The future

Hopefully you will now appreciate the potential the fungi offer in bioremedial technologies.  This can be improved upon in many ways, obviously further research is needed in situ and in the laboratory. It is clear that for future bioremediation research, fungi seem to have to edge over bacteria.

 

This can be attributed to several different reasons:

  • Fungal tolerance: they are able to withstand a wide range of environmental conditions, including oxygen availability, temperature range and pH.  Their tolerance to highly toxic conditions is far greater than bacteria, and so fungi are able to survive in high concentrations of pollutants in contrast to most bacteria.

  • Their mode of growth, which is by growing filamentous hyphae, extends the surface area available for transformation and allows fungi to invasively explore the polluted substratum. Bacteria, being single celled organisms, do not have these capabilities.

  • Fungi degrade a wider range of xenobiotics than bacteria.

  • Their principle nutrient source ( lignocellulose) is inexpensive and abundant.

  • Fungi do not have to be preconditioned or treated to survive in situ, unlike many bacteria.

  • Their method of chemical transformation is non-specific allowing the degradation of a mixture of organopollutants in soil, which is what is likely to be found in the environment.

However we should not rule out bacterial bioremediation as there is potential for systems that use both fungi and bacteria for synergistic chemical transformation. 

 

There are also problems to overcome, such as providing sufficient biomass of fungi for efficient removal of organopollutants.  Also, a way of controlling competition from indigenous populations of bacteria and other microorganisms in the soil would improve the biodegrading ability of the fungal inoculant.

 

Future research could also look into different aspects, including genetics, isolation of fungal enzymes, and possible discovery of new fungi with better degradative properties.

 

Genetic analysis of the processes involved in ligninolytic enzymes could shed light on why certain enzymes are produced, by which type of fungi, and at what stage. Also there are genetic engineering possibilities, such as transferring the ligninolytic enzymes from one fungus to another fungus which has a higher tolerance for toxic soil, essentially making a super-bioremedial fungus. 

 

If the enzymes were isolated efficiently, they could perhaps be used by themselves in sites where it is too toxic for any organism to prosper.

 

Then there is the untapped potential of the undiscovered fungi around the world.  As it is estimated that there are over 1.5 million species, of which only 98,000 have been identified so far, the chances are that there are fungi out there deep in rainforests which have a far greater ligninolytic system and would be even more useful to bioremediation research.

Further information about bioremediation can be found in the new textbook 21st Century Guidebook to Fungi by David Moore, Geoffrey D. Robson & Anthony P.J. Trinci. Published 2011 by Cambridge University Press: ISBN: 9780521186957. URL: ttp://www.cambridge.org/gb/knowledge/isbn/item6026594/?site_locale=en_GB. View Amazon page.

Updated December 15, 2016