Untapped Potential of the Antarctic Strain Actinacidiphila fildesensis DEC002: Integrative Genome Analysis and Functional Profiling
Journal
DIVERSITY-BASEL
Date Issued
2026
Author(s)
Lavin, Paris
Chen, ZiAng
Wong, Clemente Michael Vui Ling
Teoh, Chui Peng
Fierro-Vasquez, Natalia
Oses, Romulo
Banerjee, Aparna
Cabrera-Barjas, Gustavo
Purcarea, Cristina
Abstract
The actinobacterial strain DEC002 was isolated recently from volcanic soils of Deception Island. Its taxonomic identity was resolved through a polyphasic strategy integrating morphology, physiological profiling, multilocus phylogeny, and genome-wide comparisons to resolve its identity. Concatenated core gene trees together with average nucleotide identity and digital DNA-DNA hybridization values place DEC002 within Actinacidiphila fildesensis with robust support. This is the first molecular confirmation of the species beyond King George Island and secures a second verified locality within the South Shetland Archipelago. Growth at low temperature with tolerance to moderate salinity indicates a psychrotolerant lifestyle. Cell-free supernatants inhibited representatives of foodborne Gram-negative and Gram-positive bacteria, including representatives of Enterobacteriaceae, Vibrio, Staphylococcus and Streptococcus. Genome analysis revealed enrichment in multiple biosynthetic gene clusters for nonribosomal peptides, polyketides, terpenes, and ribosomally synthesized and post-translationally modified peptides (RiPPs), supporting the biosynthetic potential of the strain. Functional annotations emphasize replication and repair modules, mobile element-associated proteins, helix-turn-helix regulators, and versatile transport systems, features coherent with cold stress and oligotrophic soils. Antibiotic susceptibility assays indicate a broad resistance phenotype under the experimental conditions tested, together with extracellular antimicrobial activity. These data refine the biogeography of A. fildesensis and indicate DEC002 as a credible Antarctic source of specialized metabolites with antimicrobial promise.


