Publication Date

Spring 5-7-2025

Document Type

Student Project

First Advisor

Grayburn, Scott

Degree Name

B.S. (Bachelor of Science)

Department

Department of Biological Sciences

Abstract

Some fungi, such as Aspergillus, can cause significant economic losses in food production and produce mycotoxins that are carcinogenic to humans. Similarly, certain cyanobacteria, which are often present in harmful algal blooms, can kill animals and also produce toxins that are harmful to humans. The goal of this study was to determine if living Pseudomonas 20ei1 bacteria and their cell-free extracts inhibit the growth of Aspergillus nidulans and cyanobacteria. Plating experiments were performed to assess growth inhibition. In plating assays, both live P. 20ei1 bacteria and their cell-free extracts showed inhibition of A. nidulans and cyanobacteria. However, the cell-free extracts consistently produced clearer zones of inhibition for the fungus and bacteria. Molecular techniques, including cDNA synthesis and quantitative polymerase chain reaction (qPCR) procedures, were performed to find correlations between gene expression and growth inhibition in monocultures and co-cultures. Preliminary results indicated differential gene expression related to iron accumulation. Specifically, qPCR experiments showed pyochelin, a gene in Pseudomonas 20ei1 involved in iron accumulation with siderophores, was expressed at elevated levels in a co-culture with live P. 20ei1 and A. nidulans. The next steps of research will be to continue studies of extracts and gene expression.

Download

Share

COinS