Using Microbial Warfare for GoodSeptember 30th, 2011 by Jeremy E. Ellis Ph.D.
Typically the industrial sector has focused on mechanical, chemical, or engineering methods to solve production problems; however, biology is a potent tool that is often overlooked. The term “fighting fire with fire” is often relevant in systems that use biological processes, especially those that have industrial importance. In fact, the antibiotic revolution (widespread medical use of antibiotics to save individuals from life threatening bacterial infections) is ultimately a hijacking of microbial warfare for our own use. Plants, fungi, and bacteria often produce compounds that inhibit or outright kill competing or pathogenic organisms. Sir Alexander Flemming discovered the first antibiotic, pennicillin, in 1929 whereby a fungi, Penicillium, inhibited the growth of Staphylococcus, a medically important group of bacteria. As technology advances and our understanding of biology increases the sophistication and specificity of such biologically informed solutions continues to improve. Current studies in the complexity of mixed microbial communities have shed much light on the use of species and class specific inhibitory or stimulatory compounds .
Of particular interest is the targeted use of viruses in biotechnology. Phages, viruses that specifically infect bacteria, have been long studied and have previously been considered as potential therapeutic agents against bacterial infection. The use of viruses to treat bacterial infections is called Phage Therapy . These concepts are now starting to yield testable and promising agents. A UK based company is now applying Phage Therapy that targets MRSA (methicillin-resistant Staphylococcus aureus) that has become an increasing concern in human medicine . Even now the FDA is reviewing a bacteriophage for use in soft cheeses that targets the dangerous Listeria bacteria . Lastly, a poxvirus may even hold a breakthrough in the treatment of cancer !
So, how does the “fighting fire with fire” concept apply to Aquaculture? In the future, concepts such as this will likely assist in the control of many diseases that plague the industry. Of note is the recent study that demonstrates when several Bacillus species isolated from the guts of healthy L. vannamei are added to the water individually or in combination with other Bacillus species can actually provide a protective effect against several Vibrio species (a significant problem faced by shrimp farmers) . So much so, that the “probiotic” effect appears to be superior to some commercial shrimp probiotics and the use of an antibiotic that is commonly used in aquaculture! The mechanism of the observed protective effect is not known, although it is not hard to imagine that the Bacillus could be indirectly competing for physical space with the Vibrio or that Bacillus produces a compound that represses or inhibits the pathogenicity or growth of Vibrio species.
The future and efficiency of the aquaculture industry depends on the successful implmenetation of this and related biological principles. Can you think of other ways to pit microbes against one another to our benefit?