Ayako Tomio

Osaka University, Suika, Ōsaka, Japan

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Publications (4)4.95 Total impact

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    ABSTRACT: The current study focused on the tea plant (Camellia sinensis) as a target for artificial cultivation because of the variation in its components in response to light conditions. We analyzed its sensory quality by multi-marker profiling using multicomponent data based on metabolomics to optimize the conditions of light and the environment during cultivation. From the analysis of high-quality tea samples ranked in a tea contest, the ranking predictive model was created by the partial least squares (PLS) regression analysis to examine the correlation between the amino-acid content (X variables) and the ranking in the tea contest (Y variables). The predictive model revealed that glutamine, arginine, and theanine were the predominant amino acids present in high-ranking teas. Based on this result, we established a cover-culture condition (i.e., a low-light intensity condition) during the later stage of the culture process and obtained artificially cultured tea samples, which were predicted to be high-quality teas. The aim of the current study was to optimize the light conditions for the cultivation of tea plants by performing data analysis of their sensory qualities through multi-marker profiling in order to facilitate the development of high-quality teas by plant factories.
    No preview · Article · Jun 2014 · Journal of Bioscience and Bioengineering
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    ABSTRACT: A thermotolerant Saccharomyces cerevisiae yeast strain, YK60-1, was bred from a parental strain, MT8-1, via stepwise adaptation. YK60-1 grew at 40°C, a temperature at which MT8-1 could not grow at all. YK60-1 exhibited faster growth than MT8-1 at 30°C. To investigate the mechanisms how MT8-1 acquired thermotolerance, DNA microarray analysis was performed. The analysis revealed the induction of stress-responsive genes such as those encoding heat shock proteins and trehalose biosynthetic enzymes in YK60-1. Furthermore, nontargeting metabolome analysis showed that YK60-1 accumulated more trehalose, a metabolite that contributes to stress tolerance in yeast, than MT8-1. In conclusion, S. cerevisiae MT8-1 acquired thermotolerance by induction of specific stress-responsive genes and enhanced intracellular trehalose levels.
    No preview · Article · Sep 2013 · Biotechnology Progress
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    ABSTRACT: Objective: Putrescine, spermidine, spermine and cadaverine are the most widely distributed cellular polyamines and are essential for both prokaryotic and eukaryotic cells. Bacterial polyamines have been also suggested to be linked to bacterial virulence such as biofilm formation. Here, we investigated effects of exogenous polyamines on biofilm development and dispersion in Porphyromonas gingivalis and Streptococcus gordonii using confocal laser scanning microscopy (CLSM). Furthermore, altered levels of metabolites in polyamine treated cells were comprehensively analyzed using non-targeted gas chromatography/mass spectrometry (GC/MS)-based metabolomics. Method: P. gingivalis and S. gordonii cells in modified chemically defined medium (mCDM) were incubated in CultureWell system, respectively. Result ing biofilms were stained with BacLight™ following overnight culturing in mCDM containing each polyamine. Fluorescent biofilm cells and newly-released planktonic cells were examined using CLSM. For metabolomic analyses, internal metabolites were extracted from polyamine treated P. gingivaliscells with a solvent mixture then GC/MS analysis was performed. Result: Microscopic observations revealed that putrescine significantly accelerated the biofilm growth and increased living planktonic cells in P. gingivalis, whereas spermidine stimulated biofilms to form floating clumps. On the other hand, all examined polyamines showed negligible effects on phenotype change of S. gordonii biofilm cells into planktonic cells. Metabolomics study illustrated that profiles of metabolites in P. gingivalis cells were altered in the presence of either spermidine or putrescine. Spermidine increased hydroxyfatty acid and metabolites in the polyamine biosynthesis pathway, though amino acids were decreased. In contrast, a large number of amino acids showed a tendency to increase in the presence of putrescine. Conclusion: P. gingivalis biofilm microstructure and dispersal ability were differently affected by each polyamine, whereas S. gordonii biofilm was not sensitive against examined polyamines. Effective polyamines, such as putrescine and spermidine, have been shown to be captured by P. gingivalis and alter its internal metabolomic profile.
    No preview · Conference Paper · Mar 2013
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    ABSTRACT: A new hexadienamide derivative named sarmentosamide (1) was identified from the culture of Streptomyces sp. SBI108 isolated from Thai soil under an herb. The structure was elucidated on the basis of spectroscopic data, and the absolute configuration was determined by chemical degradation.
    Full-text · Article · Mar 2012 · Natural product research