The genes coding for the expression of a ropy exopolysaccharide responsible for commercially desirable textural and rhealogical traits in fermented milk products by a natural lactococcal ropy isolate were sought. Using a transposon mutagenesis vector, pGh9:ISS1, three mutants lacking expression of the ropy exopolysaccharide were isolated. One of the mutants was chosen for further characterization. Using a Southern hybridization analysis, the interrupted gene was localized to the chromosome. The non-ropy mutant was further characterized and shown to be unable to produce ropy exopolysaccharide in fermented milk.
A 2006 by fragment of the interrupted gene was sequenced. The DNA sequence over a short region showed homology to sugar transfer enzymes found in exopolysaccharide biosynthesis pathways. The DNA sequence was translated into its predicted amino acid sequences and two partial open reading frames of 236 and 338 amino acid residues in length were identified. These open reading frames were found to exhibit identity to glycosyltransferases present in exopolysaccharide biosynthesis pathways in other bacteria. / Graduation date: 1999
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/33616 |
| Date | 05 June 1998 |
| Creators | Knoshaug, Eric P. |
| Contributors | Trempy, Janine E. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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