Another isolate in the ''military'' lineage, Dugway, is clearly derived from the Detrick lineage by SNP/indel profiling yet has a metabolic profile that is much closer to the parental strain. Like the Detrick isolates, the Dugway strain grows better at low pH, but many of the other conditions do not promote elevated growth relative to 1942. Only one mutation differentiates that isolate from the Detrick-2 isolate -a 2-bp insertion in the yojO gene encoding a putative activator of nitric oxide (NO) synthesis. Again, the physiological role of this mutation is unclear, although nitric oxide synthesis plays a critical role in modulating antibiotic resistance in Bacillus spp. [39] . In addition to its role in promoting resistance to antibacterial drugs, NO is known to modulate B. subtilis genes involved in nitrate respiration when oxygen is limited [40] ; thus the lowered growth in this strain may reflect the inability to grow to higher densities and overcome the resulting lower oxygen tension. An additional isolate, BACI051 is clearly derived from Dugway, yet two variants have accumulated additional mutations in sigH (spo0H), hpr/scoC, and ebrB. Notably, the phenotype of BACI051-E on plates more closely resembles the 1942 strain ( Figure 2B ).