01/22/14

It’s known that a tip-high gradient of Ca2+ plays a regulatory role in mycelial tip growth in fungi and so I wondered whether potassium would have the same direct results. Unfortunately, as stated in my previous blog post, I found that this was not the case—either because something went wrong during the process of my experiment or whether there is a scientific explanation. As I had predicted after seeing my results, according to “The Effect of Cations on the Growth of Fungi” by E.B.G. Jones and D.H. Jennings, “Sodium stimulates dry weight production at low concentrations but inhibits is at high concentrations.” This statement fits very well with my results as the set of plates that was inserted with a low concentration of potassium bicarbonate exhibited some growth as compared to the plate that was given an excess of the very cation. Consequently, in my opinion, it seems that the reason the set of plates with the greater amount of potassium bicarbonate did not grow at all is because if I had inserted too much of the substance into my agar mix.

While researching for this very explanation, I came across several other published papers concerning potassium bicarbonate and mycelium. More-so-than serving as a growth stimulator like Ca2+, it seems to be that KHCO3 is a very effective natural fungicide. It has been found that increased concentrations of potassium bicarbonate (KHCO3) can act as an alternative to synthetic fungicides. Thus, it was concluded that potassium bicarbonate was an alternative chemical agent for controlling in particular, a natural antagonist: R. solani AG 4 HG-I and S. sclerotiorum.

If I were a researcher at Ecovative that had the goal of researching about potassium bicarbonate and mycelium growth, I would continue to experiment with these two substances, trying to find the ideal percentage of the cation. This is what many scientists like my mentor do, in hopes of bettering their mushroom product for their consumers. However, I do not believe I will be continuing on with this project as my mentor has notified me that mold had started to form on the different plates as a result of my long stay away from the lab.

01/15/14: A New Year @ Ecovative!

This week, I went into Evocative and as usual continued to experiment on my own experiment. For those who do not remember what this was about, the purpose of this experiment is to determine the effect of potassium bicarbonate on the growth rate of the mycelium in plated agar culture. During my last visit, I made 3 sets of plates: one set was made with a high concentration of Potassium Bicarbonate (17.6 g/L), one was made with a low concentration of Potassium Bicarbonate (1.76 g/L) , and a control set (made with your every-day Potato Glucose Agar [PGA]). Thus, all combined, I made a total of 24 plates.

Upon measuring the plates, I have found that the mycelium placed within a medium made with a high concentration did not grow at all. In addition, I was also shocked to find that the mycelium placed within the control agar plates, in general, grew the most. Those in low concentration did how, but only ever so slightly. An added observation that I noted was that there was no mold on any of the plates—thus, I knew my results were not the effect of contamination. This made me come to the conclusion that it is highly possible that the amount of high concentration I used (17.6 g/L) inhibited the mycelium from growing at all. As of now, I do not have a clear reason why this is so and consequently, this calls for more research on my part which I am also excited about! I really love unexpected results like these and rather than being disappointed at my results, this unanticipated outcome is one of the very reasons why I love science and it’s factor of the unknown J!!

Starting from the top down and in the picture in the left (and from left to right in the picture above) are 2 high concentration, low concentration, and control plates.

Although due to the condensation that formed inside the plates the growth is not that visible, the results, as mentioned in my post were very surprising!