Terreus Fermentation Conditions On Cell Morphology And Product Yield

As a main producing-lovastatin fungi, the wild strain of Aspergillus terreus produces lower lovastatin, however, limiting its industrial production greatly. In this paper, an efficient and easy biological screening method based on the sensitivity to lovastatin of Neurospora crassa was built to deal with the mutant strain rudely by UV mutation. A high-level strain was screened in the shaking flask culture.An primary optimization for medium composition in shake flask showed the best carbon source, nitrogen source , culture volume , incubating quantity and pH after having completed studying the relation between thalli form,zymotic condition and metabolized yields .Having tantamount quantity of carbon source,it is proved that glycerol is the best carbon source.But taking into account economical reasons,we select glucose as the best carbon source. The shorter the diameter of mycelial is ,the shorter the free hyphal is, the higher the production we get .Different nitrogen source will result in distinct diameter,distinct free hyphal length and different symmetrical distribution of hair length, that leads to diverse yields .Through a great deal of experimental datas,we know that yeast powder 1%, (NH4)2SO40.1%, peptone 0% is the best nitrogen source as well as pH is 6.5.In such situation,we can achieve the level of Lovastatin which is some 499mg/L.The effects of culture volume and incubating quantity on mycelial forms and Lovastatin production yield in shaking flask was researched. The experimental datas indicate higher spore density would lead to smaller diameter of pellet and shorter free mycelial which can contribute to high-level lovastatin effectively. A 2 X 107spore/mL suspensions and a 100ml culture volume in shaking flask will result in a better effect.The relation between barmy condition ,myccelial form and Lovastatin production is studied in the 2L fermentor based on its batch culture.In fed-batch culture,we will research how to effectively affect mycelial shape and increase Lovastatin yields by controlling limiting culture medium concentration. The dynamics of mycelium growth and end-products formation in the lovastatin production by Aspergillus terreus strain was studied. At the same time, the batch fermenting dynamics model of lovastatin was also built and the model parameters were subsequently estimated, which fitted to the experimental results better.