Unstably stratified cultures of luminous cells

Abstract

Dense and open to air cultures of luxCDABE-gene fused Ralstonia eutropha in a cylindrical vessel exhibit bioconvection, which accounts for fluctuating bioluminescence. The characteristic period of fluctuations is ~10 min, when an unstable oxic–anoxic interface develops in close proximity (~1 mm) to the meniscus. Formation of a particular interface in the deeper layers (~2–3 mm) results in a noise which is close to Brownian. Keywords: bioconvection, bioluminescence, fluctuations, lux-genes, oscillations