Zinc-Induced Siderophore Production in Penicillium and Rhizosphere Fungi Original paper
Researched by:
-
Karen Pendergrass
ID
Karen Pendergrass
Read MoreKaren Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease—four years before the first published case study.
-
Microbes
Microbes
Microbes, short for microorganisms, are tiny living organisms that are ubiquitous in the environment, including on and inside the human body. They play a crucial role in human health and disease, functioning within complex ecosystems in various parts of the body, such as the skin, mouth, gut, and respiratory tract. The human microbiome, which is […]
-
Karen Pendergrass
Read More
Researched by:
-
Karen Pendergrass
ID
Karen Pendergrass
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Karen Pendergrass
What was studied?
This study investigated the effect of zinc ions (Zn²⁺) on siderophore production in fungi isolated from the rhizosphere of Panax ginseng. Siderophores are metal-chelating compounds primarily produced by microorganisms in response to iron limitation. However, their production can also be influenced by the presence of other metals, including Zn²⁺. The researchers focused on how varying concentrations of Zn²⁺ (50–250 µg/ml) modulate siderophore output, using chrome azurol S (CAS) assays for quantification. One strain, Penicillium commune JJHO, was further characterized chemically using UV, FTIR, and MALDI-TOF-MS spectroscopy, with its siderophore confirmed as hydroxamate-type ferrichrome.
Who was studied?
The study evaluated 23 fungal strains isolated from P. ginseng rhizosphere soils in Korea. These isolates represented diverse taxonomic groups, including Ascomycetes (Penicillium commune, Trichoderma harzianum, Fusarium oxysporum, Metarhizium anisopliae), Zygomycetes (Mortierella turficola), and Basidiomycota (Rhodosporidium toruloides). One bacterial control strain, Pseudomonas aeruginosa, previously known for its siderophore activity, was also tested under the same Zn²⁺ treatments for comparative purposes.
Most important findings
Zinc ions significantly affected siderophore production across all tested fungi. Spectral analysis of Penicillium JJHO confirmed the presence of ferrichrome, a cyclic hexapeptide siderophore, based on UV absorbance at 425 nm, FTIR peaks at 1,640, 1,680, and 3,500 cm⁻¹, and MALDI-TOF-MS (peak at 763.0 Da). The most potent production generally occurred at 150 µg/ml Zn²⁺, though the response varied by species:
| Fungal Strain | Siderophore Production at 150 µg/ml Zn²⁺ (%) |
|---|---|
| Penicillium commune JJHO | 72.65 |
| Metarhizium anisopliae KHAU | 72.43 |
| Fusarium oxysporum FCHA | 68.76 |
| Trichoderma harzianum TR274 | 67.63 |
| Rhodosporidium toruloides K-1-8 | 34.82 |
| Mortierella turficola CQ1 | 37.96 (Peak at 200 µg/ml: 39.62%) |
Key implications
The findings highlight zinc’s dual role as both a stressor and an inducer of siderophore biosynthesis. Importantly, siderophore production was not only preserved but enhanced under Zn²⁺ exposure in most fungal isolates. This suggests that rhizosphere fungi may use siderophores not only to acquire iron but also to mitigate zinc-induced toxicity. The study underscores the broader ecological and agricultural significance of siderophores in metal-contaminated soils, presenting potential applications in phytoremediation and plant growth promotion under heavy metal stress. From a microbiome perspective, siderophore-producing fungi like Penicillium commune JJHO may be key microbial associates in zinc-rich or contaminated environments, possibly shaping local microbial community structures via competitive metal acquisition strategies.
Zinc
Zinc is an essential trace element vital for cellular functions and microbiome health. It influences immune regulation, pathogen virulence, and disease progression in conditions like IBS and breast cancer. Pathogens exploit zinc for survival, while therapeutic zinc chelation can suppress virulence, rebalance the microbiome, and offer potential treatments for inflammatory and degenerative diseases.