Fermentation of <i>Acremonium tubakii</i> W. Gams isolated from a soil sample collected from the University of Utah led to the isolation and characterization of six new linear pentadecapeptides, emerimicins V-X (<b>1</b>-<b>6</b>). Peptaibols containing 15-residues are quite rare, with only 22 reported. Genome mining and bioinformatic analysis were used to identify the emerimicin 60 kbp <i>eme</i> biosynthetic cluster harboring a single 16-module hybrid polyketide-nonribosomal peptide synthetase. A detailed bioinformatic investigation of the corresponding 15 adenylation domains, combined with 1D and 2D NMR experiments, LC-MS/MS data, and advanced Marfey's method, allowed for the elucidation and absolute configuration of all proteinogenic and nonproteinogenic amino acid residues in <b>1</b>-<b>6</b>. As some peptaibols possess cytotoxic activity, a zebrafish embryotoxicity assay was used to evaluate the toxicity of the six emerimicins and showed that emerimicin V (<b>1</b>) and VI (<b>2</b>) exhibit the most potent activity. Additionally, out of the six emerimicins, <b>1</b> displayed modest activity against <i>Enterococcus faecalis</i>, methicillin-resistant <i>Staphylococcus aureus</i>, and vancomycin-resistant <i>Enterococcus faecium</i> with MIC values of 64, 32, and 64 μg/mL, respectively.