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179 results on '"Amano, Yoshihiko"'

4. Comparison of Free Flavonoids and the Polyphenol Content in the Bran of a Newly Developed Sorghum Variety and Two Commercially Available Sorghum Varieties.

Author

Santos, Mariely Cristine Dos, Tanaka, Naoki, Kasuga, Shigemitsu, Tanabe, Kazuhiro, Hayashi, Chihiro, Mizuno, Masahiro, and Amano, Yoshihiko

Subjects
SORGHUM, SORGO, CAPILLARY electrophoresis, MASS spectrometers, BIOACTIVE compounds, TANNINS, ANTHOCYANINS
Abstract

Background/Objectives: Sorghum bicolor is a source of many bioactive components, such as polyphenols. Those components are present mainly in its bran, often removed in industrial processes through decortication. In that sense, this work aimed to analyze the polyphenol content, especially free flavonoids, from the bran of a newly developed variety compared to other commercially available varieties. Methods: The samples were white sorghum TDN® Sorgho, red sorghum Mini Sorgho, and the newly developed red sorghum RILN-156. First, decortication was conducted to obtain the bran samples, which were triturated and then sieved. The use of colorimetric methods allowed the general quantification of the polyphenolic components. First, the polyphenol content was extracted using 70% methanol. Then, the samples' total phenolic content, total flavonoid content, total tannin content, total anthocyanin content, and antioxidant potential were determined. To analyze the different components and identify the free flavonoids, an untargeted metabolomics analysis (with liquid chromatography coupled with mass spectrometer (LC/MS) and capillary electrophoresis coupled with a mass spectrometer (CE/MS)) was performed. Results: The results have shown that apart from anthocyanin and tannin, the newly developed variety, RILN-156, presented the highest concentration of polyphenolic content, including a higher antioxidant capacity. The exploratory analysis identified 19 flavonoids within the samples, with galangin and daidzein being the most abundant ones. Conclusions: These results show a promising finding for using this newly developed sorghum variety (RILN-156) industrially and further investigating its health benefits. They also elucidate the differences between colored sorghum within themselves and with white sorghum varieties. [ABSTRACT FROM AUTHOR]

Published
2024
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16. Characterization of Acetylxylan Esterase from White-Rot Fungus Irpex lacteus

Author

Koh, Sangho, Imamura, Seika, Fujino, Naoto, Mizuno, Masahiro, Sato, Nobuaki, Makishima, Satoshi, Biely, Peter, and Amano, Yoshihiko

Subjects
deacetylation, kinetics, acetylxylan esterase, Irpex lacteus, Regular Paper, xylooligosaccharide, xylan
Abstract

The carbohydrate esterase family 1 (CE1) in CAZy contains acetylxylan esterases (AXEs) and feruloyl esterases (FAEs). Here we cloned a gene coding for an AXE belonging to CE1 from Irpex lacteus (IlAXE1). IlAXE1 was heterologously expressed in Pichia pastoris, and the recombinant enzyme was purified and characterized. IlAXE1 hydrolyzed p-nitrophenyl acetate, α-naphthyl acetate and 4-methylumbelliferyl acetate, however, it did not show any activity on ethyl ferulate and methyl p-coumarate. We also examined the activity on partially acetylated and feruloylated xylan extracted from corncob by hydrothermal reaction. Similarly, ferulic and p-coumaric acids were not liberated, and acetic acid was only detected in the reaction mixture. The results indicated that IlAXE1 is an acetylxylan esterase actually reacted to acetyl xylan. However, since IlAXE1 was unable to completely release acetic acid esterifying xylopyranosyl residues, it is assumed that acetyl groups exhibiting resistance to deacetylation by IlAXE1 are present in corn cob xylan.

Published
2019

21. Hydrophilic domains of scaffolding protein CbpA promote glycosyl hydrolase activity and localization of cellulosomes to the cell surface of Clostridium cellulovorans

Author

Kosugi, Akihiko, Amano, Yoshihiko, Murashima, Koichiro, and Doi, Roy H.

Subjects
Clostridium -- Research, Clostridium -- Physiological aspects, Bacteriology -- Research, Biological sciences
Abstract

CbpA, the scaffolding protein of Clostridium cellulovorans cellulosomes, possesses one family 3 cellulose binding domain, nine cohesin domains, and four hydrophilic domains (HLDs). Among the three types of domains, the function of the HLDs is still unknown. We proposed previously that the HLDs of CbpA play a role in attaching the cellulosome to the cell surface, since they showed some homology to the surface layer homology domains of EngE. Several recombinant proteins with HLDs (rHLDs) and recombinant EngE (rEngE) were examined to determine their binding to the C. cellulovorans cell wall fraction. Tandemly linked rHLDs showed higher affinity for the cell wall than individual rHLDs showed. EngE was shown to have a higher affinity for cell walls than rHLDs have. C. cellulovorans native cellulosomes were found to have higher affinity for cell walls than rHLDs have. When immunoblot analysis was carried out with the native cellulosome fraction bound to cell wall fragments, the presence of EngE was also confirmed, suggesting that the mechanism anchoring CbpA to the C. cellulovorans cell surface was mediated through EngE and that the HLDs play a secondary role in the attachment of the cellulosome to the cell surface. During a study of the role of HLDs on cellulose degradation, the mini-cellulosome complexes with HLDs degraded cellulose more efficiently than complexes without HLDs degraded cellulose. The rHLDs also showed binding affinity for crystalline cellulose and carboxymethyl cellulose. These results suggest that the CbpA HLDs play a major role and a minor role in C. cellulovorans cellulosomes. The primary role increases cellulose degradation activity by binding the cellulosome complex to the cellulose substrate; secondarily, HLDs aid the binding of the CbpA/cellulosome to the C. cellulovorans cell surface.

Published
2004

37. Creation of Bacterial Cellulose-Fabric Complexed Material

Author

Mizuno, Masahiro; gFDmbpkh, Kamiya, Yousuke, Katsuta, Tomoka, Oshima, Naohisa, Nozaki, Kouichi; jpyFbpkh, Amano, Yoshihiko; gVTVZVkh, Mizuno, Masahiro; gFDmbpkh, Kamiya, Yousuke, Katsuta, Tomoka, Oshima, Naohisa, Nozaki, Kouichi; jpyFbpkh, and Amano, Yoshihiko; gVTVZVkh

Abstract

The acetic acid bacterium Gluconacetobacter xylinus synthesizes a unique cellulose molecule called bacterial cellulose (BC) as an extracellular polysaccharide. The cellulose ribbons of BC are very fine and form a three-dimensional knitted structure. To add properties to the surfaces of fabrics, we produced hybrid materials composed of BC and fabric by culturing G. xylinus with fabrics as scaffolds. Nine kinds of fabric were soaked in medium, and then G. xylinus was statically cultured with the fabric at 25 degrees C. After the cultivation, the fabrics were purified by alkaline treatment and press-dried. BC displayed greater affinity for cotton and viscose rayon than for wool, silk, nylon, polyester, and Kevlar (R). The surfaces of all fabrics were uniformly coated with a BC sheet and became shiny. However, when viscose rayon was used and the fabric was inverted during the cultivation process, both surfaces were coated with the BC sheet. It is suggested that the G. xylinus cells adhered to the surface of the fabric and produced BC in the vicinity of the air-water interface. During the inversion, the cells entered the interior of the fabric, and the resultant BC sheets surrounded each fabric. (Received 11 July, 2011; Accepted 10 November, 2011)

Published
2013

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