Untersuchungen über das wachstum des pilzstammes Mucor circinelloides (1 M) II. Das wachstum in batch- und kontinuierlicher kultur

Abstract

Summary The time and output of growth of the fungus strain Mucor circinelloides (1 M) was equal in comparison with the inoculates suspension of sporangiospores and mycelial fragments in a culture medium with glucose. There was the same result in culture substrate with a n-alkanes mixture as sole C and energy source. The fungus strain preferred n-hexadecane, n-octadecane and n-heptadecane from tested individual n-alkanes while the hydrogencarbon with the chain length from C5 to C8 and from C12 to C15 were converted much smaller. The growth curves were determined from the filamentous (F) and cellular (Z) growth forms of the fungus strain in a glucose medium (Glc) and a n-alkane mixture medium (KW). Further the dry weight, protein, RNA and DNA quantity of the biomass and the consumtion of glucose, ammonium-nitrogen (N) and phosphate-phosphorus (P) from the nutrition solution for formation of fungi biomass were investigated. The growth decreased in the experiment variants from F-Glc over Z-Glc and F-KW to Z-KW measured on the cultivation time and the production of dry weight per hour. The per cent quantity of protein, RNA and DNA of the biomass was identical within the four experiment variants. The relation dry weight-protein-RNA-DNA was 100: 20: 1: 0.3. The yield coefficient (Y) of glucose was 0.42 and 0.43 in both growth forms of the fungus strain. The consumtion of N and P quantity within the four experiment variants was general identical. Sporangiospores produced on malt agar or KW agar were identical in size and biomass. The dry weight and DNA quantity per spore and the number of nucleotides per g DNA were calculated. By continuous cultures limited with glucose the limits of the dilutation rate (D) prevented a wash out of biomasse were determined for growth of hyphae D ≤ 0.08 and for growth of cells D ≤ 0.048 corresponded with the time for biomass duplication ta ≥ 12.5 respectively 20.8 hours. The results were discussed.