Biofilms are the main platform of growth for bacteria in many environments. In the marine environment biofilms include the pioneer micro-organisms that attract other larger and more troublesome organisms to congregate, also know as biofouling communities. Hence being a Marine Biology student I am naturally interested in biofilms. However biofilms are also prevalent in the terrestrial world, and have a huge impact on human health, so the prevention and treatment of biofilm formation is very important. Marine bacteria produce several compounds which may be of biotechnological interest, and in particular, culture supernatants derived from most of them have been shown to exhibit anti- biofilm activity. In this study Pseudoalteromonas haloplanktis TAC125, a marine bacteria from the Antarctic, is shown to contain anti- biofilm molecules which prevents the adherence of Staphylococcus epidermidis, which is the main micro-oganism responsible for chronic graft infections.
Methods
In this study the anti-biofilm activities of two P. haloplanktis supernatants were obtained from a Brain Heart Infusion Broth cultured from a P. haloplanktis biofilm. The SN4B supernatant was grown and obtained from a static medium and a SN4A supernatant was grown and obtained from a dynamic medium. The formation of S. epidermisis and Staphylococcal aureus biofilms when subject to the two supernatants were then evaluated using crystal violet stains and bioassays. To gain information on the biofilm- inhibiting compound, the heat sensitivity and Proteinase K affects of the antifouling properties were also examined
and compared using a microtier plate assay against S epidermidis.Results and Discussion
Results obtained showed that only the SN4B supernatant had an anti- biofilm affect by decreasing the attachment of S. epidermisis and but not S. aureus. The SN4B supernatant was from a static growth medium, thus the active compounds could be produced by the planktonic cells stimulated by the oxygen limitation since the bacteria are grown without shaking. The anti-biofilm affect was very species specific, not affecting other tested Staphylococcus species, and highly dependent on what dilution of SN4B was introduced to S. epidermisis. The anti- biofilm action was not restricted to just initial bacterial attachment on an abiotic surface but was also effective on mature S. epidermidis biofilms, suggesting that the anti- biofilm compound could act as a signal rather than a surfactant. The effectiveness of SN4B was not decreased when subject to 50° C heat, and Proteinase K treatment didn't affect inhibiting activity either.
My View
This study proves that P. haloplanktis is of high importance to decrease chronic graft infections, which is a fantastic discovery but is it very specific. I was hoping to find that the study would open up and discuss a wide array of uses for marine bacterial anti- biofilm properties, but nothing was mentioned. I felt all tests were very relevant to the study, such as the heat test as it showed P. haloplanktis can withstand high temperatures even if it is originally found in a polar region, showing its world wide importance. But did not feel the authors explained the relevance of the Proteinase K test.
This study provided great insight and development of new and very important science. The identification of the active molecules in the SN4B supernatant could lead a wider understanding of the potential of the use of bacterial compounds to reduce dangerous and troublesome biofilms across the globe. I feel polar oceans contain such a huge reservoir of microbe biodiversity, which may in the future lead to new biotechnologies, and this study is a great example of that.
Papa, Rosanna, et al. "Anti-biofilm
activity of the Antarctic marine bacterium< i> Pseudoalteromonas
haloplanktis</i> TAC125." Research in microbiology 164.5
(2013): 450-456.
Available at: http://www.sciencedirect.com/science/article/pii/S0923250813000119
Hi Elyssa
ReplyDeleteThanks for posting such an interesting paper. I am also a big fan of biofilms. Indeed, this research will have massive implications on biofouling and health care, both of which have large economic costs associated with the effects of biofilm formation. Apologies for a silly question but what is the Proteinase K test that you mentioned or did the paper not explain what this was? (it sounds familiar, I just can't think what it shows!)
Thanks
Anita H
Hi Anita,
ReplyDeleteYes, I agree there is a lot of potential in this research, and there doesn't seem to be a lot anywhere. One of my favourite papers, which you must read is- Shimeta, Jeff, et al. "Influences of biofilm-associated ciliates on the settlement of marine invertebrate larvae." Marine Ecology Progress Series 449 (2012): 1-12. It is so interesting that the use of ciliates can be used to control biofouling communities. I wonder what scale this could be taken to?
That is definitely not a silly question, I didn't really get the gist of it from the paper, have a read and let me know if you come to any conclusions. My only guess is that it is an enzyme, and it may have been used to see if it broke down the SN4B? And it didn't break it down so that shows that it is even more effective.
Let me know!
Elyssa
Ok thanks Elyssa and I'll look up that paper you suggested as well
DeleteAnita
Hay, had a flick through the paper to find out about protinase K. Protinase K itself is an enzyme which is used to breakdown other proteins. From reading it looks like protinase K was used to see if the anti-biofilm agents in the supernatant were protein based. Treating it with protinase k did not affect its ability to inhibit biofilm formation, therefore it wasent a protein. They then showed with another test that the anti-biofilm agents were probably polysaccharides. Hope that helps :)
DeleteThanks Tom, that clarifies things for me now :)
DeleteInteresting stuff! I think the most interesting aspect is that it the effect so species specific. A lot of organisms form biofilms in our body's and not all of them are harmful to us, so if you were to treat people with anti-biofilm agents which hit a wide range of bacteria you would imagine it would have additional complications for a persons health. So being able to target one specific bacteria looks like it could be really useful for medicine. But yea not useful for application where a broad spectrum is required, like anti-fouling.
ReplyDeleteHi Tom,
ReplyDeleteThankyou for clearing up the Protinase K, similar to what I thought, but much much better explained! Yes and you are right, as it is so specific, using it for medical problems is perfect as it will only target one biofilm. Hopefully some research will be done to control biofouling in a more environmentally friendly manner, similar to what I have done for my dissertation but using microbiology. Masters research maybe! Thanks
Thanks to Tom for clarifiying the proteinase K - it's a widely used heat-stable proteinase, which tells us that the compound isn't proteinaceous. The authors did some other test that suggested the compound is a polysaccharide. The authors make some interesting suggestions as to how this might inhibit or detabilise the biofilm.
ReplyDeleteLeading on from Tom's point, the use of a species specific anti-biofilm compounds may be of great beneficial value. As mentioned in the paper this work is focused on reducing virulence rather than growth, there is potential that this method may have a weaker selective pressure on antibiotic resistance relative to current antibiotics. If this theory holds up this could help decrease the amount of antibiotic resistant bacteria and the detrimental impacts they bring to both health and the economy.
ReplyDelete