Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was studied?
This original research article applied a metagenomic approach to analyze the fungal community diversity and metabolic potential in soils contaminated with heavy metal(s) in the Macacos Creek region of Juazeiro, Ceará, Brazil. The study sought to uncover both the phylogenetic composition and the functional gene repertoire of fungal communities inhabiting four distinct sediment samples, each characterized by differing heavy metal contamination profiles. Using next-generation sequencing, the authors retrieved fungal DNA from soils and subjected it to high-throughput sequencing, followed by bioinformatic analyses to identify taxonomic groups and genes involved in heavy metal metabolism, tolerance, DNA repair, and biosorption. The focus keyphrase, “fungal community diversity in heavy metal contaminated soils,” is central to the investigation, offering valuable insights for heavy metal tested and certified (HTMC) programs seeking to understand microbial adaptation to contamination and inform bioremediation strategies.
Who was studied?
The subjects of the study were environmental fungal communities residing in four sediment samples collected from creek banks and lagoons within the Macacos Creek region. The sites included a control area with minimal contamination (Grangeiro River, RG), a moderately contaminated lagoon (APUC Lagoon, RA), a site with high contamination primarily by copper, nickel, and zinc (Macacos Creek, RM), and a site with the most severe contamination, dominated by lead and chromium (Salesianoo Creek, RS). Soil samples were taken at a depth of up to 20 cm, representing locations influenced by industrial effluents from nearby manufacturing activities. The fungal populations studied included both culturable and, crucially, uncultured taxa, as revealed by the metagenomic sequencing, thus providing a comprehensive overview of the environmental fungal diversity in heavy metal-contaminated soils.
Most Important Findings
| Finding Category | Details |
|---|---|
| Fungal Composition & Diversity | Twelve fungal orders across Ascomycota, Basidiomycota, Chytridiomycota, and Blastocladiomycota were identified. Ascomycota was the most abundant phylum, with Basidiomycota following. The highest fungal diversity and sequence abundance were observed in the uncontaminated control sample (RG). In contrast, severe lead contamination in the RS site resulted in the lowest diversity and sequence recovery, highlighting lead’s pronounced toxicity to fungal communities. |
| Tolerance & Bioremediation Potential | Genera such as Aspergillus, Chaetomium, Neosartorya, Neurospora, and Podospora were robustly represented in contaminated soils, indicating significant heavy metal tolerance and potential for bioremediation. Notably, the presence of these genera increased with contamination, except where lead concentrations were extreme. Saccharomycetes (yeasts) also displayed resilience, with mechanisms such as metal efflux and sequestration. |
| Functional Genes and Pathways | Genes associated with heavy metal metabolism, biosorption, and DNA repair were detected, primarily within Ascomycota sequences. The RM (high contamination) sample showed a predominance of biosorption-related genes, while DNA repair genes were more prevalent in moderately contaminated sites. Functional annotation revealed gene clusters tied to metabolism, genetic information processing, and cellular processes essential for survival under heavy metal stress. Some potential unknown functional genes were also recovered, suggesting further metabolic versatility. |
| Impact of Specific Metals | Lead was found to be the most detrimental to fungal community abundance and diversity, causing the greatest reduction in both taxonomic richness and functional gene recovery. Other metals, such as copper, zinc, and chromiu,m had less pronounced effects, with some fungal taxa displaying adaptive tolerance. |
| Environmental Factors | High organic carbon and nitrogen content in soils correlated with greater fungal abundance, suggesting that nutrient-rich environments can partially mitigate the stress imposed by heavy metals. Alkaline pH (above 8) may also favor metal biosorption by fungi. |
Key implications
This study has significant implications for heavy metal certification and monitoring programs such as HTMC. The diversity and resilience of fungal communities in contaminated soils, particularly Ascomycota and genera like Aspergillus and Chaetomium, highlight their potential as bioindicators and bioremediation agents. The marked decline in fungal diversity under high lead exposure underscores the need for stricter regulation of this metal. Metagenomic analyses further demonstrate the importance of including uncultured microbial taxa in risk assessments, as culture-based methods underestimate adaptive and bioremediation capacity. The identification of functional genes related to biosorption and DNA repair offers molecular targets for standardized biomarkers within certification frameworks. Incorporating fungal community profiling and gene analysis into heavy metal testing can strengthen environmental monitoring, guide remediation, and improve safety assessments of contaminated sites.
Citation
Passarini MRZ, Ottoni JR, Costa PES, Hissa DC, Falcão RM, Melo VMM, Balbino VQ, Mendonça LAR, Lima MGS, Coutinho HDM, Verde LCL. Fungal Community Diversity of a Heavy Metal Contaminated Soils Revealed by Metagenomics. Archives of Microbiology. 2022 Apr 12. https://doi.org/10.1007/s00203-022-02860-7
Heavy metals are high-density elements that accumulate in the body and environment, disrupting biological processes. Lead, cadmium, arsenic, mercury, nickel, tin, aluminum, and chromium are of greatest concern due to persistence, bioaccumulation, and health risks, making them central to the HMTC program’s safety standards.
