Related Experiment Video

Updated: Aug 11, 2026

Quantification of Fungal Colonization, Sporogenesis, and Production of Mycotoxins Using Kernel Bioassays
10:01

Quantification of Fungal Colonization, Sporogenesis, and Production of Mycotoxins Using Kernel Bioassays

Published on: April 23, 2012

Nitrogen repression of fumonisin B1 biosynthesis in Gibberella fujikuroi

W B Shim1, C P Woloshuk

  • 1Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.

FEMS Microbiology Letters
|August 7, 1999
PubMed

Insights

High nitrogen levels, specifically ammonium phosphate, significantly repress fumonisin B1 (FB1) production in fungi. This nitrogen metabolite repression suggests strategies targeting nitrogen metabolism can reduce fumonisin contamination in food.

Area of Science:

  • Mycology
  • Food Science
  • Biochemistry

Background:

  • Fumonisins are mycotoxins produced by the fungus Gibberella fujikuroi.
  • Fumonisin B1 (FB1) is a major concern due to its potential toxicity.

Purpose of the Study:

  • To investigate the effect of ammonium phosphate concentration on fumonisin B1 production.
  • To understand the regulatory mechanisms controlling fumonisin biosynthesis.

Main Methods:

  • Culturing Gibberella fujikuroi in defined media with varying ammonium phosphate concentrations.
  • Resuspending mycelia in media with different nitrogen levels.
  • Analyzing FB1 production in cracked corn cultures with ammonium phosphate addition.

Main Results:

  • Ammonium phosphate repressed FB1 production, with repression duration increasing at higher concentrations (10 mM and 20 mM).
  • Total FB1 production was higher in resuspension cultures with increased ammonium phosphate, but accumulation was independent of inoculum size and C/N ratio.
  • Addition of ammonium phosphate to cracked corn cultures reduced FB1 production by 97%.

Conclusions:

  • Fumonisin B1 biosynthesis is regulated by nitrogen metabolite repression.
  • Targeting nitrogen metabolism pathways offers a potential strategy to control fumonisin contamination in food products.

More Related Videos

Sexual Development and Ascospore Discharge in Fusarium graminearum08:20

Sexual Development and Ascospore Discharge in Fusarium graminearum

Published on: March 29, 2012

Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Transgenic Maize Expressing the α-amylase Inhibitor from Lablab purpureus L.09:21

Inhibition of Aspergillus flavus Growth and Aflatoxin Production in Transgenic Maize Expressing the α-amylase Inhibitor from Lablab purpureus L.

Published on: February 15, 2019

Related Concept Videos

The Roles of Bacteria and Fungi in Plant Nutrition02:11

The Roles of Bacteria and Fungi in Plant Nutrition

Plants have the impressive ability to create their own food through photosynthesis. However, plants often require assistance from organisms in the soil to acquire the nutrients they need to function correctly. Both bacteria and fungi have evolved symbiotic relationships with plants that help the species to thrive in a wide variety of environments.
Riboswitches01:56

Riboswitches

Riboswitches are non-coding mRNA domains that regulate the transcription and translation of downstream genes without the help of proteins. Riboswitches bind directly to a metabolite and can form unique stem-loop or hairpin structures in response to the amount of the metabolite present. They have two distinct regions – a metabolite-binding aptamer and an expression platform.
The aptamer has high specificity for a particular metabolite which allows riboswitches to specifically regulate...
Overview of Metabolism01:40

Overview of Metabolism

Living cells constantly carry out various chemical reactions which are necessary for their proper functioning. These reactions are interlinked to one another via multiple pathways. The collection of these chemical reactions is known as metabolism.
Plant Metabolism
Sunlight, the primary source of energy in plants, is first absorbed by the chlorophyll pigments present in their leaves. Plants then use this energy to carry out photosynthesis, where water is oxidized into oxygen and carbon dioxide...
Inorganic Nitrogen Assimilation01:22

Inorganic Nitrogen Assimilation

Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme nitrate reductase...
Transcriptional Regulation: Riboswitches01:23

Transcriptional Regulation: Riboswitches

Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...
Gene Regulation During Sporulation01:17

Gene Regulation During Sporulation

Sporulation is a complex developmental process that allows certain Gram-positive bacteria, such as Bacillus subtilis and Clostridium species, to survive extreme environmental conditions. This process is tightly regulated by a series of signaling cascades and transcriptional controls, ensuring the formation of a highly resistant endospore.Sporulation is triggered by unfavorable conditions, such as nutrient depletion, and is governed by a phosphorelay system. One of the sensor kinases, such as...