Week 4: A Waiting Game

     My fourth week at CMOP consisted mostly of me monitoring the subcultures from Roberto’s PC2 experiment from April, waiting eagerly for them to oxidize. With the Halomonas LOB-5 it's been the same story, waiting to see manganese oxidation, waiting to see the colonies turn orange or brown. I did look at a handful of the cultures under a microscope, mostly the RA26A subcultures, and determined that within those there are at least two different types of cells, one that is motile and another that isn't.
     My logbook is now brimming with charts full of varying amounts of plusses--signifying the very approximate degree to which a particular culture had grown--and I eventually decided to stop recording their growth, once all of them were thick enough. As it turns out, Roberto can tell that I'm impatient as well. About once a day I ask him to have a look at a culture that I think has start to oxidize, only for him to tell me that "it's probably just pigment," or "it's not obvious enough to test." However, he did humor me a couple times and I tested colonies with LBB, only for them to come up negative each time.
     On Friday, I checked the primary subcultures and was overjoyed to see little yellow colonies growing amongst the other types on the plate. I even photographed them at every semi-important angle I could think of. To my dismay, however, the LBB didn't show the slightest amount of blue, only a bit of yellow from the gregarious number of cells that I mixed in. Also on Friday, we decided that we'd had enough of waiting for the LOB-5 to oxidize manganese and that it was time to try to go for iron oxidation. So, we made up some tubes with opposite iron and oxygen gradients, so that the iron would not abiotically oxidize, and stabbed the media with pickfuls of LOB-5 just before leaving for the day.