| Budget Amount *help |
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1985: ¥5,800,000 (Direct Cost: ¥5,800,000)
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| Research Abstract |
1. Effect of <Zn^(2+)> ion on morphological differentiation and cephalosporin C production of the genus Acremonium We have previously shown that Acremonium chrysogenum ATCC14553, which formed thick, swollen arthrospore-like cells, produced the morphogenic substance which induce similar cells in filamentous hyphae of A. strictum ATCC20339. However, during the continuing research, A. chrysogenum has lost the ability to produce arthrospore-like cells and the morphogenic substance. We then searched for the culture conditions under which the fungus formed arthrospore-like cells, and as a result, <Zn^(2+)> ion was found to be effective on the formation of these cells. <Zn^(2+)> ion also induced similar morphological differentiation in A. chrysogenum ATCC11550, A. strictum ATCC20339 and Cephalosporium chrysogenum IFO30055. Relationship between morphological differentiation and cephalosporin C production was studied by using A. strictum ATCC20339. The strain induced morphological differentiati
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on at 1 ug/ml of <ZnSO_4> , and filamentous hyphae became thick, swollen and shortened. An extent of differentiation enhanced as an <ZnSO_4> concentration increased untill 25 ug/ml. On the other hand, the cephalosporin C production by the strain reached the maximum at 2.5 ug/ml of <ZnSO_4> and the higher concentrations rather decreased its production. Therefore, the cephalosporin C production seemed not to correlate with <Zn^(2+)> ion-induced morphological differentiation.
2. A morphogenic substance of Acremonium chrysogenum To clarify the presence of a true morphogenic substance produced by the fungus itself, A. chrysogenum ATCC14553 was treated with nitrosoguanidine. Two hundreds of mutants were collected, and among them, two strains that formed arthrospore-like cells in the absence of <Zn^(2+)> ion were obtained. The concentrated culture filtrate of the strain No.14, thus, induced morphological differentiation in its parent strain. Preliminary examination revealed that this morphogenic substance was stable to heat, acid and alkali, and showed water-soluble basic property. The similar morphogenic substance was ascertained to be contained in the culture filtrate of the parent strain with <Zn^(2+)> ion. Less
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