Exploration of Mycoremediation Candidate Screening: Uptake and Tolerance of Bismuth by Native Fungi

Heavy metal (HM) pollutants are problematic in our increasingly industrialized world due to their toxicity in small concentrations and inability to decompose. While industrial methods of remediation are effective for large spills, chronic and widespread pollutant exposure is not efficiently remediated by such methods and they can be expensive and damaging to the ecosystem. Alternatively, bioremediation is effective at remediating HM pollution as microbes have diverse biochemistry. Microbes have an array of surface functional groups and extracellular enzymes capable of detoxifying or sequestering pollutants. Furthermore, bioremediation is inexpensive and eco-friendly, with the caveat that potential ecosystemic interactions should be considered with bioremediation candidates. Fungi have relatively diverse biochemistry, even compared to other microbes, making them uniquely effective in bioremediation, a process specifically known as mycoremediation. However, each mycoremediation candidate has different optimal growth conditions and reactivity to different pollutants, which makes it complicated to determine effective native mycoremediation candidates for pollutants of interest. Sadañoski et al. proposed a protocol whereby the pollutant tolerance, measured by growth rate differential, is used to screen for mycoremediation candidates. In this study, this principle was applied to HM pollution, utilizing bismuth due to its lower toxicity relative to other HM pollutants. Per the protocol of Sadañoski et al., growth rate was measured by determining the radial expansion both at the largest and smallest diameters, at various concentrations of bismuth. The preliminary data showed fungi had diminished growth rate when exposed to bismuth while experimental data showed general increased growth rate in experimental conditions. The bismuth uptake was determined using energy dispersive spectroscopy (EDS). The results demonstrated that all environmental fungi tested could grow in the presence of bismuth and there was evidence of uptake by the four fungi tested, especially in T. villosa, however there was not a significant correlation between bismuth tolerance and uptake. As a consequence, it does not appear that bismuth tolerance can be used to predict its uptake in native fungi although this method’s efficacy in screening for mycoremediation candidates warrants further investigation with other HMpollutants.

Discipline thesis:degree_discipline

Biology

Grantor

Texas State University

Year dc:date.issued

2024

Author dc:creator

• Heflin, Royce

Advisor dc:contributor.advisor

• McLean, Robert J. C.

Committee member dc:contributor.committeemember

• Anderson, Joyce

• mycoremediation
• bioremediation
• heavy metals
• heavy metal pollution
• mycology
• fungi
• mushrooms

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10877/19339

OAI identifier oai:identifier

oai:digital.library.txst.edu:10877/19339