Granite?

[cynical]

Bacillus Endospores Isolated from Granite: Close Molecular Relationships to Globally Distributed Bacillus spp. from Endolithic and Extreme Environments

Just thinking about this again. We have a lot of granite in our kitchen.

Bacteria in Your Granite Countertop

[cynical]

Blue fluorescence of endolithic Bacillus isolates. During streak purification of the 56 isolates, it was noticed that under certain lighting conditions, some of the isolates exhibited a slight bluish-green color. Upon further examination, we found that many, but not all, of the 56 isolates fluoresced blue under medium-wavelength UV light (Fig. ​(Fig.2A).2A). To our knowledge, the production of blue fluorescent compounds by Bacillus spp. has not been reported to date. In a search of the literature, we were able to find a publication describing the characterization of chlorxanthomycin, a yellow fluorescent compound, produced by a strain of Bacillus isolated from soil (28). In contrast to the yellow fluorescent compound, which is located intracellularly (28), the blue fluorescent compound from the granite isolates diffused out of the cells and accumulated in the surrounding medium (Fig. ​(Fig.2B).2B). We reasoned that production of the blue fluorescent compound could be used as a further distinguishing characteristic to group the granite isolates (Fig. ​(Fig.3).3). At this time, the identity of the blue fluorescent compound is unknown; details of its purification and characterization will be reported elsewhere.