High RNA accumulation in Candida tropicalis is affected by specific growth rate and different medium composition

Batch and continuous fermentation were adopted to investigate the effect of specific growth rate and amino acid components on RNA accumulation inCandida tropicalis ATCC 20408 in fermentation medium (FM),yeast peptone dextrose medium (YPD),molasses fermentation medium (MFM) and FM without corn steep liquor. The data showed that obvious differences in intracellular RNA accumulation were observed at different cell growth phases in bath fermentation prosess,and RNA level reached 11.8%(g-RNA /g-DCW) during exponential phase,and only 6.9% during stationary phases. It was also found that intracellular RNA accumulation increased with the increase of specific growth rate in continue fermentation prosess,and the highest RNA level reached 15.6% with the glucose conversion rate of 42.8% at the dilution rate of 0.5 h^-1. Furthermore,the data showed that RNA lever was notably increased in batch fermentation process when amino acids or peptone was added into the fermentation medium containing no corn steep liquor. Taken together,it was reported for the first time that specific growth rate and amino acid components plays a leading role on the intracellular RNA accumulation in C.tropicalis,and specific growth rate is more important.