Some Distinguishable Properties between Acid-Stable and Neutral Types of α-Amylases from Acid-Producing Koji

Suganuma, Toshihiko; Fujita, Kiyotaka; Kitahara, Kuninori

doi:10.1263/jbb.104.353

Cited by 57 publications

(31 citation statements)

References 48 publications

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“…During koji production, A. kawachii produces two types of ␣-amylases, acid-labile ␣-amylase (alAA) (AmyA, AKAW_11452) and acid-stable ␣-amylase (asAA) (AamA, AKAW_02026) (22,23). asAA is critical for shochu koji production due to large amounts of citric acid produced by A. kawachii.…”

Section: Genome Comparisonmentioning

confidence: 99%

Transcriptomic Analysis of Temperature Responses of Aspergillus kawachii during Barley Koji Production

Futagami

Mori

Wada³

et al. 2015

Appl Environ Microbiol

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cThe koji mold Aspergillus kawachii is used for making the Japanese distilled spirit shochu. During shochu production, A. kawachii is grown in solid-state culture (koji) on steamed grains, such as rice or barley, to convert the grain starch to glucose and produce citric acid. During this process, the cultivation temperature of A. kawachii is gradually increased to 40°C and is then lowered to 30°C. This temperature modulation is important for stimulating amylase activity and the accumulation of citric acid. However, the effects of temperature on A. kawachii at the gene expression level have not been elucidated. In this study, we investigated the effect of solid-state cultivation temperature on gene expression for A. kawachii grown on barley. The results of DNA microarray and gene ontology analyses showed that the expression of genes involved in the glycerol, trehalose, and pentose phosphate metabolic pathways, which function downstream of glycolysis, was downregulated by shifting the cultivation temperature from 40 to 30°C. In addition, significantly reduced expression of genes related to heat shock responses and increased expression of genes related with amino acid transport were also observed. These results suggest that solid-state cultivation at 40°C is stressful for A. kawachii and that heat adaptation leads to reduced citric acid accumulation through activation of pathways branching from glycolysis. The gene expression profile of A. kawachii elucidated in this study is expected to contribute to the understanding of gene regulation during koji production and optimization of the industrially desirable characteristics of A. kawachii.

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Section: Genome Comparisonmentioning

confidence: 99%

Transcriptomic Analysis of Temperature Responses of Aspergillus kawachii during Barley Koji Production

Futagami

Mori

Wada³

et al. 2015

Appl Environ Microbiol

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“…It is well known that in beer and whisky brewing, starch is saccharified by β-amylase in the malt. In Asian brewing, moulds are also used as a source of starch hydrolases 14,18 . In the manufacturing processes of sake and shochu, moulds are grown as solid cultures on cereal crops such as rice and barley.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Volatile Compounds in Shochu Koji, Sake Koji, and Steamed Rice by Gas Chromatography-Mass Spectrometry

Yoshizaki

Yamato

Takamine

et al. 2010

Journal of the Institute of Brewing

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The volatile compounds in three types of koji (yellow, white, and black) and steamed rice were investigated using gas chromatography-mass spectrometry. The objective of this study was to characterize each koji type based on its profile of volatile compounds. From the steamed rice and rice koji samples examined, a total of 29 volatile compounds were identified. Butanal, hexanal, dimethyl trisulfide and cyclohexyl isothiocyanate were detected only in steamed rice. The volatile profile of yellow koji (sake koji) was distinct from those of white and black kojis (shochu koji). On the basis of relative peak areas, alcohols and aldehydes were identified as being more abundant in yellow koji. White and black kojis had similar volatile profiles, and had a greater abundance of furans than yellow koji. We assume that the different suites of volatile compounds identified in shochu and sake kojis impart the respective characteristic flavours to shochu and sake.

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“…2B; Table 2). Kuro-koji fungi have two types of a-amylase, an acidlabile type and an acid-stable type (Suganuma et al, 2007), and the detected AmyA was the acid-labile type. CBB staining also indicated a more intense staining of these two bands than in the wt strain, indicating that the higher amylolytic activity of strain U1 can be attributed to a higher level of secretion of GlaA and AmyA.…”

Section: Comparison Of Starch Degradation Enzyme Activities On Agar Mmentioning

confidence: 98%

Characterization of amylolytic enzyme overproducing mutant of <i>Aspergillus luchuensis</i> obtained by ion beam mutagenesis

Kojo

Kadooka

Komohara

et al. 2017

J. Gen. Appl. Microbiol.

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Some Distinguishable Properties between Acid-Stable and Neutral Types of α-Amylases from Acid-Producing Koji

Cited by 57 publications

References 48 publications

Transcriptomic Analysis of Temperature Responses of Aspergillus kawachii during Barley Koji Production

Transcriptomic Analysis of Temperature Responses of Aspergillus kawachii during Barley Koji Production

Analysis of Volatile Compounds in Shochu Koji, Sake Koji, and Steamed Rice by Gas Chromatography-Mass Spectrometry

Characterization of amylolytic enzyme overproducing mutant of <i>Aspergillus luchuensis</i> obtained by ion beam mutagenesis

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