The perylenequinones derivatives (PQDs) are potential photosensitizers, which have a high effective light-induced biological activity, such as anti-HIV, antimicrobial and anticancer activities. In this work, the submerged fermentation process of filamentous fungus shiraia sp. AL18 producing PQDs in a stirring fermentation tank was investigated through single factor optimization. The effect of the stirring speed (450 r/min, 500 r/ min and 550 r/min at ventilation quantity for volumes of air per volume of liquid per minute (VVM) = 1:1) and ventilation quantity (VVM = 1:0.8, 1:0.65 and 1:0.5 at stirring speed of 500 r/min) on the process of submerged fermentation by stirring fermentation tank in batch fermentation was investigated using the monosyllabic test. The results suggest that the optimum stirring speed for biomass is 500 r/min and the optimum ventilation quantity for biomass is VVM = 1:0.65, and the maximum dry cell weight (DCW) reached to 19.67 g/L. The stirring speed for the optimum yield of PQDs is 500 rpm and the ventilation quantity for the optimum yield of PQDs is VVM=1: 0.8, and the maximum yield of PQDs reached to 0.3218 g/L. The yield of PQDs was correlated with pH value, dissolved oxygen (DO) value, the content of reduced sugar in the period of fermentation.
Optimization of submerged fermentation process for improved production of β-carotene by Exiguobacterium acetylicum S01
