Monday we spot plated our isolates on carbohydrate utilization media which took the majority of the class period. We also began a 4oC temperature test any isolate that grew at 10oC was plated and put in the 4oC cold room. Any isolates that had become contaminated over time were also streaked onto new stock plates. The carbohydrate utilization media contains only inorganic nutrients, chemicals the cell can’t make on its own like certain vitamins and a single carbon source. The inorganic nutrients and unmakeable chemicals were provided in the media’s Yeast Extract component. Calcium Carbonate was also added this was to absorb any acid that was made in the carbohydrate utilization process. A clearing around the cell mass will be seen if acid was actually produced. Salt was added to the media because some of our organisms grow best on MA and require at least a little salt and all of the organisms will tolerate a little salt. Finally a carbohydrate was added as a carbon source. Taking all this into consideration the Final Media consisted of .25% Yeast Extract .5% CaCO3, 1%NaCl and 1g/L carbohydrate. The media is a modified version that Leudemann used in his paper “Geodermatophilus, a New Genus of Dermatophilaceae ( Actinomycetales)”. 16 carbohydrates and 1 control were tested this day. Results will give a large amount of data to be used further our knowledge about these isolates.
Wednesday was a busy day we extracted DNA from organisms that lived in Soil Samples. The Soil was taken from the same location that our previous Soil experiments was taken from in my case it is sample N97 which is from Nevada. The extraction process was performed with a 10g sample of soil and was fairly similar to the process of DNA extraction from cells. Before we began extracting DNA we graded our pH test that was started after the midterm examination. All already described species have a wide range of possible pHs they grow at. This experiment can help us further align our isolates with which described species it best resembles. The majority of my group’s results showed a decent growth from ph6-10 with a few exceptions. These exceptions are not surprising in that they could be one of the Modestobacter sp. that have a range of pH 3-12. A color change at higher pH occurred usually around pH 9 and maintaining through pH 10. There was one exception which is shown in the provided pictures and that was isolate number 7 it usually has a dark orangey center with a light cream to pinkish ring around the outside and as the pH increased the pinkish ring got small and the orangey middle got darker, but at pH 9 it changed to just the cream pink color and reverted back to the orange and pink morphology at pH 10. As one can see in the pH6 photo this isolate seems to have a mixture of colony colors the pink and orange so the normal morphology is not a far stretch of the imagination. However, what would be the reason for only the growth of one colony morphology between pHs.
I would like to thank Cristi for her help in jogging my memory about Monday.
Wednesday was a busy day we extracted DNA from organisms that lived in Soil Samples. The Soil was taken from the same location that our previous Soil experiments was taken from in my case it is sample N97 which is from Nevada. The extraction process was performed with a 10g sample of soil and was fairly similar to the process of DNA extraction from cells. Before we began extracting DNA we graded our pH test that was started after the midterm examination. All already described species have a wide range of possible pHs they grow at. This experiment can help us further align our isolates with which described species it best resembles. The majority of my group’s results showed a decent growth from ph6-10 with a few exceptions. These exceptions are not surprising in that they could be one of the Modestobacter sp. that have a range of pH 3-12. A color change at higher pH occurred usually around pH 9 and maintaining through pH 10. There was one exception which is shown in the provided pictures and that was isolate number 7 it usually has a dark orangey center with a light cream to pinkish ring around the outside and as the pH increased the pinkish ring got small and the orangey middle got darker, but at pH 9 it changed to just the cream pink color and reverted back to the orange and pink morphology at pH 10. As one can see in the pH6 photo this isolate seems to have a mixture of colony colors the pink and orange so the normal morphology is not a far stretch of the imagination. However, what would be the reason for only the growth of one colony morphology between pHs.
I would like to thank Cristi for her help in jogging my memory about Monday.
pH4 no growth
pH5 no growth
pH6 growth notice the two colony morphologies of isolate 7 
pH7 decent growth 
pH8 decent growth 
pH9 notice color change of isolate 7 
pH10 again color change of isolate 7
in reference to that lighter colored ring around the colony you were talking about which im pretty sure we had more than one case of, do yall think it is similar to the ring around the colony in crisiti's blog?? and why are we only seeing them on pH plates???
ReplyDeleteYour welcome! It may be similar but at lower pHs 69 had a greenish color. Maybe a certain pigment is activated by different pHs and inhibited by others. Just a thought!
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