Ultradian rhythms and the lux-gene reporter system

'Noisy' bioluminescence of an unstirred and exposed-to-air microculture of lux -gene fused Escherichia coli was interpreted, assuming two oscillatory processes: cyclic induction of the lac promoter, resulting in oscillatory reporter lux -gene expression, and oscillatory respiration in the culture. Biological support for the theoretical argument, that two rhythms can interact in cells to produce additional rhythms, is provided. These results, along with previously obtained data on oscillatory bioluminescence, indicate the deterministic nature of observed noise-like fluctuations and promising perspectives of lux gene reporter systems in investigations of ultradian rhythm.