Record Details
The inhibitory effect of Streptococcus diacetilactis on the growth of Staphylococcus aureus in milk and vanilla cream filling
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | The inhibitory effect of Streptococcus diacetilactis on the growth of Staphylococcus aureus in milk and vanilla cream filling |
| Names |
Radich, Ruth Elaine
(creator) Sandine, W. E. (advisor) |
| Date Issued | 1969-07-28 (iso8601) |
| Note | Graduation date: 1970 |
| Abstract | Trypticase-Soy Broth (TSB) was inoculated with Streptococcus diacetilactis, incubated at 21C for 24 hours and centrifuged to remove the cells. When the spent TSB was inoculated with Staphylococcus aureus, it allowed 99.8% less growth than fresh TSB. If the spent TSB were supplemented with 0.08 μg/ml of niacinamide, this inhibition was reversed by about 9%. Sterile nonfat milk was also inoculated with S. diacetilactis, incubated at 21C for 24 hours and pasteurized. When the spent milk was inoculated with S. aureus, it supported 98.4% less growth than fresh nonfat milk. Supplementation with niacinamide failed to reverse this inhibition; however, the addition of 1% protein hydrolysate completely reversed the inhibition. When grown associatively with S. diacetilactis in nonfat milk, S. aureus cells showed a 99.8% reduction in cell numbers after 24 hours at 30C as compared to staphyloccoci grown alone. In vanilla cream filling, associative growth brought about a 99.9% reduction after 24 hours at 25C. The addition of catalase did not reverse the inhibition. These results suggest the possible use of S. diacetilactis cells to prevent staphylococcus food poisoning in cream filled bakery items and meat products. |
| Genre | Thesis/Dissertation |
| Topic | Milk -- Microbiology |
| Identifier | http://hdl.handle.net/1957/46229 |
