genes.
Main Results:
- Five bacterial strains from the genera Clavibacter, Arthrobacter, and Acidocella were isolated.
- All isolates demonstrated growth on naphthalene as a sole carbon source at low pH (2.5-3.5).
- Known PAH degradation genes (nahAc, nahAd, etc.) were not detected in the isolates.
- One Acidocella isolate exhibited tolerance to high mercury levels, with mer operon genes suggesting detoxification mechanisms.
Conclusions:
- Acidophilic bacteria possess the capability to degrade PAHs, potentially through uncharacterized pathways.
- The isolated Acidocella strain possesses a mercury detoxification system, indicating a potential for co-contaminant bioremediation.
- These findings highlight the potential of extremophiles in environmental cleanup applications.
Related Concept Videos
01:28Microbial Nutrition
Organisms exhibit remarkable metabolic diversity, categorized based on how they acquire energy and carbon. These strategies enable survival in various ecological niches and are essential for maintaining energy flow and nutrient cycling within ecosystems.Energy and Carbon SourcesOrganisms are classified as phototrophs or chemotrophs based on energy acquisition. Phototrophs use light as their energy source, while chemotrophs rely on oxidizing chemical compounds. Further differentiation arises...
01:28Anoxygenic Phototrophic Bacteria
Anoxygenic phototrophic bacteria are a diverse group of microorganisms that perform photosynthesis without producing oxygen. They primarily include purple sulfur bacteria, purple nonsulfur bacteria, green sulfur bacteria, and green nonsulfur bacteria. These bacteria are classified into the Gammaproteobacteria, Alphaproteobacteria, Betaproteobacteria, Chlorobi, and Chloroflexi lineages, each with distinct physiological and ecological adaptations.Purple sulfur bacteria belong to the...
01:21Hyperthermophilic Bacteria
Domain Bacteria includes some unique hyperthermophilic species. They exhibit remarkable adaptations that enable survival in extreme environments.Thermotoga species are rod-shaped, gram-negative, non-sporulating hyperthermophiles that form a sheath-like envelope called a toga. They ferment sugars or starch, producing lactate, acetate, CO₂, and H₂, and can also grow via anaerobic respiration using H₂ and ferric iron. Found in hot springs and hydrothermal vents, over 20% of their genes show strong...
01:18Other Unique Bacteria
Magnetic bacteria exhibit a directed movement called magnetotaxis, driven by structures called magnetosomes. These magnetosomes consist of chains of magnetic particles made of either magnetite (Fe₃O₄) or greigite (Fe₃S₄) and are organized in a linear conformation by a protein scaffold within invaginations of the cell membrane. The bacteria align along the north–south magnetic field lines, much like a compass needle. They are typically microaerophilic or anaerobic and are commonly found near the...
01:25Microbial Mats
Microbial communities forming biofilms and mats represent complex, spatially structured ecosystems where metabolic processes are stratified according to light, oxygen, and nutrient gradients. Biofilms are initial colonization stages, only a few millimeters thick, while mature microbial mats can reach centimeter-scale thickness and display intricate vertical organization. Their structural and functional heterogeneity allows microorganisms to occupy distinct ecological niches within a few...
01:18Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...