This week was very productive and fun!

On Monday, we started our carbon utilization tests (using 16 different carbon sources and a control). Each type of plate started with a basal (or is it basic?) medium which contains yeast extract, calcium carbonate, and 1% NaCl. The salt was added since some strains grow best on MA and all strains grew on the 1% salt plates. To this basal medium a carbon source was added (1 g/L). We are hoping that we will find more growth on media with a carbon source than on the basal medium (which does not contain a carbon source). Does this mean that organisms growing on the basal medium are autotrophs? Anyway, we spotted 10 uL of sample on each type of plate (17 types of plates). We put 6 samples on each plate. Before we used the sample, it was washed with saline to remove other carbon sources. Also, we restreaked strains that grew at 10C onto new plates and incubated them at 4C. Surprisingly, most of our strains (21 out of 26) grew at 10C. This was surprising to me since the optimum temperatures for Geodermatophilus, Blastococcus, and Modestobacter species is around 25-30C.On Wednesday, we analyzed our pH experiment plates and recorded their growth in a spread sheet. Very few of our strains grew at 4 and 5 pH, but most grew at 9-10 pH…this shows that our strains prefer more basic pH rather than a more acidic pH. We also extracted DNA from our Gobi soil sample on Wednesday. We followed the protocol given by the MoBio kit. This procedure took a long time, but it wasn’t bad since we had YUMMY donuts and got to socialize :-) . Hopefully, we performed a good DNA extraction.

Below you can see a picture of our suspected M. versicolor strain! We love this strain! It seems to change color in the media from coral to green/black and we think this is because it may be running out of nutrients (since this species is coral on nutrient rich media but black/green/brown on low nutrient media)! This is a picture from our pH 7 plate (strain 69 is in bottom right corner):