Isolation of Live Cretaceous (121–112 Million Years Old) HalophilicArchaeafrom Primary Salt Crystals

Abstract

Recent reports have described the isolation and analysis of living microbes and/or DNA fragments from halite crystals of significant geological age. This manuscript describes the isolation of six living strains of halophilic Archaea from Cretaceous (121-112 MYA) halite crystals. These 6 live strains represent the oldest Archaea isolated to date. This manuscript also presents the first isolation of representatives from two different archaeal genera in a single event. The data presented show that the organisms that inhabited these hypersaline environments today are similar to those present during the Cretaceous age. Considering the number of ancient samples that have now yielded living microbes or DNA fragments the evidence for long-term survival of microbes (at least within halite) is becoming increasingly definitive. While there are obviously still other trapped microbes to find, it may now be time to begin investigating the implications of these ancient microbes and the mechanisms that foster long-term survival.

Ribosomal RNA gene fragments from fossilized cyanobacteria identified in primary gypsum from the late Miocene, Italy

“…Although numerous chemical analyses have demonstrated that fluid inclusions retain the chemistry of their original source waters (Lowenstein & Hardie, 1985; Satterfield et al. , 2005) and preserve living micro‐organisms (Vreeland et al. , 2000, 2006, 2007; Powers et al.…”

“…, 2008). Evaporites may host living microbes for long periods after deposition and advanced techniques have permitted isolation of micro‐organisms and DNA from brine inclusions in halite crystals (Vreeland et al. , 2000, 2007; Fish et al.…”

How do prokaryotes survive in fluid inclusions in halite for 30 k.y.?

“…The archaeon Natronobacterium sp. 2-24-1, independently isolated at a separate laboratory (Vreeland et al, 2007) from a halite crystal in the same hypersaline lake interval of the Death Valley core, was the most similar known relative to isolate DV462A (Table 1). This result shows interlaboratory reproducibility in ancient halite (Stan-Lotter et al, 1999;Willerslev et al, 2004).…”

“…old, are at the center of the debate about longterm survival of microorganisms on Earth and elsewhere in the solar system (Grant et al, 1998;McGenity et al, 2000;Mormile et al, 2003;Stan-Lotter et al, 1999;Vreeland et al, 2000Vreeland et al, , 2007. Critics of the evidence for protracted survival of microorganisms in ancient salt formations point to potential recrystallization of halite and late movement of brines and question whether environmental and laboratory contamination can be ruled out (Graur and Pupko, 2001;Hazen and Roedder, 2001;Hebsgaard et al, 2005;Nickle et al, 2002;Willerslev and Hebsgaard, 2005).…”

Acidophilic Halophilic Microorganisms in Fluid Inclusions in Halite from Lake Magic, Western Australia

“…Fish Fendrihan and Stan-Lotter, 2004;Adamski et al, 2006;Fendrihan et al, 2006;Vreeland et al, 2007;Lowenstein, 2008). For example, Mormile et al (2003) isolated a bacterium from fluid inclusions in 97,000-year-old halite from Death Valley.…”