| Summary: | 碩士 === 國立交通大學 === 生物科技研究所 === 84 === The Production of extracellular by Ganoderma lucidumRZ
carried out in shake flasks as well as in batch submerged
fermentation was investigated in this study. In shake-flask
experiments,the target polysaccharide was accumulated
extracellularlyduring both the growth and stationary phases of
the microorganism. Medium HCHN and HCLac with high initial
glucose concentration resulted in high product concentration and
highspecific productivity.Using peptone as nitrogen source was
also shown advantageous for cell growth.After extracted by hot
water,some intracellular glucan could also be recovered.
During batch-wise fermentation cultivation,the yeast-like growth
dominated the culture at high pH values.Under the culture
condition of pH 4.5,the yeast-like growth was obviously
inhibited whereas pellet and mycellium dominated the culture.Our
results reveal that when pH was kept constant at 4.5,the largest
specific growth rat was obtained.In addition,its product
formation rate and the specific productivity were higher than
those of the other controlled cultures.In the experiment ith pH
control and pellet inoculation,the demand of dissolved oxygen
for cells was extremely larger than that in the uncontrolled
experiment.In our study,we also found that the acidic
environment caused by purging carbon dioxide would inhibit the
growth of the microorganism.
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