The effects of medium composition and operating conditions on the producton of extracellular polysaccharide by Ganoderma lucidumRZ and its morphological change in shake-flask and batchwise fermentatio

• Main Authors: Yu, Ying chin, 游英欽
• Other Authors: Chaster Ho
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/78709872650074240895

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.