Related Experiment Video

Updated: May 11, 2026

Genome-wide Analysis of Histone Modifications Distribution using the Chromatin Immunoprecipitation Sequencing Method in Magnaporthe oryzae
09:25

Genome-wide Analysis of Histone Modifications Distribution using the Chromatin Immunoprecipitation Sequencing Method in Magnaporthe oryzae

Published on: June 2, 2021

2.8K

Isolation and characterization of koji mold (Aspergillus oryzae) from nature in Niigata

Kanae Sakai1, Keigo Sato2, Mitsuoki Kaneoke2

  • 1Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.

Journal of Bioscience and Bioengineering
|September 3, 2024
PubMed

Insights

Researchers isolated environmental Aspergillus oryzae strains in Japan, finding 26 non-aflatoxin producers. Genetic and enzymatic analyses revealed diverse properties, expanding potential industrial applications for koji mold.

Area of Science:

  • Microbiology
  • Food Science
  • Biotechnology

Background:

  • Koji mold (Aspergillus oryzae) is crucial for Japanese fermentation and brewing.
  • Environmental isolation of A. oryzae can yield strains with unique properties.

Purpose of the Study:

  • To isolate and characterize environmental koji mold strains from Niigata Prefecture.
  • To assess the mycotoxin production and fermentation capabilities of isolated strains.
  • To explore the potential of these diverse strains for industrial applications.

Main Methods:

  • Isolation of Aspergillus section Flavi-like strains from environmental samples using a rice-wood ash medium.
  • Morphological characterization, sequencing of ITS and calmodulin genes, and analysis of aflatoxin biosynthetic gene clusters and alpha-amylase genes.
  • DNA-seq analysis of mycotoxin biosynthetic gene clusters (aflatoxin, cyclopiazonic acid, aflatrem) and fermentation-related genes.
  • Enzymatic activity assays and classification based on morphology and mating types.

Main Results:

  • 36 Aspergillus section Flavi-like strains were obtained, with 26 confirmed as non-aflatoxin producers.
  • Genetic analysis confirmed the absence of mycotoxin production in some strains, but enzyme activity variations were not fully explained by amino acid substitutions.
  • The 26 isolates were classified into 6 morphology types, showing correlations between morphology, enzymatic profiles, and gene sequences.
  • Significant diversity in properties among environmental koji mold isolates was observed.

Conclusions:

  • Environmental isolation yielded diverse Aspergillus oryzae strains with potential for industrial use.
  • Understanding the genetic and enzymatic diversity of koji mold is key to optimizing fermentation processes.
  • Further research into these strains could expand the industrial applications of koji mold.
Keywords:
Aspergillus oryzaeGenome sequenceKoji-moldMycotoxinNature origin

More Related Videos

Isolation of Culturable Yeasts and Molds from Soils to Investigate Fungal Population Structure10:33

Isolation of Culturable Yeasts and Molds from Soils to Investigate Fungal Population Structure

Published on: May 27, 2022

5.4K
Isolation, Characterization, and Total DNA Extraction to Identify Endophytic Fungi in Mycoheterotrophic Plants06:53

Isolation, Characterization, and Total DNA Extraction to Identify Endophytic Fungi in Mycoheterotrophic Plants

Published on: May 5, 2023

2.6K

Related Concept Videos

Differential Staining Technique01:26

Differential Staining Technique

Differential staining is an essential microbiological technique that exploits variations in cell wall structures to classify and identify microorganisms. It facilitates the distinction of bacteria, aiding in diagnostic and research applications. Two of the most widely used differential staining methods are Gram staining and acid-fast staining, both of which rely on the chemical and structural differences in bacterial cell walls.Gram Staining TechniqueGram staining differentiates bacteria by...
Special Staining Techniques01:13

Special Staining Techniques

Specialized staining techniques play a vital role in microbiology by enabling the visualization of specific bacterial structures that remain undetectable with standard microscopy methods. These techniques not only enhance the structural visualization of bacterial cells but also provide critical insights into their pathogenicity and classification. Additionally, they support diagnostic and research endeavors in microbiology by identifying key bacterial features.Capsule Staining for Virulence...
Bacterial Phylum Actinobacteria01:30

Bacterial Phylum Actinobacteria

Coryneform bacteria are gram-positive, aerobic, nonmotile rods that exhibit irregular, club-shaped, or V-shaped arrangements. Their V-shape results from snapping division, where the inner cell wall layer forms the cross-wall, while the outer layer remains intact until it ruptures on one side, causing the daughter cells to bend away.The primary genera are Corynebacterium and Arthrobacter. Corynebacterium includes diverse species, ranging from saprophytes to pathogens like Corynebacterium...
Fungal Group Zygomycota01:29

Fungal Group Zygomycota

Zygomycota, previously classified as a distinct fungal group, are primarily terrestrial, saprophytic molds that play a crucial role as decomposers. Recent phylogenetic studies have revealed that these fungi are now divided into two major clades — Mucoromycota, which includes many symbiotic species, and Zoopagomycota, which primarily consists of parasitic and pathogenic fungi. These groups exhibit distinct ecological roles and reproductive strategies while sharing key structural and...
Fungal Phylum Ascomycota01:28

Fungal Phylum Ascomycota

Phylum Ascomycota, a major division within the subkingdom Dikarya, comprises a diverse range of fungal species, including both unicellular yeasts and filamentous molds such as Aspergillus and Penicillium. These fungi thrive in a variety of habitats, from aquatic ecosystems to terrestrial environments, playing crucial ecological and economic roles.Morphology and ReproductionThe defining characteristic of Ascomycetes, commonly referred to as sac fungi, is the ascus—a sac-like structure that...
Microbial Spoilage of Food01:23

Microbial Spoilage of Food

Microbial food spoilage refers to the degradation of food quality resulting from the metabolic activity of microorganisms such as bacteria, yeasts, and molds. These microbes proliferate on various food substrates depending on factors such as moisture content, nutrient availability, and storage conditions, leading to undesirable sensory and structural changes.Bacteria are primary agents of spoilage in high-moisture, nutrient-dense foods like meat, milk, and vegetables. Microbial spoilage occurs...