I’m so glad that it’s the end of the week to get to catch up on some sleep. Unfortunately, I have a Monday test! I’ve given up on having a social life until after graduation. I’m excited that I’m getting to go see the movie “He’s just not that into you” tomorrow night. Any girls in the class are invited to come! We are going at 7:50 at the movie theater by the mall. The midterm is over thank goodness! I’m a little worried about getting my grade back because I was unclear on some of the questions. I hoped that I answered them pretty thoroughly. Does anybody know if microwaving was to sterilize the PCA media or was it just to dissolve the agar? I was confused on that one even though it was so simple. I hope that the study guide was helpful to everyone. I’m sorry I didn’t get it to you sooner which would have been more helpful for us all, but as most of you know my ex-boyfriend committed suicide last weekend so I didn’t get a chance to work on it.
Anyways, I’m very excited that we are really starting to work on isolates that made be species within the family Geodermatophilaceae. On Monday, we looked at our isolates (GB 11-20) which were irradiated with 5 kGy. We recorded growth and color on a spreadsheet that should be posted on airset. I’m very excited that were able to isolate some cream and pink colonies and one black from these irradiated isolates. These definitely have the potential to be Modestobacter or Blastococcus. The black colony could even possible be Geodermatophilus. I know that this question was asked in a previous blog, but is the media we are using oligotrophic or copiotrophic? I think that it would interesting to try plating some of the pink isolates on oligotrophic or copiotrophic media to look for color change since this is a characteristic of M. versicolor. A few weeks ago we noted that most of our dark pigmented strains were insoluble when inoculated in the broths. This is now more meaningful to me, because the dark pigment produced in M. versicolor is eumelanin and is insoluble in liquid. Maybe we have some of that on our hands.
DNA was extracted from Modestobacter suspects GB 2, 3, 4, 6, 8, 11-20.
We looked at the ability of our strains to hydrolyze starch via amylase by flooding the plates with iodine. The strains differed greatly in their ability to hydrolyze starch. Plates were denoted as negative, weakly positive, and positive judged on the clearing observed in the plates. Our data is recorded in a spreadsheet on airset. The image of strain 78 displays a weakly positive result, and the image of strain 60 is a negative result.
Strain 60 - starch hydrolysis - negative :
Anyways, I’m very excited that we are really starting to work on isolates that made be species within the family Geodermatophilaceae. On Monday, we looked at our isolates (GB 11-20) which were irradiated with 5 kGy. We recorded growth and color on a spreadsheet that should be posted on airset. I’m very excited that were able to isolate some cream and pink colonies and one black from these irradiated isolates. These definitely have the potential to be Modestobacter or Blastococcus. The black colony could even possible be Geodermatophilus. I know that this question was asked in a previous blog, but is the media we are using oligotrophic or copiotrophic? I think that it would interesting to try plating some of the pink isolates on oligotrophic or copiotrophic media to look for color change since this is a characteristic of M. versicolor. A few weeks ago we noted that most of our dark pigmented strains were insoluble when inoculated in the broths. This is now more meaningful to me, because the dark pigment produced in M. versicolor is eumelanin and is insoluble in liquid. Maybe we have some of that on our hands.
DNA was extracted from Modestobacter suspects GB 2, 3, 4, 6, 8, 11-20.
We also looked at the growth of the plates of the strains that were irradiated at 0, 3, 6, and 16 kGy. I’m also excited about a black colony that was formed from strain 54 on 0, 3, and 6 kGy. A pink colony was formed from 57 at 0, 3, and 6 kGy. This is definitely a potential strain of Modestobacter. On the 0 kGy the black colony from 54 was accompanied with yellow contamination. We are going to try irradiating the samples at 9-10 kGy sometime in the near future. This will give us a better radiation resistance range for those strains that grew when dosed with 6 kGy and did not grow at 16 kGy. None of our 26 strains grew after receiving a dose of 16 kGy.
Strains after exposure to 0kGy:
Strains after exposure to 3kGy:
Strains after exposure to 6kGy:
Strains after exposure to 6kGy:Strains after exposure to 16kGy:
We looked at the ability of our strains to hydrolyze starch via amylase by flooding the plates with iodine. The strains differed greatly in their ability to hydrolyze starch. Plates were denoted as negative, weakly positive, and positive judged on the clearing observed in the plates. Our data is recorded in a spreadsheet on airset. The image of strain 78 displays a weakly positive result, and the image of strain 60 is a negative result. Strain 78 - starch hydrolysis - weak :
Strain 60 - starch hydrolysis - negative :Strain 66 was contaminated and was restreaked. We will test for its ability to hydrolyze starch next week.
We have solved the great strain 56 anomaly. In contrast to our original finding which is recorded on the first spreadsheet we ever did that denotes which media each strain grows best one, strain 56 grows best on PCA rather than on MA.
On Wednesday we took the midterm which I hope I did well on and prepared the pH plates. The various pH we are using are pH 4-10. We put 6 strains per plate. The solutions containing the strains were vortexed and 10 ul of each was put on each pH plate.
We have solved the great strain 56 anomaly. In contrast to our original finding which is recorded on the first spreadsheet we ever did that denotes which media each strain grows best one, strain 56 grows best on PCA rather than on MA.
On Wednesday we took the midterm which I hope I did well on and prepared the pH plates. The various pH we are using are pH 4-10. We put 6 strains per plate. The solutions containing the strains were vortexed and 10 ul of each was put on each pH plate.
I talked to Dr. Rainey this morning about the question I proposed about our media as to whether it was copiotrophic or oligotrophic. He said that the majority of our media with the exception of 1/100 PCA could be argued to be copiotrophic. Next week I hope to have some time and streak some of the pink and beige colonies that grow on media other than 1/100 PCA on some oligotrophic media with a sufficient nitrogen source and see if any eumelanin (the dark black/brown pigment produced by M. versicolor) is produced.
ReplyDeletegood idea cristi
ReplyDeleteno...i think autoclaving it was used for sterilization
ReplyDeleteautoclaving was used for sterilization - microwaving to dissolve the agar.....
ReplyDeletedang thats what i thout, but can't microwaving sterilize things too. I know that I microwave my dish sponges to clean them! Maybe some partial credit?
ReplyDeletehaha I have never heard of that
ReplyDeleteDr. Hale-Donze always says to microwave dish sponges or put them in the dishwasher, so I guess it does clean them. unless shes lying.
ReplyDelete