Microbiology Commons^™

A Pectin Histochemical Study Of The Host Pathogen Relationship Between Pyrenochaeta Terrestris And Allium Cepa, Leroy Richard Cobia

Theses and Dissertations

The involvement of pectin and pectinases in the host pathogen interaction of P. terrestris and Allium cepa were investigated by use of pectin histochemical stains at the electron microscope level. Several different pectin histochemical stains were used, but only two (the hydroxylamine reaction, and the pectin stain developed in this study) gave reliable results. It was observed that by the time the fungus has reached the host cell wall pectinesterase and endoplygalacturonase have fully removed the pectin from the host cell wall. When this has occurred, cellulases are released which continue to degrade the host cell wall. Electron transparent areas …

Ultrastructural And Histochemical Investigations Of Ipomoea Batatus Lam. Infected By Rhizopus Stolonifer (Fr.) Lind, Kendall O. Smith

Theses and Dissertations

The ultrastructural aspects of Rhizopus stolonifer (Fr.) Lind. Infection in Ipomoea batatus Lam. Roots and the histochemistry of cell walls affected by enzymes secreted by the fungus were investigated. Specimens were prepared for viewing in the electron microscope by thin-sectioning techniques. Degradation of cellular membreanes and host tissues in advance of the fungus was evident. Breakdown of the middle lamella was detected by special histochemical stains for pectin. Breakdown occurred in the following was: (1) maceration of the middle lamella before maceration of the cell wall, (2) simultaneous degradation of both the middle lamella and the cell wall, (3) maceration …

The Effect Of Antibiotics On Thermophilic Blue-Green Algae, Erleen Blanche Christenson

Dissertations and Theses

The nature of the action of penicillin on the cell walls of bacteria is reviewed. The composition of bacterial cell walls is compared to cell walls of blue-green algae.

The test organisms used were thermophilic: Anacystis nidulans grew optimally at 35⁰C, whereas Synechococcus lividus grew best at 45⁰ C. Growth was recorded by reading optical densities.

Cells of these two thermophilic blue-green algae were treated with varying dosages of penicillin and streptomycin. Penicillin inhibited growth of Anacystis nidulans and Synechococcus lividus in concentrations of 3.0 µg/ml and 0.03 µg/ml respectively. However, when 0.3 µg/ml of penicillin was added to Anacystis …

Sturt Pea Hosts Collar Rot Fungus, M D. Marcley

Journal of the Department of Agriculture, Western Australia, Series 4

Evidence that Western Australia's Sturt Pea can be attacked by collar rot fungus suggests a reason for the occurrence of collar rot in places where the fungus should not survive.

At Carnarvon for instance, in spite of the hot, dry conditions, the collar rot fungus has been found on eggplants and Tuart trees.

The Lichen Flora Of Rocky Branch Nature Preserve, Clark County, Illinois, James E. Wiedman

Masters Theses

No abstract provided.