When Pathologists mention the word “Pseudomonas”, either orly or in written reports, one would tend to panic, owing to its extreme virulence to human health. Strains of this Gram-negative, rod-shaped bacterial species could be so potent, that they may be resistant to almost all the therapeutic strategies employed against it. P.aeruginosa is the most frequently isolated strain of Pseudomonads in the clinical laboratory, particularly in those of hospitals, as they are the number one cause of hospital-based infections, or Nosocomial Infections, this stem from the fact that it may require a simple nutritional medium for growth. It may also normally inhabit soil, water, vegetation, as well as decaying organic matter. These characteristics of Pseudomonads in general, make them opportunistic pathogens, and thus provide them with the ability to cause virulent and sometimes fatal courses of infections in humans.
Despite the overwhelmingly dangerous path certain Pseudomonads can take at 37ºC, these species have surprisingly proved to be environmentally beneficial. How could such a health-destructive microbe, have a role in the environment one might ask?
Well, interestingly, Pseudomonads, such as P.fluorescens, and which are applied to soil, can aid plants' resistance to other harmful microbes. This could be accomplished either by competing with these pathogens for nutrition, or by generating an antibiotic that would inhibit plant pathogen growth. Here, Pseudomands employed in this application could act as Bio-control agents that assist plants in surviving the wrath of plant microbes.
Another environmental role that is commonly attributed to other microbes is Bioremediation; the microbial treatment of organic contaminants in the soil and surface or subsurface waters. Pseudomonads possess the metabolic tools, such as enzymes, among other proteins, that would allow them to feed on any contamination (eg oil spills). Through this process, microbes would derive the nutrition for growth and reproduction, as wastes are digested into final metabolic products (water and carbon dioxide), thus providing the Pseudomonad with the energy to live.
Bioremediation with microbial species can occur in two manners: either in situ, having microbes injected into the location of contamination, or Ex situ, which is the process by which the contaminated area is excavated and treated in another location. In either process, Pseudomonads have the ability to digest the following organic compounds normally involved in pollution:
• Petroleum or hydrocarbon products (ie gasoline, diesel, fuel oil)
• Hazardous crude oil compounds (ie benzene, toluene, xylene, naphthalene)
• Some polynuclear aromatics
• Some pesticides (ie malathion)
• Coal compounds (ie phenols and cyanide in coal tars and coke waste)
• Some industrial solvents (ie acetone)
• Others: ethers; simple alcohol such as methanol, methylethylketone; ethylene glycol
Who knew that a pathogen as potent to humans as Pseudomonas could actually be isolated for environmental use? Whether to rescue plants from various opportunistic pathogens, or to clean spills, pollutants, and other contaminations, Pseudomonads are provided to be appropriate environmental alternatives to several techniques implemented for the same roles. I wonder what other challenges these microbes could take on. They're already surprising enough!