著者

高橋 節子 北原 久子 貝沼 圭二

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.28, no.3, pp.151-159, 1981-06-30 (Released:2010-06-28)

参考文献数

27

被引用文献数

11 7

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調理材料として各種の澱粉を使用する立場から緑豆およびサゴ澱粉の性質について,馬鈴薯およびトウモロコシ澱粉を対照として,顕微鏡観察,アミログラフィー,フォトペーストグラフィー,膨潤度・溶解度,アミロース含量,β-アミラーゼによる分解限度,白度,X線回折,澱粉ゲルの物性測定等の実験を行った.その結果,緑豆澱粉の性質から緑豆澱粉を原料とする豆麺の物性に及ぼす要因を考察した. 最後にX線回折を測定していただきました千葉大学渡邊幸雄博士に心より厚くお礼申しあげます.

著者

藤本 滋生

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.19, no.4, pp.169-177, 1972-12-25 (Released:2010-03-16)

参考文献数

17

被引用文献数

2 1

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Starch granules involve various amounts of fatty acids as “Fat by Hydrolysis” in different plant sources. These fatty acids are possibly embraced in amylose component and concerned in affecting some properties of the granules, but it is not yet clear through what process they are embraced into the granules in vivo.In this study, starch samples differing in granular size were prepared from sweet potato tubers of different maturity, and were studied on quantative and qualitative changes in the embraced fatty acids and transitions of some chemical and physical properties with the development of granular size.Each X-ray diffraction pattern of the samples of small granules was clearly characterized by the respective season when the tubers were harvested. This suggests that the small granules have developed just before the harvest. Such starch granules in earlier stage of development were shown to be higher in contents of both amylose and the embraced fatty acids, the major component of which was palmitic acid. Both contents decreased with the development of granules, while the quantity of oleic acid incorporated was found to be approximately constant throughout the developing duration.These results suggest that palmitic acid contributes to the occurrence of starch granules in vivo, because incorporation of palmitic acid into amylose may result in repressing the free movement of amylose molecules and in bringing about formation of amylose gel.

著者

Ken Tokuyasu Kenji Yamagishi Yasumasa Ando Nobuya Shirai

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0003, (Released:2022-08-29)

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Cabbage core (CC) is regarded as a waste part of the vegetable, despite being edible and containing various nutritional and functional compounds. We investigated the properties of CC powder with particle sizes <1 mm as a new food material. CC powder was more resistant to structural deformation than leaf-derived powder, particularly CC powder with particles ≥0.3 mm in size. To examine the application of CC powder in 3D printed foods, we investigated the effects of “nata puree,” a disintegrated nata de coco made with tamarind seed gum (NPTG), on paste made with CC powder. NPTG promoted stable binding of paste made using CC powder, which was successfully extruded using a syringe to form a bar with a granular structure. Thus, CC powder possesses unique textural/structural properties for its application in next-generation foods.

著者

中村 保典

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.50, no.4, pp.511-512, 2003-10-20 (Released:2010-06-28)

参考文献数

5

著者

Eri Kokubo Hirofumi Sonoki Kenta Aizawa Hiroki Takagi Masayasu Takada Ayako Ito Yuki Nakazato Yasuhiro Takeda Kazuhiro Miyaji

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2021_0013, (Released:2022-04-19)

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Slowly digestible carbohydrates are needed for nutritional support in diabetic patients with malnutrition. They are a good source of energy and have the advantage that their consumption produces a low postprandial peak in blood glucose levels because they are slowly and completely digested in the small intestine. A high-amount isomaltomegalosaccharide containing carbohydrate (H-IMS), made from starch by dextrin dextranase, is a mixture of glucose polymers which has a continuous linear structure of α-1,6-glucosidic bonds and a small number of α-1,4-glucosidic bonds at the reducing ends. It has a broad degree of polymerization (DP) distribution with glucans of DP 10-30 as the major component. In our previous study, H-IMS has been shown to exhibit slow digestibility in vitro and not to raise postprandial blood glucose to such levels as that raised by dextrin in vivo. This marks it out as a potentially useful slowly digestible carbohydrate, and this study aimed to evaluate its in vivo digestibility. The amount of breath hydrogen emitted following oral administration of H-IMS was measured to determine whether any indigestible fraction passed through to and was fermented in the large intestine. Total carbohydrate in the feces was also measured. H-IMS, like glucose and dextrin, did not result in breath hydrogen excretion. Carbohydrate excretion with dietary H-IMS was no different from that of glucose or water. These results show that the H-IMS is completely digested and absorbed in the small intestine, indicating its potential as a slowly digestible carbohydrate in the diet of diabetic patients.

著者

Yuitsu Otsuka Koki Sato Shigekazu Yano Haruki Kanno Wasana Suyotha Hiroyuki Konno Koki Makabe Toki Taira

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2022_0002, (Released:2022-04-14)

被引用文献数

5

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The GH-16 type β-1,3-glucanase (BgluC16MK) gene of Lysobacter sp. MK9-1 was cloned to study its antifungal activities. BgluC16MK displays amino acid sequence similarity with GluC from L. enzymogenes strain N4-7. BgluC16MK includes a signal sequence, a catalytic domain and carbohydrate-binding module family 6-type β-glucan binding domain (B-GBD). The expression of the BgluC16MK gene in Escherichia coli without the signal sequence resulted in antifungal activity at a dose of 0.6–0.8 nmol/disk. However, BgluC16MK displayed antifungal activity at a dose of 0.025 nmol/disk in combination with Chi19MK. Substrate-specific assay revealed that purified BgluC16MK hydrolyzed insoluble curdlan more readily than the soluble substrate. Furthermore, to explore the binding selectivity of B-GBD of BgluC16MK, we constructed a fusion protein (B-GBD-GFP) using the B-GBD and green fluorescent protein. The activity of the fusion protein against various substrates indicates that B-GBD was selective for glucans with β-1,3-linkages. An additional study demonstrated the binding ability of BGBD-GFP to the cell-wall of living fungi, such as T. reesei and Aspergillus oryzae. These findings suggest that BgluC16MK can be utilized to generate antifungal enzyme preparations and that the fusion protein B-GBD-GFP can be used to identify the fungal cell surface structure using β-glucans.

著者

Ken Tokuyasu Kenji Yamagishi Junko Matsuki Daisuke Nei Tomoko Sasaki Masakazu Ike

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.68, no.4, pp.77-87, 2021-11-20 (Released:2021-11-20)

参考文献数

28

被引用文献数

5

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Pulverization is a potentially powerful solution for the resource management of surplus- and non-standard agricultural products, maintaining their nutritional values for long and ensuring their homogeneity, whereas their original textures could disappear to narrow the application ranges. Therefore, new technologies should be developed for reconstructing the powders to provide them with new physical characteristics. Herein, we developed a novel food material, nata puree (NP), by nata de coco (bacterial cellulose gel) disintegration with a water-soluble polysaccharide using a household blender. The process worked well with (1,3)(1,4)-β-glucan (BGL) as the polysaccharide, which could be substituted with barley extract. Lichenase treatment of the NP dramatically modified its physical properties, suggesting the importance of the BGL polymeric forms. NP exhibited distinct potato powder and starch binding activities, which would be attributed to its interactions with the cell wall components and a physical capture of powders by the NP network, respectively. NP supplementation into the potato paste improved its firmness and enabled its printable range shift for 3D food printing to a lower powder-concentration. NP also promoted the dispersion of powders in its suspension, and designed gelation could also be successfully performed by the laser irradiation of an NP suspension containing dispersed curdlan and turmeric powders. Therefore, NP could be applied as a powder modifier to a wide range of products in both conventional cooking, food manufacturing, and next generation processes such as 3D food printing.

著者

Trinh Ngoc Dang Le Akane Matsumoto Kiyoshi Kawai

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.68, no.4, pp.69-76, 2021-11-20 (Released:2021-11-20)

参考文献数

31

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Wheat flour-based batter containing 0 to 20 % trehalose was deep-fried, dried and held in various water activity (aw) conditions. The effects of trehalose content and aw on oil content, water sorption, isothermal mechanical relaxation, and fracture properties were investigated. For comparison, the fracture properties of freeze-dried porous waxy corn starch solids were also investigated. The 10 % trehalose sample had the lowest oil content, water content, and aw. A force-reduction value (∆F) of the samples was evaluated as a typical mechanical relaxation parameter. ∆F gradually increased with increasing aw and sharply increased above a specific aw presumed to be associated with the glass to rubber transition. Compared to ∆F values among the glassy samples, 10 and 20 % trehalose samples had higher ∆F values (were more rigid) than 0 and 5 % trehalose samples. From the fracture measurements of the glassy samples, the first fracture force increased linearly and the number of fracture peaks decreased linearly with increasing aw. At each aw, 10 % trehalose had the lowest first fracture force and the highest the number of fracture peaks. Freeze-dried porous waxy corn starch solids showed similar fracture properties to deep-fried samples. These findings suggest that around 10 % trehalose content is optimal for producing deep-fried foods with a brittle texture.

著者

並木 信重郎 神郡 邦男 長手 尊俊 杉田 和彦 原 寛 森 恵津子 大村 貞文 大関 正弘

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.27, no.2, pp.107-113, 1980-04-30 (Released:2010-06-28)

参考文献数

13

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TAI-A and TAI-B showed inhibitory activities against sucrase, maltase and isomaltase isolated from hog small intestine according to the method of Dahlqvist. TAI suppressed the increase of the blood glucose level of fasting mice administered with maltose. TAI suppressed the increase of the blood glucose level and the secretion of insulin of rats which were fasted and then forced-fed cooked corn starch, because of the inhibition against the starch digestion in the small intestine. The suppression of the increase in the body weight was observed in the 3 months toxicity test on the groups which were given diet containing 1.82 and 908 GIU/g of TAI, respectively . Hematological and histopathological examinations did not reveal any remarkable difference among all the experimental animals. TAI inhibited the growth of some anaerobic bacteria belonging to Clostridia, but did not show any inhibitory activity against other anaerobic bacteria. TAI and maltotriose showed an synergistic effect on the antibacterial activity.

著者

Hiroki Hosaka Sayaka Shirai Sora Fujita Mitsuru Tashiro Takako Hirano Wataru Hakamata Toshiyuki Nishio

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.4, pp.129-135, 2020-11-20 (Released:2020-11-20)

参考文献数

24

被引用文献数

1

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Utilizing transglycosylation reaction catalyzed by β-N-acetylhexosaminidase of Stenotrophomonas maltophilia, β-D-fructofuranosyl-(2↔1)-α-N, N´diacetylchitobioside (GlcNAc2-Fru) was synthesized from N-acetylsucrosamine and N, N´-diacetylchitobiose (GlcNAc2), and β-D-fructofuranosyl-(2↔1)-α-N, N´, N´´-triacetylchitotrioside (GlcNAc3-Fru) was synthesized from GlcNAc2-Fru and GlcNAc2. Through purification by charcoal column chromatography, pure GlcNAc2-Fru and GlcNAc3-Fru were obtained in molar yields of 33.0 % and 11.7 % from GlcNAc2, respectively. The structures of these oligosaccharides were confirmed by comparing instrumental analysis data of fragments obtained by enzymatic hydrolysis and acid hydrolysis of them with known data of these fragments.

著者

Tomonari Tanaka Ayane Matsuura Yuji Aso Hitomi Ohara

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.4, pp.119-127, 2020-11-20 (Released:2020-11-20)

参考文献数

33

被引用文献数

2

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Glycopolymers have attracted increased attention as functional polymeric materials, and simple methods for synthesizing glycopolymers remain needed. This paper reports the aqueous one-pot and chemoenzymatic synthesis of four types of glycopolymers via two reactions: the β-galactosidase-catalyzed glycomonomer synthesis using 4,6-dimetoxy triazinyl β-D-galactopyranoside and hydroxy group-containing (meth)acrylamide and (meth)acrylate derivatives as the activated glycosyl donor substrate and as the glycomonomer precursors, respectively, followed by radical copolymerization of the resulting glycomonomer and excess glycomonomer precursor without isolating the glycomonomers. The resulting glycopolymers bearing galactose moieties exhibited specific and strong interactions with the lectin peanut agglutinin as glycoclusters.

著者

Midori Umekawa Kaito Hamada Naoto Isono Shuichi Karita

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.4, pp.103-109, 2020-11-20 (Released:2020-11-20)

参考文献数

20

被引用文献数

6

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Hexokinases catalyze glucose phosphorylation at the first step in glycolysis in eukaryotes. In the budding yeast Saccharomyces cerevisiae, three enzymes for glucose phosphorylation have long been known: Hxk1, Hxk2, and Glk1. In this study, we focus on Emi2, a previously uncharacterized hexokinase-like protein of S. cerevisiae. Our data show that the recombinant Emi2 protein (rEmi2), expressed in Escherichia coli, possesses glucose-phosphorylating activity in the presence of ATP and Mg2+. It was also found that rEmi2 phosphorylates not only glucose but also fructose, mannose and glucosamine in vitro. In addition, we examined changes in the level of endogenous Emi2 protein in S. cerevisiae in the presence or absence of glucose and a non-fermentable carbon source. We found that the expression of Emi2 protein is tightly suppressed during proliferation in high glucose, while it is strongly upregulated in response to glucose limitation and the presence of a non-fermentable carbon source. Our data suggest that the expression of the endogenous Emi2 protein in S. cerevisiae is regulated under the control of Hxk2 in response to glucose availability in the environment.

著者

檜作 進 伊藤 恵子 前田 巌 二国 二郎

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.19, no.2, pp.70-75, 1972-09-15 (Released:2011-07-01)

参考文献数

5

被引用文献数

6 6

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1)玉蜀黍,小麦,馬鈴薯,甘藷,糯玉蜀黍,糯米の5%でんぷん糊を,0~70℃ の定温(10℃ ごと)に1時間保存し,老化の温度依存性を調べた。糊化度は,グルコアミラーゼによる消化法(A法)と電流滴定による結合ヨード量の測定(I法)で行なった。でんぷん糊は,5%のでんぷん懸濁液を100℃ に5分および30分間加熱して調製した。 2)調製時の糊の糊化度は,甘藷や馬鈴薯でんぷんでは,糊化時間の長短,測定方法にかかわらず完全糊化(糊化度97%以上)と判定された。小麦や玉蜀黍でんぷんは,30分の糊化で,A法では完全に糊化しているとみられたが,I法では90%程度の糊化度を示し,アミロース分子の糊化が十分でないことが示唆された。玉蜀黍でんぷんの5分糊化の糊では糊化度はさらに悪く,82%であった。 3)いずれのでんぷんも,5分加熱の糊のほうが30分加熱の糊よりも老化しやすく,低温ほど老化が速やかで,0℃ が最も老化しやすかった。 4)糯質のでんぷんは最も老化し難く,0℃ においても老化は感知されなかった。ついで甘藷でんぷんが老化し難く,30分加熱の糊では0℃ においてもほとんど老化を起こさなかったが,5分加熱の糊では0~10℃ でわずかであるが老化がみられた。馬鈴薯でんぷんも甘藷でんぷんと同様な結果を示したが,甘藷よりは少し変化を起こしやすい性質が認められた。小麦でんぷんは,いも類でんぷんよりもはるかに老化しやすく,40~50℃以下の温度で老化が速やかになった。玉蜀黍でんぷんは小麦でんぷんと優劣をつけ難いが,50~60℃ 以下の温度で老化が速やかであった。 5)いずれの場合も,老化によってI法による糊化度の低下が顕著で,アミロース分子が老化を主導していることが示唆され,でんぷんの種類により,アミロース分子の老化の温度依存性に明らかな特徴がみられた。

著者

Feunai Agape Papalii Tautau Minoru Izumi Emiko Matsunaga Yujiro Higuchi Kaoru Takegawa

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.3, pp.87-93, 2020-09-03 (Released:2020-09-03)

参考文献数

36

被引用文献数

2

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α-L-Rhamnosidases (α-L-Rha-ases, EC 3.2.1.40) are glycosyl hydrolases (GHs) that hydrolyze a terminal α-linked L-rhamnose residue from a wide spectrum of substrates such as heteropolysaccharides, glycosylated proteins, and natural flavonoids. As a result, they are considered catalysts of interest for various biotechnological applications. α-L-rhamnose (6-deoxy-L-mannose) is structurally similar to the rare sugar α-L-mannose. Here we have examined whether microbial α-L-Rha-ases possess α-L-mannosidase activity by synthesizing the substrate 4-nitrophenyl α-L-mannopyranoside. Four α-L-Rha-ases from GH78 and GH106 families were expressed and purified from Escherichia coli cells. All four enzymes exhibited both α-L-rhamnosyl-hydrolyzing activity and weak α-L-mannosyl-hydrolyzing activity. SpRhaM, a GH106 family α-L-Rha-ase from Sphingomonas paucimobilis FP2001, was found to have relatively higher α-L-mannosidase activity as compared with three GH78 α-L-Rha-ases. The α-L-mannosidase activity of SpRhaM showed pH dependence, with highest activity observed at pH 7.0. In summary, we have shown that α-L-Rha-ases also have α-L-mannosidase activity. Our findings will be useful in the identification and structural determination of α-L-mannose-containing polysaccharides from natural sources for use in the pharmaceutical and food industries.

著者

Sora Yamaguchi Naoki Sunagawa Mikako Tachioka Kiyohiko Igarashi Masahirog Samejima

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.3, pp.79-86, 2020-09-03 (Released:2020-09-03)

参考文献数

22

被引用文献数

4

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Thermal inactivation of saccharifying enzymes is a crucial issue for the efficient utilization of cellulosic biomass as a renewable resource. Cellobiohydrolases (CBHs) are a kind of cellulase. In general, CBHs belonging to glycoside hydrolase (GH) family 6 (Cel6) act synergistically with CBHs of GH family 7 (Cel7) and other carbohydrate-active enzymes during the degradation of cellulosic biomass. However, while the catalytic rate of enzymes generally becomes faster at higher temperatures, Cel6 CBHs are inactivated at lower temperatures than Cel7 CBHs, and this represents a limiting factor for industrial utilization. In this study, we produced a series of mutants of the glycoside hydrolase family 6 cellobiohydrolase PcCel6A from the fungus Phanerochaete chrysosporium, and compared their thermal stability. Eight mutants from a random mutagenesis library and one rationally designed mutant were selected as candidate thermostable mutants and produced by heterologous expression in the yeast Pichia pastoris. Comparison of the hydrolytic activities at 50 and 60 °C indicated that the thermal stability of PcCel6A is influenced by the number and position of cysteine residues that are not involved in disulfide bonds.

著者

鈴木 綾子

出版者

The Japanese Society of Applied Glycoscience

雑誌

澱粉科学 (ISSN:00215406)

巻号頁・発行日

vol.40, no.2, pp.233-243, 1993-06-30 (Released:2010-06-28)

参考文献数

19

被引用文献数

1 4

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Starch is a main component of cereal and vegetable foods . In addition, it is added to many kinds of foods to improve the texture and taste as an ingredient . Starch changes its physicochemical properties by gelatinization, when it is cooked. Consequently, the behaviors of pasting and the paste properties of starches, such as gelatinization temperature, and transparency, viscosity, and retrogradation tendency of the paste, etc. give important effects on cooking and the processing of foods. In this article, the properties of various kinds of starches and their relations with the functions and roles on cooking were discussed.

著者

Yu Teshigahara Ikuko Kakizaki Wataru Hirao Kanji Tanaka Ryoki Takahashi

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.2, pp.63-66, 2020-05-20 (Released:2020-05-20)

参考文献数

17

被引用文献数

2

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Human urinary trypsin inhibitor (UTI) is a proteoglycan composed of one core protein covalently linked to one glycosaminoglycan, which is a low sulfated chondroitin 4-sulfate. It is used as an anti-inflammatory medicine based on the protease inhibitory activity of the core protein. However, functions of the chondroitin sulfate have not been clarified. Recently, we succeeded in remodeling the UTI chondroitin sulfate to hyaluronan to create hyaluronan hybrid UTI, without changing the core protein. Here, we investigated the effect of the remodeled chondroitin sulfate on the activities of serine proteases. Native UTI showed stronger protease inhibitory activity than hyaluronan hybrid UTI or hydrolyzed glycosaminoglycan UTI. Chondroitin 4-sulfate chains with a small peptide derived from the native UTI did not show any protease inhibitory activity. These results suggest that the chondroitin sulfate chain linked covalently to core protein enhances protease inhibitor activity of UTI although the chondroitin sulfate chain itself does not.

著者

Masakazu Ike Ken Tokuyasu

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0019, (Released:2020-02-19)

被引用文献数

1

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The aim of this study was to investigate the effect of pH control by CO2 pressurization on the enzymatic hydrolysis of herbaceous feedstock in the calcium capturing by carbonation (CaCCO) process for fermentable sugar production. The pH of the slurry of 5% (w/w) Ca(OH)2-pretreated/CO2-neutralized rice straw could be controlled between 5.70 and 6.38 at 50 °C by changing the CO2 partial pressure (pCO2) from 0.1 to 1.0 MPa. A mixture of fungal enzyme preparations, namely, Trichoderma reesei cellulases/hemicellulases and Aspergillus niger β-glucosidase, indicated that pH 5.5–6.0 is optimal for solubilizing sugars from Ca(OH)2-pretreated rice straw. Enzymatic saccharification of pretreated rice straw under various pCO2 conditions revealed that the highest soluble sugar yields were obtained at pCO2 0.4 MPa and over, which is consistent with the expected pH at the pCO2 without enzymes and demonstrates the effectiveness of pH control by CO2 pressurization.

著者

Kiyohiko Igarashi Satoshi Kaneko Motomitsu Kitaoka Masahiro Samejima

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

vol.67, no.2, pp.51-57, 2020-05-20 (Released:2020-05-20)

参考文献数

40

被引用文献数

2

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Cellobiose dehydrogenase (CDH) is a flavocytochrome catalyzing oxidation of the reducing end of cellobiose and cellooligosaccharides, and has a key role in the degradation of cellulosic biomass by filamentous fungi. Here, we use a lineup of glucose/xylose-mixed β-1,4-linked disaccharides and trisaccharides, enzymatically synthesized by means of the reverse reaction of cellobiose phosphorylase and cellodextrin phosphorylase, to investigate the substrate recognition of CDH. We found that CDH utilizes β-D-xylopyranosyl-(1→4)-D-glucopyranose (Xyl-Glc) as an electron donor with similar Km and kcat values to cellobiose. β-D-Glucopyranosyl-(1→4)-D-xylopyranose (Glc-Xyl) shows a higher Km value, while xylobiose does not serve as a substrate. Trisaccharides show similar behavior; i.e., trisaccharides with cellobiose and Xyl-Glc units at the reducing end show similar kinetics, while the enzyme was less active towards those with Glc-Xyl, and inactive towards those with xylobiose. We also use docking simulation to evaluate substrate recognition of the disaccharides, and we discuss possible molecular mechanisms of substrate recognition by CDH.

著者

Atsushi Kawano Kansuke Fukui Yuji Matsumoto Atsushi Terada Akihiro Tominaga Nozomi Nikaido Takashi Tonozuka Kazuhide Totani Nozomu Yasutake

出版者

The Japanese Society of Applied Glycoscience

雑誌

Journal of Applied Glycoscience (ISSN:13447882)

巻号頁・発行日

pp.jag.JAG-2019_0015, (Released:2020-03-06)

被引用文献数

9

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According to whole-genome sequencing, Aspergillus niger produces multiple enzymes of glycoside hydrolases (GH) 31. Here we focus on a GH31 α-glucosidase, AgdB, from A. niger. AgdB has also previously been reported as being expressed in the yeast species, Pichia pastoris; while the recombinant enzyme (rAgdB) has been shown to catalyze tranglycosylation via a complex mechanism. We constructed an expression system for A. niger AgdB using Aspergillus nidulans. To better elucidate the complicated mechanism employed by AgdB for transglucosylation, we also established a method to quantify glucosidic linkages in the transglucosylation products using 2D NMR spectroscopy. Results from the enzyme activity analysis indicated that the optimum temperature was 65 °C and optimum pH range was 6.0–7.0. Further, the NMR results showed that when maltose or maltopentaose served as the substrate, α-1,2-, α-1,3-, and small amount of α-1,1-β-linked oligosaccharides are present throughout the transglucosylation products of AgdB. These results suggest that AgdB is an α-glucosidase that serves as a transglucosylase capable of effectively producing oligosaccharides with α-1,2-, α-1,3-glucosidic linkages.