1Dept. of Biological Sciences, Chuo Univ.
Nanobubbles that have diameters smaller than one micrometer are expected to be applied for many different field of biotechnology. We could generate very small air-nanobubbles, smaller than 100 nm, in water using a hand mixer. The bubbles were stable in water containing 1% ethanol more than one month. The zeta potential of the bubbles was between -30 to -40 mV. The addition of NaCl to nanobubble-water made the bubbles larger in size and lesser in numbers. When a cyanobacterium, Anabaena sp. PCC7120 was grown in the culture medium containing air-nanobubbles, it showed better growth than that in usual one. Dark respiration of the cyanobacterial cells was enhanced by air-nanobubbles. Nanobubbles may somehow affect physiology of microorganisms.