Date of Award
5-2021
Degree Type
Honors College Thesis
Academic Program
Biological Sciences BS
Department
Biological Sciences
First Advisor
Dmitri Mavrodi, Ph.D.
Advisor Department
Biological Sciences
Abstract
Gynuella sunshinyii is a newly characterized bacterium with a remarkable ability to produce multiple secondary metabolites that act as potential antibiotics for medical applications. Currently, little is known about gene regulation in this unusual microorganism. In 2018, studies conducted of rhizosphere microbiomes of tidal marsh grasses on Deer Island, MS, resulted in multiple isolates of halophilic, aerobic, Gram-negative bacteria with antagonistic properties. One of the most active antagonists was identified as Gynuella sunshinyii 449. The genome of strain 449 was sequenced with Illumina MiSeq, assembled with Unicycler and SPAdes, and annotated with RASTtk. The annotation revealed a 6.09 Mb genome that encodes 52 RNAs and 5,608 proteins, 2,822 of which had functional assignments. The analysis also revealed that the strain harbored genes for the production of numerous polyketides with potential cytotoxic and antibacterial activities. In many Gammaproteobacteria, the production of secondary metabolites, surface motility, and biofilm formation are regulated by the GacS/GacA system. The G. sunshinyii 449 genome encodes well-conserved homologs of GacA and GacS, and we hypothesized that these genes might be involved in the motility and ability to produce bioactive metabolites. To test this hypothesis, we constructed a knockout plasmid by cloning the gacA gene of strain 449. This plasmid will be used in the future to create an isogenic mutant that will be tested for alterations in the motility and ability to produce polyketides. This study provides insights into pathways conferring the regulatory and metabolic flexibility in a species that serves as a rich source of bioactive metabolites.
Copyright
Copyright for this thesis is owned by the author. It may be freely accessed by all users. However, any reuse or reproduction not covered by the exceptions of the Fair Use or Educational Use clauses of U.S. Copyright Law or without permission of the copyright holder may be a violation of federal law. Contact the administrator if you have additional questions.
Recommended Citation
Truong, Anhthu, "The Role of Gac/Rsm Signal Transduction Pathway in the Biology of Antagonistic Marine Bacterium Gynuella sunshinyii 449" (2021). Honors Theses. 813.
https://aquila.usm.edu/honors_theses/813