記述言語：英語   出版者・発行元：日本応用糖質科学会  

DOI： 10.5458/jag.jag.jag-2023_0006

PubMed

CiNii Research

記述言語：日本語   出版者・発行元：Journal of Bioscience and Bioengineering  

A putative methyltransferase, LaeA, controls citric acid production through epigenetic regulation of the citrate exporter gene, cexA, in the white koji fungus Aspergillus luchuensis mut. kawachii. In this study, we investigated the role of another epigenetic regulator, heterochromatin protein 1, HepA, in citric acid production. The ΔhepA strain exhibited reduced citric acid production in liquid culture, although to a lesser extent compared to the ΔlaeA strain. In addition, the ΔlaeA ΔhepA strain showed citric acid production similar to the ΔlaeA strain, indicating that HepA plays a role in citric acid production, albeit with a less-significant regulatory effect than LaeA. RNA-seq analysis revealed that the transcriptomic profiles of the ΔhepA and ΔlaeA strains were similar, and the expression level of cexA was reduced in both strains. These findings suggest that the genes regulated by HepA are similar to those regulated by LaeA in A. luchuensis mut. kawachii. However, the reductions in citric acid production and cexA expression observed in the disruptants were mitigated in rice koji, a solid-state culture. Thus, the mechanism by which citric acid production is regulated differs between liquid and solid cultivation. Further investigation is thus needed to understand the regulatory mechanism in koji.

DOI： 10.1016/j.jbiosc.2023.09.004

Scopus

PubMed

記述言語：日本語   出版者・発行元：Bioscience, Biotechnology and Biochemistry  

In this study, we developed an efficient gene targeting system for the osmophilic fungus Aspergillus chevalieri, which is commonly used in the production of a dried bonito, katsuobushi. Specifically, we utilized the clustered regularly interspaced short palindromic repeats/Cas9 system to disrupt the ATP sulfurylase encoding sC gene. This results in methionine auxotroph and selenate-resistance. Additionally, we disrupted the DNA ligase IV encoding ligD gene, which is required for nonhomologous end joining. Using the sC marker and selenate-resistance as a selection pressure, we were able to rescue the sC marker and generate a ligD sC strain. We determined that the gene targeting efficiency of the ligD sC strain was significantly higher than that of the parental sC strain, which indicates that this strain provides efficient genetic recombination for the genetic analysis of A. chevalieri.

DOI： 10.1093/bbb/zbad033

Scopus

PubMed

記述言語：日本語   出版者・発行元：Journal of Bioscience and Bioengineering  

Kokuto-shochu is a traditional Japanese spirit prepared from kokuto, obtained by evaporating water from sugarcane (Saccharum officinarum L.) juice. To clarify the effects of sugarcane cultivars on the sensory quality of kokuto-shochu, we investigated the flavor characteristics and composition of volatiles in kokuto-shochu prepared from kokuto using three different sugarcane cultivars, NiF8, Ni15, and RK97-14. Furthermore, experiments were conducted by using the cultivars collected between 2018 and 2020 to observe annual variations in their properties. The amino acid content of the three kokuto varieties did not differ significantly, but the amino acid content of NiF8 was two to five times higher than that of RK97-14, which was the same for all samples collected in the selected years. The browning degrees of kokuto were also higher in NiF8, and they were positively correlated to the amino acid contents of kokuto. The kokuto-like aroma of shochu made from Ni15 was stronger than that of shochu made from RK97-14. The concentration of ethyl lactate in shochu made from Ni15 was higher, however, the concentration of guaiacol was the lowest in the three cultivars’ products. Shochu made from NiF8 had the highest levels of Maillard reaction products (MRPs; pyrazines and furans), β-damascenone, and guaiacol amounts. In contrast, shochu made from RK97-14 tended to have a fruity flavor, and lower MRP levels than those made from NiF8. Thus, it was shown that sugarcane cultivars affect the sensory characteristics and volatiles in kokuto-shochu.

DOI： 10.1016/j.jbiosc.2023.03.010

Scopus

PubMed

記述言語：日本語   出版者・発行元：Journal of Bioscience and Bioengineering  

In shochu-making, a small amount of fermenting moromi is added to a koji/water mixture instead of yeast culture to initiate fermentation. This is a characteristic process called Sashi-moto. It is known that shochu yeast is replaced by wild yeast upon repetition of Sashi-moto. The shochu yeast strains Kagoshima No. 2 (K2), Kagoshima No. 4 (C4), and Kagoshima No. 5 (H5), but not Kagoshima No. 6 (A6), were replaced by wild yeast (strain No. S5-g). K2 and C4 were easily replaced compared to H5, and the specific growth rates of K2 and C4 were lower than that of S5-g under higher osmotic pressure. Although the specific growth rate of H5 was higher than that of S5-g, its yeast population at the stationary phase was smaller than S5-g. On the other hand, both the specific growth rate and yeast population of A6 were higher than those of S5-g. The specific growth rate of yeast would be affected by osmotic tolerance and specific characters of the yeast strain.

DOI： 10.1016/j.jbiosc.2022.07.011

Scopus

PubMed

記述言語：日本語   出版者・発行元：Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids  

Autophagy is regulated by phosphoinositides. We have previously shown that phosphatidylinositol 4-phosphate (PtdIns(4)P) is localized in the autophagosomal membrane. Additionally, in yeast cells, phosphatidylinositol 4-kinases Pik1p and Stt4p play important roles in the formation of the autophagosome and its fusion with the vacuole, respectively. In this study, we analyzed the primary role of PtdIns(4)P phosphatases in yeast autophagy. The PtdIns(4)P labeling densities in the membranes of the vacuoles, mitochondria, nucleus, endoplasmic reticulum, and plasma membrane dramatically increased in the phosphatase deletion mutants sac1∆ and sjl3∆, and the temperature-sensitive mutant sac1ts/sjl3∆ at the restrictive temperature. GFP-Atg8 processing assay indicated defective autophagy in the sac1∆ and sac1ts/sjl3∆ mutants. In contrast to the localization of PtdIns(4)P in the luminal leaflet of autophagosomal membranes in the wild-type yeast, PtdIns(4)P was localized in both the luminal and cytoplasmic leaflets of the autophagosomal membranes in the sac1∆ strain. In addition, the number of autophagic bodies in the vacuole significantly decreased in the sac1∆ strain, although autophagosomes were present in the cytoplasm. In the sac1ts/sjl3∆ strain, the number of autophagosomes in the cytoplasm dramatically decreased at the restrictive temperature. Considering that the numbers of autophagosomes and autophagic bodies in the sjl3∆ strain were comparable to those in the wild-type yeast, we found that the autophagosome could not be formed when PtdIns(4)P phosphatase activities of both Sac1p and Sjl3p were diminished. Together, these results indicate that the turnover of PtdIns(4)P by phosphatases is essential for autophagosome biogenesis.

DOI： 10.1016/j.bbalip.2022.159184

Scopus

PubMed

記述言語：英語   出版者・発行元：John Wiley & Sons Australia, Ltd  

Massa Medicata Fermentata(MMF)はAspergillus属やRhizopus属による微生物発酵でコムギと数種のハーブから調製されるので、微生物発酵の影響について検討した。National Standard for Chinese Patent Drugsに従ってMMFの原材料を混合し、Aspergillus oryzae培養で調製(MMF-A)またはRhizopus oryzae培養で調製(MMF-R)した。MMFの調製により酵素活性は上昇した。MMF-AはMMF-Rよりもα-アミラーゼとリパーゼの活性が高かった。プロテアーゼ活性はMMF-Rがわずかに高かった。テルペノイドは発酵で低下したが、2,3-ブタンジオール、アセトイン、グアヤコールはMMFだけで検出された。1-オクテン-3-オールのC8化合物はMMF-RよりもMMF-Aで高く、4-ビニルグアヤコールとピラジンの芳香族化合物はMMF-Rで高かった。

記述言語：日本語   出版者・発行元：Traditional and Kampo Medicine  

Aim: Massa Medicata Fementata (MMF) is a crude drug used in East Asia to treat anorexia and dyspepsia. It is prepared from wheat and several herbs through microbial fermentation using Aspergillus sp. and Rhizopus sp. There is great difference in the quality of commercial MMF, and the microbes of MMF are suggested to affect its quality. We investigated the effects of microbial fermentation on the quality of MMF. Methods: Raw materials of MMF were mixed according to the ratio listed in the National Standard for Chinese Patent Drugs, and MMF was prepared using pure cultures of Aspergillus oryzae or Rhizopus oryzae. Digestive enzyme activities (α-amylase, protease, and lipase) and volatile compounds were measured using an analytical kit and GC–MS, respectively. Results: Enzyme activity increased in MMF. MMF prepared with A. oryzae (MMF-A) showed higher α-amylase and lipase activities than that prepared with R. oryzae (MMF-R). Protease activity was marginally higher in MMF-R than in MMF-A. GC–MS analysis revealed that terpenoids decreased with fermentation; however, 2,3-butanediol, acetoin, and guaiacol were detected in MMF only. C8 compounds such as 1-octen-3-ol were higher in MMF-A than MMF-R; however, aromatic compounds such as 4-vinylguaiacol and pyrazines were higher in MMF-R than MMF-A. Conclusion: Microbial fermentation contributes to increased enzyme activity and changes in MMF volatiles. These properties of MMF were considerably affected by the microbes used, and it is proposed in this study that it is important to have microbial control in the production of commercial MMF.

DOI： 10.1002/tkm2.1303

Scopus

記述言語：英語  

DOI： 10.1016/j.dib.2022.107888

PubMed

記述言語：日本語   出版者・発行元：公益財団法人 日本醸造協会  

<p>米麹と主原料を別々に仕込む二次仕込み法と呼ばれる焼酎特有の仕込み法に，中国の蒸留酒である米香型白酒の仕込み法である固体糖化を融合した新規な仕込み法による芋焼酎の製造の可能性について検討した。その結果，最適な糖化条件は，糖化温度は60℃，糖化時間は24時間，麹歩合は10%であり，この時の糖化率は48.5%であった。サツマイモに含まれるスクロースが米麹由来の酵素により分解されることが分かった。麹歩合を上げても，糖化率は向上しなかった。これは，α-アミラーゼの蒸し米への無効吸着が原因であることが分かった。ニューラーゼF3G（プロテアーゼ）を添加すると糖化率は70 %に向上した。最適な糖化条件で芋焼酎を製造すると，従来の仕込み法と比べ発酵は遜色なかった。得られた焼酎は，従来法の焼酎と比べ，香りは焼芋様や花様が強く，味は苦味の評点が高くまた，キレと濃厚さがあった。また，香気成分は同定された42成分のほとんどが，固体糖化焼酎が従来焼酎と比べて僅かではあるが高濃度に含まれ，その内17成分が両焼酎間の濃度に有意差があった。これらのことから，焼酎製造における二次仕込み法に中国の米香型白酒の固体糖化工程を融合する新規な芋焼酎製造が可能であるとともに，酒質の多様化が期待できることが分かった。</p>

DOI： 10.6013/jbrewsocjapan.117.712

CiNii Research

記述言語：日本語   出版者・発行元：公益財団法人 日本醸造協会  

<p>本研究ではサトイモ焼酎の製造と特徴香気および焼酎粕の機能性の探索を試みた。サトイモのデンプン価を測定し，サツマイモ焼酎の仕込み配合を参考とし，二次もろみのアルコール度数が同程度になるように主原料由来のデンプン量を合わせ，さらに汲み水も調整した仕込み配合表でサトイモ焼酎を仕込んだ。サトイモは，皮付きのもの（皮あり）または，皮を除いたもの（皮なし）を用いて焼酎を製造し，サツマイモ焼酎と比較した。サトイモ焼酎のもろみは，サツマイモ焼酎とほぼ同等に発酵した。このことからサトイモの外皮および外側部分は発酵に影響を与えないことが確認された。またサトイモ焼酎のもろみ酸度はサツマイモ焼酎よりも高く，サトイモの成分が酵母の生育にストレスを与えたと考えた。蒸留歩合はサツマイモより，サトイモの蒸留歩合が低いものの，十分蒸留できると判断した。焼酎の官能評価より，サツマイモ焼酎と比べて，サトイモ焼酎の香りは草様が強いことが特徴であった。味は，渋味，苦味，濃厚さが強い傾向であることが分かった。香気成分分析よりサトイモ焼酎は，サツマイモ焼酎より果実香や花様の香りを有するエステル化合物やテルペン化合物の含量少なく，一方で草様やセッケン様の香りを有するアルコールやアルデヒドを多く含むことが明らかになった。加えて，サトイモ焼酎粕の上清液には，抗糖化活性と強いACE阻害活性を持つことを確認した。このことから，サトイモ焼酎の香味はサツマイモ焼酎と比べて草様が強く，果実香と花様の香りが弱い特徴を持つが，全体としては全ての項目に強弱なく，均整が取れていることが確認された。さらにサトイモは，焼酎粕の有効活用も期待できる原料であることが示された。</p>

DOI： 10.6013/jbrewsocjapan.117.701

CiNii Research

記述言語：日本語   出版者・発行元：Food Bioscience  

In this study, we compared the flavor profiles Chinese rice-flavor baijiu and Japanese awamori—traditional liquors with similar manufacturing processes. Citric acid and lactic acid were the major acid constituents in the mash of awamori and rice-flavor baijiu, respectively. The amino acid content of awamori mash was greater than that of rice-flavor baijiu owing to the higher proteolytic activities in the former. The high amino acid content also induced yeast growth at the early stage of fermentation in awamori mash, thus increasing the fermentation rate. Sensory evaluation revealed that rice-flavor baijiu had a significantly stronger alcoholic, floral, and fruity aroma, whereas the awamori had a strong sour, koji-like, oily, and cereal-like aromas. We determined the aroma threshold of (+)-ethyl D-lactate (15,400 μg/L) and (−)-ethyl L-lactate (12,500 μg/L). Both compounds have a common sweet, fruity, and green leaves-like aroma and a different nuance; (+)-ethyl D-lactate has a peach- and citrus-like aromas, and (−)-ethyl L-lactate has an apple-like and milky aromas. In rice-flavor baijiu, (−)-ethyl L-lactate constitutes the major isoform, as evident from the higher concentration of L (+)-lactic acid in the mash. Higher alcohols, (−)-ethyl L-lactate, and isoamyl acetate contents were greater in rice-flavor baijiu, while 1-octen-3-ol and acetic acid were greater in awamori. These results showed that solid-state saccharification contributed to the production of ethyl lactate by supplying in the mash a large amount of lactic acid produced by Rhizopus oryzae and koji contributed to the production of 1-octen-3-ol via the high fatty acid oxygenase activity produced by Aspergillus luchuensis.

DOI： 10.1016/j.fbio.2021.101375

Scopus

記述言語：日本語   出版者・発行元：Journal of Food Science  

Rice-flavor baijiu is a traditional Chinese liquor. The flavor profile and volatiles presented with or without the solid-state saccharification (SSS) were investigated to reveal the effects of SSS process on the quality of rice-flavor baijiu. The liquor prepared with SSS had a sweet flavor. It contained significantly higher contents of β-phenylethyl alcohol, β-phenylethyl acetate, and ethyl lactate with odor active value of >1. The liquor prepared without SSS had a cheese-like flavor. It was confirmed that the cheese-like flavor derived from butanoic acid was only detected in the liquor prepared without SSS. SSS facilitated the biosynthesis of β-phenylethyl alcohol and ethyl lactate by supplying a large amount of phenylalanine and lactic acid at the initial stage of fermentation, and it prevented contamination. These results indicated that the SSS process contributed to produce the characteristic flavor compounds of rice-flavor baijiu. Practical Application: Solid-state saccharification (SSS) process of rice-flavor baijiu contributes not only in brewing, but also in the production of the characteristic flavor compounds and the repression of the off-flavor derived from the contamination. Therefore, SSS is a critical process to control the flavor of rice-flavor baijiu.

DOI： 10.1111/1750-3841.15935

Scopus

PubMed

記述言語：日本語   出版者・発行元：Microbiology Resource Announcements  

Aspergillus puulaauensis strain MK2 was isolated from a dead hard tick (Haemaphysalis longicornis). Here, we determined the chromosome-level genome sequence of A. puulaauensis MK2.

DOI： 10.1128/MRA.00372-21

Scopus

PubMed

記述言語：日本語   出版者・発行元：Microbiology Resource Announcements  

In this study, we report the chromosome-level genome sequence of the osmophilic filamentous fungus Aspergillus chevalieri M1, which was isolated from a dried bonito, katsuobushi. This fungus plays a significant role in the fermentation and ripening process. Thus, elucidating the sequence data for this fungus will aid in subsequent genomic research on the fungi involved in katsuobushi production.

DOI： 10.1128/MRA.00385-21

Scopus

PubMed

記述言語：日本語   出版者・発行元：Microbiology Resource Announcements  

Aspergillus luchuensis is used for the production of awamori and shochu, which are traditional Japanese distilled alcoholic beverages. Here, we determined the chromosome-level genome sequence of A. luchuensis RIB2601.

DOI： 10.1128/MRA.00384-21

Scopus

PubMed

記述言語：日本語   出版者・発行元：Bioscience, biotechnology, and biochemistry  

Escherichia coli strain, whose gene is one of the subunits of succinate dehydrogenase (sdhA), and gene of the transcriptional repressor of isocitrate lyase (iclR) were disrupted, accumulated 6.6 times as much intracellular succinate as the wild-type MG1655 strain in aerobic growth, but succinate was not found in the culture medium. E. coli citT gene that encodes a citrate transporter was cloned under the control of the lacI promoter in pBR322-based plasmid and the above strain was transformed. This transformant, grown under aerobic condition in M9-tryptone medium with citrate, accumulated succinate in the medium while no succinate was found in the medium without citrate. CitT was active as a succinate transporter for 168 h by changing the culture medium or for 24 h in fed-batch culture. This study suggests that the CitT transporter functions as a succinate exporter in E. coli for succinate production in the presence of citrate.

DOI： 10.1093/bbb/zbaa109

Scopus

PubMed

記述言語：日本語   出版者・発行元：LWT  

We investigated the contribution of the complex expressions of two α-amylases, namely acid-stable α-amylase (AS-amylase) and acid-labile α-amylase (AL-amylase), from Aspergillus kawachii to the microstructure of koji and the brewing. AL-amylase was found to be the primary contributor to the decomposition of starch in the early stage of koji making. From the middle stage, both α-amylases decomposed the starch in a coordinated manner, and at the final stage, acid-stable α-amylase and glucoamylase decomposed the starch granules. Characterization of koji prepared by the single disruptions of AS-amylase or AL-amylase genes, double disruption of both α-amylase genes, and triple disruption of two α-amylase and glucoamylase genes in A. kawachii cells indicated that both α-amylases can work in a synergistic manner to decompose starches during koji making. AL-amylase was found, for the first time, to play an important role in starch decomposition in koji. The speed of alcohol fermentation and ester contents of the fermented mash were higher the mash prepared the control strain, followed by single, double, and triple disruptants. These results indicate that the microstructure of koji plays a role in promoting alcohol fermentation and flavor development.

DOI： 10.1016/j.lwt.2020.110580

Scopus

記述言語：日本語   出版者・発行元：Journal of Food Science  

Abstract: Additional moisture in preparing red koji, Monascus-fermented rice, is a characteristic production process. To determine how additional moisture affects red koji preparation as per quality, we compared the growth of Monascus purpureus, enzyme and pigment production, and related gene expressions using our findings. We considered two kinds of red koji: one prepared with additional moisture at the middle part of the preparation and the other prepared without additional moisture. Our results showed that additional moisture did not promote the growth of M. purpureus, but it was significantly increased the pigment (red and yellow) and tended to increase the α-amylase level and saccharification power. Although adding a high amount of moisture (approximately 60% moisture content) promoted pigment production, it slightly repressed enzyme production. In contrast, adding approximately 50% moisture content promoted enzyme production. These findings showed that the additional moisture can affect the quality of red koji on the purpose. The expression of 10 pigment biosynthetic gene clusters and two glycohydrolase genes in red koji after adding moisture was analyzed through real-time qPCR. Eight genes were upregulated within 1 hr after adding water, with mppR2 being the first upregulated gene within 30 min. The expression of genes as per pigment production quickly responded to additional moisture during solid-state fermentation. Moreover, acetyl-CoA, which is a starting substrate for pigment content in red koji was increased within 3 hr after adding water. This study first described the relationship between additional moisture and expression of pigment biosynthetic genes by Monascus spp. during red koji preparation.

DOI： 10.1111/1750-3841.15610

Scopus

PubMed

記述言語：日本語   出版者・発行元：Journal of Bioscience and Bioengineering  

Citrate exporter CexA plays a key role in the production of citric acid in fungi; however, its role in intracellular metabolism has remained unclear. In this study, we comparably characterized homologous cexA genes in the white koji fungus Aspergillus luchuensis mut. kawachii and the yellow koji fungus Aspergillus oryzae, which exhibit high and low abilities, respectively, to produce citric acid. Disruption of cexA caused a significant decline of both extracellular and intracellular citric acid accumulation in Aspergillus kawachii, while overexpression of the A. kawachii cexA gene (AkcexA) into A. oryzae significantly enhanced both extracellular and intracellular citric acid accumulation in A. oryzae to a level comparable to that of A. kawachii. In addition, overexpression of two intrinsic cexA homologs (AocexA and AocexB) in A. oryzae also enhanced its extracellular and intracellular citric acid accumulation. Comprehensive analysis of intracellular metabolites from an AkcexA-overexpressing strain of A. oryzae compared with its control strain identified metabolic changes associated with intracellular citric acid accumulation via the glycolytic pathway, pentose phosphate pathway, and tricarboxylic acid cycle. Our results indicate that citric acid export enhances not only extracellular citric acid accumulation but also intracellular metabolic fluxes to generate citric acid.

DOI： 10.1016/j.jbiosc.2020.09.002

Scopus

PubMed

記述言語：日本語   出版者・発行元：Journal of the Institute of Brewing  

DOI： 10.1002/jib.674

Scopus

記述言語：日本語   出版者・発行元：公益財団法人 日本醸造協会  

<p>芋焼酎の製造に用いられている，黄麴，白麴，黒麴を用いて，麴以外はすべて同一条件で行い，芋焼酎における麴が違うことで生じる差異を検討した。 市販種麴を用いて作製した麴は，麴酸度は白麴および黒麴で高く，黄麴は非常に低い値であった。酵素活性ではAA活性は黄麴が白麴および黒麴と比較して非常に高い活性であったが，酸性条件下での液化に関与するAsAA活性は白麴および黒麴で黄麴の10倍の活性となった。白麴および黒麴ではBG活性，CEL活性，AP活性，LIP活性が黄麴よりも高い。白麴と黒麴の比較では，BG活性およびCEL活性以外の酵素活性は白麴が高い傾向を示した。 得られた麴を用いて小仕込みを行ったところ，各醪共に問題なく発酵が行われた。クエン酸生成能が高い白麴および黒麴醪のpHおよび醪酸度は黄麴醪と比べ，一次および二次醪共にpHは低く，酸度は高かった。黄麴醪では二次醪の初期に白麴および黒麴醪とは異なり，醪の流動性が低下した。黄麴は白麴および黒麴よりもAP活性およびCEL活性が低いことから，流動性に差異が生じ，醪のアルコール濃度も白麴および黒麴醪が高かった。また，AP活性の高い白麴および黒麴ではアミノ酸濃度は黄麴よりも高かった。一次醪末期の総アミノ酸濃度は黄麴醪が高く，二次醪末期では白麴および黒麴醪が高くなった。黄麴醪では一次醪から二次醪にかけて高級アルコール生成に関わるアミノ酸の減少が大きかった。醪中の有機酸は白麴および黒麴醪では麴由来のクエン酸濃度が高くなった。</p>

DOI： 10.6013/jbrewsocjapan.116.39

CiNii Research

記述言語：日本語   出版者・発行元：公益財団法人 日本醸造協会  

<p>白麹菌は，製麹過程で多量のクエン酸を生産することが以前から知られていたが，その分子機構については長年不明であった。著者らは，近年，遺伝子解析や遺伝子工学的手法によりミトコンドリアおよび細胞膜に存在する複数のトランスポーター（輸送体）が重要な役割をしていることを明らかとした。さらに，これらトランスポーターの発現のコントロール機構についても研究を重ねている。一方，黄麹菌においても，これら白麹菌のクエン酸輸送体に相当するトランスポーターをコードする遺伝子の存在を見出し，それらを強制発現することで，黄麹菌のクエン酸生産を示した。本稿では，著者らの研究成果を中心に，麹菌のクエン酸輸送体の最新の知見について解説いただいた。</p>

DOI： 10.6013/jbrewsocjapan.116.810

CiNii Research

記述言語：日本語   出版者・発行元：公益財団法人 日本醸造協会  

<p>芋焼酎の製造に用いられている，黄麴，白麴，黒麴を用いて，麴以外はすべて同一条件で行い，芋焼酎における麴が違うことで生じる香気成分及び官能評価の差異を検討した。 GC-MSによる香気成分は，黄麴製では一般的な芋焼酎香気成分を基本として，高級アルコールおよび酢酸エチルエステル，含硫化合物含量が高かった。白麴および黒麴製は類似した傾向を示している中で，黄麴製よりもアルデヒド類，テルペン類が多かった。白麴製と黒麴製の比較では，全体的に白麴製のエステル類の香気成分濃度が高かった。その中で，DL-2-メチル酪酸エチルが黒麴製と比較して大きな差異のある成分であった。黒麴製は低級脂肪酸エステル類の濃度が白麴製よりも低く，中鎖脂肪酸エチルエステルでは同等であり，サリチル酸メチルの濃度が白麴製と大きく異なっていた。また，黒麴製では白麴製と比較して，1-オクテン-3-オールが高い結果となった。1-オクテン-3-オール濃度の麴での差異^8）および全麴仕込みによる白麴および黒麴製の差異^9）から，黒麴菌由来のひとつの特徴であると考えられた。芋焼酎における白麴製と黒麴製の香気成分はこれらの濃淡，重厚さに関与する成分によって違いが生み出されていることが明らかとなった。 官能評価では，黄麴製の香りは華やか，麴の香り，焼菓子，草やハーブ様と指摘された。白麴および黒麴製は，共通して果実様，ロースト，ナッツ様といったコメントが多かった。白麴製は軽快，シャープのコメントがあり，黒麴製はオイリー，まろやか，クリーム等のコメントが特徴的であった。味のコメントは香りと類似した傾向を示し，白麴製ではドライ，バランスといったコメントがみられるのに対し，黒麴製では芳醇，重厚といったコメントが得られた。どの焼酎がどの麴を用いたものであるかのブラインドテストにおいても概ね利き分けが出来ていることが認められた。これまで，酒質に与える麴の影響については経験的に述べられてきたが，本研究により，麴の違いによる芋焼酎の香味の特徴的な表現が明らかとなった。</p>

DOI： 10.6013/jbrewsocjapan.116.49

CiNii Research

出版者・発行元：Journal of Bioscience and Bioengineering  

DOI： 10.1016/j.jbiosc.2020.05.006

Scopus

PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2323/jgam.2019.09.003.

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

出版者・発行元：(公社)日本生物工学会  

白コウジカビAspergillus luchuensis mut. kawachiiの固相培養における、デンプン分解酵素とクエン酸産生の調節に対するサーチュインの役割を解析した。5種のサーチュイン遺伝子破壊株の性質解析により、これらの遺伝子がデンプン分解活性と酸性化に関与し、特にsirD破壊株では酸安定なα-アミラーゼ活性とクエン酸産生が低下した。sirD破壊株は菌糸の色が変化し、細胞壁合成阻害剤に高い感受性を示し、分生子形成が低下した。キャップ分析遺伝子発現と定量的RT-PCRを行ったところ、sirD破壊株において酸安定性α-アミラーゼ遺伝子とクエン酸エクスポーターの転写体レベルが低下していた。SirDはA.kawachiiの固相発酵において、酸安定性α-アミラーゼとクエン酸の産生を含む全体の転写調節に重要な役割を果たしていると考えられた。

出版者・発行元：Applied and Environmental Microbiology  

DOI： 10.1128/AEM.01950-19

Scopus

PubMed

DOI： 10.3389/fnut.2020.00115

PubMed

出版者・発行元：公益社団法人 日本食品科学工学会  

<p>This study aimed to reveal the chemical and flavor profiles of rice-flavor <i>baijiu</i> by comparison with <i>awamori</i> and <i>kome-shochu</i>, traditional Japanese liquors. Rice-flavor <i>baijiu</i> is similar to <i>awamori</i> and <i>kome-shochu</i> with regard to ingredients and the fermentation starter. Of the 15 rice-flavor <i>baijiu</i> samples in this study, 3 had a light yellow to dark-brown color. Dark-brown samples had high glucose and low amino acid contents. Lactic acid was detected in all rice-flavor <i>baijiu</i> samples. Compared to <i>awamori</i> and <i>kome-shochu</i>, rice-flavor <i>baijiu</i> contained more acetic acid. Thirty-four volatile compounds in rice-flavor <i>baijiu</i> were identified and quantified. In all, 18 compounds in rice-flavor <i>baijiu</i>, 15 in <i>awamori</i> and 13 in <i>kome-shochu</i> had an odor activity value (OAV) of >1. Of these, 11 compounds showed a three-fold higher OAV in rice-flavor <i>baijiu</i> than in <i>awamori</i> and <i>kome-shochu</i>. Principal component analysis revealed that ethyl lactate is a key volatile compound that is distinct to rice-flavor <i>baijiu</i>.</p>

DOI： 10.3136/fstr.26.411

CiNii Research

出版者・発行元：Bioscience, Biotechnology and Biochemistry  

DOI： 10.1080/09168451.2020.1792761

Scopus

PubMed

出版者・発行元：Biochimica et Biophysica Acta - Molecular and Cell Biology of Lipids  

DOI： 10.1016/j.bbalip.2019.05.004

Scopus

PubMed

出版者・発行元：Letters in Applied Microbiology  

DOI： 10.1111/lam.13148

Scopus

出版者・発行元：Applied and Environmental Microbiology  

DOI： 10.1128/AEM.03136-18

Scopus

PubMed

出版者・発行元：European Journal of Cell Biology  

DOI： 10.1016/j.ejcb.2018.03.007

Scopus

PubMed

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Society for Microbiology  

出版者・発行元：Yeast  

DOI： 10.1002/yea.3243

Scopus

PubMed

出版者・発行元：Food Chemistry  

DOI： 10.1016/j.foodchem.2016.12.005

Scopus

PubMed

出版者・発行元：一般社団法人 日本生薬学会  

<p>"<i>Shinkiku</i>" is a traditional digestive drug prepared by the fermentation of wheat and some herbs with fermentative microbes. <i>Shinkiku</i> is manufactured in China and Korea, and also used in Japanese <i>Kampo</i> medicine as a component of <i>Hangebyakujutsutemmato</i>. However, there are currently no quality standards for <i>shinkiku</i>, and thus, the quality of <i>shinkiku</i> has considerable variation depending on its manufacturer. Although these variations would be partially derived from the differences in fermentative microbes, there are no studies about microbial diversities or chemical constituents in commercial <i>shinkiku</i>. Thus, we investigated the microbial diversity and chemical constituents of 15 commercial <i>shinkiku</i> samples to standardize its quality. PCR-denaturing gradient gel electrophoresis of 16S rDNA and ITS1 sequences revealed that different microbes such as <i>Lactobacillus</i> sp. and <i>Candida</i> sp. were present in each <i>shinkiku</i> sample. On the other hand, most <i>shinkiku</i> samples showed amylase (12/15 samples) and lipase activities (9/15 samples) that behave as digestants. In addition, all samples commonly contained ferulic acid (>10 nmol/g), which has anti-inflammatory and anti-oxidant activities. Thus, enzyme activities and ferulic acid were suggested to be one of the candidates for use as reference standards for the quality control of <i>shinkiku</i>. Exceptional <i>shinkiku</i> samples without enzyme activities showed a baked brown color, and ferulic acid content was inversely related with the brightness color of <i>shinkiku</i> (R²=0.47). Therefore, it seems that color indices would be effective to predict the quality of <i>shinkiku</i> such as enzyme activities and ferulic acid.</p>

DOI： 10.24684/jspharm.71.1_41

CiNii Research

出版者・発行元：公益財団法人　応用微生物学・分子細胞生物学研究奨励会  

<p><i>Aspergillus luchuensis</i> is a kuro (black) koji fungus that has been used as a starch degrader for the awamori- and shochu-making industries in Japan. In this study, we investigated the effect of ion beam irradiation on <i>A. luchuensis</i> RIB2601 and obtained a high starch-degrading mutant strain U1. Strain U1 showed reduced growth rate, whereas it showed higher α-amylase, glucoamylase, and α-glucosidase activities on a mycelial mass basis than the wild type (wt) strain both on agar plates and in rice koji. In addition, strain U1 showed higher <i>N</i>-acetylglucosamine content in the cell wall and higher sensitivity to calcofluor white, suggesting a deficiency in cell wall composition. Interestingly, produced protein showed higher expression of acid-labile α-amylase (AmyA) and glucoamylase (GlaA) in strain U1, although real-time RT-PCR indicated no significant change in the transcription of the <i>amyA</i> or <i>glaA</i> gene. These results suggested that the high amylolytic activity of strain U1 is attributable to a high AmyA and GlaA production level, but the elevated production is not due to transcriptional regulation of the corresponding genes. Furthermore, RNA-seq analysis indicated that strain U1 shows transcriptional changes in at least 604 genes related to oxidation-reduction, transport, and glucosamine-containing compound metabolic processes, which may be involved in the deficient cell wall composition of strain U1.</p>

DOI： 10.2323/jgam.2017.02.004

Scopus

PubMed

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）