Going Green

Thus far, only the static flasks that have shown the obvious change of a precipitate have been kept and transferred for iron-reducing bacteria.  Today, I happen to take a closer look at a static flask of which the contents were going to be tossed out.  The media had a slight green tint.  After comparing to a control flask, there was certainly a color difference.  !!!  Note that the media used for this experiment is a very dark red/brown color and difficult to detect slight color changes, even in 250 mL flasks.  A color change from red/brown to green is expected of the iron-reducing bacteria.  Even though the flask with the green tinted media is fairly old, an attempt to transfer any live bacteria will be made.  A larger flask will be kept, as well as capped test tubes in hopes of more readily seeing a color change occur.  Here's to hoping some bacteria are still alive...