Materials and Procedures:
Viruses from Sulfolobus and close relatives—The following
methods are basically method “A” of Zillig et al. (1994) and
were described recently in detail by Prangishvili (2006). These
methods consist of enrichment cultures followed by host isolation
and screening for virus production in both these isolates
and enrichment cultures. These techniques are very similar
to those used for bacteriophages, with the major exception
being the extreme growth conditions (80°C, pH 3).
Preparation of anaerobic tubes for sample transport—For each
sample to be collected, one anaerobic collection vessel (Fig. 1A
inset) is prepared. A small amount (ca. 50–220 mg) of elemental
sulfur (e.g., Riedel-deHaën) is placed in an anaerobic tube,
and 0.1 mL of a 2% resazurin solution and 0.1 mL of water saturated
with H2S are added (a fresh Na2S solution can also be