By Terry Taylor
Originally published in BC Nature, Summer 2016, Vol. 54 No. 2
If you go to your favourite field or forest and decide to make a species list of everything you see – birds, insects, plants, mosses, mushrooms, etc., you will only have a list of a small percentage of what is actually living there. It is estimated that one half of the world’s biomass is microscopic organisms. In terrestrial areas most of these organisms are living in the soil. Molecular research has shown that a handful of fertile soil contains at least 10,000 different kinds of bacteria! Bergey’s Manual, a compendium that lists all the described species of bacteria contains about 5,000 species. In other words, most of the bacteria surrounding us is either unknown or known only from its genetic signature.
This soil environment is still essentially a mystery and contains by far the most important reservoir for potential medically active compounds. Two-thirds of our antibiotics are derived from soil bacteria and it is becoming imperative to discover new ones.
One chemical that could become an important anti-cancer agent was discovered by a UBC research project in 2003. It is uncialamycin, named for the lichen Cladonia uncialis. It is produced by a soil bacterium in the genus Streptomyces. But why is it named for a lichen? Because it was found on the surface of this lichen growing on a rock bluff. This group of bacteria produces a large number of different antibiotics. Streptomycin is one of them.
It takes many years to take a potential medicine from the discovery stage to the production stage. Uncialamycin is extremely poisonous, but is produced in extremely small amounts. It readily destroys any DNA it contacts. At the time of discovery its potential value was very theoretical. That, however, was 13 years ago and medical research has changed this outlook. Uncialamycin has been successfully synthesized and a research team at Rice University in Texas has been able to produce it in quantities that may make it available at a future date as a chemotherapy agent. This research is aimed at the possibility of attaching uncialamycin to antibodies specific to cancer cells.
This same UBC laboratory was recently in the news for another potential medication from the earth. It is a clay from the north coast, and has been used for generations by the Heiltsuk First Nation to treat skin infections. A sample of this clay was tested, with surprising results. It killed cultures of infective bacteria that produce skin infections that are very difficult to treat. At the present time nobody knows what the active components of this clay or their mode of action.
Once a promising compound is discovered other possibilities also open up. Many medicines are synthetically produced, but are modifications of compounds produced in nature. By studying the DNA of pathogenic bacteria, molecular biologists can sometimes ascertain the genes that produce that pathogenicity. The chemists may then be able to modify the structure of naturally occurring medicines to make them more effective.
We conserve natural areas to protect what we know, but it is also important to protect what we do not know. As has been said there are things we don’t know we don’t know, and it is from these things that the future is built. Old-growth forests are protected for the ancient trees, but these trees are what we perceive at our level of awareness. It may be that the more important reason to protect the remaining old growth is not the trees, but the ancient soils produced by the ancient trees. They harbour the biodiversity.
If you go to your favourite field or forest and decide to make a species list of everything you see – birds, insects, plants, mosses, mushrooms, etc., you will only have a list of a small percentage of what is actually living there. It is estimated that one half of the world’s biomass is microscopic organisms. In terrestrial areas most of these organisms are living in the soil. Molecular research has shown that a handful of fertile soil contains at least 10,000 different kinds of bacteria! Bergey’s Manual, a compendium that lists all the described species of bacteria contains about 5,000 species. In other words, most of the bacteria surrounding us is either unknown or known only from its genetic signature.
This soil environment is still essentially a mystery and contains by far the most important reservoir for potential medically active compounds. Two-thirds of our antibiotics are derived from soil bacteria and it is becoming imperative to discover new ones.
One chemical that could become an important anti-cancer agent was discovered by a UBC research project in 2003. It is uncialamycin, named for the lichen Cladonia uncialis. It is produced by a soil bacterium in the genus Streptomyces. But why is it named for a lichen? Because it was found on the surface of this lichen growing on a rock bluff. This group of bacteria produces a large number of different antibiotics. Streptomycin is one of them.
It takes many years to take a potential medicine from the discovery stage to the production stage. Uncialamycin is extremely poisonous, but is produced in extremely small amounts. It readily destroys any DNA it contacts. At the time of discovery its potential value was very theoretical. That, however, was 13 years ago and medical research has changed this outlook. Uncialamycin has been successfully synthesized and a research team at Rice University in Texas has been able to produce it in quantities that may make it available at a future date as a chemotherapy agent. This research is aimed at the possibility of attaching uncialamycin to antibodies specific to cancer cells.
This same UBC laboratory was recently in the news for another potential medication from the earth. It is a clay from the north coast, and has been used for generations by the Heiltsuk First Nation to treat skin infections. A sample of this clay was tested, with surprising results. It killed cultures of infective bacteria that produce skin infections that are very difficult to treat. At the present time nobody knows what the active components of this clay or their mode of action.
Once a promising compound is discovered other possibilities also open up. Many medicines are synthetically produced, but are modifications of compounds produced in nature. By studying the DNA of pathogenic bacteria, molecular biologists can sometimes ascertain the genes that produce that pathogenicity. The chemists may then be able to modify the structure of naturally occurring medicines to make them more effective.
We conserve natural areas to protect what we know, but it is also important to protect what we do not know. As has been said there are things we don’t know we don’t know, and it is from these things that the future is built. Old-growth forests are protected for the ancient trees, but these trees are what we perceive at our level of awareness. It may be that the more important reason to protect the remaining old growth is not the trees, but the ancient soils produced by the ancient trees. They harbour the biodiversity.