| 1. |
- Fredlund, E., et al.
(författare)
-
Metabolite profiles of the biocontrol yeast Pichia anomala J121 grown under oxygen limitation
- 2004
-
Ingår i: Applied Microbiology and Biotechnology. - : Springer. - 0175-7598 .- 1432-0614. ; 64:3, s. 403-409
-
Tidskriftsartikel (refereegranskat)abstract
- The biocontrol yeast Pichia anomala J121 prevents mould growth during the storage of moist grain under low oxygen/high carbon dioxide conditions. Growth and metabolite formation of P. anomala was analyzed under two conditions of oxygen limitation: (a) initial aerobic conditions with restricted oxygen access during the growth period and (b) initial microaerobic conditions followed by anaerobiosis. Major intra- and extracellular metabolites were analyzed by high-resolution magic-angle spinning (HR-MAS) NMR and HPLC, respectively. HR-MAS NMR allows the analysis of major soluble compounds inside intact cells, without the need for an extraction step. Biomass production was higher in treatment (a), whereas the specific ethanol production rate during growth on glucose was similar in both treatments. This implies that oxygen availability affected the respiration and not the fermentation of the yeast. Following glucose depletion, ethanol was oxidized to acetate in treatment (a), but continued to be produced in (b). Arabitol accumulated in the culture substrate of both treatments, whereas glycerol only accumulated in treatment (b). Trehalose, arabitol, and glycerol accumulated inside the cells in both treatments. The levels of these metabolites were generally significantly higher in treatment (b) than in (a), indicating their importance for P. anomala during severe oxygen limitation/anaerobic conditions.
|
|
| 2. |
- Hogberg, L, et al.
(författare)
-
The impact of active intervention on the spread of penicillin-resistant streptococcus pneumoniae in Swedish day-care centres
- 2004
-
Ingår i: Scandinavian Journal of Infectious Diseases. - : Informa UK Limited. - 1651-1980 .- 0036-5548. ; 36:9, s. 629-635
-
Tidskriftsartikel (refereegranskat)abstract
- Policies for handling cases of penicillin-non-susceptible Streptococcus pneumoniae (PNSP) in day-care groups vary between different counties in Sweden. The aim of this study was to evaluate the epidemiological effect of excluding PNSP-carriers from children's day-care centres (DCC). We followed the incidence in 14 DCC groups with ongoing PNSP-spread, by repeated group screens until no further cases could be identified. All identified carriers were excluded from DCC attendance in study area A (Skane region) while they remained in the group in study area B (Goteborg and Orebro), according to local policies. The intervention effect was evaluated by comparing the number of additional cases after the baseline screen (start of the intervention period) between the 2 study areas. All PNSP-isolates were characterized by resistance pattern, serotype and pulse-field gel electrophoresis. The relative risk for children in DCCs without active intervention was 6.4 (95% CI: 2.0-20.7). Each prevented case in area A can be estimated to have demanded the exclusion of 2 other children from day care for approximately 4 weeks each. The total cost-benefit outcome of this action has to be seen in the light of the local situation with regard to the population prevalence and the distribution of other risk factors.
|
|
| 3. |
|
|
| 4. |
- Fredlund, Elisabeth, et al.
(författare)
-
Physiological characteristics of the biocontrol yeast Pichia anomala J121
- 2002
-
Ingår i: FEMS yeast research (Print). - : Elsevier. - 1567-1356 .- 1567-1364. ; 2:3, s. 395-402
-
Tidskriftsartikel (refereegranskat)abstract
- The yeast Pichia anomala J121 prevents mold spoilage and enhances preservation of moist grain in malfunctioning storage systems. Development of P. anomala J121 as a biocontrol agent requires in-depth knowledge about its physiology. P. anomala J121 grew under strictly anaerobic conditions, at temperatures between 3degreesC and 37degreesC, at pH values between 2.0 and 12.4, and at a water activity of 0.92 (NaCl) and 0.85 (glycerol). It could assimilate a wide range of C- and N-sources and produce killer toxin. A selective medium containing starch, nitrate, acetic acid, and chloramphenicol was developed for P. anomala. P. anomala was equally sensitive as Candida albicans to common antifungal compounds. Growth ability at a range of environmental conditions contributes to the competitive ability of the biocontrol yeast P. anomala J121.
|
|
