oai:scholarworks.umt.edu:etd-1191
type: CreativeWork
name: Catechin, a novel root exudate of Centaurea stoebe, exhibits pleiotropic effects on the soil microbial community and individual soil isolates, and undergoes chemical changes with numerous abiotic factors from soil
description: Allelopathy has been studied for (±)-catechin, a root exudate of spotted knapweed, as a plausible mechanism that facilitates knapweed invasion in North America. Phytotoxic effects are observed in invaded fields as well as greenhouse experiments when employing catechin or growing spotted knapweed, demonstrating similar effects on native plant species. However, many studies ignore the impact of catechin on microbial populations in soil. Understanding the impact of catechin on microbial processes will greatly aid our understanding of how spotted knapweed invasion can alter soil chemistry and biological processes. Chapter 2 will address the impact of soil and media parameters on catechin stability and extraction from soil. My results show catechin to be a highly reactive compound and that redox metals, the pH of the surrounding environment, and the aerobicity of the system can greatly alter catechin auto-oxidation rates. Chapter 3 expands on these findings by testing the impact of catechin-metal complexes on catechin phytotoxicity reported in the current literature. I demonstrate metals that lower the amount "pure" catechin in the system have differential effects on native plant species. I further reveal that conditions of increased environmental stress can further exacerbate this phytotoxic phenomenon. Chapter 4 addresses the impact of catechin on soil bacterial communities as well as individual bacterial populations. I confirm that catechin is not bacteriocidal, but instead should be categorized as bacteriostatic. In chapter 5, I extend the findings in chapter 4 to include a repressive effect to various bacterial genera but show that species capable of altering catechin stability can overcome this bacteriostatic effect. More importantly, I reveal that two simple organic acids were capable of restoring previously inhibited bacterial species. Chapter 6 focuses on the ability of catechin to prevent endospore formation, germination, and to alter cell morphology in many gr…
abstract: Allelopathy has been studied for (±)-catechin, a root exudate of spotted knapweed, as a plausible mechanism that facilitates knapweed invasion in North America. Phytotoxic effects are observed in invaded fields as well as greenhouse experiments when employing catechin or growing spotted knapweed, demonstrating similar effects on native plant species. However, many studies ignore the impact of catechin on microbial populations in soil. Understanding the impact of catechin on microbial processes will greatly aid our understanding of how spotted knapweed invasion can alter soil chemistry and biological processes. Chapter 2 will address the impact of soil and media parameters on catechin stability and extraction from soil. My results show catechin to be a highly reactive compound and that redox metals, the pH of the surrounding environment, and the aerobicity of the system can greatly alter catechin auto-oxidation rates. Chapter 3 expands on these findings by testing the impact of catechin-metal complexes on catechin phytotoxicity reported in the current literature. I demonstrate metals that lower the amount "pure" catechin in the system have differential effects on native plant species. I further reveal that conditions of increased environmental stress can further exacerbate this phytotoxic phenomenon. Chapter 4 addresses the impact of catechin on soil bacterial communities as well as individual bacterial populations. I confirm that catechin is not bacteriocidal, but instead should be categorized as bacteriostatic. In chapter 5, I extend the findings in chapter 4 to include a repressive effect to various bacterial genera but show that species capable of altering catechin stability can overcome this bacteriostatic effect. More importantly, I reveal that two simple organic acids were capable of restoring previously inhibited bacterial species. Chapter 6 focuses on the ability of catechin to prevent endospore formation, germination, and to alter cell morphology in many gr…
author: Pollock, Jarrod LeRoy
keywords: bacteriostatic, catechin, filament, microbial, polyphenol, sporostatic
date published: 2010-01-01T08:00:00Z
date modified: 2026-07-24T03:10:28Z
provider: University of Montana
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Montana