An Astrobiology Spinoff? Microbe Recovered From Mars 2020 Cleanroom May Have Commercial Applications
During microbial surveillance of the Mars 2020 spacecraft assembly facility, two novel bacterial strains, potentially capable of producing lasso peptides, were identified.
Characterization using a polyphasic taxonomic approach, whole-genome sequencing and phylogenomic analyses revealed a close genetic relationship among two strains from Mars 2020 cleanroom floors (179-C4-2-HS, 179-J1A1-HS), one strain from the Agave plant (AT2.8), and another strain from wheat-associated soil (V4I25).
All four strains exhibited high 16S rRNA gene sequence similarity (>99.2%) and low average nucleotide identity (ANI) with Neobacillus niacini NBRC 15566T, delineating new phylogenetic branches within the genus. Detailed molecular analyses, including gyrB (90.2%), ANI (86.4%), average amino acid identity (87.8%) phylogenies, digital DNA-DNA hybridization (32.6%), and percentage of conserved proteins (77.7%) indicated significant divergence from N. niacini NBRC 15566T.
Isolation of N. driksii from cleanrooms, Agave plants, and dryland wheat soils, suggested niche-specific ecology and resilience under various environmentally challenging conditions. The discovery of potent antimicrobial agents from novel N. driksii underscores the importance of genome mining and the isolation of rare microorganisms. — RamanLab/Neobacillus GitHub
Consequently, these strains have been designated Neobacillus driksii sp. nov., with the type strain 179-C4-2-HST (DSM 115941T = NRRL B-65665T). N. driksii grew at 4°C to 45°C, pH range of 6.0 to 9.5, and 0.5% to 5% NaCl. The major cellular fatty acids are iso-C15:0 and anteiso-C15:0. The dominant polar lipids include diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, and an unidentified aminolipid.
Metagenomic analysis within NASA cleanrooms revealed that N. driksii is scarce (17 out of 236 samples). Genes encoding the biosynthesis pathway for lasso peptides were identified in all N. driksii strains and are not commonly found in other Neobacillus species, except in 7 out of 26 recognized species. This study highlights the unique metabolic capabilities of N. driksii, underscoring their potential in antimicrobial research and biotechnology.
Importance: The microbial surveillance of the Mars 2020 assembly cleanroom led to the isolation of novel N. driksii with potential applications in cleanroom environments, such as hospitals, pharmaceuticals, semiconductors, and aeronautical industries. N. driksii genomes were found to possess genes responsible for producing lasso peptides, which are crucial for antimicrobial defense, communication, and enzyme inhibition.
Maximum likelihood phylogeny of strains of N. driksii (n=4) and 25 established species of Neobacillus based on WGS. Scanning electron microscopy image of N. driksii 179-C4-2-HST. Scale bar, 5 μm. Spores are depicted with arrow marks.
Bioactive gene clusters potentially producing nicotianamine-like siderophores were found in N. driksii genomes. These siderophores can be used for bioremediation to remove heavy metals from contaminated environments, promote plant growth by aiding iron uptake in agriculture, and treat iron overload conditions in medical applications.
Molecular characteristics of paeninodin peptide. (A) Maximum likelihood phylogenetic analysis of peptide sequences (bootstrap values > 70% after 1,000 replications are shown in branching point; Scale, 0.1 substitution per position) and alignment of precursor peptides found in Neobacillus driksii and other Neobacillus species. (B) Overview of the lasso peptide pathway between the paeninodin-producing strains. Asn synthases are marked in dark green, precursor peptides are marked in red, Hpr kinase/phosphatases are marked in light blue, proteins B1 and B2 are marked in yellow, nucleotidyl transferases are marked in gray, and ABC transporters are marked in dark blue. Putative promoters (with Promotech prediction score ≥0.5, see Methods) are marked in light green. Adjacent genes (miscellaneous) are marked in orange and YdcF family protein is marked in pink. (C) Structural alignment of N. driksii 179-C4-2-HST/179-J1A1-HS (green) and N. driksii AT2.8/V4I25 (cyan) precursor peptide alignment. — Microbiol Spectr via PubMed
- Neobacillus driksii sp. nov. isolated from a Mars 2020 spacecraft assembly facility and genomic potential for lasso peptide production in Neobacillus, Microbiol Spectr via PubMed (open access)
- Planetary Protection Implementation and Verification Approach for the Mars 2020 Mission
- RamanLab/Neobacillus, GitHub
- New bacteria found in spacecraft assembly cleanroom, Nature : “Researchers have discovered two novel bacterial strains from the NASA Mars 2020 spacecraft assembly facility (SAF) cleanroom1. Classified as Neobacillus driksii, they carry genes for lasso peptides, molecules with antimicrobial, antiviral and enzyme-inhibiting properties, promising advances in biotechnology.”
Astrobiology,
