The archaeal class Halobacteria and astrobiology: Knowledge gaps and research opportunities

Jia-Hui Wu; Terry J McGenity; Petra Rettberg; Marta F Simões; Wen-Jun Li; André Antunes

doi:10.3389/fmicb.2022.1023625

The archaeal class Halobacteria and astrobiology: Knowledge gaps and research opportunities

Front Microbiol. 2022 Oct 13:13:1023625. doi: 10.3389/fmicb.2022.1023625. eCollection 2022.

Authors

Jia-Hui Wu^{1

2}, Terry J McGenity³, Petra Rettberg⁴, Marta F Simões^{1

2}, Wen-Jun Li⁵, André Antunes^{1

2}

Affiliations

¹ State Key Laboratory of Lunar and Planetary Sciences, Macau University of Science and Technology (MUST), Taipa, Macau SAR, China.
² China National Space Administration (CNSA), Macau Center for Space Exploration and Science, Taipa, Macau SAR, China.
³ School of Life Sciences, University of Essex, Colchester, United Kingdom.
⁴ German Aerospace Center (DLR), Institute of Aerospace Medicine, Köln, Germany.
⁵ State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-sen University, Guangzhou, China.

Abstract

Water bodies on Mars and the icy moons of the outer solar system are now recognized as likely being associated with high levels of salt. Therefore, the study of high salinity environments and their inhabitants has become increasingly relevant for Astrobiology. Members of the archaeal class Halobacteria are the most successful microbial group living in hypersaline conditions and are recognized as key model organisms for exposure experiments. Despite this, data for the class is uneven across taxa and widely dispersed across the literature, which has made it difficult to properly assess the potential for species of Halobacteria to survive under the polyextreme conditions found beyond Earth. Here we provide an overview of published data on astrobiology-linked exposure experiments performed with members of the Halobacteria, identifying clear knowledge gaps and research opportunities.

Keywords: Halobacteria; Mars; archaea; astrobiology; extremophiles; icy moons.

Grants and funding

This work of J-HW, MS, and AA is funded by the Science and Technology Development Fund, Macao SAR, China. AA and MS are supported by Faculty Research Grants of Macau University of Science and Technology’s (FRG, AA: grant No. FRG-22-079-LPS; MS: grant No. FRG-22-RG-22-080-LPS).