Breeding of high ethanol producing yeast by screening from mutant library

Ogino, Chiaki*; Kahar, P.*; Lee, J. M.*; Sato, Katsuya; Ono, Yutaka; Kondo, Akihiko*

JAEA-Review 2015-022, JAEA Takasaki Annual Report 2014, P. 105, 2016/02

https://doi.org/10.11484/jaea-review-2015-022

Effect of minerals on accumulation of Cs by fungus

Onuki, Toshihiko; Sakamoto, Fuminori; Yamasaki, Shinya*; Kozai, Naofumi; Shiotsu, Hiroyuki; Utsunomiya, Satoshi*; Watanabe, Naoko*; Kozaki, Tamotsu*

Journal of Environmental Radioactivity, 144, p.127 - 133, 2015/06

https://doi.org/10.1016/j.jenvrad.2015.02.018

The accumulation of Cs by unicellular fungus of in the presence of minerals has been studied to elucidate the role of microorganisms in the migration of radioactive Cs in the environment. In the presence of minerals in the agar medium, the radioactivity in the yeast cells was in the order of mica smectite, illite vermiculite, phlogopite, zeolite. This order is inversely correlated to the ratio of the concentration of radioactive Cs between the minerals and the medium solution. These results strongly suggest that the yeast accumulates radioactive Cs competitively with minerals.

Genome analysis of high ethyl caproate producing sake yeasts generated by ion beam breeding

Masubuchi, Takashi*; Hyuga, Hirokazu*; Ueda, Ryoshiro; Hayashi, Hidenori*; Ikenaga, Hiroshi*; Sato, Katsuya; Ono, Yutaka

JAEA-Review 2014-050, JAEA Takasaki Annual Report 2013, P. 123, 2015/03

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2014-050.pdf#page=155

Effects of CeO nanoparticles on microbial metabolism

Masaki, Shota*; Shiotsu, Hiroyuki; Onuki, Toshihiko; Sakamoto, Fuminori; Utsunomiya, Satoshi*

Chemical Geology, 391, p.33 - 41, 2015/01

https://doi.org/10.1016/j.chemgeo.2014.10.026

Distinct organic species and intracellular proteins were expressed after exposure of yeast cells to CeNPs. Although cytotoxicity was not caused by CeNPs, the results of the peptide mass fingerprint analysis of the intracellular protein revealed that Eno2p, a glycolysis enzyme, was expressed after the exposure to CeNPs. These results suggest that nanoparticles have the potential to alter microbial metabolism, leading to changes in the compositions of the released substances in the surrounding environment.

Effect of uranium (VI) on the growth of yeast and influence of metabolism of yeast on adsorption of U (VI)

Sakamoto, Fuminori; Onuki, Toshihiko; Kozai, Naofumi; Wakai, Eiichi; Fujii, Tsutomu*; Iefuji, Haruyuki*; Francis, A. J.

Journal of Nuclear and Radiochemical Sciences, 6(1), p.99 - 101, 2005/07

https://doi.org/10.14494/jnrs2000.6.99

We have carried out the growth experiments of 3 strains of yeast in a medium containing uranium (VI) to elucidate the effect of U (VI) on the growth of microorganisms. Hansenula fabianii J640 grew in the liquid medium containing 0.1 mM U (VI) at lower rate than the control, but Saccharomyces cerevisiae did not grow under this condition. The H. fabianii J640 pre-cultured for 21 h in the liquid medium without U (VI) grew even after the exposure to 1 mM U (VI), but did not grow without pre-cultivation. For the pre-cultured H. fabianii J640, radioactivity of U in the medium was the same as the initial one for 110 h, and then gradually decreased. TEM-EDS analysis of H. fabianii J640 exposed to 1 mM U (VI) for 165 h showed accumulation of U (VI) on the cells. When H. fabianii J640 was not pre-cultured, radioactivity of U in the medium was lower than the initial one. These results indicated that U (VI) inhibits the growth of yeast, and that the adsorption of U (VI) by the cells depends on the metabolism of yeast.

Application of micro-PIXE technique to uptake study of cesium by

Onuki, Toshihiko; Sakamoto, Fuminori; Kozai, Naofumi; Ozaki, Takuo; Narumi, Issei; Francis, A. J.*; Iefuji, Haruyuki*; Sakai, Takuro; Kamiya, Tomihiro; Sato, Takahiro; et al.

Nuclear Instruments and Methods in Physics Research B, 210, p.378 - 382, 2003/09

https://doi.org/10.1016/S0168-583X(03)01067-X

We examined the accumulation of Cs and Co, and the presence of other elements in yeast (Saccharomyces cerevisiae) cells by the particle induced X-ray emission (PIXE) system, which has low concentration detection limit of ppm, developed at the TIARA facility, JAERI, and by energy dispersive spectroscopy (EDS) equipped with scanning electron microscope. Addition of 1mM Cs did not have any effect on the growth of the yeast, whereas 0.5 mM Co inhibited its growth. Cells exposed to Cs showed an increase in Cs peak intensity, decrease in P, and no change in Fe, Zn and K with time. In the presence of Co, the intensity of Co and Fe peaks increased with time up to 21 hours while P, K and Zn exhibited no clear trend. These results suggest that PIXE is a useful technique to detect low concentration of elements in microbial cells as well as monitor their changes as function of growth.

Search for yeast genes involved in cesium accumulation

Sakamoto, Fuminori; Kozai, Naofumi; Shiina, Kazuhiro; Tanaka, Kenji; Onuki, Toshihiko

no journal, , 

no abstracts in English

Genome analysis of high ethyl caproate producing sake yeasts generated by ion beam breeding

Masubuchi, Takashi*; Hyuga, Hirokazu*; Ikenaga, Hiroshi*; Hayashi, Hidenori*; Sato, Katsuya; Ono, Yutaka

no journal, , 

no abstracts in English

Behavior of heavy elements in a simple microbial food chain

Kozai, Naofumi; Sakamoto, Fuminori; Onuki, Toshihiko; Sato, Takahiro; Koka, Masashi; Kamiya, Tomihiro; Esaka, Fumitaka

no journal, , 

To reveal the role of protozoa in environmental migration of radionuclides, this study investigated behavior of heavy elements (U, Eu) during culture of Paramecium sp. with yeast on which heavy elements were sorbed. Paramecium was chosen as model protozoa. After the exposure of yeast cells to a dilute heavy element aqueous solution, phosphates of these elements formed on yeast cells. Paramecium cells were cultured with those yeast cells. Only very small fractions of the presorbed heavy elements were dissolved from yeast cells during the Paramecium culture. As culture time advances, membranous precipitates formed which contained undigested and digested yeast cells and dense membranous organic substance filling gaps between those cells. In the precipitates many phosphate particles which size and morphology are similar to those on the yeast cells were observed. These results suggest that the immobilization effect of yeast cells for heavy elements was preserved in the prey-predator system.

Genome sequence analysis of high ethyl caproate producing sake yeasts generated by ion beam breeding, 3

Masubuchi, Takashi*; Toguchi, Kazuki*; Ikenaga, Hiroshi*; Hayashi, Hidenori*; Sato, Katsuya; Ono, Yutaka

no journal, , 

no abstracts in English