Novel Archaea and Bacteria Dominate Stable Microbial Communities in North America’s Largest Hot Spring

Abstract

Boiling Springs Lake is an approximately 12,000 m(2), 55 degrees C, pH 2 thermal feature located in Lassen Volcanic National Park in northern California, USA. We assessed the microbial diversity in the lake by analyzing approximately 500 sequences from clone libraries constructed using three different primer sets targeted at 16S rRNA genes and one targeted at 18S rRNA genes. We assessed the stability of the microbial community by constructing terminal restriction fragment length polymorphism (T-RFLP) profiles using DNA extracts collected in four separate years over a 7-year period. The four most prevalent phylotypes in the clone libraries shared an average approximately 85% sequence identity with their closest cultured relatives, and three fourths of the prokaryotic sequences shared less than 91% identity. Phylogenetic analyses revealed novel lineages devoid of cultivated representatives in the Bacterial and Archaeal domains. Many detected phylotypes were related to taxonomically diverse genera previously associated with high-temperature environments, while others were related to diverse Proteobacteria and Firmicutes that would not be expected to grow within BSL conditions. All of the 18S rRNA sequences most closely matched fungi in the phyla Ascomycota and Basidiomycota (91-99% identity). T-RFLP detected fragments corresponding to the most prevalent phylotypes detected in 16S rRNA gene libraries. The T-RFLPs from separate years were similar, and the water-derived T-RFLPs were similar to the sediment-derived (average pairwise Sorenson's similarity index of 0.74, and 0.78, respectively). Collectively, these results indicate that a stable community of diverse novel microorganisms exists in Boiling Springs Lake.

Microbial Community Structures of Novel Icelandic Hot Spring Systems Revealed by PhyloChip G3 Analysis

“…As documented previously in Thailand's Bor Khlueng neutral pH hot spring systems (50-57°C), members of major phyla were well represented in the P1, P2, and P3 samples (Kanokratana et al, 2004). Similarly, bacteria of high abundance (Aquificales, Nitrospira, and Thermodesulfobacterium) detected during this study were also shown to be major constituents in nearby sulfide-rich and silica-depositing Icelandic hot springs that were alkaliphilic (pH 8-10) and thermophilic (*65°C) (Tobler and Benning, 2011), as well as in other silica-precipitating hot springs in New Zealand (Childs et al, 2008), Japan (Yamamoto et al, 1998), and the USA (Blank et al, 2002;Wilson et al, 2008). In Hverager+i wastewater drain sample with a temperature of about 70°C, Aquificae represented about 11% of OTUs (Tobler and Benning, 2011).…”

Bacterial and archeal community composition in hot springs from Indo-Burma region, North-east India

“…The other dominant OTUs within Betaproteobacteria were OTU 128, 1320 and 940 were classified under the order Burkholderiales, Thiobacterales and Hydrogenophilales respectively (Additional file 1: Table S1). Previous studies show the predominance Proteobacteria , particularly of Betaproteobacteria in a circumneutral hot spring from the Uzon Caldera, Kamchatka, Russia (Wemheuer et al 2013; Chan et al 2015) and other acidic thermal springs (Wilson et al 2008). The information on distribution of genera is listed in Additional file 1: Table S2.…”

A novel virus genome discovered in an extreme environment suggests recombination between unrelated groups of RNA and DNA viruses

“…BSL is an acidic, high temperature lake (ranging between 52°C and 95°C, with a pH of approximately 2.5), which sustains a purely microbial ecosystem comprised of novel Archaea, Bacteria and several species of unicellular Eukarya [21,22]. …”