The tale of the blue soy products – from contaminated soy milk to a new publication

A new paper is out from my lab. This one is a remarkable story of work by PhD Student Marina E. De León (

It started with her pouring out some soy milk from her fridge that was blue.

See her Tweet about this here:

And then she isolated bacteria from the soy milk and from some blue tofu in her fridge, identified them, did experiments to see if these isolated bacteria could cause soy milk to turn blue, found some that did, sequenced their genomes, and analyzed them to show that these ones had similar properties to other bacteria known to cause blue discoloration of food products. A truly remarkable piece of work.

See the paper here: “Draft Genome Sequences and Genomic Analysis for Pigment Production in Bacteria Isolated from Blue Discolored Soymilk and Tofu

And thanks to Guillaume Jospin and Harriet Wilson who helped with the work and all the people in my lab and via social media that encouraged and supported Marina along the way.

And see also: