On 2014 Oct 02, Morgan Price commented:

The authors predict that 36% of bacteria cannot synthesize phenylalanine, but many (most?) of these predictions are erroneous. I looked over the predictions, which were graciously provided by Dr. Kost, and noticed the following errors. First, many cyanobacteria are predicted auxotrophs (i.e., Synechococcus elongatus PCC 6301, and members of the genera Prochlorococcus, Anabaena, Cyanothece, Nostoc, and Gloeobacter) . However cyanobacteria are normally grown in a mineral medium with no organic carbon. Second, our group studies the sulfate-reducing bacteria Desulfovibrio alaskensis G20 and D. vulgaris Miyazaki F, which grow in a defined minimal medium without any amino acids, yet these are predicted to be phenylalanine auxotrophs. Third, Caulobacter crescentus CB15 is predicted to be a phenylalanine auxotroph, but it can grow at very low nutrient levels, including in defined mineral media with a small amount of sugar added.

On 2014 Oct 02, Morgan Price commented:

The authors predict that 36% of bacteria cannot synthesize phenylalanine, but many (most?) of these predictions are erroneous. I looked over the predictions, which were graciously provided by Dr. Kost, and noticed the following errors. First, many cyanobacteria are predicted auxotrophs (i.e., Synechococcus elongatus PCC 6301, and members of the genera Prochlorococcus, Anabaena, Cyanothece, Nostoc, and Gloeobacter) . However cyanobacteria are normally grown in a mineral medium with no organic carbon. Second, our group studies the sulfate-reducing bacteria Desulfovibrio alaskensis G20 and D. vulgaris Miyazaki F, which grow in a defined minimal medium without any amino acids, yet these are predicted to be phenylalanine auxotrophs. Third, Caulobacter crescentus CB15 is predicted to be a phenylalanine auxotroph, but it can grow at very low nutrient levels, including in defined mineral media with a small amount of sugar added.