Life Sciences Commons^™

A Possible Luxr Solo Type Regulator Of An Antibiotic-Like Compound From The Soil Bacterium Rhodococcus, Katelyn Sellick

Electronic Theses and Dissertations

Rhodococcus, a species of bacteria commonly found in the soil, is an under-explored producer of small bioactive compounds including siderophores, pigments and antibiotics. MTM3W5.2 is a strain of Rhodococcus that was previously discovered to produce an antibiotic-like compound that has inhibitory effects on other Rhodococcus strains, including the veterinary pathogen, R. equi. The biosynthetic gene cluster responsible for production of the antibiotic has been identified, and a small gene, BTZ20_3964 at the start of the operon is believed to be a luxR solo regulator of the gene cluster. The goal of this project was to determine this gene’s …

Identification Of Genes Required To Synthesize An Antibiotic-Like Compound From The Soil Bacterium Rhodococcus Sp. Mtm3w5.2, Amber L. Ward

Electronic Theses and Dissertations

Rhodococcus is a soil bacterium, member of the Actinobacteria, and a close relative of the prolific small molecule producer Streptomyces. Recent interest in Rhodococcus as an under investigated source of possible bioactive secondary metabolites is sparked by the discovery of many polyketide synthase and non-ribosomal peptide synthetase genes of unknown function from sequenced Rhodococcus genomes. Rhodococcus species strain MTM3W5.2 was recently shown to produce a strong inhibitory compound with activity against most strains of Rhodococcus and closely related genera. A goal of this investigation is to discover the gene(s) required to synthesize this inhibitory molecule. The engineered Rhodococcus …

Investigating Potential Bioactive Compounds From Rhodococcus And Their Effects On Mcf7 Breast Cancer Cells, Megan N. Crabtree

Electronic Theses and Dissertations

Many drugs used in the treatment of various cancers are derived from or influenced by compounds from nature. The soil bacterium Rhodococcus is of interest because of its identified secondary metabolic pathways and the production of novel natural antibiotics from several strains. In this study, a solid agar extraction method was used to collect compounds from strains of Rhodococcus. These bacterial compound extracts were then tested using a MTT assay in order to evaluate their effectiveness in augmenting MCF7 breast cancer cell death. The results of two way ANOVA analyses revealed 18 compound extracts from 15 strains of Rhodococcus that …

Isolation Of A Rhodococcus Soil Bacterium That Produces A Strong Antibacterial Compound., Ralitsa Bogomilova Borisova

Electronic Theses and Dissertations

Rhodococci are notable for their ability to degrade a variety of natural and xenobiotic compounds. Recently, interest in Rhodococcus has increased due to the discovery of a large number of genes for secondary metabolism. Only a few secondary metabolites have been characterized from the rhodococci (including 3 recently described antibiotics). Twenty-four new Rhodococcus strains were isolated from soils in East Tennessee using acetonitrile enrichment culturing and identified using 16S rRNA analysis. Forty-seven Rhodococcus strains were screened for antibiotic production using a growth inhibition assay. One strain, MTM3W5.2, had 90% similarity to the Rhodococcus opacus 16S rRNA gene sequence and produced …

Discovery And Characterization Of An Antibiotic From The Soil Bacterium Bacillus Sp., Thomas S. Barber

Electronic Theses and Dissertations

Many important antibiotics have become nearly obsolete due to the rise of antibiotic resistant pathogens. Rhodococcus, an actinomycete related to the prolific antibiotic producing genus Streptomyces, harbors over 30 genes for secondary metabolism that could be involved in antibiotic production. Several antibiotics have already been reported for Rhodococcus, suggesting the genus may be a good source for new inhibitory compounds. Fifty four soil bacteria were isolated using enrichment culture techniques (including 37 Rhodococcus) and screened for antibiotic producers. BTHX2, a species of Bacillus was found to have activity against Micrococcus luteus and Rhodococcus erythropolis. BTHX2 …

Iron Acquisition In Rhodococcus Erythropolis Strain Igts8: Characterization Of A Mutant Strain That Over Produces Siderophore., Melanie Anne Pratt

Electronic Theses and Dissertations

Iron is an essential nutrient for most bacteria because enzymes like nitrate reductase and cytochromes use it as a cofactor. However, in most aerobic, neutral pH environments, iron is essentially insoluble and not easily available for bacteria to use. Many bacteria respond to this problem by releasing small organic compounds called siderophores that bind and effectively solubilize iron so that it can be transported into the cell for growth. The focus of this study was to learn more about the iron acquisition and especially the transport of iron by the soil bacterium Rhodococcus erythropolis. To fulfill this aim, mutant …

Iron Acquisition In Rhodococcus Erythrolpolis: The Isolation Of Mutant(S) That Do Not Produce A Siderophore., Jaishree M. Vellore

Electronic Theses and Dissertations

Rhodococcus, a soil bacterium, displays a diverse range of metabolic capabilities with a number of potential practical applications. To exploit the metabolic potential of Rhodococcus, their basic physiology, genetics, and especially the acquisition of essential nutrients like iron, must be understood.

R. erythropolis strain IGTS8 releases a small compound called a siderophore, that scavenges ferric iron from the environment. To learn more about the genetic control of iron acquisition, mutant(s) defective in siderophore production were isolated. Mutants were generated, by inserting a mutagenic plasmid, pJCS506, into the bacterial cell using electroporation. The plasmid, which cannot replicate in these …