The following properties of A. oryzae strains are important in rice saccharification for sake brewing: [7]
- Growth: rapid mycelial growth on and into the rice kernels
- Enzymes: strong secretion of amylases ( α-amylase and glucoamylase); some carboxypeptidase; low tyrosinase
- Aesthetics: pleasant fragrance; accumulation of flavoring compounds
- Color: low production of deferriferrichrome (a siderophore ), flavins, and other colored substances
Full Answer
What is Aspergillus oryzae?
Aspergillus oryzae is a filamentous fungus with septate hyphae. It exhibits all the classic processes of life: growth, reproduction (through asexual methods), responsiveness, and metabolism.
What is the temperature of Aspergillus oryzae?
Most other enzymes found in A. oryzae grow at a temperature of around 30-35 degrees Celsius.[6] Members of the Aspergillus genus are distinct from other microbes due to the fact that they utilize both a primary and secondary metabolic system.
What is the role of Aspergillus oryzae in fermentation?
Aspergillus oryzae not only provides the needed enzymes for transforming raw materials into more readily digestible components but also contributes to the color, flavor, aroma, and texture of the fermented products.
How many genes are in Aspergillus oryzae?
It contains 12,074 genes, and is 7-9Mb longer (or 25-30% larger) than other members of the Aspergillus genus, namely the species A. nidulans and A. fumigates. A. oryzae 's linear genome is made up of 48.25% GC-content, or guanine-cytosine content, which is an indicator of a higher melting point.
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What is the function of Aspergillus oryzae?
Aspergillus oryzae is a fungus widely used in traditional Japanese fermentation industries, including soy sauce, sake, bean curd seasoning and vinegar production. Filamentous fungi generally have the ability to produce various and vast amounts of enzymes in a secretory manner.
What are the characteristics of Aspergillus niger?
Cultural Characteristics of Aspergillus niger Generally, they have a cottony appearance; initially white to yellow and then turning black. Made up of felt-like conidiophores. The reverse is white to yellow. In microscopy, the conidial heads are radiate with conidiogenous cells biseriate.
What is the meaning of Aspergillus oryzae?
Aspergillus oryzae, also known as kōji mold (Japanese: ニホンコウジカビ (日本麹黴), Hepburn: nihon kōji kabi), is a filamentous fungus (a mold) used in East Asia to saccharify rice, sweet potato, and barley in the making of alcoholic beverages such as sake and shōchū, and also to ferment soybeans for making soy sauce and miso.
What color is Aspergillus oryzae?
oryzae show yellow–green color [4], but it sometimes appears in other anomalous color (such as white, or brown) in proliferation process. It has been reported that some genes are involved in formation of conidial pigments in Aspergillus species.
What are the characteristics of Aspergillus fumigatus?
Cultural Characteristics of Aspergillus fumigatus Aspergillus fumigatus is thermophilic hence it in temperatures as high as 55°C and can survive in temperatures of up to 70°C. It is a fast-growing fungus in fungal culture. It grows well in the basic fungal medium, Sabouraud Dextrose Agar (SDA).
What are the characteristics of Aspergillus flavus?
Aspergillus flavus colonies are commonly powdery masses of yellowish-green spores on the upper surface and reddish-gold on the lower surface. In both grains and legumes, infection is minimized to small areas, and discoloration and dullness of affected areas is often seen.
What type of organism is Aspergillus oryzae?
oryzae is an aerobic filamentous fungus and belongs to the Aspergillus subgenus Circumdati section Flavi, previously known as the A. flavus group. Aspergillus section Flavi contains industrially important species, such as A. oryzae, as well as agronomically and medically significant fungi, such as A.
Where is Aspergillus oryzae from?
Aspergillus Oryzae grows on the heads of rice plants in East Asia. This is their optimal breeding ground. It can be found natural in the rice fields of Japan, China, and Korea, and harvested by hand by workers tromping through the soggy fields.
Is Aspergillus oryzae healthy?
Preventive actions and reducing risk. Although Aspergillus oryzae strain ATCC 11866 is not considered to be harmful to human health or to the environment at current levels of exposure, it could become harmful to human health if exposure levels were to increase.
Is Aspergillus oryzae a probiotic?
Aspergillus oryzae and its fermentation by products also are used as probiotic and feed supplements for livestock.
Is Aspergillus oryzae vegan?
Shirayuri Koji (Aspergillus oryzae), Gluten Free, Vegan.
What is Aspergillus oryzae fermentation extract?
Aspergillus oryzae fermentation product is designed to provide the highest levels of fungal alpha-amylase and a source of Unidentified Growth Factors (UGF's) for animal feed applications. The UGF activity is the highest in any product available and can survive the pelleting process.
Why is Aspergillus niger significant?
Aspergillus niger is a filamentous ascomycete fungus that is ubiquitous in the environment and has been implicated in opportunistic infections of humans. In addition to its role as an opportunistic human pathogen, A. niger is economically important as a fermentation organism used for the production of citric acid.
What disease is caused by Aspergillus niger?
Aspergillus niger causes several diseases including black mold (or black rot) of onions and garlic, crown rot of peanuts, and vine canker of table grapes. In black rot of onions and garlic, A. niger develops between the outer (dead, flaky) skin and the first fleshy scales of the bulb which become water soaked.
What is Aspergillus niger used for?
Aspergillus niger is a haploid filamentous fungus which is used for waste management and biotransformations in addition to its industrial uses, such as production of citric acid and extracellular enzymes.
How can you identify Aspergillus under a microscope?
Microscopic characteristics for the identification were conidial heads, stipes, color and length vesicles shape and seriation, metula covering, conidia size, shape and roughness also colony features including diameter after 7 days, color of conidia, mycelia, exudates and reverse, colony texture and shape.
What are the characteristics of Aspergillus oryzae?
It exhibits all the classic processes of life: growth, reproduction (through asexual methods), responsiveness, and metabolism.
How does Oryzae reproduce?
A. oryzae reproduces asexually using hyphae to quickly gain footholds on its growth substrate. Conidiospores land on a suitable site and germinate creating a network of hyphae, root-like structures that excrete enzymes, breakdown nutrients, and reabsorb them for use.
Is A. oryzae asexual?
Asexual Life Cycle of A. oryzae [3] Although it is directly related to A. flavus, a known human pathogen that produces a powerful toxin, aflatoxin, A. oryzae doesn't have the capability to produce it.
Can you see Oryzae with a microscope?
A. oryzae can be easily seen with low levels of magnification, a bright field light microscope would be advised when observing the overall structure of the conidium. For greater detail of the individual parts such as spores, condita, or hyphae a Scanning Electron Microscope would provide high detail for observation.
Is iodine staining necessary for A. oryzae?
Because much of the life cycle of A. oryzae is visible to the naked eye, staining is rarely necessary. However, a simple iodine stain may be used to increase contrast in hyphae when viewing under a microscope. In nature A. oryzae is a chemoheterotroph found in soil and decaying plant material.
Is A. oryzae a saprotropic microorganism?
(Barbesgaard, 1991) As a saprotropic microorganism A. oryzae utilizes production of enzymes to break down nutrients found in the substances it grows on and reabsorb them into itself.
Morphology
Initially, the fungus culture shows a whitish color, then it turns yellowish-green. Sexual reproduction has not been observed in this mold, but the asexual spores (conidia) are easy to distinguish and are released into the air.
Genetics
The A. oryzae genome sequencing, shrouded in mystery for decades, was finally published in 2005 by a team that included 19 institutions in Japan, including the Brewing Association, Tohoku University, the University of Agriculture and Technology in Japan. Tokyo (Machida et al. 2005).
Biogeography
Kōji is primarily associated with the human environment, but outside of this area, it has also been sampled from soil and decaying plant material. Apart from China, Japan and the rest of the Far East, it has been reported in India, USSR, Czechoslovakia, Tahiti, Peru, Syria, Italy and even in the United States and the British Isles.
Bibliography
Barbesgaard P. Heldt-Hansen H. P. Diderichsen B. (1992) On the safety of Aspergillus royzae: a review. Applied Microbiology and Biotechnology 36: 569-572.
Natural Product Biosynthesis by Microorganisms and Plants, Part C
Khomaizon A. K. Pahirulzaman, ... Colin M. Lazarus, in Methods in Enzymology, 2012
Enzymatic conversions of starch
Aspergillus oryzae is a good source of beta amylase. 903–908 The enzyme, after purification, produced glucose during the initial stage of starch hydrolysis. 908 Beta amylase secreted by A. awamori also hydrolyzes potato starch in a similar manner, with yields reaching 90%. Phosphate groups are not cleaved. 909
Analysis of Gene Expression
The start of transcription may be located by primer extension or by using S1 nuclease.
Advances in Applied Microbiology
Very recently, the genome sequencing of Aspergillus oryzae has been initiated. The sequencing effort is being conducted through collaboration of several governmental institutes, universities, and companies in Japan.
Sake and shochu
Koji is a substance produced by growing koji fungi ( Aspergillus mould) on steamed grain. It contains a wide variety of enzymes and vitamins that are a source of nutrition for other microorganisms, such as yeast.
Quantification of Specific mRNAs by Nuclease Protection
Robert E. FarrellJr. Ph.D, in RNA Methodologies (Fourth Edition), 2010
What is the species of Aspergillus?
Aspergillus. Species: A. oryzae. Binomial name. Aspergillus oryzae. (Ahlburg) E. Cohn. Aspergillus oryzae, also known as kōji mold ( Japanese: ニホンコウジカビ (日本麹黴), Hepburn: nihon kōji kabi), is a filamentous fungus (a mold) used in East Asia to saccharify rice, sweet potato, and barley in the making of alcoholic beverages such as sake and shōchū, ...
What are the properties of A. oryzae?
oryzae strains are important in rice saccharification for sake brewing: Growth: rapid mycelial growth on and into the rice kernels. Enzymes: strong secretion of amylases ( α-amylase and glucoamylase); some carboxypeptidase; low tyrosinase. Aesthetics: pleasant fragrance; accumulation of flavoring compounds.
How long does it take for Aspergillus to grow?
Four Aspergillus colonies grown at 37 °C for three days on rich media: The bottom two are A. oryzae strains.
How many genes are in the genome of A. oryzae?
The eight chromosomes together comprise 37 million base pairs and 12 thousand predicted genes. The genome of A. oryzae is thus one-third larger than that of two related Aspergillus species, the genetics model organism A. nidulans and the potentially dangerous A. fumigatus. Many of the extra genes present in A. oryzae are predicted to be involved in secondary metabolism. The sequenced strain isolated in 1950 is called RIB40 or ATCC 42149; its morphology, growth, and enzyme production are typical of strains used for sake brewing.
Is A. oryzae a genetic model organism?
The genome of A. oryzae is thus one-third larger than that of two related Aspergillus species, the genetics model organism A. nidulans and the potentially dangerous A. fumigatus. Many of the extra genes present in A. oryzae are predicted to be involved in secondary metabolism.
What is the purpose of Aspergillus oryzae?
oryzae is utilized in solid-state cultivation (SSC), which is a form of fermentation in a solid rather than a liquid state. This fungi is essential to the fermentation processes because of its ability to secrete large amounts of various degrading enzymes, which allows it to decompose the proteins of various starches into sugars and amino acids. [1] This fungi is characterized by a round vesicle with extending conodial chains, which appear as white and fluffy strands on the substrate that the fungi inhabits. [3]
How does Aspergillus function?
The functionality of the Aspergillus metabolism depends on its carboxylic acids, which break down into fatty acid chains that are composed of a unique set of fatty acid synthase complexes. These chains aid in the development of the Aspergillus cell membrane and the enzyme storage vesicles. The primary metabolism of A. oryzae receives its energy through contact with energy sources (e.g. grains or starches). Once it makes contact with an energy source, it secretes enzymes that degrade the proteins and peptide bonds within the starch and convert them into amino acids and sugars for consumption. [8]
Why is A. oryzae domesticated?
Because A. oryzae has been domesticated, it is possible that gene expansion is due to horizontal gene transfer, as is seen in A. oryzae -specific genes , which use clonal lines to transfer chromosomes. [2] The fermentation of A. oryzae to make sake, a Japanese alcohol. Photo credited to Kazuo Kikuchi.
How many tRNA genes are in the genome of Aspergillus oryzae?
Additionally, the A. oryzae genome contains 270 tRNA genes, and only 3 rRNA genes. [7] When comparing the three Aspergillus species, it was found that in A. oryzae a combination of syntenic blocks derived from a singular ancestral region and blocks specific to A. oryzae arranged mosaically comprised the full genome.
What is the A. oryzae sequence?
oryzae -specific sequence codes for metabolite synthesis and specific gene expansion for secreting hydrolytic enzymes when used in SSF, or solid-state fermentation, which makes it such an effective microbe in fermentation processes. [7]
What is the temperature of amylase?
This enzyme is most efficient at a temperature of 35-40 degrees Celsius. Most other enzymes found in A. oryzae grow at a temperature of around 30-35 degrees Celsius. [6]
How many ORFs are there in the genome?
There are 12,084 ORFs (open reading frames) within the genome, which may potentially code for essential proteins or peptides. Coding regions account for 44.02% of the genome, whereas there are only 7.48% intronic regions. Additionally, the A. oryzae genome contains 270 tRNA genes, and only 3 rRNA genes. [7]
Content
Taxonomy
- Domain: Eukaryota.
- Fungi kingdom.
- Phylum: Ascomycota.
- Subphylum: Pezizomycotina.
Morphology
- Initially, the fungus culture shows a whitish color, then it turns yellowish-green. Sexual reproduction has not been observed in this mold, but the asexual spores (conidia) are easy to distinguish and are released into the air. The conidiophores are hyaline and mostly have rough walls. Some isolates are predominantly uniseriate, others predominantl...
Genetics
- The A. oryzae genome sequencing, shrouded in mystery for decades, was finally published in 2005 by a team that included 19 institutions in Japan, including the Brewing Association, Tohoku University, the University of Agriculture and Technology in Japan. Tokyo (Machida et al. 2005). Its genetic material, with 8 chromosomes of 37 million base pairs (104 genes), has 30% more gene…
Biogeography
- Kōji is primarily associated with the human environment, but outside of this area, it has also been sampled from soil and decaying plant material. Apart from China, Japan and the rest of the Far East, it has been reported in India, USSR, Czechoslovakia, Tahiti, Peru, Syria, Italy and even in the United States and the British Isles. However, A. oryzae has rarely been observed in temperate cli…
Traditional Uses and Biotechnology Industry
- Traditionally A. oryzae has been used to: 1. Make soy sauce and fermented bean paste. 2. Sacarify rice, other grains, and potatoes in the making of alcoholic beverages such as huangjiu, sake, makgeolli, and shōchū. 3. Rice vinegar production (Barbesgaard et al. 1992). Historically it has been easily cultivated in various natural (carrots, cereals) or synthetic (Raulin liquid, among …
Bibliography
- Barbesgaard P. Heldt-Hansen H. P. Diderichsen B. (1992) On the safety of Aspergillus royzae: a review. Applied Microbiology and Biotechnology 36: 569-572.
- Domsch K.H., Gams W., Anderson T.H. (1980) Compendium of soil fungi. Academic Press, New York.
- Klich M.A., Pitt J.I. (1988) Differentiation of Aspergillus flavus from A. parasiticus and other c…
- Barbesgaard P. Heldt-Hansen H. P. Diderichsen B. (1992) On the safety of Aspergillus royzae: a review. Applied Microbiology and Biotechnology 36: 569-572.
- Domsch K.H., Gams W., Anderson T.H. (1980) Compendium of soil fungi. Academic Press, New York.
- Klich M.A., Pitt J.I. (1988) Differentiation of Aspergillus flavus from A. parasiticus and other closely related species. Trans Br Mycol Soe 91: 99-108.
- Machida, M., Asai, K., Sano, M., Tanaka, T., Kumagai, T., Terai, G.,… & Abe, K. (2005) Genome sequencing and analysis of Aspergillus oryzae Nature 438 (7071 ): 1157-1161.
Overview
Aspergillus oryzae, also known as kōji mold (Japanese: ニホンコウジカビ (日本麹黴), Hepburn: nihon kōji kabi), is a filamentous fungus (a mold) used in East Asia to saccharify rice, sweet potato, and barley in the making of alcoholic beverages such as sake and shōchū, and also to ferment soybeans for making soy sauce and miso. However, in the production of fermented foods of soybeans such as so…
Varieties used for shōchū making
Three varieties of kōji mold are used for making shōchū, each with distinct characteristics.
Genichirō Kawachi (1883 -1948), who is said to be the father of modern shōchū and Tamaki Inui (1873 -1946), a lecturer at University of Tokyo succeeded in the first isolation and culturing of aspergillus species such as A. kawachii, A. awamori, and a variety of subtaxa of A. oryzae, which let to great progress in producing shōchū in Japan. Since then, aspergillus developed by Kawach…
Properties desirable in sake brewing and testing
The following properties of A. oryzae strains are important in rice saccharification for sake brewing:
• Growth: rapid mycelial growth on and into the rice kernels
• Enzymes: strong secretion of amylases (α-amylase and glucoamylase); some carboxypeptidase; low tyrosinase
Genome
Initially kept secret, the A. oryzae genome was released by a consortium of Japanese biotechnology companies in late 2005. The eight chromosomes together comprise 37 million base pairs and 12 thousand predicted genes. The genome of A. oryzae is thus one-third larger than that of two related Aspergillus species, the genetics model organism A. nidulans and the potentially dangerous A. fumigatus. Many of the extra genes present in A. oryzae are predicted to be involve…
Use in biotechnology
Trans-resveratrol can be efficiently cleaved from its glucoside piceid through the process of fermentation by A. oryzae.
A. oryzae is a good choice as a secondary metabolite factory because of its relatively few endogenous secondary metabolites. Transformed types can produce: polyketide synthase-derived 1,3,6,8-tetrahydroxynaphthalene, alternapyrone, and 3-methylorcinaldehyde; citrinin; terrequinon…
History of kōji in a broad sense
麹 (Chinese qū, Japanese kōji) which means mold used in fermented foods, was first mentioned in the Zhouli (Rites of the Zhou dynasty) in China in 300 BCE. Its development is a milestone in Chinese food technology, for it provides the conceptual framework for three major fermented soy foods: soy sauce, jiang/miso, and douchi, not to mention grain-based wines (including Japanese sake and Chinese huangjiu) and li (the Chinese forerunner of Japanese amazake).
Gallery
• Conidiophores with conidia of the microscopic fungus A. oryzae under light microscope
• Four Aspergillus colonies grown at 37 °C for three days on rich media: The bottom two are A. oryzae strains.
See also
• Qū
• Akira Endo
• Aspergillus sojae
• Lactase
• Medicinal molds