Combination of Rolling Vibration and Serpentinite Induces the Formation of Penetration-Intermediates

Abstract

Bacterial cells with nano-sized acicular materials were placed in a sliding friction field between a hydrogel and an interface-forming material, after which cells with surrounding materials, namely penetration-intermediates, were formed. This phenomenon is defined as the Yoshida effect. The Yoshida effect requires the following conditions: a nano-sized acicular material, a hydrogel, an interface-forming material, and a power source for inducing sliding friction. The penetration-intermediate in the Yoshida effect has been demonstrated to readily incorporate exogenous genes and to be transformed genetically based on the acquired genes. To predict the occurrence of the Yoshida effect in the natural environment, transformation efficiency of the penetration-intermediate with plasmid DNA was investigated, and chrysotile, gellan gum, serpentinite, and artificial rolling vibration were selected as the nano-sized acicular material, hydrogel, interface-forming material, and power source for inducing sliding friction, respectively. Colloidal solution consisting of Pseudomonas sp. or Bacillus subtilis as recipient cells, donor plasmid, and chrysotile was placed on the interface between gellan gum and the serpentinite plate. To generate a sliding friction field, the serpentinite plate in contact with gellan gum was subjected to rolling vibration at 30 to 520 Gal. The sliding friction allowed recipient bacteria to become antibiotic resistant by taking up donor plasmids. Incorporation of plasmids into bacteria at the interface of gellan gum required both rolling vibration and nano-sized acicular materials such as chrysotile. Chrysotile-bound plasmid DNA was protected from catalytic reactions by DNase I and Kpn I.

Keywords:

• Yoshida effect
• sliding friction
• plasmid
• chrysotile
• serpentinite
• biofilm
• transformation

Acknowledgments

This work was supported by a Grant-in-Aid for Scientific Research (C-2058371) from the Ministry of Education, Culture, Sports, Science, and Technology of Japan.