Thanks to Magnus Ivarsson for his contribution!
Microbe of the episode: Streptomyces griseosporeus
- Ivarsson M, Skogby H, Phichaikamjornwut B, Bengtson S, Siljeström S, Ounchanum P, Boonsoong A, Kruachanta M, Marone F, Belivanova V, Holmström S. 2018. Intricate tunnels in garnets from soils and river sediments in Thailand – Possible endolithic microborings. PLOS ONE 13:e0200351.
Other interesting stories
- Swimming algae can move through bloodstream to deliver drugs
- Mosquito microbes engineered to inhibit spread of malaria (paper)
- A probiotic inhibits a pathogen by interfering with its signaling between cells
- Healthy microbiota seems important for mice recovering from heart attack
Episode outlineBackground: Caves actually nice place to live
- Durable, well-conditioned, stylish
- Not necessarily roomy or bright or easy to furnish
- Endoliths – microbes living in substrate like rock, or shells, corals, or wood
- Often chemolithotrophs, eating minerals, but sometimes heterotrophs or photoauto
- Usually chemical, like acid or chelators; also some force involved, if filamentous
- Harder substrates usually have less deep excavations
The press release says this is a finding about boring microorganisms, but I think they're actually quite interesting!
Methods: Here's Dr. Ivarsson describing the study: "Our study is on complex networks of microsized tunnels in garnets found all over Thailand. We find them in river sediments, soils, etc. We believe the tunnels were formed by microbial dissolution, most probably by fungi; they are the only type of microbe that can produce these sort of very complex mycelium-like networks."
Microscopic, mineral, and chemical analyses
- Not conclusive evidence that tunnels caused by living thing, but suggestive
- Some have red filamentous structures inside
- And fatty acids of various compositions found inside
- Could have come in from outside, but none found on outside
Next important questions: how could they bore through such hard mineral? And why?
- Iron available in garnets could be useful
Sometimes microbes chewing stuff makes it more valuable, like yeast and grapes
- Other times, not so much!