Browsing by Author "Saida Hanoune"

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    Optimization of Lactobacillus fermentum DSM 20049 Growth on Whey and Lupin Based Medium Using Response Surface Methodology
    (Advance Journal of Food Science and Technology, 2015-09-15) Saida Hanoune
    Abstract: The aim of this study was to evaluate the potential use of whey components and lupin proteins as cheap nutrients in the formulation of optimum medium for lactic acid bacteria growth, for this purpose a Plackett and Burman design was used to screen variables (medium components and physical parameters) that have significant effects on the growth of Lactobacillus fermentum DSM 20049 in whey and lupin based medium. Statistical analysis of the results allowed selecting two factors having a significant positive effect on the bacterial growth (tween 80 and inoculum size). Central composite design was used to determine the optimum level of the selected factor. Under these optimized conditions, the composition of WLM (Whey and Lupin Medium) was the basic medium of whey and lupin supplemented with 1.56 mL/L of tween and inoculated at a rate of 5.25% with a maximum OD600 value of 6.88. Based on the comparison of Lactobacillus fermentum DSM 20049 growth on the formulated medium with that observed on MRS (standard laboratory medium), the growth of the strain in WLM is much higher than that observed in MRS medium with a maximum OD600 values of 7.04 on LWM and 4.08 on MRS medium, respectively and Lactobacillus fermentum DSM 20049 growth in the new medium was 72.54% higher than that on MRS. Thus, whey and lupin hydrolysates are good alternative sources of nitrogen that lead to a better growth of the strain and can be used for large-scale production
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    Optimization of Split Pea and Dry Figs-Based Media for the Growth of Lactobacillus plantarum through Plackett-Burman and Response Surface Methodological Approaches
    (Pakistan Journal of Biological Sciences, 2015-06-19) Saida Hanoune
    Plackett-Burman design was used to determine the most influential of 9 variables (glucose, lactulose, tween80, K2HPO4, sodium acetate, MgSO4, pH, shaking and inoculum size) on the growth of L. plantarum BH14. Glucose, lactulose, MgSO4 and shaking had a significant effect on growth of this strain at a 70% confidence level. Glucose, lactulose and MgSO4 showed positive coefficient but shaking had a negative coefficient, thus shaking was avoided in subsequent experiments. Composite design was used to determine the optimum concentrations of the significant variables. An optimized formulation of nutrition levels was suggested from the software at the following concentrations: 11.59 g LG1 glucose, 11.59 g LG1 lactulose and 0.23 g LG1 MgSO4. Growth of L plantarum was compared to that recorded on the reference medium ‘vegetal MRS’. The results showed that viable counts in the optimized culture medium were significantly higher than those in the vegetal MRS medium.