Fat formation in preformed fungal mats of penicillium notatum

Abstract

A fat-forming fungus:Penicillium notatum was grown on a physiologically balanced medium for 4 days. The old medium was then replaced by a fat-promoting medium and the fungal cultures were reincubated for a further period of 10 days. Active growth was resumed. Protein synthesis also continued actively at the expense of the low nitrogen supply in the replacement medium and soon stopped when proteolysis started. Fat formation, on the other hand, started and proceeded for a longer period at a very high rate leading to a very high fat yield.

When the fungal mats were replaced on the fat-promoting medium at different nitrogen concentrations, the medium with the lowest nitrogen supply gave rise to weak growth and low fat yield as well. The highest nitrogen supply gave rise to active growth with high protein content and low fat yield. At a certain concentration of nitrogen, there was a high growth rate involving the highest fat yield. It is concluded that replacement medium deficient in nitrogen is not the most favorable for fat formation. The nitrogen level in the replacement medium should be adjusted so as to afford good growth and consequently good utilization of excess carbohydrates in fat syntheses.