Abstract
A novel actinobacterial strain, designated E54(T), was isolated from a hyper-arid desert soil sample collected from the Kumtagh Desert in Dunhuang, Gansu Province, China. Phylogenetic analysis based on 16S rRNA gene sequences placed strain E54(T) within the genus Lentzea, showing highest similarity to Lentzea waywayandensis DSM 44232(T) (98.9%) and Lentzea flava NBRC 15743(T) (98.5%). However, whole-genome comparisons revealed that the average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between E54(T) and these related strains were below the thresholds for species delineation. Strain E54(T) exhibited typical morphological characteristics of the genus Lentzea, forming a branched substrate. It grew optimally at 28-30 °C, pH 7.0-9.0, and tolerated up to 10% NaCl. The cell wall contained meso-diaminopimelic acid, the predominant menaquinone was MK-9(H(4)), and major fatty acids included iso-C(16:0). The polar lipid profile comprised diphosphatidyl glycerol, phosphatidyl ethanolamine, phosphatidyl inositol, hydroxyphosphatidyl ethanolamine, and an unidentified lipid. The characteristic amino acid type of the cell wall was meso-DAP. Whole-cell hydrolysis experiments revealed the characteristic cell wall sugar fractions: ribose and galactose. The genome of strain E54(T) is approximately 8.0 Mb with a DNA G+C content of 69.38 mol%. Genome mining revealed 39 biosynthetic gene clusters (BGCs), including non-ribosomal peptide synthetases (NRPS), polyketide synthases (PKS), terpenes, and siderophores. Comparative antiSMASH-based genome analysis across 38 Lentzea strains further demonstrated the genus' remarkable biosynthetic diversity. NRPS and type I PKS (T1PKS) were the most prevalent BGC types, indicating a capacity to synthesize structurally complex and pharmacologically relevant metabolites. Together, these findings underscore the untapped biosynthetic potential of the genus Lentzea and support the proposal of strain E54(T) as a novel species. The strain E54(T) (=JCM 34936(T) = GDMCC 4.216(T)) should represent a novel species, for which the name Lentzea xerophila sp. nov. is proposed.