title: Microbial growth at hyperaccelerations up to 403,627 x g.
abstract: It is well known that prokaryotic life can withstand extremes of temperature, pH, pressure, and radiation. Little is known about the proliferation of prokaryotic life under conditions of hyperacceleration attributable to extreme gravity, however. We found that living organisms can be surprisingly proliferative during hyperacceleration. In tests reported here, a variety of microorganisms, including Gram-negative Escherichia coli, Paracoccus denitrificans, and Shewanella amazonensis; Gram-positive Lactobacillus delbrueckii; and eukaryotic Saccharomyces cerevisiae, were cultured while being subjected to hyperaccelerative conditions. We observed and quantified robust cellular growth in these cultures across a wide range of hyperacceleration values. Most notably, the organisms P. denitrificans and E. coli were able to proliferate even at 403,627 × g. Analysis shows that the small size of prokaryotic cells is essential for their proliferation under conditions of hyperacceleration. Our results indicate that microorganisms cannot only survive during hyperacceleration but can display such robust proliferative behavior that the habitability of extraterrestrial environments must not be limited by gravity.
authors.affiliation: Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology, Yokosuka 237-0061, Japan. shigeru.deguchi@jamstec.go.jp
authors.forename: Shigeru
authors.initials: S
authors.lastname: Deguchi
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Shimoshige
authors.forename: Mikiko
authors.initials: M
authors.lastname: Tsudome
authors.forename: Sada-atsu
authors.initials: SA
authors.lastname: Mukai
authors.forename: Robert W
authors.initials: RW
authors.lastname: Corkery
authors.forename: Susumu
authors.initials: S
authors.lastname: Ito
authors.forename: Koki
authors.initials: K
authors.lastname: Horikoshi
mesh_terms: D000054:Acceleration; D001419:Bacteria / Q000166:cytology / Q000254:growth & development*; D004926:Escherichia coli / Q000254:growth & development; D018559:Exobiology; D005118:Extraterrestrial Environment; D005658:Fungi / Q000166:cytology / Q000254:growth & development*; D006090:Gram-Negative Bacteria / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000254:growth & development; D006874:Hydrostatic Pressure; D018471:Hypergravity; D010231:Paracoccus denitrificans / Q000254:growth & development; D012441:Saccharomyces cerevisiae / Q000254:growth & development; D013314:Stress, Mechanical