Life Sciences Commons^™

Response Of A Nitrifying Biofilm To Copper, Denise Moldroski Mott

Masters Theses

In pure cultures of Nitrosomonas, copper is known to cause a stimulation of nitrification at low levels (≤ 0.03 mg Cu⁺²/1) and an inhibition affect at higher levels (≥ 0.05 mg Cu⁺²/1). Nitrifying activated sludges are much more tolerant of copper showing only 75% inhibition at 150mg Cu⁺²/1. The purpose of this paper was to determine the copper sensitivity of a nitrifying biofilm grown in a continuous flow trickling filter system.

A continuous flow trickling filter system was built using limestone chips for the biofilm substrate. The biofilm was established from secondary effluent. …

A Comparison Of The Acidic Extracellular Polysaccharides From Rhizobium Trifolii Mutants Affected In Trifolium Repens Root Hair Curling, Brian Andrew Hanley

Masters Theses

The compositions and sugar linkages of the acidic extracellular polysaccharide (EPS) from several Rhizobium trifolii mutants were compared. These mutants were derived from a wild type Rhizobium trifolii, ANU843, and are unable to cause normal root hair curling, Hac-, or nodulate clover, Nod-. Three of the mutants contain a Tn5 insertion in a 5.3 kb BglII fragment of the symbiotic plasmid (pSym). A fourth mutant is missing the pSym, which includes much of the 5.3 kb BglII fragment, both of these deletions result in Hac-Nod- phenotypes. When the 5.3 kb BglII fragment is cloned (pRT150) and reinserted into the …