The bacterial flagellum is a motility organelle consisting of a long helical filament as a propeller and a rotary motor that drives rapid filament rotation to produce thrust. Salmonella enterica serovar Typhimurium has two genes of flagellin. fljB and fliC. for flagellar filament formation and autonomously switches their expression at a frequency of 10−3−10−4 per cel... https://www.roneverhart.com/Turbosound-TS-18SW700-8A-18-Low-Frequency-Loudspeaker-p31480/