Biological treatment of drinking water

One possible step in the treatment of water to make it potable is to pass it through a charcoal filter colonized with bacteria and protozoa. The microorganisms feed on the organic waste present in the water. This filter, also called a biological filter, because the bacteria have lodged in it naturally, helps produce biologically stable potable water which maintains its quality throughout the water distribution network.

The filtration plant also puts microbes to work!

The Auteuil filtration plant in Laval, Quebec, cleans wastewater before returning it to the river. It uses shale (a rock with a layered structure) biofilters containing bacteria that contribute to the water purification process, as do decantation and decontamination with UV radiation.

Biological treatment of drinking water

One possible step in the treatment of water to make it potable is to pass it through a charcoal filter colonized with bacteria and protozoa. The microorganisms feed on the organic waste present in the water. This filter, also called a biological filter, because the bacteria have lodged in it naturally, helps produce biologically stable potable water which maintains its quality throughout the water distribution network.

The filtration plant also puts microbes to work!

The Auteuil filtration plant in Laval, Quebec, cleans wastewater before returning it to the river. It uses shale (a rock with a layered structure) biofilters containing bacteria that contribute to the water purification process, as do decantation and decontamination with UV radiation.


© Armand-Frappier Museum, 2008. All rights reserved.

Filamentous bacteria can colonize biological charcoal filters and thus contribute to the degradation of organic material. On the microphotography presented here (Baclight Coloration, 1000X), the active bacterial cells, whose membranes are intact, are green-colored whereas the dead bacterial cells, with damaged membranes, are red-colored.

Water treatment plant in Ste-Rose

© Water treatment plant in Ste-Rose


Biofilters

Photo : Nicole Catellier

© Nicole Catellier, Cinémanima inc.


In recent decades, industrial spillages of various chemical products such as petroleum hydrocarbons or polychlorinated biphenyls (PCBs) have created an environmental pollution problem. Furthermore, some of these products may cause health problems.

The enzymes of some organisms found in the environment, bacteria and fungi, are capable of breaking the chemical structure of these substances and reducing them to harmless compounds. These microorganisms may be used as a biological alternative to conventional methods of decontamination (incineration, for example) or burial, offering a promising approach to the treatment of contaminated sites.

It is possible to optimize the use of microorganisms for the biodegradation of hydrocarbons and other contaminants.

The big petroleum companies such as Shell Canada hire experts to characterize and biologically treat contaminated industrial soils in order to restore them. According to the guidelines established by the Soil Protection Policy of the Ministry of Environment (criteria: A 100 ppm, B 700 ppm, C 3500 ppm), biotreated soils containing a maximum of 15 000 ppm (parts per million) of petroleum hydrocarbons can be cl Read More

In recent decades, industrial spillages of various chemical products such as petroleum hydrocarbons or polychlorinated biphenyls (PCBs) have created an environmental pollution problem. Furthermore, some of these products may cause health problems.

The enzymes of some organisms found in the environment, bacteria and fungi, are capable of breaking the chemical structure of these substances and reducing them to harmless compounds. These microorganisms may be used as a biological alternative to conventional methods of decontamination (incineration, for example) or burial, offering a promising approach to the treatment of contaminated sites.

It is possible to optimize the use of microorganisms for the biodegradation of hydrocarbons and other contaminants.

The big petroleum companies such as Shell Canada hire experts to characterize and biologically treat contaminated industrial soils in order to restore them. According to the guidelines established by the Soil Protection Policy of the Ministry of Environment (criteria: A 100 ppm, B 700 ppm, C 3500 ppm), biotreated soils containing a maximum of 15 000 ppm (parts per million) of petroleum hydrocarbons can be classified as biotreated soils instead of contaminated soils. However, these soils must be used as industrial soils, for the burial of domestic waste, for example.

At the Shell Canada treatment platform in Montreal, the contaminated soils are aerated in order to facilitate the development of the microorganisms (bacteria and fungi). Naturally present in the soil, these microorganisms then feed on hydrocarbons. The bacteria Pseudomonas aeruginosa is one of these useful indigenous bacteria. If necessary, the soil can be inoculated with other bacteria or fungi to accelerate the process. In these cases, the fungi Phanerochaete chryssosporium, a microscopic fungus of white rot, may be added. This fungus naturally degrades lignin (a molecule present in bark of trees) due to the presence of a non-specific enzyme. It can also rapidly degrade recalcitrant hydrocarbons.


© Armand-Frappier Museum, 2008. All rights reserved.

Pseudomonas aeruginosa

Photo : Richard Villemur

© Richard Villemur, INRS- Institut Armand-Frappier


The vaccine: a harmless copy

Vaccines are used with the intention of showing our immune system a harmless copy of a microbe. When the real microbe tries to infect us, our immune system will rapidly recognize it and prevent it from reproducing. As the number of immunized people increases, the microbe has less opportunity to spread and an epidemic can be prevented.

Babies are naturally protected against many diseases, thanks to the antibodies that they receive from their mother at birth. Unfortunately, this protection is temporary and disappears during the first year of life. Vaccination therefore provides a new and solid immunity against certain diseases.

Vaccines can be produced in different ways. They can be constituted from microbes that are alive but attenuated, which then produce benign or asymptomatic diseases, from microbes similar to those causing a disease, from dead microbes, from certain parts of a microbe, or even from the DNA of the harmful microbe. In certain cases, it is even possible to produce vaccines in eggs, as is the case for the flu vaccine (Preventing the flu: from the egg to the vaccine, the title of the 8 mm vide Read More

The vaccine: a harmless copy

Vaccines are used with the intention of showing our immune system a harmless copy of a microbe. When the real microbe tries to infect us, our immune system will rapidly recognize it and prevent it from reproducing. As the number of immunized people increases, the microbe has less opportunity to spread and an epidemic can be prevented.

Babies are naturally protected against many diseases, thanks to the antibodies that they receive from their mother at birth. Unfortunately, this protection is temporary and disappears during the first year of life. Vaccination therefore provides a new and solid immunity against certain diseases.

Vaccines can be produced in different ways. They can be constituted from microbes that are alive but attenuated, which then produce benign or asymptomatic diseases, from microbes similar to those causing a disease, from dead microbes, from certain parts of a microbe, or even from the DNA of the harmful microbe. In certain cases, it is even possible to produce vaccines in eggs, as is the case for the flu vaccine (Preventing the flu: from the egg to the vaccine, the title of the 8 mm video involving the participation of BioChem Parma).


© Armand-Frappier Museum, 2008. All rights reserved.

Influenza vaccine

Photo : Barbara Bélanger

© Barbara Bélanger, Armand-Frappier Museum


A medicinal mold
As is often the case in science, chance was at the basis of a revolutionary discovery, e.g., penicillin. Nevertheless, the circumstances surrounding its discovery in no way diminish the importance of penicillin in medicine. Several diseases that used to be deadly are nowadays easily treatable infections. However, we must be vigilant, since the microbes responsible for these diseases have not said their last word…

When luck is on our side
We are in England in 1927. Arriving one morning at his laboratory, the microbiologist Alexander Fleming realizes, disheartened, that several of the bacterial colonies he has been studying are dead. Halfheartedly, Fleming decides to examine the dead bacteria before disposing of them. He notices that the bacterial colonies have been contaminated by a fungus called Penicillium. He then concludes that the fungus produces a substance that is toxic to the bacteria. He baptizes this substance "penicillin".

How to produce industriel quantities of penicillin?
Following the discovery of Alexander Fleming, the demand for penici Read More

A medicinal mold
As is often the case in science, chance was at the basis of a revolutionary discovery, e.g., penicillin. Nevertheless, the circumstances surrounding its discovery in no way diminish the importance of penicillin in medicine. Several diseases that used to be deadly are nowadays easily treatable infections. However, we must be vigilant, since the microbes responsible for these diseases have not said their last word…

When luck is on our side
We are in England in 1927. Arriving one morning at his laboratory, the microbiologist Alexander Fleming realizes, disheartened, that several of the bacterial colonies he has been studying are dead. Halfheartedly, Fleming decides to examine the dead bacteria before disposing of them. He notices that the bacterial colonies have been contaminated by a fungus called Penicillium. He then concludes that the fungus produces a substance that is toxic to the bacteria. He baptizes this substance "penicillin".

How to produce industriel quantities of penicillin?
Following the discovery of Alexander Fleming, the demand for penicillin grew quickly, notably because of the Second World War where thousands of soldiers died from bacterial infections. Production techniques were then developed to manufacture penicillin on a large scale. These methods are still being perfected. Research on Penicillium has identified the ideal conditions that allow the fungus to produce the largest quantities of penicillin. Today, penicillin is produced in enormous tanks.

But they are tough, these bacteria!
With more and more widespread use of penicillin, certain bacteria developed resistance mechanisms. Some of them are capable today of blocking the action of penicillin as well as that of several other antibiotics. Furthermore, this resistance can be transmitted between bacteria and to future generations! In order to limit the appearance of these resistant bacteria, our use of penicillin as well as that of other antibiotics must be restrained.


© Armand-Frappier Museum, 2008. All rights reserved.

Penicillium notatum

Dennis Kunkel Microscopy, Inc.

© Dennis Kunkel Microscopy, Inc.


Biological insecticides
While using chemical insecticides, humans quickly realized that it would be necessary for them to use other means to protect the environment. The use of microbes pathogenic only to insects nowadays allows for biological control, which restricts the damage caused by devastating insects without harming other organisms.

The case of the spruce budworm
The spruce budworm (SB) is a devastating insect that is very costly to the Quebec forest industry. In epidemic situations, fir and spruce trees infected by SB often die, which rapidly makes them unusable for the industry.

Microorganisms to the rescue of the vegetable kingdom
Microorganisms are widely used in agriculture and forestry. They can be used as biological insecticides, acting on insects in different ways. The bacterium Bacillus thuringiensis (B.t.) and Baculovirus infect an insect when it ingests them. Others, such as the microscopic fungi, Beauveria bassiana, deposit themselves on the insect’s carapace and infiltrate the organism. This intrusion is fatal to the ravaging insect.

Biological insecticides
While using chemical insecticides, humans quickly realized that it would be necessary for them to use other means to protect the environment. The use of microbes pathogenic only to insects nowadays allows for biological control, which restricts the damage caused by devastating insects without harming other organisms.

The case of the spruce budworm
The spruce budworm (SB) is a devastating insect that is very costly to the Quebec forest industry. In epidemic situations, fir and spruce trees infected by SB often die, which rapidly makes them unusable for the industry.

Microorganisms to the rescue of the vegetable kingdom
Microorganisms are widely used in agriculture and forestry. They can be used as biological insecticides, acting on insects in different ways. The bacterium Bacillus thuringiensis (B.t.) and Baculovirus infect an insect when it ingests them. Others, such as the microscopic fungi, Beauveria bassiana, deposit themselves on the insect’s carapace and infiltrate the organism. This intrusion is fatal to the ravaging insect.


© Armand-Frappier Museum, 2008. All rights reserved.

The microscopic fungus Beauveria bassiana clings to the insect’s carapace and infiltrates the organism to kill it.

Photo : Claude Guertin

© Claude Guertin - INRS-Institut Armand-Frappier


Learning Objectives

The learner will:
  • familiarize himself with the vocabulary used in microbiology;
  • explain the relationship between developments in imaging technology and the current understanding of the cell;
  • identify which microorganisms are infectious, how the immune system fights against them, and the reinforcements of modern medicine;
  • describe the benefits of microorganisms .

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