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Author Samina, Mehnaz ♦ Baig, Deeba Noreen ♦ Jamil, Farrukh ♦ Weselowski, Brian ♦ Lazarovits, George
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Sugarcane Stem ♦ Protease Activity ♦ Uv Spectrum ♦ Pseudomonas Aurantiaca ♦ Important Pathogen ♦ Homoserine Lactones ♦ Substrate-specific Medium ♦ Fusarium Oxysporium ♦ Biochemical Characteristic ♦ Indole Acetic Acid ♦ Enzyme Revealed Lipase ♦ Maldi-toff Spectrum ♦ Pathogenic Isolates ♦ Bacterial Identification Kit ♦ Thin-layer Chromatography ♦ Tlc Data ♦ Dual Culture Assay ♦ N-hexanoyl Homoserine Lactone ♦ Colletotrichum Falcatum ♦ Api50 Ch ♦ Antifungal Metabolite ♦ Rrna Gene Sequence Analysis ♦ Phenazine-1-carboxylic Acid ♦ Novel Strain ♦ Fluorescent Pseudomonad ♦ Antifungal Activity ♦ Surface-sterilized Stem
Abstract A novel strain of fluorescent pseudomonad (PB-St2) was isolated from surface-sterilized stems of sugarcane grown in Pakistan. The bacterium was identified as Pseudomonas aurantiaca on the basis of 16S rRNA gene sequence analysis and results from physiological and biochemical characteristics carried out with API50 CH and QTS 24 bacterial identification kits. Assays using substrate-specific media for enzymes revealed lipase and protease activities but cellulase, chitinase, or pectinase were not detected. The bacterium was unable to solubilize phosphate or produce indole acetic acid. However, it did produce HCN, siderophores, and homoserine lactones. In dual culture assays on agar, the bacterium showed antifungal activity against an important pathogen of sugarcane in Pakistan, namely Colletotrichum falcatum, as well as for pathogenic isolates of Fusarium oxysporium and F. lateritium but not against F. solani. The antifungal metabolites were identified using thin-layer chromatography, UV spectra, and MALDI-TOFF spectra and shown to be phenazine-1-carboxylic acid (PCA), 2-hydroxyphenazine(2-OH-PHZ), and N-hexanoyl homoserine lactone (HHL) (assessed using only TLC data). The capacity of this bacterium to produce HCN and 2-OH-PHZ, as well as to inhibit the growth of C. falcatum, has not been previously reported.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Publisher Date 2009-01-01