Читать книгу EXTREMOPHILES as Astrobiological Models - Группа авторов - Страница 25

Steam deposit samples from Hawai’i H1 nonsulfur cave were collected by scraping lightly along the inside of the steam cave ceiling. Lava presents a hard surface that cannot be penetrated with a slight 50 mL polypropylene collection tube scraping able to collect steam deposits. We used an adjacent nonfumarolic, ambient temperature lava cave and performed an identical collection procedure with scraping-tube collection used for the steam cave. The other soft surfaces of Lassen nonsulfur cave SW1 and SW2 sulfur cave and Hawai’i H5 salt cave were shallow samplings only a few mm of thick deposits and did not include material other than from the nonsulfur steam deposits, salt deposits or sulfur sublimates. Steam deposit controls were analyzed and evaluated along with the collected steam cave/ vent samples, as described above for PCR, DAPI microscopy and thermophile culture and were negative. We are currently expanding our controls in several ways to evaluate the contribution growing cells might make to the chemical profile from EDX analysis.

Figure 1.3 Steam caves/vents spectra: (a) Hawai’i H1 nonsulfur cave. (b) Lassen nonsulfur cave SW1. (c) Lassen iron vent SW4. (Image credit: the authors).