Life Sciences Commons^™

Aqueous Extracts Of Hibiscus Sabdariffa As Antimicrobials In Foods, Kristen Liane Higginbotham

Masters Theses

Hibiscus sabdariffa L. is a tropical shrub species cultivated in multiple countries and is mainly produced for its red calyces that are used for a tea beverage. Aqueous, lyophilized extracts of Hibiscus were examined for their chemical composition and antimicrobial activity against Escherichia coli O157:H7, Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Listeria monocytogenes.

Lyophilized, dialyzed extracts of commercially aquired calyces were examined in microbiological medium and milk at various fat levels for antimicrobial activity against E. coli O157:H7 and S.aureus. Extracts were either filtered or autoclaved to sterilize and tested in microbiological medium. Autoclaved extracts were more effective …

Genetic And Ecological Characterization Of Indigoidine Production By Phaeobacter Sp. Strain Y4i, William Nathan Cude

Doctoral Dissertations

The Roseobacter clade is a widely distributed, abundant, and biogeochemically active lineage of marine alpha-proteobacteria. Members of the Roseobacter lineage are prolific surface colonizers in marine coastal environments, and antimicrobial secondary metabolite production has been hypothesized to provide a competitive advantage in colonization. In this work, Phaeobacter sp. strain Y4I was found to produce the water soluble, blue pigment indigoidine via a nonribosomal peptide synthase-based biosynthetic pathway encoded by a novel series of genetically linked genes, termed igiBCDFE. Comparison of wildtype, non-pigmented, and hyper-pigmented Y4I insertional mutants demonstrated a perfect correlation between indigoidine production and the inhibition of Vibrio …