Heat Balance Analysis During the Production of Jadomycin C

Abstract

Jadomycins are novel antibiotics that exhibit biological activity against bacteria and yeast and also demonstrate cytotoxicity against cancer cells. Jadomycin C was successfully produced from 10 L of fermentation media in a 19 L bioreactor using Streptomyces venezuelae ISP5230 which was shocked with ethanol. The bioreactor temperature and pH were successfully maintained at 30°C and 7, respectively. The heat of mixing from the agitator was 4.9 J·s^-1. The heat of metabolism was 4.4 J·s^-1 and the heat provided by the water circulator was 6.2 J·s^-1 during the fermentation. A substantial portion of heat (26.45%) was lost with the exhaust air leaving the bioreactor, while 69.03% was lost through the walls and 1.94% and 2.85% were lost through the top and bottom of the bioreactor. Once the bioreactor was inoculated, there was no lag period evident and a specific growth rate of 0.23 h^-1 was achieved. The rate of jadomycin production initially increased rapidly and reached a maximum level within 15 hours after the ethanol shock. The dissolved oxygen (DO) concentration during the experiment was inversely related to the growth of the bacteria.