Genomic Analysis of Vulcanisaeta thermophila Type Strain CBA1501T Isolated from Solfataric Soil

Hyperthermophilic archaea have been isolated from high-temperature environments such as geothermally heated soils, sulfur-rich hot springs, and submarine volcanic habitats; optimal growth of these organisms occurs above 80C (Stetter, 1999, 2006, 2013). The genus Vulcanisaeta belongs to the family Thermoproteaceae, order Thermoproteales, phylum Crenarchaeota, and was first proposed by Itoh et al. (2002). It currently includes 3 validly named species, that is, Vulcanisaeta distributa (Itoh et al., 2002), V. souniana (Itoh et al., 2002), and V. thermophila (Yim et al., 2015), as per the List of Prokaryotic Names with Standing in Nomenclature database (Parte, 2014). Members of the genus Vulcanisaeta are rod-shaped, anaerobic, hyperthermophilic, and acidophilic (Itoh et al., 2002). To date, 15 genomes, including two complete genomes,V. distributa and “Vulcanisaeta moutnovskia” (Mavromatis et al., 2010; Gumerov et al., 2011), have been reported for the genus Vulcanisaeta, as per the NCBI genome database (http://www.ncbi.nlm.nih.gov/genome/). Hyperthermophilic enzymes are stable and active at high temperatures of >70C (Vieille et al., 1996). These enzymes can be studied using model systems to elucidate enzyme mechanisms and evolution of proteins stable at high temperatures and to determine the higher temperature limit for enzyme stability (Vieille and Zeikus, 2001). In a previous study, V. thermophila CBA1501T (= ATCC BAA-2415T = JCM 17228T) was isolated from solfataric soil in the Republic of the Philippines (Yim et al., 2015). It was found to grow at 75–90C, pH 4.0–6.0, and 0–1.0% (w/v) NaCl, with optimal growth at 85C, pH 5.0, and 0% (w/v) NaCl. Here, a genome sequence of V. thermophila CBA1501T has been reported and information of hyperthermophilic enzymes of high biotechnological value has been provided.