Minerals Essential for Growth of the Filamentous Fungus, Mortierella alpina

摘要

Potato protein and dextrose are ideal media for cultivation of Morlierella alpina, that produces arachidonic acid. Corn peptide-dextrose medium is not suitable for growth of the fungus although amino acid compositions of the two are similar. Thus, to corn peptide- dex- trose medium was added metallic salt containing quasi-major element, sodium, calcium, magne- sium, phosphor, or potassium in amounts from 0.05 - 0.30/100 and used for liquid cultivation at 20 deg. C in a 500-mL shake flask for 14 days. Cell growth was greatly enhanced but the lipid accu- mulation ratio of methyl esters (g)/dry cell weight (g) reached only 70% that of lipid in cells grown in potato-dextrose medium. Iron, copper, zinc, or manganese was then added at 2 x 10~-5 - 1 x l0~-3/100 to corn peptide-dextrose medium on top of phosphor and potassium for cultiva- tion. Iron and manganese increased the lipid accumulation ratio to essentially the same extent as above with nitrogen content in the medium the same. Phosphor and potassium may be con- cluded essential for the growth of M. alpina and iron and manganese to have significant roles in lipid synthesis.