Takuo Yano

Publications (5)5.95 Total impact

• Article: Optimization of compost fermentation of glycerol by-product discharged from biodiesel fuel production process

  Yuta Sadano, Ryota Toshimitsu, Jiro Kohda, Yasuhisa Nakano, Takuo Yano
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  ABSTRACT: Development of a cheap system for reuse of glycerol by-product discharged from the biodiesel fuel (BDF) production process is needed in parallel with development of a low-cost BDF production system. In this article, optimization of compost fermentation of glycerol by-product was studied. The type and amount of additive nitrogen source was studied, and good utilization of glycerol was observed when 0.5 g of urea was added to a mixture of 625 g dry sawdust, 25 g of microbial seed, and 50 g of glycerol by-product. To achieve efficient compost fermentation, repeated batch fermentation was applied and five batch cultures were repeated. Although the pH level and nitrogen and water contents were maintained at suitable levels for microbial growth, the glycerol consumption rate gradually decreased with accumulation of oily compounds in the compost. Finally, a material cost evaluation of the compost fermentation proposed in this study was performed. The total material cost decreased to ¥0.57 /l of BDF when employing an existing compost system for the fermentation process, although sawdust used for mushroom cultivation was used in this study at the very high cost of ¥123 /kg dry sawdust. However, the cost of disposal of the glycerol byproduct as an industrial waste was ¥5.2 /l of BDF produced; therefore, there might be an economical advantage to compost fermentation of glycerol by-product from BDF production. Key wordsBiodiesel by-product-Glycerol-Compost-C/N ratio-Repeated batch culture
  Journal of Material Cycles and Waste Management 04/2012; 12(4):308-313. · 0.72 Impact Factor
• Article: Stabilization of free and immobilized enzymes using hyperthermophilic chaperonin.

  Jiro Kohda, Hirofumi Kawanishi, Ken-Ichiro Suehara, Yasuhisa Nakano, Takuo Yano
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  ABSTRACT: Chaperonins suppress the denaturation of proteins and promote protein folding in vivo. Because hyperthermophilic chaperonins are expected to be used as a stabilizer for proteins, the effects of a group II chaperonin from a hyperthermophilic archaeum, Thermococcus strain KS-1 (T. KS-1 cpn), on the stabilization of mesophilic and thermophilic free enzymes and an enzyme co-immobilized with T. KS-1 cpn were studied. T. KS-1 cpn prevented the thermal inactivation of yeast alcohol dehydrogenase (ADH), jack bean urease, and Thermus flavus malate dehydrogenase (MDH) at high temperatures. T. KS-1 cpn also improved the long-term stability of ADH at lower temperatures. Moreover, the residual ADH activity of ADH co-entrapped with T. KS-1 cpn was improved and maintained at a higher level than that of the entrapped ADH without chaperonin. T. KS-1 cpn is useful for the stabilization of free and immobilized enzymes and applicable to various fields of biotechnology.
  Journal of Bioscience and Bioengineering 03/2006; 101(2):131-6. · 1.79 Impact Factor
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  Available from: claremont.edu

  Article: Biological treatment of wastewater discharged from biodiesel fuel production plant with alkali-catalyzed transesterification.

  Ken-ichiro Suehara, Yoshihiro Kawamoto, Eiko Fujii, Jiro Kohda, Yasuhisa Nakano, Takuo Yano
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  ABSTRACT: The biological treatment of wastewater discharged from a biodiesel fuel (BDF) production plant conducting alkali catalysis transesterification was investigated. BDF wastewater has a high pH and high hexane-extracted oil and low nitrogen concentrations, and inhibits the growth of microorganisms. The biological treatment of BDF wastewater is difficult because the composition of such wastewater is not suitable for microbial growth. To apply the microbiological treatment of BDF wastewater using an oil degradable yeast, Rhodotorula mucilaginosa, the pH was adjusted to 6.8 and several nutrients such as a nitrogen source (ammonium sulfate, ammonium chloride or urea), yeast extract, KH2PO4 and MgSO4.7H2O were added to the wastewater. The optimal initial concentration of yeast extract was 1 g/l and the optimal C/N ratio was between 17 and 68 when using urea as a nitrogen source. A growth inhibitor was also present in the BDF wastewater, and this growth inhibitor could be detected by measuring the solid content in an aqueous phase after the hexane extraction of the wastewater. Microorganisms could not grow at solid contents higher than 2.14 g/l in the wastewater. To avoid the growth inhibition, the BDF wastewater was diluted with the same volume of water. Oil degradation in the diluted BDF wastewater was observed and the best result was obtained under the determined optimal conditions. This treatment system is simple because no controllers, except for a temperature, are necessary. These results suggest that the biological treatment system developed for BDF wastewater is useful for small-scale BDF production plants.
  Journal of Bioscience and Bioengineering 11/2005; 100(4):437-42. · 1.79 Impact Factor
• Article: Bioprocess monitoring using near-infrared spectroscopy.

  Ken-ichiro Suehara, Takuo Yano
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  ABSTRACT: Near-infrared spectroscopy (NIR) is a nondestructive analytical technique that has been used for simultaneous prediction of the concentrations of several substrates, products and constructs in mixtures sampled from fermentation processes. In this chapter, we discuss applications of NIR for the monitoring of bioprocesses involving rice vinegar, compost, glycolipid, L-glutamic acid, lactic acid fermentation, mushroom cultivation, and Koji production. This includes detailed discussion of applications of NIR to process management of rice vinegar fermentation and compost fermentation. In the present study, absorbance at wavelengths between 400 and 2500 nm was measured at 2 nm intervals. To obtain calibration equations, multiple linear regression (MLR) was performed on NIR spectral data and conventional analysis values of a calibration sample set. To validate these calibration equations, they were used to calculate concentrations of a prediction sample set, which were then compared with concentrations measured by conventional methods. There was excellent agreement between the results of the conventional method and those of the NIR method, when both were used to analyze culture broth of rice vinegar fermentation and solid-state fermented compost. These results indicate that NIR is a useful method for monitoring and control of bioprocesses.
  Advances in biochemical engineering/biotechnology 02/2004; 90:173-98. · 1.64 Impact Factor
• Article: Prediction of the concentrations of ethanol and acetic acid in the culture broth of a rice vinegar fermentation using near-infrared spectroscopy

  Takuo Yano, Tadanori Aimi, Yasuhisa Nakano, Masahiro Tamai
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  ABSTRACT: Near-infrared spectroscopy (NIR), which is a nondestructive analytical technique, was employed for the simultaneous prediction of the concentrations of ethanol and acetic acid in the culture broth sampled from a rice vinegar fermentation. The broth was placed in a near-infrared spectrophotometer and the absorbance at wavelengths between 400 and 2,500 nm was measured at 2 nm intervals. To obtain calibration equations, multiple linear regression (MLR) was conducted on the NIR spectral data and on the ethanol and acetic acid concentrations obtained by gas chromatography of a calibration sample set. The value of the multiple correlation coefficient (R) was 0.999 when using the wavelengths of 1,686 and 1,738 nm for ethanol. The value of R for acetic acid was 0.940 when using the wavelengths of 1,674 and 1,718 nm. To validate the calibration equations obtained, ethanol and acetic acid concentrations in a prediction sample set which was not used for calibration were calculated using the calibration equation, and compared with the concentrations measured by gas chromatography. Excellent agreement between the results of the conventional method and those of NIR was observed for both constituents. The concentrations of ethanol and acetic acid in the culture broth could be analyzed simultaneously by NIR. The procedure of NIR was simple, and the operation time required to predict the concentrations was only 5 min. These results indicate that NIR may be a useful method for the monitoring and control of rice vinegar fermentation.
  Journal of Fermentation and Bioengineering.