| Summary: | 碩士 === 東海大學 === 化學工程與材料工程學系 === 105 === Kluyveromyces marxianus 4G5-6 is a recombinant yeast, use the genetic engineering to combine the DNA that can produce cellulase into the yeast DNA, so in the process of cell growth can produce cellulase, the purpose of this experiment is to test what conditions can raise enzyme activity.
In flask experiment, by changing the carbon source, it was found that Galactose had the highest enzyme activity of 0.10 mg/mg min, but Galactose is too expensive, so we use Glucose to be a carbon source in this experiment, had the enzyme activity 0.084 mg/mg min. By changing the nitrogen source, Inorganic nitrogen source had the highest enzyme activity of 0.17 mg/mg min, but had the lowest biomass, so we chose the Yeast Extract to be a nitrogen source had the enzyme activity of 0.133 mg/mg min, biomass of 8.6 g/L. In different carbon source concentration experiment, 90 g/L had the biomass of 8.3 g/L and highest enzyme activity of 0.1640 mg/mg min. Therefore, 90 g/L as the initial carbon source concentration in fermentation experiments.
At air life experiment, we test different carbon source concentration and different air inflow, we can found that 90 g/L had the enzyme activity of 0.2908 mg/mg min, and 120 g/L had the enzyme activity of 0.4742 mg/mg min, so 120 g/L to be an initial concentration is the best. In different air inflow, we can found that 2.5 vvm had the highest enzyme activity of 2.4246 mg/mg min, second is 2.0 vvm of 0.7185 mg/mg min, third is 1.5 vvm of 0.4742 mg/mg min, so we can know that highest air inflow can get high enzyme activity.
In enzyme reaction temperature experiment, we found that 37 ℃had the best enzyme activity of 1.6873 mg/mg min, and in stability experiment, 4 ℃had a better performance.
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