Related Experiment Video
Updated: Jan 28, 2026
15:19
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
10.1K
Diverse aromatic-degrading bacteria present in a highly enriched autotrophic nitrifying sludge
Haohao Sun1, Takashi Narihiro2, Xueyan Ma1
1State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
The Science of the Total Environment
|February 25, 2019
Summary
Heterotrophic bacteria in nitrifying sludge play a key role in aromatic compound biodegradation, a function previously overlooked. Metagenomic and metatranscriptomic data reveal their significant contribution to breaking down complex organics.
Area of Science:
- Environmental microbiology
- Biotechnology
- Bioremediation
Background:
- Nitrifying sludge is crucial for wastewater treatment, primarily known for ammonia oxidation by autotrophic microorganisms.
- The role of heterotrophic bacteria within these sludges in degrading complex organic compounds, particularly aromatics, is often underestimated.
- Understanding the full microbial community function is essential for optimizing bioremediation processes.
Purpose of the Study:
- To investigate the contribution of heterotrophic bacteria in enriched autotrophic nitrifying sludge to aromatic biotransformation and biodegradation.
- To identify specific bacterial groups and genes responsible for aromatic degradation within this microbial community.
- To analyze the functional gene expression in response to aromatic compound exposure.
Main Methods:
- Metagenomic sequencing to identify the genetic potential for aromatic degradation.
- Metatranscriptomic analysis to assess gene expression levels under specific conditions.
- Genome binning to assign functional genes to specific bacterial taxa.
- Exposure of nitrifying sludge to phenol to observe transcriptional responses.
Main Results:
- Diverse genes encoding enzymes for the degradation of at least 15 complex aromatic compounds were identified in the nitrifying sludge.
- These aromatic degradation genes were primarily found in heterotrophic bacteria belonging to Bacteroidetes, Alphaproteobacteria, and Betaproteobacteria.
- Metatranscriptomic analysis showed significant upregulation of aromatic degradation genes, especially phenol degradation genes, upon phenol exposure.
Conclusions:
- Heterotrophic bacteria within nitrifying sludge are significant contributors to aromatic biotransformation and biodegradation.
- The study reveals specific bacterial taxa and metabolic pathways involved in these processes.
- This research enhances the understanding of the metabolic capabilities and ecological roles of nitrifying sludge microbial communities.
Related Concept Videos
02:58Regulated Protein Degradation
8.8K
It is vital to regulate the activity of enzymatic as well as non-enzymatic proteins inside the cell. This can be achieved either through creating a balance between their rate of synthesis and degradation or regulating the intrinsic activity of the protein. Both these regulation mechanisms play an essential role in the normal functioning of cells.
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
8.8K
02:11Proteins: From Genes to Degradation
14.5K
Within a biological system, the DNA encodes the RNA, and the nucleotide sequence in the RNA further defines the amino acid sequence in the protein. This is referred to as “The Central Dogma of Molecular Biology” - a term coined by Francis Crick. Central dogma is a firm principle in biology that defines the flow of genetic information within any life form. The two fundamental steps in central dogma are - transcription and translation.
Transcription is the synthesis of RNA...
Transcription is the synthesis of RNA...
14.5K
02:11Proteins: From Genes to Degradation
4.5K
4.5K
01:14Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
2.7K
Treating arylamines with nitrous acid gives aryldiazonium salts that are effective substrates in nucleophilic aromatic substitution reactions. The diazonio group in these salts can be easily displaced by different nucleophiles, yielding a wide variety of substituted benzenes. The leaving group departs as nitrogen gas, and this easy elimination is the driving force for the substitution reaction.
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
2.7K
01:30Diversity of Archaea I
605
Archaea, a domain of single-celled microorganisms, are classified into five major phyla based on genetic and biochemical characteristics: Euryarchaeota, Crenarchaeota, Thaumarchaeota, Korarchaeota, and Nanoarchaeota. Among these, the phylum Euryarchaeota is notable for its remarkable diversity in morphology, metabolism, and ecological adaptations.Morphological and Metabolic DiversityMembers of Euryarchaeota exhibit a variety of cellular shapes, including rods and cocci. Their metabolic pathways...
605
01:13Cell Diversity
5.0K
The concept of a cell started with microscopic observations of dead cork tissue by Robert Hooke in 1665. Hooke coined the term "cell" based on the resemblance of the small subdivisions in the cork to the rooms that monks inhabited, called cells. About ten years later, Antonie van Leeuwenhoek became the first person to observe the living and moving cells under a microscope. In the century that followed, the theory that cells represented the basic unit of life developed.
Multicellular...
Multicellular...
5.0K