This summer I did some preliminary test with 4 strains (2 glycogen consumers, RL_010 and RL_011, and 2 non-consumers RL_009 and RL_026) to see whether maltose is a suitable substrate to be able to compare activity between glycogen consuming and glycogen non-consuming strains of L. crispatus. I also used this experiment to get some additional replicates for Figure 3 of the bigger June blog post (this one). Will be updating this soon. First need to repurchase a GraphPad PRISM serial code 🙁
Preliminary observations of the experiment:
-something went wrong with the dilution of the culture for strain 9 (5 times instead of 10 times diluted), so I won’t be able to use this data point.
-the 2 glycogen consuming strains show starch degrading activity in both pellets as in the supernatants, like I saw before. (could this be the S-layer effect?)
-strains grow well on maltose but the activity is still somewhat repressed (or not induced?) just like on glucose. Next step is to try this on maltotriose to see if this may be a substrate that all strains will grow on and pullulanase activity will also be present.
-suprisingly, one strain (RL_011) does seem to induce (or fails to repress) the pullulanase activity on glucose and on maltose. Is there another level of variation in this aspect?