## 3 Results and Discussion  
### Taxonomic Characterization of Lentzea sp. JNUCC 0626  
Strain JNUCC 0626 exhibited robust growth on ISP2, ISP4, ISP5, and AIA plates. The aerial mycelium of JNUCC 0626 was smooth and powdery, and predominantly white on these media (Figure 1). The substrate mycelium exhibited a yellow coloration. Strain JNUCC 0626 was capable of growing in tryptic soy broth (TSB) at temperatures between 15 \({}^{\circ}\)C and 35 \({}^{\circ}\)C, at pH values ranging from 4.0 to 10.0, and in the presence of 0-4.0% (\(w/v\)) NaCl. Optimal growth occurred on tryptic soy agar (TSA) at 25-30 \({}^{\circ}\)C, at pH 7.0, and in the presence of 0.5-1.0% (\(w/v\)) NaCl. In contrast, the aerial and substrate mycelia of the closest relatives, _Lentzea cavernae_ KCTC 39804 and _Lentzea pudingi_ KCTC 39694, exhibited differences in coloration compared to JNUCC 0626 (Table S1).  
The major fatty acids (>15%) of strain JNUCC 0626 were iso-C16:0 (19.6%), iso-C15:0 (18.8%), and C15:0 anteiso (17.4%). The detailed fatty acid profiles of the strains are presented in Table S2. The polar lipids of strain JNUCC 0626 were composed of diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), unidentified phospholipid (UPL), unidentified lipid (UL), and unidentified aminophospholipid (UAPL) (Figure S1). Strain JNUCC 0626 contained ubiquinone Q-9 as a predominant respiratory quinone, as observed in other _Lentzea_ species. Strain JNUCC 0626 exhibited enzymatic activities for alkaline phosphatase, esterase (C4), esterase lipase (C8), leucine arylamidase, naphtol-AS-BI-phosphohydrolase, N-acetyl-\(\beta\)-glucosamineaminidase, and \(\alpha\)-mannosidase, as determined using the API ZYM system. In terms of carbohydrate metabolism, cells are only capable of producing acid from esculin, as assessed by the API 50 CHB system. However, no acid production is observed from glycerol, erythiritol, D-arabinose, L-arabinose, ribose, D-xylose, L-xylose, aonitol, \(\beta\)-methyl-xyloside, galactose, D-glucose, D-fructose, D-mannose, L-sorbose, rhannose, dulticitol, inositol, mannitol, sorbitol, \(\alpha\)-methyl-D-mannoside, \(\alpha\)-methyl-D-glucose, N-acetyl-glucosamine, amygdaline, arbutin, salicine, cellobiose, maltose, lactose, melibiose, saccharose trehalose, inuline, melezitose, D-affinose, amidon, glycogen, xylitol, \(\beta\)-gentiobiose, D-turanose, D-lyxose, D-tagatose, D-fucose, L-fucose, D-arabitol, L-arabitol, gluconate, 2-ceto-gluconate, or 5-ceto-gluconate (Table S3).  
In our previous study, the 16S ribosomal RNA sequence of _Lentzea_ sp. JNUCC 0626 was analyzed using MEGA 11 software. The results indicated that _L. cavernae_ SYSU  
Figure 1: Comparison of growth of _Lentzea_ sp. JNUCC 0626, _Lentzea cavernae_ KCTC 39804, and _Lentzea pudingi_ KCTC 39694 on various actinomycete media. The aerial mycelium of JNUCC 0626 is white, and the substrate mycelium is yellow, whereas KCTC 39804 and KCTC 39694 exhibit somewhat different coloration; (**a**) shows the front view of colonies on solid media, and (**b**) shows the reverse view.  
K10001 and _L. pudingi_ CGMCC 4.7319 are the closest phylogenetic neighbors of _Lentzea_ sp. JNUCC 0626. The major fatty acids of _L. cavernae_ SYSU K10001 are iso-C16:0 (32.9%) and iso-C14:0 (17.3%), while _L. pudingi_ CGMCC 4.7319 predominantly contains iso-C16:0 (35.5%) and C16:1 (19.5%). Both species share a similar polar lipid profile, comprising DPG, PE, UPL, hydroxyphosphatidylethanolamine (HPE), phosphatidylinositol (PI), and phosphatidylinositol mannoside (PIM).